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arrow_row/
lib.rs

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17
18//! A comparable row-oriented representation of a collection of [`Array`].
19//!
20//! [`Row`]s are [normalized for sorting], and can therefore be very efficiently [compared],
21//! using [`memcmp`] under the hood, or used in [non-comparison sorts] such as [radix sort].
22//! This makes the row format ideal for implementing efficient multi-column sorting,
23//! grouping, aggregation, windowing and more, as described in more detail
24//! [in this blog post](https://arrow.apache.org/blog/2022/11/07/multi-column-sorts-in-arrow-rust-part-1/).
25//!
26//! For example, given three input [`Array`], [`RowConverter`] creates byte
27//! sequences that [compare] the same as when using [`lexsort`].
28//!
29//! ```text
30//!    ┌─────┐   ┌─────┐   ┌─────┐
31//!    │     │   │     │   │     │
32//!    ├─────┤ ┌ ┼─────┼ ─ ┼─────┼ ┐              ┏━━━━━━━━━━━━━┓
33//!    │     │   │     │   │     │  ─────────────▶┃             ┃
34//!    ├─────┤ └ ┼─────┼ ─ ┼─────┼ ┘              ┗━━━━━━━━━━━━━┛
35//!    │     │   │     │   │     │
36//!    └─────┘   └─────┘   └─────┘
37//!                ...
38//!    ┌─────┐ ┌ ┬─────┬ ─ ┬─────┬ ┐              ┏━━━━━━━━┓
39//!    │     │   │     │   │     │  ─────────────▶┃        ┃
40//!    └─────┘ └ ┴─────┴ ─ ┴─────┴ ┘              ┗━━━━━━━━┛
41//!     UInt64      Utf8     F64
42//!
43//!           Input Arrays                          Row Format
44//!     (Columns)
45//! ```
46//!
47//! _[`Rows`] must be generated by the same [`RowConverter`] for the comparison
48//! to be meaningful._
49//!
50//! # Basic Example
51//! ```
52//! # use std::sync::Arc;
53//! # use arrow_row::{RowConverter, SortField};
54//! # use arrow_array::{ArrayRef, Int32Array, StringArray};
55//! # use arrow_array::cast::{AsArray, as_string_array};
56//! # use arrow_array::types::Int32Type;
57//! # use arrow_schema::DataType;
58//!
59//! let a1 = Arc::new(Int32Array::from_iter_values([-1, -1, 0, 3, 3])) as ArrayRef;
60//! let a2 = Arc::new(StringArray::from_iter_values(["a", "b", "c", "d", "d"])) as ArrayRef;
61//! let arrays = vec![a1, a2];
62//!
63//! // Convert arrays to rows
64//! let converter = RowConverter::new(vec![
65//!     SortField::new(DataType::Int32),
66//!     SortField::new(DataType::Utf8),
67//! ]).unwrap();
68//! let rows = converter.convert_columns(&arrays).unwrap();
69//!
70//! // Compare rows
71//! for i in 0..4 {
72//!     assert!(rows.row(i) <= rows.row(i + 1));
73//! }
74//! assert_eq!(rows.row(3), rows.row(4));
75//!
76//! // Convert rows back to arrays
77//! let converted = converter.convert_rows(&rows).unwrap();
78//! assert_eq!(arrays, converted);
79//!
80//! // Compare rows from different arrays
81//! let a1 = Arc::new(Int32Array::from_iter_values([3, 4])) as ArrayRef;
82//! let a2 = Arc::new(StringArray::from_iter_values(["e", "f"])) as ArrayRef;
83//! let arrays = vec![a1, a2];
84//! let rows2 = converter.convert_columns(&arrays).unwrap();
85//!
86//! assert!(rows.row(4) < rows2.row(0));
87//! assert!(rows.row(4) < rows2.row(1));
88//!
89//! // Convert selection of rows back to arrays
90//! let selection = [rows.row(0), rows2.row(1), rows.row(2), rows2.row(0)];
91//! let converted = converter.convert_rows(selection).unwrap();
92//! let c1 = converted[0].as_primitive::<Int32Type>();
93//! assert_eq!(c1.values(), &[-1, 4, 0, 3]);
94//!
95//! let c2 = converted[1].as_string::<i32>();
96//! let c2_values: Vec<_> = c2.iter().flatten().collect();
97//! assert_eq!(&c2_values, &["a", "f", "c", "e"]);
98//! ```
99//!
100//! # Lexicographic Sorts (lexsort)
101//!
102//! The row format can also be used to implement a fast multi-column / lexicographic sort
103//!
104//! ```
105//! # use arrow_row::{RowConverter, SortField};
106//! # use arrow_array::{ArrayRef, UInt32Array};
107//! fn lexsort_to_indices(arrays: &[ArrayRef]) -> UInt32Array {
108//!     let fields = arrays
109//!         .iter()
110//!         .map(|a| SortField::new(a.data_type().clone()))
111//!         .collect();
112//!     let converter = RowConverter::new(fields).unwrap();
113//!     let rows = converter.convert_columns(arrays).unwrap();
114//!     let mut sort: Vec<_> = rows.iter().enumerate().collect();
115//!     sort.sort_unstable_by(|(_, a), (_, b)| a.cmp(b));
116//!     UInt32Array::from_iter_values(sort.iter().map(|(i, _)| *i as u32))
117//! }
118//! ```
119//!
120//! # Flattening Dictionaries
121//!
122//! For performance reasons, dictionary arrays are flattened ("hydrated") to their
123//! underlying values during row conversion. See [the issue] for more details.
124//!
125//! This means that the arrays that come out of [`RowConverter::convert_rows`]
126//! may not have the same data types as the input arrays. For example, encoding
127//! a `Dictionary<Int8, Utf8>` and then will come out as a `Utf8` array.
128//!
129//! ```
130//! # use arrow_array::{Array, ArrayRef, DictionaryArray};
131//! # use arrow_array::types::Int8Type;
132//! # use arrow_row::{RowConverter, SortField};
133//! # use arrow_schema::DataType;
134//! # use std::sync::Arc;
135//! // Input is a Dictionary array
136//! let dict: DictionaryArray::<Int8Type> = ["a", "b", "c", "a", "b"].into_iter().collect();
137//! let sort_fields = vec![SortField::new(dict.data_type().clone())];
138//! let arrays = vec![Arc::new(dict) as ArrayRef];
139//! let converter = RowConverter::new(sort_fields).unwrap();
140//! // Convert to rows
141//! let rows = converter.convert_columns(&arrays).unwrap();
142//! let converted = converter.convert_rows(&rows).unwrap();
143//! // result was a Utf8 array, not a Dictionary array
144//! assert_eq!(converted[0].data_type(), &DataType::Utf8);
145//! ```
146//!
147//! [non-comparison sorts]: https://en.wikipedia.org/wiki/Sorting_algorithm#Non-comparison_sorts
148//! [radix sort]: https://en.wikipedia.org/wiki/Radix_sort
149//! [normalized for sorting]: http://wwwlgis.informatik.uni-kl.de/archiv/wwwdvs.informatik.uni-kl.de/courses/DBSREAL/SS2005/Vorlesungsunterlagen/Implementing_Sorting.pdf
150//! [`memcmp`]: https://www.man7.org/linux/man-pages/man3/memcmp.3.html
151//! [`lexsort`]: https://docs.rs/arrow-ord/latest/arrow_ord/sort/fn.lexsort.html
152//! [compared]: PartialOrd
153//! [compare]: PartialOrd
154//! [the issue]: https://github.com/apache/arrow-rs/issues/4811
155
156#![doc(
157    html_logo_url = "https://arrow.apache.org/img/arrow-logo_chevrons_black-txt_white-bg.svg",
158    html_favicon_url = "https://arrow.apache.org/img/arrow-logo_chevrons_black-txt_transparent-bg.svg"
159)]
160#![cfg_attr(docsrs, feature(doc_cfg))]
161#![warn(missing_docs)]
162use std::cmp::Ordering;
163use std::hash::{Hash, Hasher};
164use std::iter::Map;
165use std::slice::Windows;
166use std::sync::Arc;
167
168use arrow_array::cast::*;
169use arrow_array::types::{ArrowDictionaryKeyType, ByteArrayType, ByteViewType};
170use arrow_array::*;
171use arrow_buffer::{ArrowNativeType, Buffer, OffsetBuffer, ScalarBuffer};
172use arrow_data::{ArrayData, ArrayDataBuilder};
173use arrow_schema::*;
174use variable::{decode_binary_view, decode_string_view};
175
176use crate::fixed::{decode_bool, decode_fixed_size_binary, decode_primitive};
177use crate::list::{compute_lengths_fixed_size_list, encode_fixed_size_list};
178use crate::variable::{decode_binary, decode_string};
179use arrow_array::types::{Int16Type, Int32Type, Int64Type};
180
181mod fixed;
182mod list;
183mod run;
184mod variable;
185
186/// Converts [`ArrayRef`] columns into a [row-oriented](self) format.
187///
188/// *Note: The encoding of the row format may change from release to release.*
189///
190/// ## Overview
191///
192/// The row format is a variable length byte sequence created by
193/// concatenating the encoded form of each column. The encoding for
194/// each column depends on its datatype (and sort options).
195///
196/// The encoding is carefully designed in such a way that escaping is
197/// unnecessary: it is never ambiguous as to whether a byte is part of
198/// a sentinel (e.g. null) or a value.
199///
200/// ## Unsigned Integer Encoding
201///
202/// A null integer is encoded as a `0_u8`, followed by a zero-ed number of bytes corresponding
203/// to the integer's length.
204///
205/// A valid integer is encoded as `1_u8`, followed by the big-endian representation of the
206/// integer.
207///
208/// ```text
209///               ┌──┬──┬──┬──┐      ┌──┬──┬──┬──┬──┐
210///    3          │03│00│00│00│      │01│00│00│00│03│
211///               └──┴──┴──┴──┘      └──┴──┴──┴──┴──┘
212///               ┌──┬──┬──┬──┐      ┌──┬──┬──┬──┬──┐
213///   258         │02│01│00│00│      │01│00│00│01│02│
214///               └──┴──┴──┴──┘      └──┴──┴──┴──┴──┘
215///               ┌──┬──┬──┬──┐      ┌──┬──┬──┬──┬──┐
216///  23423        │7F│5B│00│00│      │01│00│00│5B│7F│
217///               └──┴──┴──┴──┘      └──┴──┴──┴──┴──┘
218///               ┌──┬──┬──┬──┐      ┌──┬──┬──┬──┬──┐
219///  NULL         │??│??│??│??│      │00│00│00│00│00│
220///               └──┴──┴──┴──┘      └──┴──┴──┴──┴──┘
221///
222///              32-bit (4 bytes)        Row Format
223///  Value        Little Endian
224/// ```
225///
226/// ## Signed Integer Encoding
227///
228/// Signed integers have their most significant sign bit flipped, and are then encoded in the
229/// same manner as an unsigned integer.
230///
231/// ```text
232///        ┌──┬──┬──┬──┐       ┌──┬──┬──┬──┐       ┌──┬──┬──┬──┬──┐
233///     5  │05│00│00│00│       │05│00│00│80│       │01│80│00│00│05│
234///        └──┴──┴──┴──┘       └──┴──┴──┴──┘       └──┴──┴──┴──┴──┘
235///        ┌──┬──┬──┬──┐       ┌──┬──┬──┬──┐       ┌──┬──┬──┬──┬──┐
236///    -5  │FB│FF│FF│FF│       │FB│FF│FF│7F│       │01│7F│FF│FF│FB│
237///        └──┴──┴──┴──┘       └──┴──┴──┴──┘       └──┴──┴──┴──┴──┘
238///
239///  Value  32-bit (4 bytes)    High bit flipped      Row Format
240///          Little Endian
241/// ```
242///
243/// ## Float Encoding
244///
245/// Floats are converted from IEEE 754 representation to a signed integer representation
246/// by flipping all bar the sign bit if they are negative.
247///
248/// They are then encoded in the same manner as a signed integer.
249///
250/// ## Fixed Length Bytes Encoding
251///
252/// Fixed length bytes are encoded in the same fashion as primitive types above.
253///
254/// For a fixed length array of length `n`:
255///
256/// A null is encoded as `0_u8` null sentinel followed by `n` `0_u8` bytes
257///
258/// A valid value is encoded as `1_u8` followed by the value bytes
259///
260/// ## Variable Length Bytes (including Strings) Encoding
261///
262/// A null is encoded as a `0_u8`.
263///
264/// An empty byte array is encoded as `1_u8`.
265///
266/// A non-null, non-empty byte array is encoded as `2_u8` followed by the byte array
267/// encoded using a block based scheme described below.
268///
269/// The byte array is broken up into fixed-width blocks, each block is written in turn
270/// to the output, followed by `0xFF_u8`. The final block is padded to 32-bytes
271/// with `0_u8` and written to the output, followed by the un-padded length in bytes
272/// of this final block as a `u8`. The first 4 blocks have a length of 8, with subsequent
273/// blocks using a length of 32, this is to reduce space amplification for small strings.
274///
275/// Note the following example encodings use a block size of 4 bytes for brevity:
276///
277/// ```text
278///                       ┌───┬───┬───┬───┬───┬───┐
279///  "MEEP"               │02 │'M'│'E'│'E'│'P'│04 │
280///                       └───┴───┴───┴───┴───┴───┘
281///
282///                       ┌───┐
283///  ""                   │01 |
284///                       └───┘
285///
286///  NULL                 ┌───┐
287///                       │00 │
288///                       └───┘
289///
290/// "Defenestration"      ┌───┬───┬───┬───┬───┬───┐
291///                       │02 │'D'│'e'│'f'│'e'│FF │
292///                       └───┼───┼───┼───┼───┼───┤
293///                           │'n'│'e'│'s'│'t'│FF │
294///                           ├───┼───┼───┼───┼───┤
295///                           │'r'│'a'│'t'│'r'│FF │
296///                           ├───┼───┼───┼───┼───┤
297///                           │'a'│'t'│'i'│'o'│FF │
298///                           ├───┼───┼───┼───┼───┤
299///                           │'n'│00 │00 │00 │01 │
300///                           └───┴───┴───┴───┴───┘
301/// ```
302///
303/// This approach is loosely inspired by [COBS] encoding, and chosen over more traditional
304/// [byte stuffing] as it is more amenable to vectorisation, in particular AVX-256.
305///
306/// ## Dictionary Encoding
307///
308/// Dictionary encoded arrays are hydrated to their underlying values
309///
310/// ## REE Encoding
311///
312/// REE (Run End Encoding) arrays, A form of Run Length Encoding, are hydrated to their underlying values.
313///
314/// ## Struct Encoding
315///
316/// A null is encoded as a `0_u8`.
317///
318/// A valid value is encoded as `1_u8` followed by the row encoding of each child.
319///
320/// This encoding effectively flattens the schema in a depth-first fashion.
321///
322/// For example
323///
324/// ```text
325/// ┌───────┬────────────────────────┬───────┐
326/// │ Int32 │ Struct[Int32, Float32] │ Int32 │
327/// └───────┴────────────────────────┴───────┘
328/// ```
329///
330/// Is encoded as
331///
332/// ```text
333/// ┌───────┬───────────────┬───────┬─────────┬───────┐
334/// │ Int32 │ Null Sentinel │ Int32 │ Float32 │ Int32 │
335/// └───────┴───────────────┴───────┴─────────┴───────┘
336/// ```
337///
338/// ## List Encoding
339///
340/// Lists are encoded by first encoding all child elements to the row format.
341///
342/// A list value is then encoded as the concatenation of each of the child elements,
343/// separately encoded using the variable length encoding described above, followed
344/// by the variable length encoding of an empty byte array.
345///
346/// For example given:
347///
348/// ```text
349/// [1_u8, 2_u8, 3_u8]
350/// [1_u8, null]
351/// []
352/// null
353/// ```
354///
355/// The elements would be converted to:
356///
357/// ```text
358///     ┌──┬──┐     ┌──┬──┐     ┌──┬──┐     ┌──┬──┐        ┌──┬──┐
359///  1  │01│01│  2  │01│02│  3  │01│03│  1  │01│01│  null  │00│00│
360///     └──┴──┘     └──┴──┘     └──┴──┘     └──┴──┘        └──┴──┘
361///```
362///
363/// Which would be encoded as
364///
365/// ```text
366///                         ┌──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┐
367///  [1_u8, 2_u8, 3_u8]     │02│01│01│00│00│02│02│01│02│00│00│02│02│01│03│00│00│02│01│
368///                         └──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┘
369///                          └──── 1_u8 ────┘   └──── 2_u8 ────┘  └──── 3_u8 ────┘
370///
371///                         ┌──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┐
372///  [1_u8, null]           │02│01│01│00│00│02│02│00│00│00│00│02│01│
373///                         └──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┘
374///                          └──── 1_u8 ────┘   └──── null ────┘
375///
376///```
377///
378/// With `[]` represented by an empty byte array, and `null` a null byte array.
379///
380/// ## Fixed Size List Encoding
381///
382/// Fixed Size Lists are encoded by first encoding all child elements to the row format.
383///
384/// A non-null list value is then encoded as 0x01 followed by the concatenation of each
385/// of the child elements. A null list value is encoded as a null marker.
386///
387/// For example given:
388///
389/// ```text
390/// [1_u8, 2_u8]
391/// [3_u8, null]
392/// null
393/// ```
394///
395/// The elements would be converted to:
396///
397/// ```text
398///     ┌──┬──┐     ┌──┬──┐     ┌──┬──┐        ┌──┬──┐
399///  1  │01│01│  2  │01│02│  3  │01│03│  null  │00│00│
400///     └──┴──┘     └──┴──┘     └──┴──┘        └──┴──┘
401///```
402///
403/// Which would be encoded as
404///
405/// ```text
406///                 ┌──┬──┬──┬──┬──┐
407///  [1_u8, 2_u8]   │01│01│01│01│02│
408///                 └──┴──┴──┴──┴──┘
409///                     └ 1 ┘ └ 2 ┘
410///                 ┌──┬──┬──┬──┬──┐
411///  [3_u8, null]   │01│01│03│00│00│
412///                 └──┴──┴──┴──┴──┘
413///                     └ 1 ┘ └null┘
414///                 ┌──┐
415///  null           │00│
416///                 └──┘
417///
418///```
419///
420/// ## ListView Encoding
421///
422/// ListView arrays differ from List arrays in their representation: instead of using
423/// consecutive offset pairs to define each list, ListView uses explicit offset and size
424/// pairs for each element. This allows ListView elements to reference arbitrary (potentially
425/// overlapping) regions of the child array.
426///
427/// Despite this structural difference, ListView uses the **same row encoding as List**.
428/// Each list value is encoded as the concatenation of its child elements (each separately
429/// variable-length encoded), followed by a variable-length encoded empty byte array terminator.
430///
431/// **Important**: When a ListView is decoded back from row format, it is still a
432/// ListView, but any child element sharing that may have existed in the original
433/// (where multiple list entries could reference overlapping regions of the child
434/// array) is **not preserved** - each list's children are decoded independently
435/// with sequential offsets.
436///
437/// For example, given a ListView with offset/size pairs:
438///
439/// ```text
440/// offsets: [0, 1, 0]
441/// sizes:   [2, 2, 0]
442/// values:  [1_u8, 2_u8, 3_u8]
443///
444/// Resulting lists:
445/// [1_u8, 2_u8]  (offset=0, size=2 -> values[0..2])
446/// [2_u8, 3_u8]  (offset=1, size=2 -> values[1..3])
447/// []            (offset=0, size=0 -> empty)
448/// ```
449///
450/// The elements would be encoded identically to List encoding:
451///
452/// ```text
453///                         ┌──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┐
454///  [1_u8, 2_u8]           │02│01│01│00│00│02│02│01│02│00│00│02│01│
455///                         └──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┘
456///                          └──── 1_u8 ────┘   └──── 2_u8 ────┘
457///
458///                         ┌──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┐
459///  [2_u8, 3_u8]           │02│01│02│00│00│02│02│01│03│00│00│02│01│
460///                         └──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┘
461///                          └──── 2_u8 ────┘   └──── 3_u8 ────┘
462///
463///```
464///
465/// Note that element `2_u8` appears in both encoded rows, even though it was shared
466/// in the original ListView, and `[]` is represented by an empty byte array.
467///
468/// ## Union Encoding
469///
470/// A union value is encoded as a single type-id byte followed by the row encoding of the selected child value.
471/// The type-id byte is always present; union arrays have no top-level null marker, so nulls are represented by the child encoding.
472///
473/// For example, given a union of Int32 (type_id = 0) and Utf8 (type_id = 1):
474///
475/// ```text
476///                           ┌──┬──────────────┐
477///  3                        │00│01│80│00│00│03│
478///                           └──┴──────────────┘
479///                            │  └─ signed integer encoding (non-null)
480///                            └──── type_id
481///
482///                           ┌──┬────────────────────────────────┐
483/// "abc"                     │01│02│'a'│'b'│'c'│00│00│00│00│00│03│
484///                           └──┴────────────────────────────────┘
485///                            │  └─ string encoding (non-null)
486///                            └──── type_id
487///
488///                           ┌──┬──────────────┐
489/// null Int32                │00│00│00│00│00│00│
490///                           └──┴──────────────┘
491///                            │  └─ signed integer encoding (null)
492///                            └──── type_id
493///
494///                           ┌──┬──┐
495/// null Utf8                 │01│00│
496///                           └──┴──┘
497///                            │  └─ string encoding (null)
498///                            └──── type_id
499/// ```
500///
501/// See [`UnionArray`] for more details on union types.
502///
503/// # Ordering
504///
505/// ## Float Ordering
506///
507/// Floats are totally ordered in accordance to the `totalOrder` predicate as defined
508/// in the IEEE 754 (2008 revision) floating point standard.
509///
510/// The ordering established by this does not always agree with the
511/// [`PartialOrd`] and [`PartialEq`] implementations of `f32`. For example,
512/// they consider negative and positive zero equal, while this does not
513///
514/// ## Null Ordering
515///
516/// The encoding described above will order nulls first, this can be inverted by representing
517/// nulls as `0xFF_u8` instead of `0_u8`
518///
519/// ## Union Ordering
520///
521/// Values of the same type are ordered according to the ordering of that type.
522/// Values of different types are ordered by their type id.
523/// The type_id is negated when descending order is specified.
524///
525/// ## Reverse Column Ordering
526///
527/// The order of a given column can be reversed by negating the encoded bytes of non-null values
528///
529/// [COBS]: https://en.wikipedia.org/wiki/Consistent_Overhead_Byte_Stuffing
530/// [byte stuffing]: https://en.wikipedia.org/wiki/High-Level_Data_Link_Control#Asynchronous_framing
531#[derive(Debug)]
532pub struct RowConverter {
533    fields: Arc<[SortField]>,
534    /// State for codecs
535    codecs: Vec<Codec>,
536}
537
538#[derive(Debug)]
539enum Codec {
540    /// No additional codec state is necessary
541    Stateless,
542    /// A row converter for the dictionary values
543    /// and the encoding of a row containing only nulls
544    Dictionary(RowConverter, OwnedRow),
545    /// A row converter for the child fields
546    /// and the encoding of a row containing only nulls
547    Struct(RowConverter, OwnedRow),
548    /// A row converter for the child field
549    List(RowConverter),
550    /// A row converter for the values array of a run-end encoded array
551    RunEndEncoded(RowConverter),
552    /// Row converters for each union field (indexed by field position)
553    /// the type_ids for each field position, and the encoding of null rows for each field
554    Union(Vec<RowConverter>, Vec<i8>, Vec<OwnedRow>),
555}
556
557/// Computes the minimum offset and maximum end (offset + size) for a ListView array.
558/// Returns (min_offset, max_end) which can be used to slice the values array.
559fn compute_list_view_bounds<O: OffsetSizeTrait>(array: &GenericListViewArray<O>) -> (usize, usize) {
560    if array.is_empty() {
561        return (0, 0);
562    }
563
564    let offsets = array.value_offsets();
565    let sizes = array.value_sizes();
566    let values_len = array.values().len();
567
568    let mut min_offset = usize::MAX;
569    let mut max_end = 0usize;
570
571    for i in 0..array.len() {
572        let offset = offsets[i].as_usize();
573        let size = sizes[i].as_usize();
574        let end = offset + size;
575
576        if size > 0 {
577            min_offset = min_offset.min(offset);
578            max_end = max_end.max(end);
579        }
580
581        // Early exit if we've found the full range of the values array. This is possible with
582        // ListViews since offsets and sizes are arbitrary and the full range can be covered early
583        // in the iteration contrary to regular Lists.
584        if min_offset == 0 && max_end == values_len {
585            break;
586        }
587    }
588
589    if min_offset == usize::MAX {
590        // All lists are empty
591        (0, 0)
592    } else {
593        (min_offset, max_end)
594    }
595}
596
597impl Codec {
598    fn new(sort_field: &SortField) -> Result<Self, ArrowError> {
599        match &sort_field.data_type {
600            DataType::Dictionary(_, values) => {
601                let sort_field =
602                    SortField::new_with_options(values.as_ref().clone(), sort_field.options);
603
604                let converter = RowConverter::new(vec![sort_field])?;
605                let null_array = new_null_array(values.as_ref(), 1);
606                let nulls = converter.convert_columns(&[null_array])?;
607
608                let owned = OwnedRow {
609                    data: nulls.buffer.into(),
610                    config: nulls.config,
611                };
612                Ok(Self::Dictionary(converter, owned))
613            }
614            DataType::RunEndEncoded(_, values) => {
615                // Similar to List implementation
616                let options = SortOptions {
617                    descending: false,
618                    nulls_first: sort_field.options.nulls_first != sort_field.options.descending,
619                };
620
621                let field = SortField::new_with_options(values.data_type().clone(), options);
622                let converter = RowConverter::new(vec![field])?;
623                Ok(Self::RunEndEncoded(converter))
624            }
625            d if !d.is_nested() => Ok(Self::Stateless),
626            DataType::List(f)
627            | DataType::LargeList(f)
628            | DataType::ListView(f)
629            | DataType::LargeListView(f) => {
630                // The encoded contents will be inverted if descending is set to true
631                // As such we set `descending` to false and negate nulls first if it
632                // it set to true
633                let options = SortOptions {
634                    descending: false,
635                    nulls_first: sort_field.options.nulls_first != sort_field.options.descending,
636                };
637
638                let field = SortField::new_with_options(f.data_type().clone(), options);
639                let converter = RowConverter::new(vec![field])?;
640                Ok(Self::List(converter))
641            }
642            DataType::FixedSizeList(f, _) => {
643                let field = SortField::new_with_options(f.data_type().clone(), sort_field.options);
644                let converter = RowConverter::new(vec![field])?;
645                Ok(Self::List(converter))
646            }
647            DataType::Struct(f) => {
648                let sort_fields = f
649                    .iter()
650                    .map(|x| SortField::new_with_options(x.data_type().clone(), sort_field.options))
651                    .collect();
652
653                let converter = RowConverter::new(sort_fields)?;
654                let nulls: Vec<_> = f.iter().map(|x| new_null_array(x.data_type(), 1)).collect();
655
656                let nulls = converter.convert_columns(&nulls)?;
657                let owned = OwnedRow {
658                    data: nulls.buffer.into(),
659                    config: nulls.config,
660                };
661
662                Ok(Self::Struct(converter, owned))
663            }
664            DataType::Union(fields, _mode) => {
665                // similar to dictionaries and lists, we set descending to false and negate nulls_first
666                // since the encoded contents will be inverted if descending is set
667                let options = SortOptions {
668                    descending: false,
669                    nulls_first: sort_field.options.nulls_first != sort_field.options.descending,
670                };
671
672                let mut converters = Vec::with_capacity(fields.len());
673                let mut type_ids = Vec::with_capacity(fields.len());
674                let mut null_rows = Vec::with_capacity(fields.len());
675
676                for (type_id, field) in fields.iter() {
677                    let sort_field =
678                        SortField::new_with_options(field.data_type().clone(), options);
679                    let converter = RowConverter::new(vec![sort_field])?;
680
681                    let null_array = new_null_array(field.data_type(), 1);
682                    let nulls = converter.convert_columns(&[null_array])?;
683                    let owned = OwnedRow {
684                        data: nulls.buffer.into(),
685                        config: nulls.config,
686                    };
687
688                    converters.push(converter);
689                    type_ids.push(type_id);
690                    null_rows.push(owned);
691                }
692
693                Ok(Self::Union(converters, type_ids, null_rows))
694            }
695            _ => Err(ArrowError::NotYetImplemented(format!(
696                "not yet implemented: {:?}",
697                sort_field.data_type
698            ))),
699        }
700    }
701
702    fn encoder(&self, array: &dyn Array) -> Result<Encoder<'_>, ArrowError> {
703        match self {
704            Codec::Stateless => Ok(Encoder::Stateless),
705            Codec::Dictionary(converter, nulls) => {
706                let values = array.as_any_dictionary().values().clone();
707                let rows = converter.convert_columns(&[values])?;
708                Ok(Encoder::Dictionary(rows, nulls.row()))
709            }
710            Codec::Struct(converter, null) => {
711                let v = as_struct_array(array);
712                let rows = converter.convert_columns(v.columns())?;
713                Ok(Encoder::Struct(rows, null.row()))
714            }
715            Codec::List(converter) => {
716                let values = match array.data_type() {
717                    DataType::List(_) => {
718                        let list_array = as_list_array(array);
719                        let first_offset = list_array.offsets()[0] as usize;
720                        let last_offset =
721                            list_array.offsets()[list_array.offsets().len() - 1] as usize;
722
723                        // values can include more data than referenced in the ListArray, only encode
724                        // the referenced values.
725                        list_array
726                            .values()
727                            .slice(first_offset, last_offset - first_offset)
728                    }
729                    DataType::LargeList(_) => {
730                        let list_array = as_large_list_array(array);
731
732                        let first_offset = list_array.offsets()[0] as usize;
733                        let last_offset =
734                            list_array.offsets()[list_array.offsets().len() - 1] as usize;
735
736                        // values can include more data than referenced in the LargeListArray, only encode
737                        // the referenced values.
738                        list_array
739                            .values()
740                            .slice(first_offset, last_offset - first_offset)
741                    }
742                    DataType::ListView(_) => {
743                        let list_view_array = array.as_list_view::<i32>();
744                        let (min_offset, max_end) = compute_list_view_bounds(list_view_array);
745                        list_view_array
746                            .values()
747                            .slice(min_offset, max_end - min_offset)
748                    }
749                    DataType::LargeListView(_) => {
750                        let list_view_array = array.as_list_view::<i64>();
751                        let (min_offset, max_end) = compute_list_view_bounds(list_view_array);
752                        list_view_array
753                            .values()
754                            .slice(min_offset, max_end - min_offset)
755                    }
756                    DataType::FixedSizeList(_, _) => {
757                        as_fixed_size_list_array(array).values().clone()
758                    }
759                    _ => unreachable!(),
760                };
761                let rows = converter.convert_columns(&[values])?;
762                Ok(Encoder::List(rows))
763            }
764            Codec::RunEndEncoded(converter) => {
765                let values = match array.data_type() {
766                    DataType::RunEndEncoded(r, _) => match r.data_type() {
767                        DataType::Int16 => array.as_run::<Int16Type>().values_slice(),
768                        DataType::Int32 => array.as_run::<Int32Type>().values_slice(),
769                        DataType::Int64 => array.as_run::<Int64Type>().values_slice(),
770                        _ => unreachable!("Unsupported run end index type: {r:?}"),
771                    },
772                    _ => unreachable!(),
773                };
774                let rows = converter.convert_columns(std::slice::from_ref(&values))?;
775                Ok(Encoder::RunEndEncoded(rows))
776            }
777            Codec::Union(converters, field_to_type_ids, _) => {
778                let union_array = array
779                    .as_any()
780                    .downcast_ref::<UnionArray>()
781                    .expect("expected Union array");
782
783                let type_ids = union_array.type_ids().clone();
784                let offsets = union_array.offsets().cloned();
785
786                let mut child_rows = Vec::with_capacity(converters.len());
787                for (field_idx, converter) in converters.iter().enumerate() {
788                    let type_id = field_to_type_ids[field_idx];
789                    let child_array = union_array.child(type_id);
790                    let rows = converter.convert_columns(std::slice::from_ref(child_array))?;
791                    child_rows.push(rows);
792                }
793
794                Ok(Encoder::Union {
795                    child_rows,
796                    field_to_type_ids: field_to_type_ids.clone(),
797                    type_ids,
798                    offsets,
799                })
800            }
801        }
802    }
803
804    fn size(&self) -> usize {
805        match self {
806            Codec::Stateless => 0,
807            Codec::Dictionary(converter, nulls) => converter.size() + nulls.data.len(),
808            Codec::Struct(converter, nulls) => converter.size() + nulls.data.len(),
809            Codec::List(converter) => converter.size(),
810            Codec::RunEndEncoded(converter) => converter.size(),
811            Codec::Union(converters, _, null_rows) => {
812                converters.iter().map(|c| c.size()).sum::<usize>()
813                    + null_rows.iter().map(|n| n.data.len()).sum::<usize>()
814            }
815        }
816    }
817}
818
819#[derive(Debug)]
820enum Encoder<'a> {
821    /// No additional encoder state is necessary
822    Stateless,
823    /// The encoding of the child array and the encoding of a null row
824    Dictionary(Rows, Row<'a>),
825    /// The row encoding of the child arrays and the encoding of a null row
826    ///
827    /// It is necessary to encode to a temporary [`Rows`] to avoid serializing
828    /// values that are masked by a null in the parent StructArray, otherwise
829    /// this would establish an ordering between semantically null values
830    Struct(Rows, Row<'a>),
831    /// The row encoding of the child array
832    List(Rows),
833    /// The row encoding of the values array
834    RunEndEncoded(Rows),
835    /// The row encoding of each union field's child array, type_ids buffer, offsets buffer (for Dense), and mode
836    Union {
837        child_rows: Vec<Rows>,
838        field_to_type_ids: Vec<i8>,
839        type_ids: ScalarBuffer<i8>,
840        offsets: Option<ScalarBuffer<i32>>,
841    },
842}
843
844/// Configure the data type and sort order for a given column
845#[derive(Debug, Clone, PartialEq, Eq)]
846pub struct SortField {
847    /// Sort options
848    options: SortOptions,
849    /// Data type
850    data_type: DataType,
851}
852
853impl SortField {
854    /// Create a new column with the given data type
855    pub fn new(data_type: DataType) -> Self {
856        Self::new_with_options(data_type, Default::default())
857    }
858
859    /// Create a new column with the given data type and [`SortOptions`]
860    pub fn new_with_options(data_type: DataType, options: SortOptions) -> Self {
861        Self { options, data_type }
862    }
863
864    /// Return size of this instance in bytes.
865    ///
866    /// Includes the size of `Self`.
867    pub fn size(&self) -> usize {
868        self.data_type.size() + std::mem::size_of::<Self>() - std::mem::size_of::<DataType>()
869    }
870}
871
872impl RowConverter {
873    /// Create a new [`RowConverter`] with the provided schema
874    pub fn new(fields: Vec<SortField>) -> Result<Self, ArrowError> {
875        if !Self::supports_fields(&fields) {
876            return Err(ArrowError::NotYetImplemented(format!(
877                "Row format support not yet implemented for: {fields:?}"
878            )));
879        }
880
881        let codecs = fields.iter().map(Codec::new).collect::<Result<_, _>>()?;
882        Ok(Self {
883            fields: fields.into(),
884            codecs,
885        })
886    }
887
888    /// Check if the given fields are supported by the row format.
889    pub fn supports_fields(fields: &[SortField]) -> bool {
890        fields.iter().all(|x| Self::supports_datatype(&x.data_type))
891    }
892
893    fn supports_datatype(d: &DataType) -> bool {
894        match d {
895            _ if !d.is_nested() => true,
896            DataType::List(f)
897            | DataType::LargeList(f)
898            | DataType::ListView(f)
899            | DataType::LargeListView(f)
900            | DataType::FixedSizeList(f, _) => Self::supports_datatype(f.data_type()),
901            DataType::Struct(f) => f.iter().all(|x| Self::supports_datatype(x.data_type())),
902            DataType::RunEndEncoded(_, values) => Self::supports_datatype(values.data_type()),
903            DataType::Union(fs, _mode) => fs
904                .iter()
905                .all(|(_, f)| Self::supports_datatype(f.data_type())),
906            _ => false,
907        }
908    }
909
910    /// Convert [`ArrayRef`] columns into [`Rows`]
911    ///
912    /// See [`Row`] for information on when [`Row`] can be compared
913    ///
914    /// See [`Self::convert_rows`] for converting [`Rows`] back into [`ArrayRef`]
915    ///
916    /// # Panics
917    ///
918    /// Panics if the schema of `columns` does not match that provided to [`RowConverter::new`]
919    pub fn convert_columns(&self, columns: &[ArrayRef]) -> Result<Rows, ArrowError> {
920        let num_rows = columns.first().map(|x| x.len()).unwrap_or(0);
921        let mut rows = self.empty_rows(num_rows, 0);
922        self.append(&mut rows, columns)?;
923        Ok(rows)
924    }
925
926    /// Convert [`ArrayRef`] columns appending to an existing [`Rows`]
927    ///
928    /// See [`Row`] for information on when [`Row`] can be compared
929    ///
930    /// # Panics
931    ///
932    /// Panics if
933    /// * The schema of `columns` does not match that provided to [`RowConverter::new`]
934    /// * The provided [`Rows`] were not created by this [`RowConverter`]
935    ///
936    /// ```
937    /// # use std::sync::Arc;
938    /// # use std::collections::HashSet;
939    /// # use arrow_array::cast::AsArray;
940    /// # use arrow_array::StringArray;
941    /// # use arrow_row::{Row, RowConverter, SortField};
942    /// # use arrow_schema::DataType;
943    /// #
944    /// let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
945    /// let a1 = StringArray::from(vec!["hello", "world"]);
946    /// let a2 = StringArray::from(vec!["a", "a", "hello"]);
947    ///
948    /// let mut rows = converter.empty_rows(5, 128);
949    /// converter.append(&mut rows, &[Arc::new(a1)]).unwrap();
950    /// converter.append(&mut rows, &[Arc::new(a2)]).unwrap();
951    ///
952    /// let back = converter.convert_rows(&rows).unwrap();
953    /// let values: Vec<_> = back[0].as_string::<i32>().iter().map(Option::unwrap).collect();
954    /// assert_eq!(&values, &["hello", "world", "a", "a", "hello"]);
955    /// ```
956    pub fn append(&self, rows: &mut Rows, columns: &[ArrayRef]) -> Result<(), ArrowError> {
957        assert!(
958            Arc::ptr_eq(&rows.config.fields, &self.fields),
959            "rows were not produced by this RowConverter"
960        );
961
962        if columns.len() != self.fields.len() {
963            return Err(ArrowError::InvalidArgumentError(format!(
964                "Incorrect number of arrays provided to RowConverter, expected {} got {}",
965                self.fields.len(),
966                columns.len()
967            )));
968        }
969        for colum in columns.iter().skip(1) {
970            if colum.len() != columns[0].len() {
971                return Err(ArrowError::InvalidArgumentError(format!(
972                    "RowConverter columns must all have the same length, expected {} got {}",
973                    columns[0].len(),
974                    colum.len()
975                )));
976            }
977        }
978
979        let encoders = columns
980            .iter()
981            .zip(&self.codecs)
982            .zip(self.fields.iter())
983            .map(|((column, codec), field)| {
984                if !column.data_type().equals_datatype(&field.data_type) {
985                    return Err(ArrowError::InvalidArgumentError(format!(
986                        "RowConverter column schema mismatch, expected {} got {}",
987                        field.data_type,
988                        column.data_type()
989                    )));
990                }
991                codec.encoder(column.as_ref())
992            })
993            .collect::<Result<Vec<_>, _>>()?;
994
995        let write_offset = rows.num_rows();
996        let lengths = row_lengths(columns, &encoders);
997        let total = lengths.extend_offsets(rows.offsets[write_offset], &mut rows.offsets);
998        rows.buffer.resize(total, 0);
999
1000        for ((column, field), encoder) in columns.iter().zip(self.fields.iter()).zip(encoders) {
1001            // We encode a column at a time to minimise dispatch overheads
1002            encode_column(
1003                &mut rows.buffer,
1004                &mut rows.offsets[write_offset..],
1005                column.as_ref(),
1006                field.options,
1007                &encoder,
1008            )
1009        }
1010
1011        if cfg!(debug_assertions) {
1012            assert_eq!(*rows.offsets.last().unwrap(), rows.buffer.len());
1013            rows.offsets
1014                .windows(2)
1015                .for_each(|w| assert!(w[0] <= w[1], "offsets should be monotonic"));
1016        }
1017
1018        Ok(())
1019    }
1020
1021    /// Convert [`Rows`] columns into [`ArrayRef`]
1022    ///
1023    /// See [`Self::convert_columns`] for converting [`ArrayRef`] into [`Rows`]
1024    ///
1025    /// # Panics
1026    ///
1027    /// Panics if the rows were not produced by this [`RowConverter`]
1028    pub fn convert_rows<'a, I>(&self, rows: I) -> Result<Vec<ArrayRef>, ArrowError>
1029    where
1030        I: IntoIterator<Item = Row<'a>>,
1031    {
1032        let mut validate_utf8 = false;
1033        let mut rows: Vec<_> = rows
1034            .into_iter()
1035            .map(|row| {
1036                assert!(
1037                    Arc::ptr_eq(&row.config.fields, &self.fields),
1038                    "rows were not produced by this RowConverter"
1039                );
1040                validate_utf8 |= row.config.validate_utf8;
1041                row.data
1042            })
1043            .collect();
1044
1045        // SAFETY
1046        // We have validated that the rows came from this [`RowConverter`]
1047        // and therefore must be valid
1048        let result = unsafe { self.convert_raw(&mut rows, validate_utf8) }?;
1049
1050        if cfg!(debug_assertions) {
1051            for (i, row) in rows.iter().enumerate() {
1052                if !row.is_empty() {
1053                    return Err(ArrowError::InvalidArgumentError(format!(
1054                        "Codecs {codecs:?} did not consume all bytes for row {i}, remaining bytes: {row:?}",
1055                        codecs = &self.codecs
1056                    )));
1057                }
1058            }
1059        }
1060
1061        Ok(result)
1062    }
1063
1064    /// Returns an empty [`Rows`] with capacity for `row_capacity` rows with
1065    /// a total length of `data_capacity`
1066    ///
1067    /// This can be used to buffer a selection of [`Row`]
1068    ///
1069    /// ```
1070    /// # use std::sync::Arc;
1071    /// # use std::collections::HashSet;
1072    /// # use arrow_array::cast::AsArray;
1073    /// # use arrow_array::StringArray;
1074    /// # use arrow_row::{Row, RowConverter, SortField};
1075    /// # use arrow_schema::DataType;
1076    /// #
1077    /// let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
1078    /// let array = StringArray::from(vec!["hello", "world", "a", "a", "hello"]);
1079    ///
1080    /// // Convert to row format and deduplicate
1081    /// let converted = converter.convert_columns(&[Arc::new(array)]).unwrap();
1082    /// let mut distinct_rows = converter.empty_rows(3, 100);
1083    /// let mut dedup: HashSet<Row> = HashSet::with_capacity(3);
1084    /// converted.iter().filter(|row| dedup.insert(*row)).for_each(|row| distinct_rows.push(row));
1085    ///
1086    /// // Note: we could skip buffering and feed the filtered iterator directly
1087    /// // into convert_rows, this is done for demonstration purposes only
1088    /// let distinct = converter.convert_rows(&distinct_rows).unwrap();
1089    /// let values: Vec<_> = distinct[0].as_string::<i32>().iter().map(Option::unwrap).collect();
1090    /// assert_eq!(&values, &["hello", "world", "a"]);
1091    /// ```
1092    pub fn empty_rows(&self, row_capacity: usize, data_capacity: usize) -> Rows {
1093        let mut offsets = Vec::with_capacity(row_capacity.saturating_add(1));
1094        offsets.push(0);
1095
1096        Rows {
1097            offsets,
1098            buffer: Vec::with_capacity(data_capacity),
1099            config: RowConfig {
1100                fields: self.fields.clone(),
1101                validate_utf8: false,
1102            },
1103        }
1104    }
1105
1106    /// Create a new [Rows] instance from the given binary data.
1107    ///
1108    /// ```
1109    /// # use std::sync::Arc;
1110    /// # use std::collections::HashSet;
1111    /// # use arrow_array::cast::AsArray;
1112    /// # use arrow_array::StringArray;
1113    /// # use arrow_row::{OwnedRow, Row, RowConverter, RowParser, SortField};
1114    /// # use arrow_schema::DataType;
1115    /// #
1116    /// let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
1117    /// let array = StringArray::from(vec!["hello", "world", "a", "a", "hello"]);
1118    /// let rows = converter.convert_columns(&[Arc::new(array)]).unwrap();
1119    ///
1120    /// // We can convert rows into binary format and back in batch.
1121    /// let values: Vec<OwnedRow> = rows.iter().map(|r| r.owned()).collect();
1122    /// let binary = rows.try_into_binary().expect("known-small array");
1123    /// let converted = converter.from_binary(binary.clone());
1124    /// assert!(converted.iter().eq(values.iter().map(|r| r.row())));
1125    /// ```
1126    ///
1127    /// # Panics
1128    ///
1129    /// This function expects the passed [BinaryArray] to contain valid row data as produced by this
1130    /// [RowConverter]. It will panic if any rows are null. Operations on the returned [Rows] may
1131    /// panic if the data is malformed.
1132    pub fn from_binary(&self, array: BinaryArray) -> Rows {
1133        assert_eq!(
1134            array.null_count(),
1135            0,
1136            "can't construct Rows instance from array with nulls"
1137        );
1138        let (offsets, values, _) = array.into_parts();
1139        let offsets = offsets.iter().map(|&i| i.as_usize()).collect();
1140        // Try zero-copy, if it does not succeed, fall back to copying the values.
1141        let buffer = values.into_vec().unwrap_or_else(|values| values.to_vec());
1142        Rows {
1143            buffer,
1144            offsets,
1145            config: RowConfig {
1146                fields: Arc::clone(&self.fields),
1147                validate_utf8: true,
1148            },
1149        }
1150    }
1151
1152    /// Convert raw bytes into [`ArrayRef`]
1153    ///
1154    /// # Safety
1155    ///
1156    /// `rows` must contain valid data for this [`RowConverter`]
1157    unsafe fn convert_raw(
1158        &self,
1159        rows: &mut [&[u8]],
1160        validate_utf8: bool,
1161    ) -> Result<Vec<ArrayRef>, ArrowError> {
1162        self.fields
1163            .iter()
1164            .zip(&self.codecs)
1165            .map(|(field, codec)| unsafe { decode_column(field, rows, codec, validate_utf8) })
1166            .collect()
1167    }
1168
1169    /// Returns a [`RowParser`] that can be used to parse [`Row`] from bytes
1170    pub fn parser(&self) -> RowParser {
1171        RowParser::new(Arc::clone(&self.fields))
1172    }
1173
1174    /// Returns the size of this instance in bytes
1175    ///
1176    /// Includes the size of `Self`.
1177    pub fn size(&self) -> usize {
1178        std::mem::size_of::<Self>()
1179            + self.fields.iter().map(|x| x.size()).sum::<usize>()
1180            + self.codecs.capacity() * std::mem::size_of::<Codec>()
1181            + self.codecs.iter().map(Codec::size).sum::<usize>()
1182    }
1183}
1184
1185/// A [`RowParser`] can be created from a [`RowConverter`] and used to parse bytes to [`Row`]
1186#[derive(Debug)]
1187pub struct RowParser {
1188    config: RowConfig,
1189}
1190
1191impl RowParser {
1192    fn new(fields: Arc<[SortField]>) -> Self {
1193        Self {
1194            config: RowConfig {
1195                fields,
1196                validate_utf8: true,
1197            },
1198        }
1199    }
1200
1201    /// Creates a [`Row`] from the provided `bytes`.
1202    ///
1203    /// `bytes` must be a [`Row`] produced by the [`RowConverter`] associated with
1204    /// this [`RowParser`], otherwise subsequent operations with the produced [`Row`] may panic
1205    pub fn parse<'a>(&'a self, bytes: &'a [u8]) -> Row<'a> {
1206        Row {
1207            data: bytes,
1208            config: &self.config,
1209        }
1210    }
1211}
1212
1213/// The config of a given set of [`Row`]
1214#[derive(Debug, Clone)]
1215struct RowConfig {
1216    /// The schema for these rows
1217    fields: Arc<[SortField]>,
1218    /// Whether to run UTF-8 validation when converting to arrow arrays
1219    validate_utf8: bool,
1220}
1221
1222/// A row-oriented representation of arrow data, that is normalized for comparison.
1223///
1224/// See the [module level documentation](self) and [`RowConverter`] for more details.
1225#[derive(Debug)]
1226pub struct Rows {
1227    /// Underlying row bytes
1228    buffer: Vec<u8>,
1229    /// Row `i` has data `&buffer[offsets[i]..offsets[i+1]]`
1230    offsets: Vec<usize>,
1231    /// The config for these rows
1232    config: RowConfig,
1233}
1234
1235/// The iterator type for [`Rows::lengths`]
1236pub type RowLengthIter<'a> = Map<Windows<'a, usize>, fn(&'a [usize]) -> usize>;
1237
1238impl Rows {
1239    /// Append a [`Row`] to this [`Rows`]
1240    pub fn push(&mut self, row: Row<'_>) {
1241        assert!(
1242            Arc::ptr_eq(&row.config.fields, &self.config.fields),
1243            "row was not produced by this RowConverter"
1244        );
1245        self.config.validate_utf8 |= row.config.validate_utf8;
1246        self.buffer.extend_from_slice(row.data);
1247        self.offsets.push(self.buffer.len())
1248    }
1249
1250    /// Reserve capacity for `row_capacity` rows with a total length of `data_capacity`
1251    pub fn reserve(&mut self, row_capacity: usize, data_capacity: usize) {
1252        self.buffer.reserve(data_capacity);
1253        self.offsets.reserve(row_capacity);
1254    }
1255
1256    /// Returns the row at index `row`
1257    pub fn row(&self, row: usize) -> Row<'_> {
1258        assert!(row + 1 < self.offsets.len());
1259        unsafe { self.row_unchecked(row) }
1260    }
1261
1262    /// Returns the row at `index` without bounds checking
1263    ///
1264    /// # Safety
1265    /// Caller must ensure that `index` is less than the number of offsets (#rows + 1)
1266    pub unsafe fn row_unchecked(&self, index: usize) -> Row<'_> {
1267        let end = unsafe { self.offsets.get_unchecked(index + 1) };
1268        let start = unsafe { self.offsets.get_unchecked(index) };
1269        let data = unsafe { self.buffer.get_unchecked(*start..*end) };
1270        Row {
1271            data,
1272            config: &self.config,
1273        }
1274    }
1275
1276    /// Returns the number of bytes the row at index `row` is occupying,
1277    /// that is, what is the length of the returned [`Row::data`] will be.
1278    pub fn row_len(&self, row: usize) -> usize {
1279        assert!(row + 1 < self.offsets.len());
1280
1281        self.offsets[row + 1] - self.offsets[row]
1282    }
1283
1284    /// Get an iterator over the lengths of each row in this [`Rows`]
1285    pub fn lengths(&self) -> RowLengthIter<'_> {
1286        self.offsets.windows(2).map(|w| w[1] - w[0])
1287    }
1288
1289    /// Sets the length of this [`Rows`] to 0
1290    pub fn clear(&mut self) {
1291        self.offsets.truncate(1);
1292        self.buffer.clear();
1293    }
1294
1295    /// Returns the number of [`Row`] in this [`Rows`]
1296    pub fn num_rows(&self) -> usize {
1297        self.offsets.len() - 1
1298    }
1299
1300    /// Returns an iterator over the [`Row`] in this [`Rows`]
1301    pub fn iter(&self) -> RowsIter<'_> {
1302        self.into_iter()
1303    }
1304
1305    /// Returns the size of this instance in bytes
1306    ///
1307    /// Includes the size of `Self`.
1308    pub fn size(&self) -> usize {
1309        // Size of fields is accounted for as part of RowConverter
1310        std::mem::size_of::<Self>()
1311            + self.buffer.capacity()
1312            + self.offsets.capacity() * std::mem::size_of::<usize>()
1313    }
1314
1315    /// Create a [BinaryArray] from the [Rows] data without reallocating the
1316    /// underlying bytes.
1317    ///
1318    ///
1319    /// ```
1320    /// # use std::sync::Arc;
1321    /// # use std::collections::HashSet;
1322    /// # use arrow_array::cast::AsArray;
1323    /// # use arrow_array::StringArray;
1324    /// # use arrow_row::{OwnedRow, Row, RowConverter, RowParser, SortField};
1325    /// # use arrow_schema::DataType;
1326    /// #
1327    /// let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
1328    /// let array = StringArray::from(vec!["hello", "world", "a", "a", "hello"]);
1329    /// let rows = converter.convert_columns(&[Arc::new(array)]).unwrap();
1330    ///
1331    /// // We can convert rows into binary format and back.
1332    /// let values: Vec<OwnedRow> = rows.iter().map(|r| r.owned()).collect();
1333    /// let binary = rows.try_into_binary().expect("known-small array");
1334    /// let parser = converter.parser();
1335    /// let parsed: Vec<OwnedRow> =
1336    ///   binary.iter().flatten().map(|b| parser.parse(b).owned()).collect();
1337    /// assert_eq!(values, parsed);
1338    /// ```
1339    ///
1340    /// # Errors
1341    ///
1342    /// This function will return an error if there is more data than can be stored in
1343    /// a [BinaryArray] -- i.e. if the total data size is more than 2GiB.
1344    pub fn try_into_binary(self) -> Result<BinaryArray, ArrowError> {
1345        if self.buffer.len() > i32::MAX as usize {
1346            return Err(ArrowError::InvalidArgumentError(format!(
1347                "{}-byte rows buffer too long to convert into a i32-indexed BinaryArray",
1348                self.buffer.len()
1349            )));
1350        }
1351        // We've checked that the buffer length fits in an i32; so all offsets into that buffer should fit as well.
1352        let offsets_scalar = ScalarBuffer::from_iter(self.offsets.into_iter().map(i32::usize_as));
1353        // SAFETY: offsets buffer is nonempty, monotonically increasing, and all represent valid indexes into buffer.
1354        let array = unsafe {
1355            BinaryArray::new_unchecked(
1356                OffsetBuffer::new_unchecked(offsets_scalar),
1357                Buffer::from_vec(self.buffer),
1358                None,
1359            )
1360        };
1361        Ok(array)
1362    }
1363}
1364
1365impl<'a> IntoIterator for &'a Rows {
1366    type Item = Row<'a>;
1367    type IntoIter = RowsIter<'a>;
1368
1369    fn into_iter(self) -> Self::IntoIter {
1370        RowsIter {
1371            rows: self,
1372            start: 0,
1373            end: self.num_rows(),
1374        }
1375    }
1376}
1377
1378/// An iterator over [`Rows`]
1379#[derive(Debug)]
1380pub struct RowsIter<'a> {
1381    rows: &'a Rows,
1382    start: usize,
1383    end: usize,
1384}
1385
1386impl<'a> Iterator for RowsIter<'a> {
1387    type Item = Row<'a>;
1388
1389    fn next(&mut self) -> Option<Self::Item> {
1390        if self.end == self.start {
1391            return None;
1392        }
1393
1394        // SAFETY: We have checked that `start` is less than `end`
1395        let row = unsafe { self.rows.row_unchecked(self.start) };
1396        self.start += 1;
1397        Some(row)
1398    }
1399
1400    fn size_hint(&self) -> (usize, Option<usize>) {
1401        let len = self.len();
1402        (len, Some(len))
1403    }
1404}
1405
1406impl ExactSizeIterator for RowsIter<'_> {
1407    fn len(&self) -> usize {
1408        self.end - self.start
1409    }
1410}
1411
1412impl DoubleEndedIterator for RowsIter<'_> {
1413    fn next_back(&mut self) -> Option<Self::Item> {
1414        if self.end == self.start {
1415            return None;
1416        }
1417
1418        self.end -= 1;
1419
1420        // Safety: By construction we create `end >= start`, so if `end` is not equal to `start` it cannot be less than `start`
1421        //          therefore `end - 1` is within range
1422        let row = unsafe { self.rows.row_unchecked(self.end) };
1423        Some(row)
1424    }
1425}
1426
1427/// A comparable representation of a row.
1428///
1429/// See the [module level documentation](self) for more details.
1430///
1431/// Two [`Row`] can only be compared if they both belong to [`Rows`]
1432/// returned by calls to [`RowConverter::convert_columns`] on the same
1433/// [`RowConverter`]. If different [`RowConverter`]s are used, any
1434/// ordering established by comparing the [`Row`] is arbitrary.
1435#[derive(Debug, Copy, Clone)]
1436pub struct Row<'a> {
1437    data: &'a [u8],
1438    config: &'a RowConfig,
1439}
1440
1441impl<'a> Row<'a> {
1442    /// Create owned version of the row to detach it from the shared [`Rows`].
1443    pub fn owned(&self) -> OwnedRow {
1444        OwnedRow {
1445            data: self.data.into(),
1446            config: self.config.clone(),
1447        }
1448    }
1449
1450    /// The row's bytes, with the lifetime of the underlying data.
1451    pub fn data(&self) -> &'a [u8] {
1452        self.data
1453    }
1454}
1455
1456// Manually derive these as don't wish to include `fields`
1457
1458impl PartialEq for Row<'_> {
1459    #[inline]
1460    fn eq(&self, other: &Self) -> bool {
1461        self.data.eq(other.data)
1462    }
1463}
1464
1465impl Eq for Row<'_> {}
1466
1467impl PartialOrd for Row<'_> {
1468    #[inline]
1469    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
1470        Some(self.cmp(other))
1471    }
1472}
1473
1474impl Ord for Row<'_> {
1475    #[inline]
1476    fn cmp(&self, other: &Self) -> Ordering {
1477        self.data.cmp(other.data)
1478    }
1479}
1480
1481impl Hash for Row<'_> {
1482    #[inline]
1483    fn hash<H: Hasher>(&self, state: &mut H) {
1484        self.data.hash(state)
1485    }
1486}
1487
1488impl AsRef<[u8]> for Row<'_> {
1489    #[inline]
1490    fn as_ref(&self) -> &[u8] {
1491        self.data
1492    }
1493}
1494
1495/// Owned version of a [`Row`] that can be moved/cloned freely.
1496///
1497/// This contains the data for the one specific row (not the entire buffer of all rows).
1498#[derive(Debug, Clone)]
1499pub struct OwnedRow {
1500    data: Box<[u8]>,
1501    config: RowConfig,
1502}
1503
1504impl OwnedRow {
1505    /// Get borrowed [`Row`] from owned version.
1506    ///
1507    /// This is helpful if you want to compare an [`OwnedRow`] with a [`Row`].
1508    pub fn row(&self) -> Row<'_> {
1509        Row {
1510            data: &self.data,
1511            config: &self.config,
1512        }
1513    }
1514}
1515
1516// Manually derive these as don't wish to include `fields`. Also we just want to use the same `Row` implementations here.
1517
1518impl PartialEq for OwnedRow {
1519    #[inline]
1520    fn eq(&self, other: &Self) -> bool {
1521        self.row().eq(&other.row())
1522    }
1523}
1524
1525impl Eq for OwnedRow {}
1526
1527impl PartialOrd for OwnedRow {
1528    #[inline]
1529    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
1530        Some(self.cmp(other))
1531    }
1532}
1533
1534impl Ord for OwnedRow {
1535    #[inline]
1536    fn cmp(&self, other: &Self) -> Ordering {
1537        self.row().cmp(&other.row())
1538    }
1539}
1540
1541impl Hash for OwnedRow {
1542    #[inline]
1543    fn hash<H: Hasher>(&self, state: &mut H) {
1544        self.row().hash(state)
1545    }
1546}
1547
1548impl AsRef<[u8]> for OwnedRow {
1549    #[inline]
1550    fn as_ref(&self) -> &[u8] {
1551        &self.data
1552    }
1553}
1554
1555/// Returns the null sentinel, negated if `invert` is true
1556#[inline]
1557fn null_sentinel(options: SortOptions) -> u8 {
1558    match options.nulls_first {
1559        true => 0,
1560        false => 0xFF,
1561    }
1562}
1563
1564/// Stores the lengths of the rows. Lazily materializes lengths for columns with fixed-size types.
1565enum LengthTracker {
1566    /// Fixed state: All rows have length `length`
1567    Fixed { length: usize, num_rows: usize },
1568    /// Variable state: The length of row `i` is `lengths[i] + fixed_length`
1569    Variable {
1570        fixed_length: usize,
1571        lengths: Vec<usize>,
1572    },
1573}
1574
1575impl LengthTracker {
1576    fn new(num_rows: usize) -> Self {
1577        Self::Fixed {
1578            length: 0,
1579            num_rows,
1580        }
1581    }
1582
1583    /// Adds a column of fixed-length elements, each of size `new_length` to the LengthTracker
1584    fn push_fixed(&mut self, new_length: usize) {
1585        match self {
1586            LengthTracker::Fixed { length, .. } => *length += new_length,
1587            LengthTracker::Variable { fixed_length, .. } => *fixed_length += new_length,
1588        }
1589    }
1590
1591    /// Adds a column of possibly variable-length elements, element `i` has length `new_lengths.nth(i)`
1592    fn push_variable(&mut self, new_lengths: impl ExactSizeIterator<Item = usize>) {
1593        match self {
1594            LengthTracker::Fixed { length, .. } => {
1595                *self = LengthTracker::Variable {
1596                    fixed_length: *length,
1597                    lengths: new_lengths.collect(),
1598                }
1599            }
1600            LengthTracker::Variable { lengths, .. } => {
1601                assert_eq!(lengths.len(), new_lengths.len());
1602                lengths
1603                    .iter_mut()
1604                    .zip(new_lengths)
1605                    .for_each(|(length, new_length)| *length += new_length);
1606            }
1607        }
1608    }
1609
1610    /// Returns the tracked row lengths as a slice
1611    fn materialized(&mut self) -> &mut [usize] {
1612        if let LengthTracker::Fixed { length, num_rows } = *self {
1613            *self = LengthTracker::Variable {
1614                fixed_length: length,
1615                lengths: vec![0; num_rows],
1616            };
1617        }
1618
1619        match self {
1620            LengthTracker::Variable { lengths, .. } => lengths,
1621            LengthTracker::Fixed { .. } => unreachable!(),
1622        }
1623    }
1624
1625    /// Initializes the offsets using the tracked lengths. Returns the sum of the
1626    /// lengths of the rows added.
1627    ///
1628    /// We initialize the offsets shifted down by one row index.
1629    ///
1630    /// As the rows are appended to the offsets will be incremented to match
1631    ///
1632    /// For example, consider the case of 3 rows of length 3, 4, and 6 respectively.
1633    /// The offsets would be initialized to `0, 0, 3, 7`
1634    ///
1635    /// Writing the first row entirely would yield `0, 3, 3, 7`
1636    /// The second, `0, 3, 7, 7`
1637    /// The third, `0, 3, 7, 13`
1638    //
1639    /// This would be the final offsets for reading
1640    //
1641    /// In this way offsets tracks the position during writing whilst eventually serving
1642    fn extend_offsets(&self, initial_offset: usize, offsets: &mut Vec<usize>) -> usize {
1643        match self {
1644            LengthTracker::Fixed { length, num_rows } => {
1645                offsets.extend((0..*num_rows).map(|i| initial_offset + i * length));
1646
1647                initial_offset + num_rows * length
1648            }
1649            LengthTracker::Variable {
1650                fixed_length,
1651                lengths,
1652            } => {
1653                let mut acc = initial_offset;
1654
1655                offsets.extend(lengths.iter().map(|length| {
1656                    let current = acc;
1657                    acc += length + fixed_length;
1658                    current
1659                }));
1660
1661                acc
1662            }
1663        }
1664    }
1665}
1666
1667/// Computes the length of each encoded [`Rows`] and returns an empty [`Rows`]
1668fn row_lengths(cols: &[ArrayRef], encoders: &[Encoder]) -> LengthTracker {
1669    use fixed::FixedLengthEncoding;
1670
1671    let num_rows = cols.first().map(|x| x.len()).unwrap_or(0);
1672    let mut tracker = LengthTracker::new(num_rows);
1673
1674    for (array, encoder) in cols.iter().zip(encoders) {
1675        match encoder {
1676            Encoder::Stateless => {
1677                downcast_primitive_array! {
1678                    array => tracker.push_fixed(fixed::encoded_len(array)),
1679                    DataType::Null => tracker.push_fixed(2)
1680                    DataType::Boolean => tracker.push_fixed(bool::ENCODED_LEN),
1681                    DataType::Binary => push_generic_byte_array_lengths(&mut tracker, as_generic_binary_array::<i32>(array)),
1682                    DataType::LargeBinary => push_generic_byte_array_lengths(&mut tracker, as_generic_binary_array::<i64>(array)),
1683                    DataType::BinaryView => push_byte_view_array_lengths(&mut tracker, array.as_binary_view()),
1684                    DataType::Utf8 => push_generic_byte_array_lengths(&mut tracker, array.as_string::<i32>()),
1685                    DataType::LargeUtf8 => push_generic_byte_array_lengths(&mut tracker, array.as_string::<i64>()),
1686                    DataType::Utf8View => push_byte_view_array_lengths(&mut tracker, array.as_string_view()),
1687                    DataType::FixedSizeBinary(len) => {
1688                        let len = len.to_usize().unwrap();
1689                        tracker.push_fixed(1 + len)
1690                    }
1691                    _ => unimplemented!("unsupported data type: {}", array.data_type()),
1692                }
1693            }
1694            Encoder::Dictionary(values, null) => {
1695                downcast_dictionary_array! {
1696                    array => {
1697                        tracker.push_variable(
1698                            array.keys().iter().map(|v| match v {
1699                                Some(k) => values.row_len(k.as_usize()),
1700                                None => null.data.len(),
1701                            })
1702                        )
1703                    }
1704                    _ => unreachable!(),
1705                }
1706            }
1707            Encoder::Struct(rows, null) => {
1708                let array = as_struct_array(array);
1709                if rows.num_rows() > 0 {
1710                    // Only calculate row length if there are rows
1711                    tracker.push_variable((0..array.len()).map(|idx| match array.is_valid(idx) {
1712                        true => 1 + rows.row_len(idx),
1713                        false => 1 + null.data.len(),
1714                    }));
1715                } else {
1716                    // Edge case for Struct([]) arrays (no child fields)
1717                    tracker.push_variable((0..array.len()).map(|idx| match array.is_valid(idx) {
1718                        true => 1,
1719                        false => 1 + null.data.len(),
1720                    }));
1721                }
1722            }
1723            Encoder::List(rows) => match array.data_type() {
1724                DataType::List(_) => {
1725                    list::compute_lengths(tracker.materialized(), rows, as_list_array(array))
1726                }
1727                DataType::LargeList(_) => {
1728                    list::compute_lengths(tracker.materialized(), rows, as_large_list_array(array))
1729                }
1730                DataType::ListView(_) => {
1731                    let list_view = array.as_list_view::<i32>();
1732                    let (min_offset, _) = compute_list_view_bounds(list_view);
1733                    list::compute_lengths_list_view(
1734                        tracker.materialized(),
1735                        rows,
1736                        list_view,
1737                        min_offset,
1738                    )
1739                }
1740                DataType::LargeListView(_) => {
1741                    let list_view = array.as_list_view::<i64>();
1742                    let (min_offset, _) = compute_list_view_bounds(list_view);
1743                    list::compute_lengths_list_view(
1744                        tracker.materialized(),
1745                        rows,
1746                        list_view,
1747                        min_offset,
1748                    )
1749                }
1750                DataType::FixedSizeList(_, _) => compute_lengths_fixed_size_list(
1751                    &mut tracker,
1752                    rows,
1753                    as_fixed_size_list_array(array),
1754                ),
1755                _ => unreachable!(),
1756            },
1757            Encoder::RunEndEncoded(rows) => match array.data_type() {
1758                DataType::RunEndEncoded(r, _) => match r.data_type() {
1759                    DataType::Int16 => run::compute_lengths(
1760                        tracker.materialized(),
1761                        rows,
1762                        array.as_run::<Int16Type>(),
1763                    ),
1764                    DataType::Int32 => run::compute_lengths(
1765                        tracker.materialized(),
1766                        rows,
1767                        array.as_run::<Int32Type>(),
1768                    ),
1769                    DataType::Int64 => run::compute_lengths(
1770                        tracker.materialized(),
1771                        rows,
1772                        array.as_run::<Int64Type>(),
1773                    ),
1774                    _ => unreachable!("Unsupported run end index type: {r:?}"),
1775                },
1776                _ => unreachable!(),
1777            },
1778            Encoder::Union {
1779                child_rows,
1780                field_to_type_ids,
1781                type_ids,
1782                offsets,
1783            } => {
1784                let union_array = array
1785                    .as_any()
1786                    .downcast_ref::<UnionArray>()
1787                    .expect("expected UnionArray");
1788
1789                let mut type_id_to_field_idx = [0usize; 128];
1790                for (field_idx, &type_id) in field_to_type_ids.iter().enumerate() {
1791                    type_id_to_field_idx[type_id as usize] = field_idx;
1792                }
1793
1794                let lengths = (0..union_array.len()).map(|i| {
1795                    let type_id = type_ids[i];
1796                    let field_idx = type_id_to_field_idx[type_id as usize];
1797                    let child_row_i = offsets.as_ref().map(|o| o[i] as usize).unwrap_or(i);
1798                    let child_row_len = child_rows[field_idx].row_len(child_row_i);
1799
1800                    // length: 1 byte type_id + child row bytes
1801                    1 + child_row_len
1802                });
1803
1804                tracker.push_variable(lengths);
1805            }
1806        }
1807    }
1808
1809    tracker
1810}
1811
1812/// Add to [`LengthTracker`] the encoded length of each item in the [`GenericByteArray`]
1813fn push_generic_byte_array_lengths<T: ByteArrayType>(
1814    tracker: &mut LengthTracker,
1815    array: &GenericByteArray<T>,
1816) {
1817    if let Some(nulls) = array.nulls().filter(|n| n.null_count() > 0) {
1818        tracker.push_variable(
1819            array
1820                .offsets()
1821                .lengths()
1822                .zip(nulls.iter())
1823                .map(|(length, is_valid)| if is_valid { Some(length) } else { None })
1824                .map(variable::padded_length),
1825        )
1826    } else {
1827        tracker.push_variable(
1828            array
1829                .offsets()
1830                .lengths()
1831                .map(variable::non_null_padded_length),
1832        )
1833    }
1834}
1835
1836/// Add to [`LengthTracker`] the encoded length of each item in the [`GenericByteViewArray`]
1837fn push_byte_view_array_lengths<T: ByteViewType>(
1838    tracker: &mut LengthTracker,
1839    array: &GenericByteViewArray<T>,
1840) {
1841    if let Some(nulls) = array.nulls().filter(|n| n.null_count() > 0) {
1842        tracker.push_variable(
1843            array
1844                .lengths()
1845                .zip(nulls.iter())
1846                .map(|(length, is_valid)| {
1847                    if is_valid {
1848                        Some(length as usize)
1849                    } else {
1850                        None
1851                    }
1852                })
1853                .map(variable::padded_length),
1854        )
1855    } else {
1856        tracker.push_variable(
1857            array
1858                .lengths()
1859                .map(|len| variable::padded_length(Some(len as usize))),
1860        )
1861    }
1862}
1863
1864/// Encodes a column to the provided [`Rows`] incrementing the offsets as it progresses
1865fn encode_column(
1866    data: &mut [u8],
1867    offsets: &mut [usize],
1868    column: &dyn Array,
1869    opts: SortOptions,
1870    encoder: &Encoder<'_>,
1871) {
1872    match encoder {
1873        Encoder::Stateless => {
1874            downcast_primitive_array! {
1875                column => {
1876                    if let Some(nulls) = column.nulls().filter(|n| n.null_count() > 0){
1877                        fixed::encode(data, offsets, column.values(), nulls, opts)
1878                    } else {
1879                        fixed::encode_not_null(data, offsets, column.values(), opts)
1880                    }
1881                }
1882                DataType::Null => {
1883                    for offset in offsets.iter_mut().skip(1) {
1884                        variable::encode_null_value(&mut data[*offset..], opts);
1885                        *offset += 2;
1886                    }
1887                }
1888                DataType::Boolean => {
1889                    if let Some(nulls) = column.nulls().filter(|n| n.null_count() > 0){
1890                        fixed::encode_boolean(data, offsets, column.as_boolean().values(), nulls, opts)
1891                    } else {
1892                        fixed::encode_boolean_not_null(data, offsets, column.as_boolean().values(), opts)
1893                    }
1894                }
1895                DataType::Binary => {
1896                    variable::encode_generic_byte_array(data, offsets, as_generic_binary_array::<i32>(column), opts)
1897                }
1898                DataType::BinaryView => {
1899                    variable::encode(data, offsets, column.as_binary_view().iter(), opts)
1900                }
1901                DataType::LargeBinary => {
1902                    variable::encode_generic_byte_array(data, offsets, as_generic_binary_array::<i64>(column), opts)
1903                }
1904                DataType::Utf8 => variable::encode_generic_byte_array(
1905                    data, offsets,
1906                    column.as_string::<i32>(),
1907                    opts,
1908                ),
1909                DataType::LargeUtf8 => variable::encode_generic_byte_array(
1910                    data, offsets,
1911                    column.as_string::<i64>(),
1912                    opts,
1913                ),
1914                DataType::Utf8View => variable::encode(
1915                    data, offsets,
1916                    column.as_string_view().iter().map(|x| x.map(|x| x.as_bytes())),
1917                    opts,
1918                ),
1919                DataType::FixedSizeBinary(_) => {
1920                    let array = column.as_any().downcast_ref().unwrap();
1921                    fixed::encode_fixed_size_binary(data, offsets, array, opts)
1922                }
1923                _ => unimplemented!("unsupported data type: {}", column.data_type()),
1924            }
1925        }
1926        Encoder::Dictionary(values, nulls) => {
1927            downcast_dictionary_array! {
1928                column => encode_dictionary_values(data, offsets, column, values, nulls),
1929                _ => unreachable!()
1930            }
1931        }
1932        Encoder::Struct(rows, null) => {
1933            fn struct_encode_helper<const NO_CHILD_FIELDS: bool>(
1934                array: &StructArray,
1935                offsets: &mut [usize],
1936                null_sentinel: u8,
1937                rows: &Rows,
1938                null: &Row<'_>,
1939                data: &mut [u8],
1940            ) {
1941                let empty_row = Row {
1942                    data: &[],
1943                    config: &rows.config,
1944                };
1945
1946                offsets
1947                    .iter_mut()
1948                    .skip(1)
1949                    .enumerate()
1950                    .for_each(|(idx, offset)| {
1951                        let (row, sentinel) = match array.is_valid(idx) {
1952                            true => (
1953                                if NO_CHILD_FIELDS {
1954                                    empty_row
1955                                } else {
1956                                    rows.row(idx)
1957                                },
1958                                0x01,
1959                            ),
1960                            false => (*null, null_sentinel),
1961                        };
1962                        let end_offset = *offset + 1 + row.as_ref().len();
1963                        data[*offset] = sentinel;
1964                        data[*offset + 1..end_offset].copy_from_slice(row.as_ref());
1965                        *offset = end_offset;
1966                    })
1967            }
1968
1969            let array = as_struct_array(column);
1970            let null_sentinel = null_sentinel(opts);
1971            if rows.num_rows() == 0 {
1972                // Edge case for Struct([]) arrays (no child fields)
1973                struct_encode_helper::<true>(array, offsets, null_sentinel, rows, null, data);
1974            } else {
1975                struct_encode_helper::<false>(array, offsets, null_sentinel, rows, null, data);
1976            }
1977        }
1978        Encoder::List(rows) => match column.data_type() {
1979            DataType::List(_) => list::encode(data, offsets, rows, opts, as_list_array(column)),
1980            DataType::LargeList(_) => {
1981                list::encode(data, offsets, rows, opts, as_large_list_array(column))
1982            }
1983            DataType::ListView(_) => {
1984                let list_view = column.as_list_view::<i32>();
1985                let (min_offset, _) = compute_list_view_bounds(list_view);
1986                list::encode_list_view(data, offsets, rows, opts, list_view, min_offset)
1987            }
1988            DataType::LargeListView(_) => {
1989                let list_view = column.as_list_view::<i64>();
1990                let (min_offset, _) = compute_list_view_bounds(list_view);
1991                list::encode_list_view(data, offsets, rows, opts, list_view, min_offset)
1992            }
1993            DataType::FixedSizeList(_, _) => {
1994                encode_fixed_size_list(data, offsets, rows, opts, as_fixed_size_list_array(column))
1995            }
1996            _ => unreachable!(),
1997        },
1998        Encoder::RunEndEncoded(rows) => match column.data_type() {
1999            DataType::RunEndEncoded(r, _) => match r.data_type() {
2000                DataType::Int16 => {
2001                    run::encode(data, offsets, rows, opts, column.as_run::<Int16Type>())
2002                }
2003                DataType::Int32 => {
2004                    run::encode(data, offsets, rows, opts, column.as_run::<Int32Type>())
2005                }
2006                DataType::Int64 => {
2007                    run::encode(data, offsets, rows, opts, column.as_run::<Int64Type>())
2008                }
2009                _ => unreachable!("Unsupported run end index type: {r:?}"),
2010            },
2011            _ => unreachable!(),
2012        },
2013        Encoder::Union {
2014            child_rows,
2015            field_to_type_ids,
2016            type_ids,
2017            offsets: offsets_buf,
2018        } => {
2019            let mut type_id_to_field_idx = [0usize; 128];
2020            for (field_idx, &type_id) in field_to_type_ids.iter().enumerate() {
2021                type_id_to_field_idx[type_id as usize] = field_idx;
2022            }
2023
2024            offsets
2025                .iter_mut()
2026                .skip(1)
2027                .enumerate()
2028                .for_each(|(i, offset)| {
2029                    let type_id = type_ids[i];
2030                    let field_idx = type_id_to_field_idx[type_id as usize];
2031
2032                    let child_row_idx = offsets_buf.as_ref().map(|o| o[i] as usize).unwrap_or(i);
2033                    let child_row = child_rows[field_idx].row(child_row_idx);
2034                    let child_bytes = child_row.as_ref();
2035
2036                    let type_id_byte = if opts.descending {
2037                        !(type_id as u8)
2038                    } else {
2039                        type_id as u8
2040                    };
2041                    data[*offset] = type_id_byte;
2042
2043                    let child_start = *offset + 1;
2044                    let child_end = child_start + child_bytes.len();
2045                    data[child_start..child_end].copy_from_slice(child_bytes);
2046
2047                    *offset = child_end;
2048                });
2049        }
2050    }
2051}
2052
2053/// Encode dictionary values not preserving the dictionary encoding
2054pub fn encode_dictionary_values<K: ArrowDictionaryKeyType>(
2055    data: &mut [u8],
2056    offsets: &mut [usize],
2057    column: &DictionaryArray<K>,
2058    values: &Rows,
2059    null: &Row<'_>,
2060) {
2061    for (offset, k) in offsets.iter_mut().skip(1).zip(column.keys()) {
2062        let row = match k {
2063            Some(k) => values.row(k.as_usize()).data,
2064            None => null.data,
2065        };
2066        let end_offset = *offset + row.len();
2067        data[*offset..end_offset].copy_from_slice(row);
2068        *offset = end_offset;
2069    }
2070}
2071
2072macro_rules! decode_primitive_helper {
2073    ($t:ty, $rows:ident, $data_type:ident, $options:ident) => {
2074        Arc::new(decode_primitive::<$t>($rows, $data_type, $options))
2075    };
2076}
2077
2078/// Decodes a the provided `field` from `rows`
2079///
2080/// # Safety
2081///
2082/// Rows must contain valid data for the provided field
2083unsafe fn decode_column(
2084    field: &SortField,
2085    rows: &mut [&[u8]],
2086    codec: &Codec,
2087    validate_utf8: bool,
2088) -> Result<ArrayRef, ArrowError> {
2089    let options = field.options;
2090
2091    let array: ArrayRef = match codec {
2092        Codec::Stateless => {
2093            let data_type = field.data_type.clone();
2094            downcast_primitive! {
2095                data_type => (decode_primitive_helper, rows, data_type, options),
2096                DataType::Null => {
2097                    variable::decode_null_value(rows, options);
2098                    Arc::new(NullArray::new(rows.len()))
2099                }
2100                DataType::Boolean => Arc::new(decode_bool(rows, options)),
2101                DataType::Binary => Arc::new(decode_binary::<i32>(rows, options)),
2102                DataType::LargeBinary => Arc::new(decode_binary::<i64>(rows, options)),
2103                DataType::BinaryView => Arc::new(decode_binary_view(rows, options)),
2104                DataType::FixedSizeBinary(size) => Arc::new(decode_fixed_size_binary(rows, size, options)),
2105                DataType::Utf8 => Arc::new(unsafe{ decode_string::<i32>(rows, options, validate_utf8) }),
2106                DataType::LargeUtf8 => Arc::new(unsafe { decode_string::<i64>(rows, options, validate_utf8) }),
2107                DataType::Utf8View => Arc::new(unsafe { decode_string_view(rows, options, validate_utf8) }),
2108                _ => return Err(ArrowError::NotYetImplemented(format!("unsupported data type: {data_type}" )))
2109            }
2110        }
2111        Codec::Dictionary(converter, _) => {
2112            let cols = unsafe { converter.convert_raw(rows, validate_utf8) }?;
2113            cols.into_iter().next().unwrap()
2114        }
2115        Codec::Struct(converter, _) => {
2116            let (null_count, nulls) = fixed::decode_nulls(rows);
2117            rows.iter_mut().for_each(|row| *row = &row[1..]);
2118            let children = unsafe { converter.convert_raw(rows, validate_utf8) }?;
2119
2120            let child_data: Vec<ArrayData> = children.iter().map(|c| c.to_data()).collect();
2121            // Since RowConverter flattens certain data types (i.e. Dictionary),
2122            // we need to use updated data type instead of original field
2123            let corrected_fields: Vec<Field> = match &field.data_type {
2124                DataType::Struct(struct_fields) => struct_fields
2125                    .iter()
2126                    .zip(child_data.iter())
2127                    .map(|(orig_field, child_array)| {
2128                        orig_field
2129                            .as_ref()
2130                            .clone()
2131                            .with_data_type(child_array.data_type().clone())
2132                    })
2133                    .collect(),
2134                _ => unreachable!("Only Struct types should be corrected here"),
2135            };
2136            let corrected_struct_type = DataType::Struct(corrected_fields.into());
2137            let builder = ArrayDataBuilder::new(corrected_struct_type)
2138                .len(rows.len())
2139                .null_count(null_count)
2140                .null_bit_buffer(Some(nulls))
2141                .child_data(child_data);
2142
2143            Arc::new(StructArray::from(unsafe { builder.build_unchecked() }))
2144        }
2145        Codec::List(converter) => match &field.data_type {
2146            DataType::List(_) => {
2147                Arc::new(unsafe { list::decode::<i32>(converter, rows, field, validate_utf8) }?)
2148            }
2149            DataType::LargeList(_) => {
2150                Arc::new(unsafe { list::decode::<i64>(converter, rows, field, validate_utf8) }?)
2151            }
2152            DataType::ListView(_) => Arc::new(unsafe {
2153                list::decode_list_view::<i32>(converter, rows, field, validate_utf8)
2154            }?),
2155            DataType::LargeListView(_) => Arc::new(unsafe {
2156                list::decode_list_view::<i64>(converter, rows, field, validate_utf8)
2157            }?),
2158            DataType::FixedSizeList(_, value_length) => Arc::new(unsafe {
2159                list::decode_fixed_size_list(
2160                    converter,
2161                    rows,
2162                    field,
2163                    validate_utf8,
2164                    value_length.as_usize(),
2165                )
2166            }?),
2167            _ => unreachable!(),
2168        },
2169        Codec::RunEndEncoded(converter) => match &field.data_type {
2170            DataType::RunEndEncoded(run_ends, _) => match run_ends.data_type() {
2171                DataType::Int16 => Arc::new(unsafe {
2172                    run::decode::<Int16Type>(converter, rows, field, validate_utf8)
2173                }?),
2174                DataType::Int32 => Arc::new(unsafe {
2175                    run::decode::<Int32Type>(converter, rows, field, validate_utf8)
2176                }?),
2177                DataType::Int64 => Arc::new(unsafe {
2178                    run::decode::<Int64Type>(converter, rows, field, validate_utf8)
2179                }?),
2180                _ => unreachable!(),
2181            },
2182            _ => unreachable!(),
2183        },
2184        Codec::Union(converters, field_to_type_ids, null_rows) => {
2185            let len = rows.len();
2186
2187            let DataType::Union(union_fields, mode) = &field.data_type else {
2188                unreachable!()
2189            };
2190
2191            let mut type_id_to_field_idx = [0usize; 128];
2192            for (field_idx, &type_id) in field_to_type_ids.iter().enumerate() {
2193                type_id_to_field_idx[type_id as usize] = field_idx;
2194            }
2195
2196            let mut type_ids = Vec::with_capacity(len);
2197            let mut rows_by_field: Vec<Vec<(usize, &[u8])>> = vec![Vec::new(); converters.len()];
2198
2199            for (idx, row) in rows.iter_mut().enumerate() {
2200                let type_id_byte = {
2201                    let id = row[0];
2202                    if options.descending { !id } else { id }
2203                };
2204
2205                let type_id = type_id_byte as i8;
2206                type_ids.push(type_id);
2207
2208                let field_idx = type_id_to_field_idx[type_id as usize];
2209
2210                let child_row = &row[1..];
2211                rows_by_field[field_idx].push((idx, child_row));
2212            }
2213
2214            let mut child_arrays: Vec<ArrayRef> = Vec::with_capacity(converters.len());
2215            let mut offsets = (*mode == UnionMode::Dense).then(|| Vec::with_capacity(len));
2216
2217            for (field_idx, converter) in converters.iter().enumerate() {
2218                let field_rows = &rows_by_field[field_idx];
2219
2220                match &mode {
2221                    UnionMode::Dense => {
2222                        if field_rows.is_empty() {
2223                            let (_, field) = union_fields.iter().nth(field_idx).unwrap();
2224                            child_arrays.push(arrow_array::new_empty_array(field.data_type()));
2225                            continue;
2226                        }
2227
2228                        let mut child_data = field_rows
2229                            .iter()
2230                            .map(|(_, bytes)| *bytes)
2231                            .collect::<Vec<_>>();
2232
2233                        let child_array =
2234                            unsafe { converter.convert_raw(&mut child_data, validate_utf8) }?;
2235
2236                        // advance row slices by the bytes consumed
2237                        for ((row_idx, original_bytes), remaining_bytes) in
2238                            field_rows.iter().zip(child_data)
2239                        {
2240                            let consumed_length = 1 + original_bytes.len() - remaining_bytes.len();
2241                            rows[*row_idx] = &rows[*row_idx][consumed_length..];
2242                        }
2243
2244                        child_arrays.push(child_array.into_iter().next().unwrap());
2245                    }
2246                    UnionMode::Sparse => {
2247                        let mut sparse_data: Vec<&[u8]> = Vec::with_capacity(len);
2248                        let mut field_row_iter = field_rows.iter().peekable();
2249                        let null_row_bytes: &[u8] = &null_rows[field_idx].data;
2250
2251                        for idx in 0..len {
2252                            if let Some((next_idx, bytes)) = field_row_iter.peek() {
2253                                if *next_idx == idx {
2254                                    sparse_data.push(*bytes);
2255
2256                                    field_row_iter.next();
2257                                    continue;
2258                                }
2259                            }
2260                            sparse_data.push(null_row_bytes);
2261                        }
2262
2263                        let child_array =
2264                            unsafe { converter.convert_raw(&mut sparse_data, validate_utf8) }?;
2265
2266                        // advance row slices by the bytes consumed for rows that belong to this field
2267                        for (row_idx, child_row) in field_rows.iter() {
2268                            let remaining_len = sparse_data[*row_idx].len();
2269                            let consumed_length = 1 + child_row.len() - remaining_len;
2270                            rows[*row_idx] = &rows[*row_idx][consumed_length..];
2271                        }
2272
2273                        child_arrays.push(child_array.into_iter().next().unwrap());
2274                    }
2275                }
2276            }
2277
2278            // build offsets for dense unions
2279            if let Some(ref mut offsets_vec) = offsets {
2280                let mut count = vec![0i32; converters.len()];
2281                for type_id in &type_ids {
2282                    let field_idx = *type_id as usize;
2283                    offsets_vec.push(count[field_idx]);
2284
2285                    count[field_idx] += 1;
2286                }
2287            }
2288
2289            let type_ids_buffer = ScalarBuffer::from(type_ids);
2290            let offsets_buffer = offsets.map(ScalarBuffer::from);
2291
2292            let union_array = UnionArray::try_new(
2293                union_fields.clone(),
2294                type_ids_buffer,
2295                offsets_buffer,
2296                child_arrays,
2297            )?;
2298
2299            // note: union arrays don't support physical null buffers
2300            // nulls are represented logically though child arrays
2301            Arc::new(union_array)
2302        }
2303    };
2304    Ok(array)
2305}
2306
2307#[cfg(test)]
2308mod tests {
2309    use arrow_array::builder::*;
2310    use arrow_array::types::*;
2311    use arrow_array::*;
2312    use arrow_buffer::{Buffer, OffsetBuffer};
2313    use arrow_buffer::{NullBuffer, i256};
2314    use arrow_cast::display::{ArrayFormatter, FormatOptions};
2315    use arrow_ord::sort::{LexicographicalComparator, SortColumn};
2316    use rand::distr::uniform::SampleUniform;
2317    use rand::distr::{Distribution, StandardUniform};
2318    use rand::prelude::StdRng;
2319    use rand::{Rng, RngCore, SeedableRng};
2320
2321    use super::*;
2322
2323    #[test]
2324    fn test_fixed_width() {
2325        let cols = [
2326            Arc::new(Int16Array::from_iter([
2327                Some(1),
2328                Some(2),
2329                None,
2330                Some(-5),
2331                Some(2),
2332                Some(2),
2333                Some(0),
2334            ])) as ArrayRef,
2335            Arc::new(Float32Array::from_iter([
2336                Some(1.3),
2337                Some(2.5),
2338                None,
2339                Some(4.),
2340                Some(0.1),
2341                Some(-4.),
2342                Some(-0.),
2343            ])) as ArrayRef,
2344        ];
2345
2346        let converter = RowConverter::new(vec![
2347            SortField::new(DataType::Int16),
2348            SortField::new(DataType::Float32),
2349        ])
2350        .unwrap();
2351        let rows = converter.convert_columns(&cols).unwrap();
2352
2353        assert_eq!(rows.offsets, &[0, 8, 16, 24, 32, 40, 48, 56]);
2354        assert_eq!(
2355            rows.buffer,
2356            &[
2357                1, 128, 1, //
2358                1, 191, 166, 102, 102, //
2359                1, 128, 2, //
2360                1, 192, 32, 0, 0, //
2361                0, 0, 0, //
2362                0, 0, 0, 0, 0, //
2363                1, 127, 251, //
2364                1, 192, 128, 0, 0, //
2365                1, 128, 2, //
2366                1, 189, 204, 204, 205, //
2367                1, 128, 2, //
2368                1, 63, 127, 255, 255, //
2369                1, 128, 0, //
2370                1, 127, 255, 255, 255 //
2371            ]
2372        );
2373
2374        assert!(rows.row(3) < rows.row(6));
2375        assert!(rows.row(0) < rows.row(1));
2376        assert!(rows.row(3) < rows.row(0));
2377        assert!(rows.row(4) < rows.row(1));
2378        assert!(rows.row(5) < rows.row(4));
2379
2380        let back = converter.convert_rows(&rows).unwrap();
2381        for (expected, actual) in cols.iter().zip(&back) {
2382            assert_eq!(expected, actual);
2383        }
2384    }
2385
2386    #[test]
2387    fn test_decimal32() {
2388        let converter = RowConverter::new(vec![SortField::new(DataType::Decimal32(
2389            DECIMAL32_MAX_PRECISION,
2390            7,
2391        ))])
2392        .unwrap();
2393        let col = Arc::new(
2394            Decimal32Array::from_iter([
2395                None,
2396                Some(i32::MIN),
2397                Some(-13),
2398                Some(46_i32),
2399                Some(5456_i32),
2400                Some(i32::MAX),
2401            ])
2402            .with_precision_and_scale(9, 7)
2403            .unwrap(),
2404        ) as ArrayRef;
2405
2406        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2407        for i in 0..rows.num_rows() - 1 {
2408            assert!(rows.row(i) < rows.row(i + 1));
2409        }
2410
2411        let back = converter.convert_rows(&rows).unwrap();
2412        assert_eq!(back.len(), 1);
2413        assert_eq!(col.as_ref(), back[0].as_ref())
2414    }
2415
2416    #[test]
2417    fn test_decimal64() {
2418        let converter = RowConverter::new(vec![SortField::new(DataType::Decimal64(
2419            DECIMAL64_MAX_PRECISION,
2420            7,
2421        ))])
2422        .unwrap();
2423        let col = Arc::new(
2424            Decimal64Array::from_iter([
2425                None,
2426                Some(i64::MIN),
2427                Some(-13),
2428                Some(46_i64),
2429                Some(5456_i64),
2430                Some(i64::MAX),
2431            ])
2432            .with_precision_and_scale(18, 7)
2433            .unwrap(),
2434        ) as ArrayRef;
2435
2436        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2437        for i in 0..rows.num_rows() - 1 {
2438            assert!(rows.row(i) < rows.row(i + 1));
2439        }
2440
2441        let back = converter.convert_rows(&rows).unwrap();
2442        assert_eq!(back.len(), 1);
2443        assert_eq!(col.as_ref(), back[0].as_ref())
2444    }
2445
2446    #[test]
2447    fn test_decimal128() {
2448        let converter = RowConverter::new(vec![SortField::new(DataType::Decimal128(
2449            DECIMAL128_MAX_PRECISION,
2450            7,
2451        ))])
2452        .unwrap();
2453        let col = Arc::new(
2454            Decimal128Array::from_iter([
2455                None,
2456                Some(i128::MIN),
2457                Some(-13),
2458                Some(46_i128),
2459                Some(5456_i128),
2460                Some(i128::MAX),
2461            ])
2462            .with_precision_and_scale(38, 7)
2463            .unwrap(),
2464        ) as ArrayRef;
2465
2466        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2467        for i in 0..rows.num_rows() - 1 {
2468            assert!(rows.row(i) < rows.row(i + 1));
2469        }
2470
2471        let back = converter.convert_rows(&rows).unwrap();
2472        assert_eq!(back.len(), 1);
2473        assert_eq!(col.as_ref(), back[0].as_ref())
2474    }
2475
2476    #[test]
2477    fn test_decimal256() {
2478        let converter = RowConverter::new(vec![SortField::new(DataType::Decimal256(
2479            DECIMAL256_MAX_PRECISION,
2480            7,
2481        ))])
2482        .unwrap();
2483        let col = Arc::new(
2484            Decimal256Array::from_iter([
2485                None,
2486                Some(i256::MIN),
2487                Some(i256::from_parts(0, -1)),
2488                Some(i256::from_parts(u128::MAX, -1)),
2489                Some(i256::from_parts(u128::MAX, 0)),
2490                Some(i256::from_parts(0, 46_i128)),
2491                Some(i256::from_parts(5, 46_i128)),
2492                Some(i256::MAX),
2493            ])
2494            .with_precision_and_scale(DECIMAL256_MAX_PRECISION, 7)
2495            .unwrap(),
2496        ) as ArrayRef;
2497
2498        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2499        for i in 0..rows.num_rows() - 1 {
2500            assert!(rows.row(i) < rows.row(i + 1));
2501        }
2502
2503        let back = converter.convert_rows(&rows).unwrap();
2504        assert_eq!(back.len(), 1);
2505        assert_eq!(col.as_ref(), back[0].as_ref())
2506    }
2507
2508    #[test]
2509    fn test_bool() {
2510        let converter = RowConverter::new(vec![SortField::new(DataType::Boolean)]).unwrap();
2511
2512        let col = Arc::new(BooleanArray::from_iter([None, Some(false), Some(true)])) as ArrayRef;
2513
2514        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2515        assert!(rows.row(2) > rows.row(1));
2516        assert!(rows.row(2) > rows.row(0));
2517        assert!(rows.row(1) > rows.row(0));
2518
2519        let cols = converter.convert_rows(&rows).unwrap();
2520        assert_eq!(&cols[0], &col);
2521
2522        let converter = RowConverter::new(vec![SortField::new_with_options(
2523            DataType::Boolean,
2524            SortOptions::default().desc().with_nulls_first(false),
2525        )])
2526        .unwrap();
2527
2528        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2529        assert!(rows.row(2) < rows.row(1));
2530        assert!(rows.row(2) < rows.row(0));
2531        assert!(rows.row(1) < rows.row(0));
2532        let cols = converter.convert_rows(&rows).unwrap();
2533        assert_eq!(&cols[0], &col);
2534    }
2535
2536    #[test]
2537    fn test_timezone() {
2538        let a =
2539            TimestampNanosecondArray::from(vec![1, 2, 3, 4, 5]).with_timezone("+01:00".to_string());
2540        let d = a.data_type().clone();
2541
2542        let converter = RowConverter::new(vec![SortField::new(a.data_type().clone())]).unwrap();
2543        let rows = converter.convert_columns(&[Arc::new(a) as _]).unwrap();
2544        let back = converter.convert_rows(&rows).unwrap();
2545        assert_eq!(back.len(), 1);
2546        assert_eq!(back[0].data_type(), &d);
2547
2548        // Test dictionary
2549        let mut a = PrimitiveDictionaryBuilder::<Int32Type, TimestampNanosecondType>::new();
2550        a.append(34).unwrap();
2551        a.append_null();
2552        a.append(345).unwrap();
2553
2554        // Construct dictionary with a timezone
2555        let dict = a.finish();
2556        let values = TimestampNanosecondArray::from(dict.values().to_data());
2557        let dict_with_tz = dict.with_values(Arc::new(values.with_timezone("+02:00")));
2558        let v = DataType::Timestamp(TimeUnit::Nanosecond, Some("+02:00".into()));
2559        let d = DataType::Dictionary(Box::new(DataType::Int32), Box::new(v.clone()));
2560
2561        assert_eq!(dict_with_tz.data_type(), &d);
2562        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
2563        let rows = converter
2564            .convert_columns(&[Arc::new(dict_with_tz) as _])
2565            .unwrap();
2566        let back = converter.convert_rows(&rows).unwrap();
2567        assert_eq!(back.len(), 1);
2568        assert_eq!(back[0].data_type(), &v);
2569    }
2570
2571    #[test]
2572    fn test_null_encoding() {
2573        let col = Arc::new(NullArray::new(10));
2574        let converter = RowConverter::new(vec![SortField::new(DataType::Null)]).unwrap();
2575        let rows = converter.convert_columns(&[col]).unwrap();
2576        assert_eq!(rows.num_rows(), 10);
2577        // NULL element encoded as 2 bytes data
2578        assert_eq!(rows.row(1).data.len(), 2);
2579    }
2580
2581    #[test]
2582    fn test_variable_width() {
2583        let col = Arc::new(StringArray::from_iter([
2584            Some("hello"),
2585            Some("he"),
2586            None,
2587            Some("foo"),
2588            Some(""),
2589        ])) as ArrayRef;
2590
2591        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
2592        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2593
2594        assert!(rows.row(1) < rows.row(0));
2595        assert!(rows.row(2) < rows.row(4));
2596        assert!(rows.row(3) < rows.row(0));
2597        assert!(rows.row(3) < rows.row(1));
2598
2599        let cols = converter.convert_rows(&rows).unwrap();
2600        assert_eq!(&cols[0], &col);
2601
2602        let col = Arc::new(BinaryArray::from_iter([
2603            None,
2604            Some(vec![0_u8; 0]),
2605            Some(vec![0_u8; 6]),
2606            Some(vec![0_u8; variable::MINI_BLOCK_SIZE]),
2607            Some(vec![0_u8; variable::MINI_BLOCK_SIZE + 1]),
2608            Some(vec![0_u8; variable::BLOCK_SIZE]),
2609            Some(vec![0_u8; variable::BLOCK_SIZE + 1]),
2610            Some(vec![1_u8; 6]),
2611            Some(vec![1_u8; variable::MINI_BLOCK_SIZE]),
2612            Some(vec![1_u8; variable::MINI_BLOCK_SIZE + 1]),
2613            Some(vec![1_u8; variable::BLOCK_SIZE]),
2614            Some(vec![1_u8; variable::BLOCK_SIZE + 1]),
2615            Some(vec![0xFF_u8; 6]),
2616            Some(vec![0xFF_u8; variable::MINI_BLOCK_SIZE]),
2617            Some(vec![0xFF_u8; variable::MINI_BLOCK_SIZE + 1]),
2618            Some(vec![0xFF_u8; variable::BLOCK_SIZE]),
2619            Some(vec![0xFF_u8; variable::BLOCK_SIZE + 1]),
2620        ])) as ArrayRef;
2621
2622        let converter = RowConverter::new(vec![SortField::new(DataType::Binary)]).unwrap();
2623        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2624
2625        for i in 0..rows.num_rows() {
2626            for j in i + 1..rows.num_rows() {
2627                assert!(
2628                    rows.row(i) < rows.row(j),
2629                    "{} < {} - {:?} < {:?}",
2630                    i,
2631                    j,
2632                    rows.row(i),
2633                    rows.row(j)
2634                );
2635            }
2636        }
2637
2638        let cols = converter.convert_rows(&rows).unwrap();
2639        assert_eq!(&cols[0], &col);
2640
2641        let converter = RowConverter::new(vec![SortField::new_with_options(
2642            DataType::Binary,
2643            SortOptions::default().desc().with_nulls_first(false),
2644        )])
2645        .unwrap();
2646        let rows = converter.convert_columns(&[Arc::clone(&col)]).unwrap();
2647
2648        for i in 0..rows.num_rows() {
2649            for j in i + 1..rows.num_rows() {
2650                assert!(
2651                    rows.row(i) > rows.row(j),
2652                    "{} > {} - {:?} > {:?}",
2653                    i,
2654                    j,
2655                    rows.row(i),
2656                    rows.row(j)
2657                );
2658            }
2659        }
2660
2661        let cols = converter.convert_rows(&rows).unwrap();
2662        assert_eq!(&cols[0], &col);
2663    }
2664
2665    /// If `exact` is false performs a logical comparison between a and dictionary-encoded b
2666    fn dictionary_eq(a: &dyn Array, b: &dyn Array) {
2667        match b.data_type() {
2668            DataType::Dictionary(_, v) => {
2669                assert_eq!(a.data_type(), v.as_ref());
2670                let b = arrow_cast::cast(b, v).unwrap();
2671                assert_eq!(a, b.as_ref())
2672            }
2673            _ => assert_eq!(a, b),
2674        }
2675    }
2676
2677    #[test]
2678    fn test_string_dictionary() {
2679        let a = Arc::new(DictionaryArray::<Int32Type>::from_iter([
2680            Some("foo"),
2681            Some("hello"),
2682            Some("he"),
2683            None,
2684            Some("hello"),
2685            Some(""),
2686            Some("hello"),
2687            Some("hello"),
2688        ])) as ArrayRef;
2689
2690        let field = SortField::new(a.data_type().clone());
2691        let converter = RowConverter::new(vec![field]).unwrap();
2692        let rows_a = converter.convert_columns(&[Arc::clone(&a)]).unwrap();
2693
2694        assert!(rows_a.row(3) < rows_a.row(5));
2695        assert!(rows_a.row(2) < rows_a.row(1));
2696        assert!(rows_a.row(0) < rows_a.row(1));
2697        assert!(rows_a.row(3) < rows_a.row(0));
2698
2699        assert_eq!(rows_a.row(1), rows_a.row(4));
2700        assert_eq!(rows_a.row(1), rows_a.row(6));
2701        assert_eq!(rows_a.row(1), rows_a.row(7));
2702
2703        let cols = converter.convert_rows(&rows_a).unwrap();
2704        dictionary_eq(&cols[0], &a);
2705
2706        let b = Arc::new(DictionaryArray::<Int32Type>::from_iter([
2707            Some("hello"),
2708            None,
2709            Some("cupcakes"),
2710        ])) as ArrayRef;
2711
2712        let rows_b = converter.convert_columns(&[Arc::clone(&b)]).unwrap();
2713        assert_eq!(rows_a.row(1), rows_b.row(0));
2714        assert_eq!(rows_a.row(3), rows_b.row(1));
2715        assert!(rows_b.row(2) < rows_a.row(0));
2716
2717        let cols = converter.convert_rows(&rows_b).unwrap();
2718        dictionary_eq(&cols[0], &b);
2719
2720        let converter = RowConverter::new(vec![SortField::new_with_options(
2721            a.data_type().clone(),
2722            SortOptions::default().desc().with_nulls_first(false),
2723        )])
2724        .unwrap();
2725
2726        let rows_c = converter.convert_columns(&[Arc::clone(&a)]).unwrap();
2727        assert!(rows_c.row(3) > rows_c.row(5));
2728        assert!(rows_c.row(2) > rows_c.row(1));
2729        assert!(rows_c.row(0) > rows_c.row(1));
2730        assert!(rows_c.row(3) > rows_c.row(0));
2731
2732        let cols = converter.convert_rows(&rows_c).unwrap();
2733        dictionary_eq(&cols[0], &a);
2734
2735        let converter = RowConverter::new(vec![SortField::new_with_options(
2736            a.data_type().clone(),
2737            SortOptions::default().desc().with_nulls_first(true),
2738        )])
2739        .unwrap();
2740
2741        let rows_c = converter.convert_columns(&[Arc::clone(&a)]).unwrap();
2742        assert!(rows_c.row(3) < rows_c.row(5));
2743        assert!(rows_c.row(2) > rows_c.row(1));
2744        assert!(rows_c.row(0) > rows_c.row(1));
2745        assert!(rows_c.row(3) < rows_c.row(0));
2746
2747        let cols = converter.convert_rows(&rows_c).unwrap();
2748        dictionary_eq(&cols[0], &a);
2749    }
2750
2751    #[test]
2752    fn test_struct() {
2753        // Test basic
2754        let a = Arc::new(Int32Array::from(vec![1, 1, 2, 2])) as ArrayRef;
2755        let a_f = Arc::new(Field::new("int", DataType::Int32, false));
2756        let u = Arc::new(StringArray::from(vec!["a", "b", "c", "d"])) as ArrayRef;
2757        let u_f = Arc::new(Field::new("s", DataType::Utf8, false));
2758        let s1 = Arc::new(StructArray::from(vec![(a_f, a), (u_f, u)])) as ArrayRef;
2759
2760        let sort_fields = vec![SortField::new(s1.data_type().clone())];
2761        let converter = RowConverter::new(sort_fields).unwrap();
2762        let r1 = converter.convert_columns(&[Arc::clone(&s1)]).unwrap();
2763
2764        for (a, b) in r1.iter().zip(r1.iter().skip(1)) {
2765            assert!(a < b);
2766        }
2767
2768        let back = converter.convert_rows(&r1).unwrap();
2769        assert_eq!(back.len(), 1);
2770        assert_eq!(&back[0], &s1);
2771
2772        // Test struct nullability
2773        let data = s1
2774            .to_data()
2775            .into_builder()
2776            .null_bit_buffer(Some(Buffer::from_slice_ref([0b00001010])))
2777            .null_count(2)
2778            .build()
2779            .unwrap();
2780
2781        let s2 = Arc::new(StructArray::from(data)) as ArrayRef;
2782        let r2 = converter.convert_columns(&[Arc::clone(&s2)]).unwrap();
2783        assert_eq!(r2.row(0), r2.row(2)); // Nulls equal
2784        assert!(r2.row(0) < r2.row(1)); // Nulls first
2785        assert_ne!(r1.row(0), r2.row(0)); // Value does not equal null
2786        assert_eq!(r1.row(1), r2.row(1)); // Values equal
2787
2788        let back = converter.convert_rows(&r2).unwrap();
2789        assert_eq!(back.len(), 1);
2790        assert_eq!(&back[0], &s2);
2791
2792        back[0].to_data().validate_full().unwrap();
2793    }
2794
2795    #[test]
2796    fn test_dictionary_in_struct() {
2797        let builder = StringDictionaryBuilder::<Int32Type>::new();
2798        let mut struct_builder = StructBuilder::new(
2799            vec![Field::new_dictionary(
2800                "foo",
2801                DataType::Int32,
2802                DataType::Utf8,
2803                true,
2804            )],
2805            vec![Box::new(builder)],
2806        );
2807
2808        let dict_builder = struct_builder
2809            .field_builder::<StringDictionaryBuilder<Int32Type>>(0)
2810            .unwrap();
2811
2812        // Flattened: ["a", null, "a", "b"]
2813        dict_builder.append_value("a");
2814        dict_builder.append_null();
2815        dict_builder.append_value("a");
2816        dict_builder.append_value("b");
2817
2818        for _ in 0..4 {
2819            struct_builder.append(true);
2820        }
2821
2822        let s = Arc::new(struct_builder.finish()) as ArrayRef;
2823        let sort_fields = vec![SortField::new(s.data_type().clone())];
2824        let converter = RowConverter::new(sort_fields).unwrap();
2825        let r = converter.convert_columns(&[Arc::clone(&s)]).unwrap();
2826
2827        let back = converter.convert_rows(&r).unwrap();
2828        let [s2] = back.try_into().unwrap();
2829
2830        // RowConverter flattens Dictionary
2831        // s.ty = Struct("foo": Dictionary(Int32, Utf8)), s2.ty = Struct("foo": Utf8)
2832        assert_ne!(&s.data_type(), &s2.data_type());
2833        s2.to_data().validate_full().unwrap();
2834
2835        // Check if the logical data remains the same
2836        // Keys: [0, null, 0, 1]
2837        // Values: ["a", "b"]
2838        let s1_struct = s.as_struct();
2839        let s1_0 = s1_struct.column(0);
2840        let s1_idx_0 = s1_0.as_dictionary::<Int32Type>();
2841        let keys = s1_idx_0.keys();
2842        let values = s1_idx_0.values().as_string::<i32>();
2843        // Flattened: ["a", null, "a", "b"]
2844        let s2_struct = s2.as_struct();
2845        let s2_0 = s2_struct.column(0);
2846        let s2_idx_0 = s2_0.as_string::<i32>();
2847
2848        for i in 0..keys.len() {
2849            if keys.is_null(i) {
2850                assert!(s2_idx_0.is_null(i));
2851            } else {
2852                let dict_index = keys.value(i) as usize;
2853                assert_eq!(values.value(dict_index), s2_idx_0.value(i));
2854            }
2855        }
2856    }
2857
2858    #[test]
2859    fn test_dictionary_in_struct_empty() {
2860        let ty = DataType::Struct(
2861            vec![Field::new_dictionary(
2862                "foo",
2863                DataType::Int32,
2864                DataType::Int32,
2865                false,
2866            )]
2867            .into(),
2868        );
2869        let s = arrow_array::new_empty_array(&ty);
2870
2871        let sort_fields = vec![SortField::new(s.data_type().clone())];
2872        let converter = RowConverter::new(sort_fields).unwrap();
2873        let r = converter.convert_columns(&[Arc::clone(&s)]).unwrap();
2874
2875        let back = converter.convert_rows(&r).unwrap();
2876        let [s2] = back.try_into().unwrap();
2877
2878        // RowConverter flattens Dictionary
2879        // s.ty = Struct("foo": Dictionary(Int32, Int32)), s2.ty = Struct("foo": Int32)
2880        assert_ne!(&s.data_type(), &s2.data_type());
2881        s2.to_data().validate_full().unwrap();
2882        assert_eq!(s.len(), 0);
2883        assert_eq!(s2.len(), 0);
2884    }
2885
2886    #[test]
2887    fn test_list_of_string_dictionary() {
2888        let mut builder = ListBuilder::<StringDictionaryBuilder<Int32Type>>::default();
2889        // List[0] = ["a", "b", "zero", null, "c", "b", "d" (dict)]
2890        builder.values().append("a").unwrap();
2891        builder.values().append("b").unwrap();
2892        builder.values().append("zero").unwrap();
2893        builder.values().append_null();
2894        builder.values().append("c").unwrap();
2895        builder.values().append("b").unwrap();
2896        builder.values().append("d").unwrap();
2897        builder.append(true);
2898        // List[1] = null
2899        builder.append(false);
2900        // List[2] = ["e", "zero", "a" (dict)]
2901        builder.values().append("e").unwrap();
2902        builder.values().append("zero").unwrap();
2903        builder.values().append("a").unwrap();
2904        builder.append(true);
2905
2906        let a = Arc::new(builder.finish()) as ArrayRef;
2907        let data_type = a.data_type().clone();
2908
2909        let field = SortField::new(data_type.clone());
2910        let converter = RowConverter::new(vec![field]).unwrap();
2911        let rows = converter.convert_columns(&[Arc::clone(&a)]).unwrap();
2912
2913        let back = converter.convert_rows(&rows).unwrap();
2914        assert_eq!(back.len(), 1);
2915        let [a2] = back.try_into().unwrap();
2916
2917        // RowConverter flattens Dictionary
2918        // a.ty: List(Dictionary(Int32, Utf8)), a2.ty: List(Utf8)
2919        assert_ne!(&a.data_type(), &a2.data_type());
2920
2921        a2.to_data().validate_full().unwrap();
2922
2923        let a2_list = a2.as_list::<i32>();
2924        let a1_list = a.as_list::<i32>();
2925
2926        // Check if the logical data remains the same
2927        // List[0] = ["a", "b", "zero", null, "c", "b", "d" (dict)]
2928        let a1_0 = a1_list.value(0);
2929        let a1_idx_0 = a1_0.as_dictionary::<Int32Type>();
2930        let keys = a1_idx_0.keys();
2931        let values = a1_idx_0.values().as_string::<i32>();
2932        let a2_0 = a2_list.value(0);
2933        let a2_idx_0 = a2_0.as_string::<i32>();
2934
2935        for i in 0..keys.len() {
2936            if keys.is_null(i) {
2937                assert!(a2_idx_0.is_null(i));
2938            } else {
2939                let dict_index = keys.value(i) as usize;
2940                assert_eq!(values.value(dict_index), a2_idx_0.value(i));
2941            }
2942        }
2943
2944        // List[1] = null
2945        assert!(a1_list.is_null(1));
2946        assert!(a2_list.is_null(1));
2947
2948        // List[2] = ["e", "zero", "a" (dict)]
2949        let a1_2 = a1_list.value(2);
2950        let a1_idx_2 = a1_2.as_dictionary::<Int32Type>();
2951        let keys = a1_idx_2.keys();
2952        let values = a1_idx_2.values().as_string::<i32>();
2953        let a2_2 = a2_list.value(2);
2954        let a2_idx_2 = a2_2.as_string::<i32>();
2955
2956        for i in 0..keys.len() {
2957            if keys.is_null(i) {
2958                assert!(a2_idx_2.is_null(i));
2959            } else {
2960                let dict_index = keys.value(i) as usize;
2961                assert_eq!(values.value(dict_index), a2_idx_2.value(i));
2962            }
2963        }
2964    }
2965
2966    #[test]
2967    fn test_primitive_dictionary() {
2968        let mut builder = PrimitiveDictionaryBuilder::<Int32Type, Int32Type>::new();
2969        builder.append(2).unwrap();
2970        builder.append(3).unwrap();
2971        builder.append(0).unwrap();
2972        builder.append_null();
2973        builder.append(5).unwrap();
2974        builder.append(3).unwrap();
2975        builder.append(-1).unwrap();
2976
2977        let a = builder.finish();
2978        let data_type = a.data_type().clone();
2979        let columns = [Arc::new(a) as ArrayRef];
2980
2981        let field = SortField::new(data_type.clone());
2982        let converter = RowConverter::new(vec![field]).unwrap();
2983        let rows = converter.convert_columns(&columns).unwrap();
2984        assert!(rows.row(0) < rows.row(1));
2985        assert!(rows.row(2) < rows.row(0));
2986        assert!(rows.row(3) < rows.row(2));
2987        assert!(rows.row(6) < rows.row(2));
2988        assert!(rows.row(3) < rows.row(6));
2989
2990        let back = converter.convert_rows(&rows).unwrap();
2991        assert_eq!(back.len(), 1);
2992        back[0].to_data().validate_full().unwrap();
2993    }
2994
2995    #[test]
2996    fn test_dictionary_nulls() {
2997        let values = Int32Array::from_iter([Some(1), Some(-1), None, Some(4), None]).into_data();
2998        let keys =
2999            Int32Array::from_iter([Some(0), Some(0), Some(1), Some(2), Some(4), None]).into_data();
3000
3001        let data_type = DataType::Dictionary(Box::new(DataType::Int32), Box::new(DataType::Int32));
3002        let data = keys
3003            .into_builder()
3004            .data_type(data_type.clone())
3005            .child_data(vec![values])
3006            .build()
3007            .unwrap();
3008
3009        let columns = [Arc::new(DictionaryArray::<Int32Type>::from(data)) as ArrayRef];
3010        let field = SortField::new(data_type.clone());
3011        let converter = RowConverter::new(vec![field]).unwrap();
3012        let rows = converter.convert_columns(&columns).unwrap();
3013
3014        assert_eq!(rows.row(0), rows.row(1));
3015        assert_eq!(rows.row(3), rows.row(4));
3016        assert_eq!(rows.row(4), rows.row(5));
3017        assert!(rows.row(3) < rows.row(0));
3018    }
3019
3020    #[test]
3021    fn test_from_binary_shared_buffer() {
3022        let converter = RowConverter::new(vec![SortField::new(DataType::Binary)]).unwrap();
3023        let array = Arc::new(BinaryArray::from_iter_values([&[0xFF]])) as _;
3024        let rows = converter.convert_columns(&[array]).unwrap();
3025        let binary_rows = rows.try_into_binary().expect("known-small rows");
3026        let _binary_rows_shared_buffer = binary_rows.clone();
3027
3028        let parsed = converter.from_binary(binary_rows);
3029
3030        converter.convert_rows(parsed.iter()).unwrap();
3031    }
3032
3033    #[test]
3034    #[should_panic(expected = "Encountered non UTF-8 data")]
3035    fn test_invalid_utf8() {
3036        let converter = RowConverter::new(vec![SortField::new(DataType::Binary)]).unwrap();
3037        let array = Arc::new(BinaryArray::from_iter_values([&[0xFF]])) as _;
3038        let rows = converter.convert_columns(&[array]).unwrap();
3039        let binary_row = rows.row(0);
3040
3041        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
3042        let parser = converter.parser();
3043        let utf8_row = parser.parse(binary_row.as_ref());
3044
3045        converter.convert_rows(std::iter::once(utf8_row)).unwrap();
3046    }
3047
3048    #[test]
3049    #[should_panic(expected = "Encountered non UTF-8 data")]
3050    fn test_invalid_utf8_array() {
3051        let converter = RowConverter::new(vec![SortField::new(DataType::Binary)]).unwrap();
3052        let array = Arc::new(BinaryArray::from_iter_values([&[0xFF]])) as _;
3053        let rows = converter.convert_columns(&[array]).unwrap();
3054        let binary_rows = rows.try_into_binary().expect("known-small rows");
3055
3056        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
3057        let parsed = converter.from_binary(binary_rows);
3058
3059        converter.convert_rows(parsed.iter()).unwrap();
3060    }
3061
3062    #[test]
3063    #[should_panic(expected = "index out of bounds")]
3064    fn test_invalid_empty() {
3065        let binary_row: &[u8] = &[];
3066
3067        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
3068        let parser = converter.parser();
3069        let utf8_row = parser.parse(binary_row.as_ref());
3070
3071        converter.convert_rows(std::iter::once(utf8_row)).unwrap();
3072    }
3073
3074    #[test]
3075    #[should_panic(expected = "index out of bounds")]
3076    fn test_invalid_empty_array() {
3077        let row: &[u8] = &[];
3078        let binary_rows = BinaryArray::from(vec![row]);
3079
3080        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
3081        let parsed = converter.from_binary(binary_rows);
3082
3083        converter.convert_rows(parsed.iter()).unwrap();
3084    }
3085
3086    #[test]
3087    #[should_panic(expected = "index out of bounds")]
3088    fn test_invalid_truncated() {
3089        let binary_row: &[u8] = &[0x02];
3090
3091        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
3092        let parser = converter.parser();
3093        let utf8_row = parser.parse(binary_row.as_ref());
3094
3095        converter.convert_rows(std::iter::once(utf8_row)).unwrap();
3096    }
3097
3098    #[test]
3099    #[should_panic(expected = "index out of bounds")]
3100    fn test_invalid_truncated_array() {
3101        let row: &[u8] = &[0x02];
3102        let binary_rows = BinaryArray::from(vec![row]);
3103
3104        let converter = RowConverter::new(vec![SortField::new(DataType::Utf8)]).unwrap();
3105        let parsed = converter.from_binary(binary_rows);
3106
3107        converter.convert_rows(parsed.iter()).unwrap();
3108    }
3109
3110    #[test]
3111    #[should_panic(expected = "rows were not produced by this RowConverter")]
3112    fn test_different_converter() {
3113        let values = Arc::new(Int32Array::from_iter([Some(1), Some(-1)]));
3114        let converter = RowConverter::new(vec![SortField::new(DataType::Int32)]).unwrap();
3115        let rows = converter.convert_columns(&[values]).unwrap();
3116
3117        let converter = RowConverter::new(vec![SortField::new(DataType::Int32)]).unwrap();
3118        let _ = converter.convert_rows(&rows);
3119    }
3120
3121    fn test_single_list<O: OffsetSizeTrait>() {
3122        let mut builder = GenericListBuilder::<O, _>::new(Int32Builder::new());
3123        builder.values().append_value(32);
3124        builder.values().append_value(52);
3125        builder.values().append_value(32);
3126        builder.append(true);
3127        builder.values().append_value(32);
3128        builder.values().append_value(52);
3129        builder.values().append_value(12);
3130        builder.append(true);
3131        builder.values().append_value(32);
3132        builder.values().append_value(52);
3133        builder.append(true);
3134        builder.values().append_value(32); // MASKED
3135        builder.values().append_value(52); // MASKED
3136        builder.append(false);
3137        builder.values().append_value(32);
3138        builder.values().append_null();
3139        builder.append(true);
3140        builder.append(true);
3141        builder.values().append_value(17); // MASKED
3142        builder.values().append_null(); // MASKED
3143        builder.append(false);
3144
3145        let list = Arc::new(builder.finish()) as ArrayRef;
3146        let d = list.data_type().clone();
3147
3148        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
3149
3150        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3151        assert!(rows.row(0) > rows.row(1)); // [32, 52, 32] > [32, 52, 12]
3152        assert!(rows.row(2) < rows.row(1)); // [32, 52] < [32, 52, 12]
3153        assert!(rows.row(3) < rows.row(2)); // null < [32, 52]
3154        assert!(rows.row(4) < rows.row(2)); // [32, null] < [32, 52]
3155        assert!(rows.row(5) < rows.row(2)); // [] < [32, 52]
3156        assert!(rows.row(3) < rows.row(5)); // null < []
3157        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3158
3159        let back = converter.convert_rows(&rows).unwrap();
3160        assert_eq!(back.len(), 1);
3161        back[0].to_data().validate_full().unwrap();
3162        assert_eq!(&back[0], &list);
3163
3164        let options = SortOptions::default().asc().with_nulls_first(false);
3165        let field = SortField::new_with_options(d.clone(), options);
3166        let converter = RowConverter::new(vec![field]).unwrap();
3167        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3168
3169        assert!(rows.row(0) > rows.row(1)); // [32, 52, 32] > [32, 52, 12]
3170        assert!(rows.row(2) < rows.row(1)); // [32, 52] < [32, 52, 12]
3171        assert!(rows.row(3) > rows.row(2)); // null > [32, 52]
3172        assert!(rows.row(4) > rows.row(2)); // [32, null] > [32, 52]
3173        assert!(rows.row(5) < rows.row(2)); // [] < [32, 52]
3174        assert!(rows.row(3) > rows.row(5)); // null > []
3175        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3176
3177        let back = converter.convert_rows(&rows).unwrap();
3178        assert_eq!(back.len(), 1);
3179        back[0].to_data().validate_full().unwrap();
3180        assert_eq!(&back[0], &list);
3181
3182        let options = SortOptions::default().desc().with_nulls_first(false);
3183        let field = SortField::new_with_options(d.clone(), options);
3184        let converter = RowConverter::new(vec![field]).unwrap();
3185        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3186
3187        assert!(rows.row(0) < rows.row(1)); // [32, 52, 32] < [32, 52, 12]
3188        assert!(rows.row(2) > rows.row(1)); // [32, 52] > [32, 52, 12]
3189        assert!(rows.row(3) > rows.row(2)); // null > [32, 52]
3190        assert!(rows.row(4) > rows.row(2)); // [32, null] > [32, 52]
3191        assert!(rows.row(5) > rows.row(2)); // [] > [32, 52]
3192        assert!(rows.row(3) > rows.row(5)); // null > []
3193        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3194
3195        let back = converter.convert_rows(&rows).unwrap();
3196        assert_eq!(back.len(), 1);
3197        back[0].to_data().validate_full().unwrap();
3198        assert_eq!(&back[0], &list);
3199
3200        let options = SortOptions::default().desc().with_nulls_first(true);
3201        let field = SortField::new_with_options(d, options);
3202        let converter = RowConverter::new(vec![field]).unwrap();
3203        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3204
3205        assert!(rows.row(0) < rows.row(1)); // [32, 52, 32] < [32, 52, 12]
3206        assert!(rows.row(2) > rows.row(1)); // [32, 52] > [32, 52, 12]
3207        assert!(rows.row(3) < rows.row(2)); // null < [32, 52]
3208        assert!(rows.row(4) < rows.row(2)); // [32, null] < [32, 52]
3209        assert!(rows.row(5) > rows.row(2)); // [] > [32, 52]
3210        assert!(rows.row(3) < rows.row(5)); // null < []
3211        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3212
3213        let back = converter.convert_rows(&rows).unwrap();
3214        assert_eq!(back.len(), 1);
3215        back[0].to_data().validate_full().unwrap();
3216        assert_eq!(&back[0], &list);
3217
3218        let sliced_list = list.slice(1, 5);
3219        let rows_on_sliced_list = converter
3220            .convert_columns(&[Arc::clone(&sliced_list)])
3221            .unwrap();
3222
3223        assert!(rows_on_sliced_list.row(1) > rows_on_sliced_list.row(0)); // [32, 52] > [32, 52, 12]
3224        assert!(rows_on_sliced_list.row(2) < rows_on_sliced_list.row(1)); // null < [32, 52]
3225        assert!(rows_on_sliced_list.row(3) < rows_on_sliced_list.row(1)); // [32, null] < [32, 52]
3226        assert!(rows_on_sliced_list.row(4) > rows_on_sliced_list.row(1)); // [] > [32, 52]
3227        assert!(rows_on_sliced_list.row(2) < rows_on_sliced_list.row(4)); // null < []
3228
3229        let back = converter.convert_rows(&rows_on_sliced_list).unwrap();
3230        assert_eq!(back.len(), 1);
3231        back[0].to_data().validate_full().unwrap();
3232        assert_eq!(&back[0], &sliced_list);
3233    }
3234
3235    fn test_nested_list<O: OffsetSizeTrait>() {
3236        let mut builder =
3237            GenericListBuilder::<O, _>::new(GenericListBuilder::<O, _>::new(Int32Builder::new()));
3238
3239        builder.values().values().append_value(1);
3240        builder.values().values().append_value(2);
3241        builder.values().append(true);
3242        builder.values().values().append_value(1);
3243        builder.values().values().append_null();
3244        builder.values().append(true);
3245        builder.append(true);
3246
3247        builder.values().values().append_value(1);
3248        builder.values().values().append_null();
3249        builder.values().append(true);
3250        builder.values().values().append_value(1);
3251        builder.values().values().append_null();
3252        builder.values().append(true);
3253        builder.append(true);
3254
3255        builder.values().values().append_value(1);
3256        builder.values().values().append_null();
3257        builder.values().append(true);
3258        builder.values().append(false);
3259        builder.append(true);
3260        builder.append(false);
3261
3262        builder.values().values().append_value(1);
3263        builder.values().values().append_value(2);
3264        builder.values().append(true);
3265        builder.append(true);
3266
3267        let list = Arc::new(builder.finish()) as ArrayRef;
3268        let d = list.data_type().clone();
3269
3270        // [
3271        //   [[1, 2], [1, null]],
3272        //   [[1, null], [1, null]],
3273        //   [[1, null], null]
3274        //   null
3275        //   [[1, 2]]
3276        // ]
3277        let options = SortOptions::default().asc().with_nulls_first(true);
3278        let field = SortField::new_with_options(d.clone(), options);
3279        let converter = RowConverter::new(vec![field]).unwrap();
3280        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3281
3282        assert!(rows.row(0) > rows.row(1));
3283        assert!(rows.row(1) > rows.row(2));
3284        assert!(rows.row(2) > rows.row(3));
3285        assert!(rows.row(4) < rows.row(0));
3286        assert!(rows.row(4) > rows.row(1));
3287
3288        let back = converter.convert_rows(&rows).unwrap();
3289        assert_eq!(back.len(), 1);
3290        back[0].to_data().validate_full().unwrap();
3291        assert_eq!(&back[0], &list);
3292
3293        let options = SortOptions::default().desc().with_nulls_first(true);
3294        let field = SortField::new_with_options(d.clone(), options);
3295        let converter = RowConverter::new(vec![field]).unwrap();
3296        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3297
3298        assert!(rows.row(0) > rows.row(1));
3299        assert!(rows.row(1) > rows.row(2));
3300        assert!(rows.row(2) > rows.row(3));
3301        assert!(rows.row(4) > rows.row(0));
3302        assert!(rows.row(4) > rows.row(1));
3303
3304        let back = converter.convert_rows(&rows).unwrap();
3305        assert_eq!(back.len(), 1);
3306        back[0].to_data().validate_full().unwrap();
3307        assert_eq!(&back[0], &list);
3308
3309        let options = SortOptions::default().desc().with_nulls_first(false);
3310        let field = SortField::new_with_options(d, options);
3311        let converter = RowConverter::new(vec![field]).unwrap();
3312        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3313
3314        assert!(rows.row(0) < rows.row(1));
3315        assert!(rows.row(1) < rows.row(2));
3316        assert!(rows.row(2) < rows.row(3));
3317        assert!(rows.row(4) > rows.row(0));
3318        assert!(rows.row(4) < rows.row(1));
3319
3320        let back = converter.convert_rows(&rows).unwrap();
3321        assert_eq!(back.len(), 1);
3322        back[0].to_data().validate_full().unwrap();
3323        assert_eq!(&back[0], &list);
3324
3325        let sliced_list = list.slice(1, 3);
3326        let rows = converter
3327            .convert_columns(&[Arc::clone(&sliced_list)])
3328            .unwrap();
3329
3330        assert!(rows.row(0) < rows.row(1));
3331        assert!(rows.row(1) < rows.row(2));
3332
3333        let back = converter.convert_rows(&rows).unwrap();
3334        assert_eq!(back.len(), 1);
3335        back[0].to_data().validate_full().unwrap();
3336        assert_eq!(&back[0], &sliced_list);
3337    }
3338
3339    #[test]
3340    fn test_list() {
3341        test_single_list::<i32>();
3342        test_nested_list::<i32>();
3343    }
3344
3345    #[test]
3346    fn test_large_list() {
3347        test_single_list::<i64>();
3348        test_nested_list::<i64>();
3349    }
3350
3351    fn test_single_list_view<O: OffsetSizeTrait>() {
3352        let mut builder = GenericListViewBuilder::<O, _>::new(Int32Builder::new());
3353        builder.values().append_value(32);
3354        builder.values().append_value(52);
3355        builder.values().append_value(32);
3356        builder.append(true);
3357        builder.values().append_value(32);
3358        builder.values().append_value(52);
3359        builder.values().append_value(12);
3360        builder.append(true);
3361        builder.values().append_value(32);
3362        builder.values().append_value(52);
3363        builder.append(true);
3364        builder.values().append_value(32); // MASKED
3365        builder.values().append_value(52); // MASKED
3366        builder.append(false);
3367        builder.values().append_value(32);
3368        builder.values().append_null();
3369        builder.append(true);
3370        builder.append(true);
3371        builder.values().append_value(17); // MASKED
3372        builder.values().append_null(); // MASKED
3373        builder.append(false);
3374
3375        let list = Arc::new(builder.finish()) as ArrayRef;
3376        let d = list.data_type().clone();
3377
3378        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
3379
3380        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3381        assert!(rows.row(0) > rows.row(1)); // [32, 52, 32] > [32, 52, 12]
3382        assert!(rows.row(2) < rows.row(1)); // [32, 52] < [32, 52, 12]
3383        assert!(rows.row(3) < rows.row(2)); // null < [32, 52]
3384        assert!(rows.row(4) < rows.row(2)); // [32, null] < [32, 52]
3385        assert!(rows.row(5) < rows.row(2)); // [] < [32, 52]
3386        assert!(rows.row(3) < rows.row(5)); // null < []
3387        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3388
3389        let back = converter.convert_rows(&rows).unwrap();
3390        assert_eq!(back.len(), 1);
3391        back[0].to_data().validate_full().unwrap();
3392
3393        // Verify the content matches (ListView may have different physical layout but same logical content)
3394        let back_list_view = back[0]
3395            .as_any()
3396            .downcast_ref::<GenericListViewArray<O>>()
3397            .unwrap();
3398        let orig_list_view = list
3399            .as_any()
3400            .downcast_ref::<GenericListViewArray<O>>()
3401            .unwrap();
3402
3403        assert_eq!(back_list_view.len(), orig_list_view.len());
3404        for i in 0..back_list_view.len() {
3405            assert_eq!(back_list_view.is_valid(i), orig_list_view.is_valid(i));
3406            if back_list_view.is_valid(i) {
3407                assert_eq!(&back_list_view.value(i), &orig_list_view.value(i));
3408            }
3409        }
3410
3411        let options = SortOptions::default().asc().with_nulls_first(false);
3412        let field = SortField::new_with_options(d.clone(), options);
3413        let converter = RowConverter::new(vec![field]).unwrap();
3414        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3415
3416        assert!(rows.row(0) > rows.row(1)); // [32, 52, 32] > [32, 52, 12]
3417        assert!(rows.row(2) < rows.row(1)); // [32, 52] < [32, 52, 12]
3418        assert!(rows.row(3) > rows.row(2)); // null > [32, 52]
3419        assert!(rows.row(4) > rows.row(2)); // [32, null] > [32, 52]
3420        assert!(rows.row(5) < rows.row(2)); // [] < [32, 52]
3421        assert!(rows.row(3) > rows.row(5)); // null > []
3422        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3423
3424        let back = converter.convert_rows(&rows).unwrap();
3425        assert_eq!(back.len(), 1);
3426        back[0].to_data().validate_full().unwrap();
3427
3428        let options = SortOptions::default().desc().with_nulls_first(false);
3429        let field = SortField::new_with_options(d.clone(), options);
3430        let converter = RowConverter::new(vec![field]).unwrap();
3431        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3432
3433        assert!(rows.row(0) < rows.row(1)); // [32, 52, 32] < [32, 52, 12]
3434        assert!(rows.row(2) > rows.row(1)); // [32, 52] > [32, 52, 12]
3435        assert!(rows.row(3) > rows.row(2)); // null > [32, 52]
3436        assert!(rows.row(4) > rows.row(2)); // [32, null] > [32, 52]
3437        assert!(rows.row(5) > rows.row(2)); // [] > [32, 52]
3438        assert!(rows.row(3) > rows.row(5)); // null > []
3439        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3440
3441        let back = converter.convert_rows(&rows).unwrap();
3442        assert_eq!(back.len(), 1);
3443        back[0].to_data().validate_full().unwrap();
3444
3445        let options = SortOptions::default().desc().with_nulls_first(true);
3446        let field = SortField::new_with_options(d, options);
3447        let converter = RowConverter::new(vec![field]).unwrap();
3448        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3449
3450        assert!(rows.row(0) < rows.row(1)); // [32, 52, 32] < [32, 52, 12]
3451        assert!(rows.row(2) > rows.row(1)); // [32, 52] > [32, 52, 12]
3452        assert!(rows.row(3) < rows.row(2)); // null < [32, 52]
3453        assert!(rows.row(4) < rows.row(2)); // [32, null] < [32, 52]
3454        assert!(rows.row(5) > rows.row(2)); // [] > [32, 52]
3455        assert!(rows.row(3) < rows.row(5)); // null < []
3456        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3457
3458        let back = converter.convert_rows(&rows).unwrap();
3459        assert_eq!(back.len(), 1);
3460        back[0].to_data().validate_full().unwrap();
3461
3462        let sliced_list = list.slice(1, 5);
3463        let rows_on_sliced_list = converter
3464            .convert_columns(&[Arc::clone(&sliced_list)])
3465            .unwrap();
3466
3467        assert!(rows_on_sliced_list.row(1) > rows_on_sliced_list.row(0)); // [32, 52] > [32, 52, 12]
3468        assert!(rows_on_sliced_list.row(2) < rows_on_sliced_list.row(1)); // null < [32, 52]
3469        assert!(rows_on_sliced_list.row(3) < rows_on_sliced_list.row(1)); // [32, null] < [32, 52]
3470        assert!(rows_on_sliced_list.row(4) > rows_on_sliced_list.row(1)); // [] > [32, 52]
3471        assert!(rows_on_sliced_list.row(2) < rows_on_sliced_list.row(4)); // null < []
3472
3473        let back = converter.convert_rows(&rows_on_sliced_list).unwrap();
3474        assert_eq!(back.len(), 1);
3475        back[0].to_data().validate_full().unwrap();
3476    }
3477
3478    fn test_nested_list_view<O: OffsetSizeTrait>() {
3479        let mut builder = GenericListViewBuilder::<O, _>::new(GenericListViewBuilder::<O, _>::new(
3480            Int32Builder::new(),
3481        ));
3482
3483        // Row 0: [[1, 2], [1, null]]
3484        builder.values().values().append_value(1);
3485        builder.values().values().append_value(2);
3486        builder.values().append(true);
3487        builder.values().values().append_value(1);
3488        builder.values().values().append_null();
3489        builder.values().append(true);
3490        builder.append(true);
3491
3492        // Row 1: [[1, null], [1, null]]
3493        builder.values().values().append_value(1);
3494        builder.values().values().append_null();
3495        builder.values().append(true);
3496        builder.values().values().append_value(1);
3497        builder.values().values().append_null();
3498        builder.values().append(true);
3499        builder.append(true);
3500
3501        // Row 2: [[1, null], null]
3502        builder.values().values().append_value(1);
3503        builder.values().values().append_null();
3504        builder.values().append(true);
3505        builder.values().append(false);
3506        builder.append(true);
3507
3508        // Row 3: null
3509        builder.append(false);
3510
3511        // Row 4: [[1, 2]]
3512        builder.values().values().append_value(1);
3513        builder.values().values().append_value(2);
3514        builder.values().append(true);
3515        builder.append(true);
3516
3517        let list = Arc::new(builder.finish()) as ArrayRef;
3518        let d = list.data_type().clone();
3519
3520        // [
3521        //   [[1, 2], [1, null]],
3522        //   [[1, null], [1, null]],
3523        //   [[1, null], null]
3524        //   null
3525        //   [[1, 2]]
3526        // ]
3527        let options = SortOptions::default().asc().with_nulls_first(true);
3528        let field = SortField::new_with_options(d.clone(), options);
3529        let converter = RowConverter::new(vec![field]).unwrap();
3530        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3531
3532        assert!(rows.row(0) > rows.row(1));
3533        assert!(rows.row(1) > rows.row(2));
3534        assert!(rows.row(2) > rows.row(3));
3535        assert!(rows.row(4) < rows.row(0));
3536        assert!(rows.row(4) > rows.row(1));
3537
3538        let back = converter.convert_rows(&rows).unwrap();
3539        assert_eq!(back.len(), 1);
3540        back[0].to_data().validate_full().unwrap();
3541
3542        // Verify the content matches (ListView may have different physical layout but same logical content)
3543        let back_list_view = back[0]
3544            .as_any()
3545            .downcast_ref::<GenericListViewArray<O>>()
3546            .unwrap();
3547        let orig_list_view = list
3548            .as_any()
3549            .downcast_ref::<GenericListViewArray<O>>()
3550            .unwrap();
3551
3552        assert_eq!(back_list_view.len(), orig_list_view.len());
3553        for i in 0..back_list_view.len() {
3554            assert_eq!(back_list_view.is_valid(i), orig_list_view.is_valid(i));
3555            if back_list_view.is_valid(i) {
3556                assert_eq!(&back_list_view.value(i), &orig_list_view.value(i));
3557            }
3558        }
3559
3560        let options = SortOptions::default().desc().with_nulls_first(true);
3561        let field = SortField::new_with_options(d.clone(), options);
3562        let converter = RowConverter::new(vec![field]).unwrap();
3563        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3564
3565        assert!(rows.row(0) > rows.row(1));
3566        assert!(rows.row(1) > rows.row(2));
3567        assert!(rows.row(2) > rows.row(3));
3568        assert!(rows.row(4) > rows.row(0));
3569        assert!(rows.row(4) > rows.row(1));
3570
3571        let back = converter.convert_rows(&rows).unwrap();
3572        assert_eq!(back.len(), 1);
3573        back[0].to_data().validate_full().unwrap();
3574
3575        // Verify the content matches
3576        let back_list_view = back[0]
3577            .as_any()
3578            .downcast_ref::<GenericListViewArray<O>>()
3579            .unwrap();
3580
3581        assert_eq!(back_list_view.len(), orig_list_view.len());
3582        for i in 0..back_list_view.len() {
3583            assert_eq!(back_list_view.is_valid(i), orig_list_view.is_valid(i));
3584            if back_list_view.is_valid(i) {
3585                assert_eq!(&back_list_view.value(i), &orig_list_view.value(i));
3586            }
3587        }
3588
3589        let options = SortOptions::default().desc().with_nulls_first(false);
3590        let field = SortField::new_with_options(d.clone(), options);
3591        let converter = RowConverter::new(vec![field]).unwrap();
3592        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3593
3594        assert!(rows.row(0) < rows.row(1));
3595        assert!(rows.row(1) < rows.row(2));
3596        assert!(rows.row(2) < rows.row(3));
3597        assert!(rows.row(4) > rows.row(0));
3598        assert!(rows.row(4) < rows.row(1));
3599
3600        let back = converter.convert_rows(&rows).unwrap();
3601        assert_eq!(back.len(), 1);
3602        back[0].to_data().validate_full().unwrap();
3603
3604        // Verify the content matches
3605        let back_list_view = back[0]
3606            .as_any()
3607            .downcast_ref::<GenericListViewArray<O>>()
3608            .unwrap();
3609
3610        assert_eq!(back_list_view.len(), orig_list_view.len());
3611        for i in 0..back_list_view.len() {
3612            assert_eq!(back_list_view.is_valid(i), orig_list_view.is_valid(i));
3613            if back_list_view.is_valid(i) {
3614                assert_eq!(&back_list_view.value(i), &orig_list_view.value(i));
3615            }
3616        }
3617
3618        let sliced_list = list.slice(1, 3);
3619        let rows = converter
3620            .convert_columns(&[Arc::clone(&sliced_list)])
3621            .unwrap();
3622
3623        assert!(rows.row(0) < rows.row(1));
3624        assert!(rows.row(1) < rows.row(2));
3625
3626        let back = converter.convert_rows(&rows).unwrap();
3627        assert_eq!(back.len(), 1);
3628        back[0].to_data().validate_full().unwrap();
3629    }
3630
3631    #[test]
3632    fn test_list_view() {
3633        test_single_list_view::<i32>();
3634        test_nested_list_view::<i32>();
3635    }
3636
3637    #[test]
3638    fn test_large_list_view() {
3639        test_single_list_view::<i64>();
3640        test_nested_list_view::<i64>();
3641    }
3642
3643    fn test_list_view_with_shared_values<O: OffsetSizeTrait>() {
3644        // Create a values array: [1, 2, 3, 4, 5, 6, 7, 8]
3645        let values = Int32Array::from(vec![1, 2, 3, 4, 5, 6, 7, 8]);
3646        let field = Arc::new(Field::new_list_field(DataType::Int32, true));
3647
3648        // Create a ListView where:
3649        // - Row 0: offset=0, size=3 -> [1, 2, 3]
3650        // - Row 1: offset=0, size=3 -> [1, 2, 3] (same offset+size as row 0)
3651        // - Row 2: offset=5, size=2 -> [6, 7] (non-monotonic offset)
3652        // - Row 3: offset=2, size=2 -> [3, 4] (offset goes back)
3653        // - Row 4: offset=1, size=4 -> [2, 3, 4, 5] (subset of values that contains row 3's range)
3654        // - Row 5: offset=2, size=1 -> [3] (subset of row 3 and row 4)
3655        let offsets = ScalarBuffer::<O>::from(vec![
3656            O::from_usize(0).unwrap(),
3657            O::from_usize(0).unwrap(),
3658            O::from_usize(5).unwrap(),
3659            O::from_usize(2).unwrap(),
3660            O::from_usize(1).unwrap(),
3661            O::from_usize(2).unwrap(),
3662        ]);
3663        let sizes = ScalarBuffer::<O>::from(vec![
3664            O::from_usize(3).unwrap(),
3665            O::from_usize(3).unwrap(),
3666            O::from_usize(2).unwrap(),
3667            O::from_usize(2).unwrap(),
3668            O::from_usize(4).unwrap(),
3669            O::from_usize(1).unwrap(),
3670        ]);
3671
3672        let list_view: GenericListViewArray<O> =
3673            GenericListViewArray::try_new(field, offsets, sizes, Arc::new(values), None).unwrap();
3674
3675        let d = list_view.data_type().clone();
3676        let list = Arc::new(list_view) as ArrayRef;
3677
3678        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
3679        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3680
3681        // Row 0 and Row 1 have the same content [1, 2, 3], so they should be equal
3682        assert_eq!(rows.row(0), rows.row(1));
3683
3684        // [1, 2, 3] < [6, 7] (comparing first elements: 1 < 6)
3685        assert!(rows.row(0) < rows.row(2));
3686
3687        // [3, 4] > [1, 2, 3] (comparing first elements: 3 > 1)
3688        assert!(rows.row(3) > rows.row(0));
3689
3690        // [2, 3, 4, 5] > [1, 2, 3] (comparing first elements: 2 > 1)
3691        assert!(rows.row(4) > rows.row(0));
3692
3693        // [3] < [3, 4] (same prefix but shorter)
3694        assert!(rows.row(5) < rows.row(3));
3695
3696        // [3] < [2, 3, 4, 5] (comparing first elements: 3 > 2)
3697        assert!(rows.row(5) > rows.row(4));
3698
3699        // Round-trip conversion
3700        let back = converter.convert_rows(&rows).unwrap();
3701        assert_eq!(back.len(), 1);
3702        back[0].to_data().validate_full().unwrap();
3703
3704        // Verify logical content matches
3705        let back_list_view = back[0]
3706            .as_any()
3707            .downcast_ref::<GenericListViewArray<O>>()
3708            .unwrap();
3709        let orig_list_view = list
3710            .as_any()
3711            .downcast_ref::<GenericListViewArray<O>>()
3712            .unwrap();
3713
3714        assert_eq!(back_list_view.len(), orig_list_view.len());
3715        for i in 0..back_list_view.len() {
3716            assert_eq!(back_list_view.is_valid(i), orig_list_view.is_valid(i));
3717            if back_list_view.is_valid(i) {
3718                assert_eq!(&back_list_view.value(i), &orig_list_view.value(i));
3719            }
3720        }
3721
3722        // Test with descending order
3723        let options = SortOptions::default().desc();
3724        let field = SortField::new_with_options(d, options);
3725        let converter = RowConverter::new(vec![field]).unwrap();
3726        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3727
3728        // In descending order, comparisons are reversed
3729        assert_eq!(rows.row(0), rows.row(1)); // Equal rows stay equal
3730        assert!(rows.row(0) > rows.row(2)); // [1, 2, 3] > [6, 7] in desc
3731        assert!(rows.row(3) < rows.row(0)); // [3, 4] < [1, 2, 3] in desc
3732
3733        let back = converter.convert_rows(&rows).unwrap();
3734        assert_eq!(back.len(), 1);
3735        back[0].to_data().validate_full().unwrap();
3736    }
3737
3738    #[test]
3739    fn test_list_view_shared_values() {
3740        test_list_view_with_shared_values::<i32>();
3741    }
3742
3743    #[test]
3744    fn test_large_list_view_shared_values() {
3745        test_list_view_with_shared_values::<i64>();
3746    }
3747
3748    #[test]
3749    fn test_fixed_size_list() {
3750        let mut builder = FixedSizeListBuilder::new(Int32Builder::new(), 3);
3751        builder.values().append_value(32);
3752        builder.values().append_value(52);
3753        builder.values().append_value(32);
3754        builder.append(true);
3755        builder.values().append_value(32);
3756        builder.values().append_value(52);
3757        builder.values().append_value(12);
3758        builder.append(true);
3759        builder.values().append_value(32);
3760        builder.values().append_value(52);
3761        builder.values().append_null();
3762        builder.append(true);
3763        builder.values().append_value(32); // MASKED
3764        builder.values().append_value(52); // MASKED
3765        builder.values().append_value(13); // MASKED
3766        builder.append(false);
3767        builder.values().append_value(32);
3768        builder.values().append_null();
3769        builder.values().append_null();
3770        builder.append(true);
3771        builder.values().append_null();
3772        builder.values().append_null();
3773        builder.values().append_null();
3774        builder.append(true);
3775        builder.values().append_value(17); // MASKED
3776        builder.values().append_null(); // MASKED
3777        builder.values().append_value(77); // MASKED
3778        builder.append(false);
3779
3780        let list = Arc::new(builder.finish()) as ArrayRef;
3781        let d = list.data_type().clone();
3782
3783        // Default sorting (ascending, nulls first)
3784        let converter = RowConverter::new(vec![SortField::new(d.clone())]).unwrap();
3785
3786        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3787        assert!(rows.row(0) > rows.row(1)); // [32, 52, 32] > [32, 52, 12]
3788        assert!(rows.row(2) < rows.row(1)); // [32, 52, null] < [32, 52, 12]
3789        assert!(rows.row(3) < rows.row(2)); // null < [32, 52, null]
3790        assert!(rows.row(4) < rows.row(2)); // [32, null, null] < [32, 52, null]
3791        assert!(rows.row(5) < rows.row(2)); // [null, null, null] < [32, 52, null]
3792        assert!(rows.row(3) < rows.row(5)); // null < [null, null, null]
3793        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3794
3795        let back = converter.convert_rows(&rows).unwrap();
3796        assert_eq!(back.len(), 1);
3797        back[0].to_data().validate_full().unwrap();
3798        assert_eq!(&back[0], &list);
3799
3800        // Ascending, null last
3801        let options = SortOptions::default().asc().with_nulls_first(false);
3802        let field = SortField::new_with_options(d.clone(), options);
3803        let converter = RowConverter::new(vec![field]).unwrap();
3804        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3805        assert!(rows.row(0) > rows.row(1)); // [32, 52, 32] > [32, 52, 12]
3806        assert!(rows.row(2) > rows.row(1)); // [32, 52, null] > [32, 52, 12]
3807        assert!(rows.row(3) > rows.row(2)); // null > [32, 52, null]
3808        assert!(rows.row(4) > rows.row(2)); // [32, null, null] > [32, 52, null]
3809        assert!(rows.row(5) > rows.row(2)); // [null, null, null] > [32, 52, null]
3810        assert!(rows.row(3) > rows.row(5)); // null > [null, null, null]
3811        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3812
3813        let back = converter.convert_rows(&rows).unwrap();
3814        assert_eq!(back.len(), 1);
3815        back[0].to_data().validate_full().unwrap();
3816        assert_eq!(&back[0], &list);
3817
3818        // Descending, nulls last
3819        let options = SortOptions::default().desc().with_nulls_first(false);
3820        let field = SortField::new_with_options(d.clone(), options);
3821        let converter = RowConverter::new(vec![field]).unwrap();
3822        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3823        assert!(rows.row(0) < rows.row(1)); // [32, 52, 32] < [32, 52, 12]
3824        assert!(rows.row(2) > rows.row(1)); // [32, 52, null] > [32, 52, 12]
3825        assert!(rows.row(3) > rows.row(2)); // null > [32, 52, null]
3826        assert!(rows.row(4) > rows.row(2)); // [32, null, null] > [32, 52, null]
3827        assert!(rows.row(5) > rows.row(2)); // [null, null, null] > [32, 52, null]
3828        assert!(rows.row(3) > rows.row(5)); // null > [null, null, null]
3829        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3830
3831        let back = converter.convert_rows(&rows).unwrap();
3832        assert_eq!(back.len(), 1);
3833        back[0].to_data().validate_full().unwrap();
3834        assert_eq!(&back[0], &list);
3835
3836        // Descending, nulls first
3837        let options = SortOptions::default().desc().with_nulls_first(true);
3838        let field = SortField::new_with_options(d, options);
3839        let converter = RowConverter::new(vec![field]).unwrap();
3840        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
3841
3842        assert!(rows.row(0) < rows.row(1)); // [32, 52, 32] < [32, 52, 12]
3843        assert!(rows.row(2) < rows.row(1)); // [32, 52, null] > [32, 52, 12]
3844        assert!(rows.row(3) < rows.row(2)); // null < [32, 52, null]
3845        assert!(rows.row(4) < rows.row(2)); // [32, null, null] < [32, 52, null]
3846        assert!(rows.row(5) < rows.row(2)); // [null, null, null] > [32, 52, null]
3847        assert!(rows.row(3) < rows.row(5)); // null < [null, null, null]
3848        assert_eq!(rows.row(3), rows.row(6)); // null = null (different masked values)
3849
3850        let back = converter.convert_rows(&rows).unwrap();
3851        assert_eq!(back.len(), 1);
3852        back[0].to_data().validate_full().unwrap();
3853        assert_eq!(&back[0], &list);
3854
3855        let sliced_list = list.slice(1, 5);
3856        let rows_on_sliced_list = converter
3857            .convert_columns(&[Arc::clone(&sliced_list)])
3858            .unwrap();
3859
3860        assert!(rows_on_sliced_list.row(2) < rows_on_sliced_list.row(1)); // null < [32, 52, null]
3861        assert!(rows_on_sliced_list.row(3) < rows_on_sliced_list.row(1)); // [32, null, null] < [32, 52, null]
3862        assert!(rows_on_sliced_list.row(4) < rows_on_sliced_list.row(1)); // [null, null, null] > [32, 52, null]
3863        assert!(rows_on_sliced_list.row(2) < rows_on_sliced_list.row(4)); // null < [null, null, null]
3864
3865        let back = converter.convert_rows(&rows_on_sliced_list).unwrap();
3866        assert_eq!(back.len(), 1);
3867        back[0].to_data().validate_full().unwrap();
3868        assert_eq!(&back[0], &sliced_list);
3869    }
3870
3871    #[test]
3872    fn test_two_fixed_size_lists() {
3873        let mut first = FixedSizeListBuilder::new(UInt8Builder::new(), 1);
3874        // 0: [100]
3875        first.values().append_value(100);
3876        first.append(true);
3877        // 1: [101]
3878        first.values().append_value(101);
3879        first.append(true);
3880        // 2: [102]
3881        first.values().append_value(102);
3882        first.append(true);
3883        // 3: [null]
3884        first.values().append_null();
3885        first.append(true);
3886        // 4: null
3887        first.values().append_null(); // MASKED
3888        first.append(false);
3889        let first = Arc::new(first.finish()) as ArrayRef;
3890        let first_type = first.data_type().clone();
3891
3892        let mut second = FixedSizeListBuilder::new(UInt8Builder::new(), 1);
3893        // 0: [200]
3894        second.values().append_value(200);
3895        second.append(true);
3896        // 1: [201]
3897        second.values().append_value(201);
3898        second.append(true);
3899        // 2: [202]
3900        second.values().append_value(202);
3901        second.append(true);
3902        // 3: [null]
3903        second.values().append_null();
3904        second.append(true);
3905        // 4: null
3906        second.values().append_null(); // MASKED
3907        second.append(false);
3908        let second = Arc::new(second.finish()) as ArrayRef;
3909        let second_type = second.data_type().clone();
3910
3911        let converter = RowConverter::new(vec![
3912            SortField::new(first_type.clone()),
3913            SortField::new(second_type.clone()),
3914        ])
3915        .unwrap();
3916
3917        let rows = converter
3918            .convert_columns(&[Arc::clone(&first), Arc::clone(&second)])
3919            .unwrap();
3920
3921        let back = converter.convert_rows(&rows).unwrap();
3922        assert_eq!(back.len(), 2);
3923        back[0].to_data().validate_full().unwrap();
3924        assert_eq!(&back[0], &first);
3925        back[1].to_data().validate_full().unwrap();
3926        assert_eq!(&back[1], &second);
3927    }
3928
3929    #[test]
3930    fn test_fixed_size_list_with_variable_width_content() {
3931        let mut first = FixedSizeListBuilder::new(
3932            StructBuilder::from_fields(
3933                vec![
3934                    Field::new(
3935                        "timestamp",
3936                        DataType::Timestamp(TimeUnit::Microsecond, Some(Arc::from("UTC"))),
3937                        false,
3938                    ),
3939                    Field::new("offset_minutes", DataType::Int16, false),
3940                    Field::new("time_zone", DataType::Utf8, false),
3941                ],
3942                1,
3943            ),
3944            1,
3945        );
3946        // 0: null
3947        first
3948            .values()
3949            .field_builder::<TimestampMicrosecondBuilder>(0)
3950            .unwrap()
3951            .append_null();
3952        first
3953            .values()
3954            .field_builder::<Int16Builder>(1)
3955            .unwrap()
3956            .append_null();
3957        first
3958            .values()
3959            .field_builder::<StringBuilder>(2)
3960            .unwrap()
3961            .append_null();
3962        first.values().append(false);
3963        first.append(false);
3964        // 1: [null]
3965        first
3966            .values()
3967            .field_builder::<TimestampMicrosecondBuilder>(0)
3968            .unwrap()
3969            .append_null();
3970        first
3971            .values()
3972            .field_builder::<Int16Builder>(1)
3973            .unwrap()
3974            .append_null();
3975        first
3976            .values()
3977            .field_builder::<StringBuilder>(2)
3978            .unwrap()
3979            .append_null();
3980        first.values().append(false);
3981        first.append(true);
3982        // 2: [1970-01-01 00:00:00.000000 UTC]
3983        first
3984            .values()
3985            .field_builder::<TimestampMicrosecondBuilder>(0)
3986            .unwrap()
3987            .append_value(0);
3988        first
3989            .values()
3990            .field_builder::<Int16Builder>(1)
3991            .unwrap()
3992            .append_value(0);
3993        first
3994            .values()
3995            .field_builder::<StringBuilder>(2)
3996            .unwrap()
3997            .append_value("UTC");
3998        first.values().append(true);
3999        first.append(true);
4000        // 3: [2005-09-10 13:30:00.123456 Europe/Warsaw]
4001        first
4002            .values()
4003            .field_builder::<TimestampMicrosecondBuilder>(0)
4004            .unwrap()
4005            .append_value(1126351800123456);
4006        first
4007            .values()
4008            .field_builder::<Int16Builder>(1)
4009            .unwrap()
4010            .append_value(120);
4011        first
4012            .values()
4013            .field_builder::<StringBuilder>(2)
4014            .unwrap()
4015            .append_value("Europe/Warsaw");
4016        first.values().append(true);
4017        first.append(true);
4018        let first = Arc::new(first.finish()) as ArrayRef;
4019        let first_type = first.data_type().clone();
4020
4021        let mut second = StringBuilder::new();
4022        second.append_value("somewhere near");
4023        second.append_null();
4024        second.append_value("Greenwich");
4025        second.append_value("Warsaw");
4026        let second = Arc::new(second.finish()) as ArrayRef;
4027        let second_type = second.data_type().clone();
4028
4029        let converter = RowConverter::new(vec![
4030            SortField::new(first_type.clone()),
4031            SortField::new(second_type.clone()),
4032        ])
4033        .unwrap();
4034
4035        let rows = converter
4036            .convert_columns(&[Arc::clone(&first), Arc::clone(&second)])
4037            .unwrap();
4038
4039        let back = converter.convert_rows(&rows).unwrap();
4040        assert_eq!(back.len(), 2);
4041        back[0].to_data().validate_full().unwrap();
4042        assert_eq!(&back[0], &first);
4043        back[1].to_data().validate_full().unwrap();
4044        assert_eq!(&back[1], &second);
4045    }
4046
4047    fn generate_primitive_array<K>(
4048        rng: &mut impl RngCore,
4049        len: usize,
4050        valid_percent: f64,
4051    ) -> PrimitiveArray<K>
4052    where
4053        K: ArrowPrimitiveType,
4054        StandardUniform: Distribution<K::Native>,
4055    {
4056        (0..len)
4057            .map(|_| rng.random_bool(valid_percent).then(|| rng.random()))
4058            .collect()
4059    }
4060
4061    fn generate_boolean_array(
4062        rng: &mut impl RngCore,
4063        len: usize,
4064        valid_percent: f64,
4065    ) -> BooleanArray {
4066        (0..len)
4067            .map(|_| rng.random_bool(valid_percent).then(|| rng.random_bool(0.5)))
4068            .collect()
4069    }
4070
4071    fn generate_strings<O: OffsetSizeTrait>(
4072        rng: &mut impl RngCore,
4073        len: usize,
4074        valid_percent: f64,
4075    ) -> GenericStringArray<O> {
4076        (0..len)
4077            .map(|_| {
4078                rng.random_bool(valid_percent).then(|| {
4079                    let len = rng.random_range(0..100);
4080                    let bytes = (0..len).map(|_| rng.random_range(0..128)).collect();
4081                    String::from_utf8(bytes).unwrap()
4082                })
4083            })
4084            .collect()
4085    }
4086
4087    fn generate_string_view(
4088        rng: &mut impl RngCore,
4089        len: usize,
4090        valid_percent: f64,
4091    ) -> StringViewArray {
4092        (0..len)
4093            .map(|_| {
4094                rng.random_bool(valid_percent).then(|| {
4095                    let len = rng.random_range(0..100);
4096                    let bytes = (0..len).map(|_| rng.random_range(0..128)).collect();
4097                    String::from_utf8(bytes).unwrap()
4098                })
4099            })
4100            .collect()
4101    }
4102
4103    fn generate_byte_view(
4104        rng: &mut impl RngCore,
4105        len: usize,
4106        valid_percent: f64,
4107    ) -> BinaryViewArray {
4108        (0..len)
4109            .map(|_| {
4110                rng.random_bool(valid_percent).then(|| {
4111                    let len = rng.random_range(0..100);
4112                    let bytes: Vec<_> = (0..len).map(|_| rng.random_range(0..128)).collect();
4113                    bytes
4114                })
4115            })
4116            .collect()
4117    }
4118
4119    fn generate_fixed_stringview_column(len: usize) -> StringViewArray {
4120        let edge_cases = vec![
4121            Some("bar".to_string()),
4122            Some("bar\0".to_string()),
4123            Some("LongerThan12Bytes".to_string()),
4124            Some("LongerThan12Bytez".to_string()),
4125            Some("LongerThan12Bytes\0".to_string()),
4126            Some("LongerThan12Byt".to_string()),
4127            Some("backend one".to_string()),
4128            Some("backend two".to_string()),
4129            Some("a".repeat(257)),
4130            Some("a".repeat(300)),
4131        ];
4132
4133        // Fill up to `len` by repeating edge cases and trimming
4134        let mut values = Vec::with_capacity(len);
4135        for i in 0..len {
4136            values.push(
4137                edge_cases
4138                    .get(i % edge_cases.len())
4139                    .cloned()
4140                    .unwrap_or(None),
4141            );
4142        }
4143
4144        StringViewArray::from(values)
4145    }
4146
4147    fn generate_dictionary<K>(
4148        rng: &mut impl RngCore,
4149        values: ArrayRef,
4150        len: usize,
4151        valid_percent: f64,
4152    ) -> DictionaryArray<K>
4153    where
4154        K: ArrowDictionaryKeyType,
4155        K::Native: SampleUniform,
4156    {
4157        let min_key = K::Native::from_usize(0).unwrap();
4158        let max_key = K::Native::from_usize(values.len()).unwrap();
4159        let keys: PrimitiveArray<K> = (0..len)
4160            .map(|_| {
4161                rng.random_bool(valid_percent)
4162                    .then(|| rng.random_range(min_key..max_key))
4163            })
4164            .collect();
4165
4166        let data_type =
4167            DataType::Dictionary(Box::new(K::DATA_TYPE), Box::new(values.data_type().clone()));
4168
4169        let data = keys
4170            .into_data()
4171            .into_builder()
4172            .data_type(data_type)
4173            .add_child_data(values.to_data())
4174            .build()
4175            .unwrap();
4176
4177        DictionaryArray::from(data)
4178    }
4179
4180    fn generate_fixed_size_binary(
4181        rng: &mut impl RngCore,
4182        len: usize,
4183        valid_percent: f64,
4184    ) -> FixedSizeBinaryArray {
4185        let width = rng.random_range(0..20);
4186        let mut builder = FixedSizeBinaryBuilder::new(width);
4187
4188        let mut b = vec![0; width as usize];
4189        for _ in 0..len {
4190            match rng.random_bool(valid_percent) {
4191                true => {
4192                    b.iter_mut().for_each(|x| *x = rng.random());
4193                    builder.append_value(&b).unwrap();
4194                }
4195                false => builder.append_null(),
4196            }
4197        }
4198
4199        builder.finish()
4200    }
4201
4202    fn generate_struct(rng: &mut impl RngCore, len: usize, valid_percent: f64) -> StructArray {
4203        let nulls = NullBuffer::from_iter((0..len).map(|_| rng.random_bool(valid_percent)));
4204        let a = generate_primitive_array::<Int32Type>(rng, len, valid_percent);
4205        let b = generate_strings::<i32>(rng, len, valid_percent);
4206        let fields = Fields::from(vec![
4207            Field::new("a", DataType::Int32, true),
4208            Field::new("b", DataType::Utf8, true),
4209        ]);
4210        let values = vec![Arc::new(a) as _, Arc::new(b) as _];
4211        StructArray::new(fields, values, Some(nulls))
4212    }
4213
4214    fn generate_list<R: RngCore, F>(
4215        rng: &mut R,
4216        len: usize,
4217        valid_percent: f64,
4218        values: F,
4219    ) -> ListArray
4220    where
4221        F: FnOnce(&mut R, usize) -> ArrayRef,
4222    {
4223        let offsets = OffsetBuffer::<i32>::from_lengths((0..len).map(|_| rng.random_range(0..10)));
4224        let values_len = offsets.last().unwrap().to_usize().unwrap();
4225        let values = values(rng, values_len);
4226        let nulls = NullBuffer::from_iter((0..len).map(|_| rng.random_bool(valid_percent)));
4227        let field = Arc::new(Field::new_list_field(values.data_type().clone(), true));
4228        ListArray::new(field, offsets, values, Some(nulls))
4229    }
4230
4231    fn generate_list_view<F>(
4232        rng: &mut impl RngCore,
4233        len: usize,
4234        valid_percent: f64,
4235        values: F,
4236    ) -> ListViewArray
4237    where
4238        F: FnOnce(usize) -> ArrayRef,
4239    {
4240        // Generate sizes first, then create a values array large enough
4241        let sizes: Vec<i32> = (0..len).map(|_| rng.random_range(0..10)).collect();
4242        let values_len: usize = sizes.iter().map(|s| *s as usize).sum::<usize>().max(1);
4243        let values = values(values_len);
4244
4245        // Generate offsets that can overlap, be non-monotonic, or share ranges
4246        let offsets: Vec<i32> = sizes
4247            .iter()
4248            .map(|&size| {
4249                if size == 0 {
4250                    0
4251                } else {
4252                    rng.random_range(0..=(values_len as i32 - size))
4253                }
4254            })
4255            .collect();
4256
4257        let nulls = NullBuffer::from_iter((0..len).map(|_| rng.random_bool(valid_percent)));
4258        let field = Arc::new(Field::new_list_field(values.data_type().clone(), true));
4259        ListViewArray::new(
4260            field,
4261            ScalarBuffer::from(offsets),
4262            ScalarBuffer::from(sizes),
4263            values,
4264            Some(nulls),
4265        )
4266    }
4267
4268    fn generate_nulls(rng: &mut impl RngCore, len: usize) -> Option<NullBuffer> {
4269        Some(NullBuffer::from_iter(
4270            (0..len).map(|_| rng.random_bool(0.8)),
4271        ))
4272    }
4273
4274    fn change_underlying_null_values_for_primitive<T: ArrowPrimitiveType>(
4275        array: &PrimitiveArray<T>,
4276    ) -> PrimitiveArray<T> {
4277        let (dt, values, nulls) = array.clone().into_parts();
4278
4279        let new_values = ScalarBuffer::<T::Native>::from_iter(
4280            values
4281                .iter()
4282                .zip(nulls.as_ref().unwrap().iter())
4283                .map(|(val, is_valid)| {
4284                    if is_valid {
4285                        *val
4286                    } else {
4287                        val.add_wrapping(T::Native::usize_as(1))
4288                    }
4289                }),
4290        );
4291
4292        PrimitiveArray::new(new_values, nulls).with_data_type(dt)
4293    }
4294
4295    fn change_underline_null_values_for_byte_array<T: ByteArrayType>(
4296        array: &GenericByteArray<T>,
4297    ) -> GenericByteArray<T> {
4298        let (offsets, values, nulls) = array.clone().into_parts();
4299
4300        let new_offsets = OffsetBuffer::<T::Offset>::from_lengths(
4301            offsets
4302                .lengths()
4303                .zip(nulls.as_ref().unwrap().iter())
4304                .map(|(len, is_valid)| if is_valid { len } else { len + 1 }),
4305        );
4306
4307        let mut new_bytes = Vec::<u8>::with_capacity(new_offsets[new_offsets.len() - 1].as_usize());
4308
4309        offsets
4310            .windows(2)
4311            .zip(nulls.as_ref().unwrap().iter())
4312            .for_each(|(start_and_end, is_valid)| {
4313                let start = start_and_end[0].as_usize();
4314                let end = start_and_end[1].as_usize();
4315                new_bytes.extend_from_slice(&values.as_slice()[start..end]);
4316
4317                // add an extra byte
4318                if !is_valid {
4319                    new_bytes.push(b'c');
4320                }
4321            });
4322
4323        GenericByteArray::<T>::new(new_offsets, Buffer::from_vec(new_bytes), nulls)
4324    }
4325
4326    fn change_underline_null_values_for_list_array<O: OffsetSizeTrait>(
4327        array: &GenericListArray<O>,
4328    ) -> GenericListArray<O> {
4329        let (field, offsets, values, nulls) = array.clone().into_parts();
4330
4331        let (new_values, new_offsets) = {
4332            let concat_values = offsets
4333                .windows(2)
4334                .zip(nulls.as_ref().unwrap().iter())
4335                .map(|(start_and_end, is_valid)| {
4336                    let start = start_and_end[0].as_usize();
4337                    let end = start_and_end[1].as_usize();
4338                    if is_valid {
4339                        return (start, end - start);
4340                    }
4341
4342                    // If reached end, we take one less
4343                    if end == values.len() {
4344                        (start, (end - start).saturating_sub(1))
4345                    } else {
4346                        (start, end - start + 1)
4347                    }
4348                })
4349                .map(|(start, length)| values.slice(start, length))
4350                .collect::<Vec<_>>();
4351
4352            let new_offsets =
4353                OffsetBuffer::<O>::from_lengths(concat_values.iter().map(|s| s.len()));
4354
4355            let new_values = {
4356                let values = concat_values.iter().map(|a| a.as_ref()).collect::<Vec<_>>();
4357                arrow_select::concat::concat(&values).expect("should be able to concat")
4358            };
4359
4360            (new_values, new_offsets)
4361        };
4362
4363        GenericListArray::<O>::new(field, new_offsets, new_values, nulls)
4364    }
4365
4366    fn change_underline_null_values(array: &ArrayRef) -> ArrayRef {
4367        if array.null_count() == 0 {
4368            return Arc::clone(array);
4369        }
4370
4371        downcast_primitive_array!(
4372            array => {
4373                let output = change_underlying_null_values_for_primitive(array);
4374
4375                Arc::new(output)
4376            }
4377
4378            DataType::Utf8 => {
4379                Arc::new(change_underline_null_values_for_byte_array(array.as_string::<i32>()))
4380            }
4381            DataType::LargeUtf8 => {
4382                Arc::new(change_underline_null_values_for_byte_array(array.as_string::<i64>()))
4383            }
4384            DataType::Binary => {
4385                Arc::new(change_underline_null_values_for_byte_array(array.as_binary::<i32>()))
4386            }
4387            DataType::LargeBinary => {
4388                Arc::new(change_underline_null_values_for_byte_array(array.as_binary::<i64>()))
4389            }
4390            DataType::List(_) => {
4391                Arc::new(change_underline_null_values_for_list_array(array.as_list::<i32>()))
4392            }
4393            DataType::LargeList(_) => {
4394                Arc::new(change_underline_null_values_for_list_array(array.as_list::<i64>()))
4395            }
4396            _ => {
4397                Arc::clone(array)
4398            }
4399        )
4400    }
4401
4402    fn generate_column(rng: &mut (impl RngCore + Clone), len: usize) -> ArrayRef {
4403        match rng.random_range(0..23) {
4404            0 => Arc::new(generate_primitive_array::<Int32Type>(rng, len, 0.8)),
4405            1 => Arc::new(generate_primitive_array::<UInt32Type>(rng, len, 0.8)),
4406            2 => Arc::new(generate_primitive_array::<Int64Type>(rng, len, 0.8)),
4407            3 => Arc::new(generate_primitive_array::<UInt64Type>(rng, len, 0.8)),
4408            4 => Arc::new(generate_primitive_array::<Float32Type>(rng, len, 0.8)),
4409            5 => Arc::new(generate_primitive_array::<Float64Type>(rng, len, 0.8)),
4410            6 => Arc::new(generate_strings::<i32>(rng, len, 0.8)),
4411            7 => {
4412                let dict_values_len = rng.random_range(1..len);
4413                // Cannot test dictionaries containing null values because of #2687
4414                let strings = Arc::new(generate_strings::<i32>(rng, dict_values_len, 1.0));
4415                Arc::new(generate_dictionary::<Int64Type>(rng, strings, len, 0.8))
4416            }
4417            8 => {
4418                let dict_values_len = rng.random_range(1..len);
4419                // Cannot test dictionaries containing null values because of #2687
4420                let values = Arc::new(generate_primitive_array::<Int64Type>(
4421                    rng,
4422                    dict_values_len,
4423                    1.0,
4424                ));
4425                Arc::new(generate_dictionary::<Int64Type>(rng, values, len, 0.8))
4426            }
4427            9 => Arc::new(generate_fixed_size_binary(rng, len, 0.8)),
4428            10 => Arc::new(generate_struct(rng, len, 0.8)),
4429            11 => Arc::new(generate_list(rng, len, 0.8, |rng, values_len| {
4430                Arc::new(generate_primitive_array::<Int64Type>(rng, values_len, 0.8))
4431            })),
4432            12 => Arc::new(generate_list(rng, len, 0.8, |rng, values_len| {
4433                Arc::new(generate_strings::<i32>(rng, values_len, 0.8))
4434            })),
4435            13 => Arc::new(generate_list(rng, len, 0.8, |rng, values_len| {
4436                Arc::new(generate_struct(rng, values_len, 0.8))
4437            })),
4438            14 => Arc::new(generate_string_view(rng, len, 0.8)),
4439            15 => Arc::new(generate_byte_view(rng, len, 0.8)),
4440            16 => Arc::new(generate_fixed_stringview_column(len)),
4441            17 => Arc::new(
4442                generate_list(&mut rng.clone(), len + 1000, 0.8, |rng, values_len| {
4443                    Arc::new(generate_primitive_array::<Int64Type>(rng, values_len, 0.8))
4444                })
4445                .slice(500, len),
4446            ),
4447            18 => Arc::new(generate_boolean_array(rng, len, 0.8)),
4448            19 => Arc::new(generate_list_view(
4449                &mut rng.clone(),
4450                len,
4451                0.8,
4452                |values_len| Arc::new(generate_primitive_array::<Int64Type>(rng, values_len, 0.8)),
4453            )),
4454            20 => Arc::new(generate_list_view(
4455                &mut rng.clone(),
4456                len,
4457                0.8,
4458                |values_len| Arc::new(generate_strings::<i32>(rng, values_len, 0.8)),
4459            )),
4460            21 => Arc::new(generate_list_view(
4461                &mut rng.clone(),
4462                len,
4463                0.8,
4464                |values_len| Arc::new(generate_struct(rng, values_len, 0.8)),
4465            )),
4466            22 => Arc::new(
4467                generate_list_view(&mut rng.clone(), len + 1000, 0.8, |values_len| {
4468                    Arc::new(generate_primitive_array::<Int64Type>(rng, values_len, 0.8))
4469                })
4470                .slice(500, len),
4471            ),
4472            _ => unreachable!(),
4473        }
4474    }
4475
4476    fn print_row(cols: &[SortColumn], row: usize) -> String {
4477        let t: Vec<_> = cols
4478            .iter()
4479            .map(|x| match x.values.is_valid(row) {
4480                true => {
4481                    let opts = FormatOptions::default().with_null("NULL");
4482                    let formatter = ArrayFormatter::try_new(x.values.as_ref(), &opts).unwrap();
4483                    formatter.value(row).to_string()
4484                }
4485                false => "NULL".to_string(),
4486            })
4487            .collect();
4488        t.join(",")
4489    }
4490
4491    fn print_col_types(cols: &[SortColumn]) -> String {
4492        let t: Vec<_> = cols
4493            .iter()
4494            .map(|x| x.values.data_type().to_string())
4495            .collect();
4496        t.join(",")
4497    }
4498
4499    #[derive(Debug, PartialEq)]
4500    enum Nulls {
4501        /// Keep the generated array as is
4502        AsIs,
4503
4504        /// Replace the null buffer with different null buffer to point to different positions as null
4505        Different,
4506
4507        /// Remove all nulls
4508        None,
4509    }
4510
4511    #[test]
4512    #[cfg_attr(miri, ignore)]
4513    fn fuzz_test() {
4514        let mut rng = StdRng::seed_from_u64(42);
4515        for _ in 0..100 {
4516            for null_behavior in [Nulls::AsIs, Nulls::Different, Nulls::None] {
4517                let num_columns = rng.random_range(1..5);
4518                let len = rng.random_range(5..100);
4519                let mut arrays: Vec<_> = (0..num_columns)
4520                    .map(|_| generate_column(&mut rng, len))
4521                    .collect();
4522
4523                match null_behavior {
4524                    Nulls::AsIs => {
4525                        // Keep as is
4526                    }
4527                    Nulls::Different => {
4528                        // Replace nulls with different nulls to allow for testing different underlying null values
4529                        arrays = arrays
4530                            .into_iter()
4531                            .map(|a| replace_array_nulls(a, generate_nulls(&mut rng, len)))
4532                            .collect()
4533                    }
4534                    Nulls::None => {
4535                        // Remove nulls
4536                        arrays = arrays
4537                            .into_iter()
4538                            .map(|a| replace_array_nulls(a, None))
4539                            .collect()
4540                    }
4541                }
4542
4543                let options: Vec<_> = (0..num_columns)
4544                    .map(|_| SortOptions {
4545                        descending: rng.random_bool(0.5),
4546                        nulls_first: rng.random_bool(0.5),
4547                    })
4548                    .collect();
4549
4550                let sort_columns: Vec<_> = options
4551                    .iter()
4552                    .zip(&arrays)
4553                    .map(|(o, c)| SortColumn {
4554                        values: Arc::clone(c),
4555                        options: Some(*o),
4556                    })
4557                    .collect();
4558
4559                let comparator = LexicographicalComparator::try_new(&sort_columns).unwrap();
4560
4561                let columns: Vec<SortField> = options
4562                    .into_iter()
4563                    .zip(&arrays)
4564                    .map(|(o, a)| SortField::new_with_options(a.data_type().clone(), o))
4565                    .collect();
4566
4567                let converter = RowConverter::new(columns).unwrap();
4568                let rows = converter.convert_columns(&arrays).unwrap();
4569
4570                // Assert that the underlying null values are not taken into account when converting
4571                // even for different inputs
4572                if !matches!(null_behavior, Nulls::None) {
4573                    assert_same_rows_when_changing_input_underlying_null_values(
4574                        &arrays, &converter, &rows,
4575                    );
4576                }
4577
4578                for i in 0..len {
4579                    for j in 0..len {
4580                        let row_i = rows.row(i);
4581                        let row_j = rows.row(j);
4582                        let row_cmp = row_i.cmp(&row_j);
4583                        let lex_cmp = comparator.compare(i, j);
4584                        assert_eq!(
4585                            row_cmp,
4586                            lex_cmp,
4587                            "({:?} vs {:?}) vs ({:?} vs {:?}) for types {}",
4588                            print_row(&sort_columns, i),
4589                            print_row(&sort_columns, j),
4590                            row_i,
4591                            row_j,
4592                            print_col_types(&sort_columns)
4593                        );
4594                    }
4595                }
4596
4597                // Validate rows length iterator
4598                {
4599                    let mut rows_iter = rows.iter();
4600                    let mut rows_lengths_iter = rows.lengths();
4601                    for (index, row) in rows_iter.by_ref().enumerate() {
4602                        let len = rows_lengths_iter
4603                            .next()
4604                            .expect("Reached end of length iterator while still have rows");
4605                        assert_eq!(
4606                            row.data.len(),
4607                            len,
4608                            "Row length mismatch: {} vs {}",
4609                            row.data.len(),
4610                            len
4611                        );
4612                        assert_eq!(
4613                            len,
4614                            rows.row_len(index),
4615                            "Row length mismatch at index {}: {} vs {}",
4616                            index,
4617                            len,
4618                            rows.row_len(index)
4619                        );
4620                    }
4621
4622                    assert_eq!(
4623                        rows_lengths_iter.next(),
4624                        None,
4625                        "Length iterator did not reach end"
4626                    );
4627                }
4628
4629                // Convert rows produced from convert_columns().
4630                // Note: validate_utf8 is set to false since Row is initialized through empty_rows()
4631                let back = converter.convert_rows(&rows).unwrap();
4632                for (actual, expected) in back.iter().zip(&arrays) {
4633                    actual.to_data().validate_full().unwrap();
4634                    dictionary_eq(actual, expected)
4635                }
4636
4637                // Check that we can convert rows into ByteArray and then parse, convert it back to array
4638                // Note: validate_utf8 is set to true since Row is initialized through RowParser
4639                let rows = rows.try_into_binary().expect("reasonable size");
4640                let parser = converter.parser();
4641                let back = converter
4642                    .convert_rows(rows.iter().map(|b| parser.parse(b.expect("valid bytes"))))
4643                    .unwrap();
4644                for (actual, expected) in back.iter().zip(&arrays) {
4645                    actual.to_data().validate_full().unwrap();
4646                    dictionary_eq(actual, expected)
4647                }
4648
4649                let rows = converter.from_binary(rows);
4650                let back = converter.convert_rows(&rows).unwrap();
4651                for (actual, expected) in back.iter().zip(&arrays) {
4652                    actual.to_data().validate_full().unwrap();
4653                    dictionary_eq(actual, expected)
4654                }
4655            }
4656        }
4657    }
4658
4659    fn replace_array_nulls(array: ArrayRef, new_nulls: Option<NullBuffer>) -> ArrayRef {
4660        make_array(
4661            array
4662                .into_data()
4663                .into_builder()
4664                // Replace the nulls
4665                .nulls(new_nulls)
4666                .build()
4667                .unwrap(),
4668        )
4669    }
4670
4671    fn assert_same_rows_when_changing_input_underlying_null_values(
4672        arrays: &[ArrayRef],
4673        converter: &RowConverter,
4674        rows: &Rows,
4675    ) {
4676        let arrays_with_different_data_behind_nulls = arrays
4677            .iter()
4678            .map(|arr| change_underline_null_values(arr))
4679            .collect::<Vec<_>>();
4680
4681        // Skip assertion if we did not change anything
4682        if arrays
4683            .iter()
4684            .zip(arrays_with_different_data_behind_nulls.iter())
4685            .all(|(a, b)| Arc::ptr_eq(a, b))
4686        {
4687            return;
4688        }
4689
4690        let rows_with_different_nulls = converter
4691            .convert_columns(&arrays_with_different_data_behind_nulls)
4692            .unwrap();
4693
4694        assert_eq!(
4695            rows.iter().collect::<Vec<_>>(),
4696            rows_with_different_nulls.iter().collect::<Vec<_>>(),
4697            "Different underlying nulls should not output different rows"
4698        )
4699    }
4700
4701    #[test]
4702    fn test_clear() {
4703        let converter = RowConverter::new(vec![SortField::new(DataType::Int32)]).unwrap();
4704        let mut rows = converter.empty_rows(3, 128);
4705
4706        let first = Int32Array::from(vec![None, Some(2), Some(4)]);
4707        let second = Int32Array::from(vec![Some(2), None, Some(4)]);
4708        let arrays = [Arc::new(first) as ArrayRef, Arc::new(second) as ArrayRef];
4709
4710        for array in arrays.iter() {
4711            rows.clear();
4712            converter
4713                .append(&mut rows, std::slice::from_ref(array))
4714                .unwrap();
4715            let back = converter.convert_rows(&rows).unwrap();
4716            assert_eq!(&back[0], array);
4717        }
4718
4719        let mut rows_expected = converter.empty_rows(3, 128);
4720        converter.append(&mut rows_expected, &arrays[1..]).unwrap();
4721
4722        for (i, (actual, expected)) in rows.iter().zip(rows_expected.iter()).enumerate() {
4723            assert_eq!(
4724                actual, expected,
4725                "For row {i}: expected {expected:?}, actual: {actual:?}",
4726            );
4727        }
4728    }
4729
4730    #[test]
4731    fn test_append_codec_dictionary_binary() {
4732        use DataType::*;
4733        // Dictionary RowConverter
4734        let converter = RowConverter::new(vec![SortField::new(Dictionary(
4735            Box::new(Int32),
4736            Box::new(Binary),
4737        ))])
4738        .unwrap();
4739        let mut rows = converter.empty_rows(4, 128);
4740
4741        let keys = Int32Array::from_iter_values([0, 1, 2, 3]);
4742        let values = BinaryArray::from(vec![
4743            Some("a".as_bytes()),
4744            Some(b"b"),
4745            Some(b"c"),
4746            Some(b"d"),
4747        ]);
4748        let dict_array = DictionaryArray::new(keys, Arc::new(values));
4749
4750        rows.clear();
4751        let array = Arc::new(dict_array) as ArrayRef;
4752        converter
4753            .append(&mut rows, std::slice::from_ref(&array))
4754            .unwrap();
4755        let back = converter.convert_rows(&rows).unwrap();
4756
4757        dictionary_eq(&back[0], &array);
4758    }
4759
4760    #[test]
4761    fn test_list_prefix() {
4762        let mut a = ListBuilder::new(Int8Builder::new());
4763        a.append_value([None]);
4764        a.append_value([None, None]);
4765        let a = a.finish();
4766
4767        let converter = RowConverter::new(vec![SortField::new(a.data_type().clone())]).unwrap();
4768        let rows = converter.convert_columns(&[Arc::new(a) as _]).unwrap();
4769        assert_eq!(rows.row(0).cmp(&rows.row(1)), Ordering::Less);
4770    }
4771
4772    #[test]
4773    fn map_should_be_marked_as_unsupported() {
4774        let map_data_type = Field::new_map(
4775            "map",
4776            "entries",
4777            Field::new("key", DataType::Utf8, false),
4778            Field::new("value", DataType::Utf8, true),
4779            false,
4780            true,
4781        )
4782        .data_type()
4783        .clone();
4784
4785        let is_supported = RowConverter::supports_fields(&[SortField::new(map_data_type)]);
4786
4787        assert!(!is_supported, "Map should not be supported");
4788    }
4789
4790    #[test]
4791    fn should_fail_to_create_row_converter_for_unsupported_map_type() {
4792        let map_data_type = Field::new_map(
4793            "map",
4794            "entries",
4795            Field::new("key", DataType::Utf8, false),
4796            Field::new("value", DataType::Utf8, true),
4797            false,
4798            true,
4799        )
4800        .data_type()
4801        .clone();
4802
4803        let converter = RowConverter::new(vec![SortField::new(map_data_type)]);
4804
4805        match converter {
4806            Err(ArrowError::NotYetImplemented(message)) => {
4807                assert!(
4808                    message.contains("Row format support not yet implemented for"),
4809                    "Expected NotYetImplemented error for map data type, got: {message}",
4810                );
4811            }
4812            Err(e) => panic!("Expected NotYetImplemented error, got: {e}"),
4813            Ok(_) => panic!("Expected NotYetImplemented error for map data type"),
4814        }
4815    }
4816
4817    #[test]
4818    fn test_values_buffer_smaller_when_utf8_validation_disabled() {
4819        fn get_values_buffer_len(col: ArrayRef) -> (usize, usize) {
4820            // 1. Convert cols into rows
4821            let converter = RowConverter::new(vec![SortField::new(DataType::Utf8View)]).unwrap();
4822
4823            // 2a. Convert rows into colsa (validate_utf8 = false)
4824            let rows = converter.convert_columns(&[col]).unwrap();
4825            let converted = converter.convert_rows(&rows).unwrap();
4826            let unchecked_values_len = converted[0].as_string_view().data_buffers()[0].len();
4827
4828            // 2b. Convert rows into cols (validate_utf8 = true since Row is initialized through RowParser)
4829            let rows = rows.try_into_binary().expect("reasonable size");
4830            let parser = converter.parser();
4831            let converted = converter
4832                .convert_rows(rows.iter().map(|b| parser.parse(b.expect("valid bytes"))))
4833                .unwrap();
4834            let checked_values_len = converted[0].as_string_view().data_buffers()[0].len();
4835            (unchecked_values_len, checked_values_len)
4836        }
4837
4838        // Case1. StringViewArray with inline strings
4839        let col = Arc::new(StringViewArray::from_iter([
4840            Some("hello"), // short(5)
4841            None,          // null
4842            Some("short"), // short(5)
4843            Some("tiny"),  // short(4)
4844        ])) as ArrayRef;
4845
4846        let (unchecked_values_len, checked_values_len) = get_values_buffer_len(col);
4847        // Since there are no long (>12) strings, len of values buffer is 0
4848        assert_eq!(unchecked_values_len, 0);
4849        // When utf8 validation enabled, values buffer includes inline strings (5+5+4)
4850        assert_eq!(checked_values_len, 14);
4851
4852        // Case2. StringViewArray with long(>12) strings
4853        let col = Arc::new(StringViewArray::from_iter([
4854            Some("this is a very long string over 12 bytes"),
4855            Some("another long string to test the buffer"),
4856        ])) as ArrayRef;
4857
4858        let (unchecked_values_len, checked_values_len) = get_values_buffer_len(col);
4859        // Since there are no inline strings, expected length of values buffer is the same
4860        assert!(unchecked_values_len > 0);
4861        assert_eq!(unchecked_values_len, checked_values_len);
4862
4863        // Case3. StringViewArray with both short and long strings
4864        let col = Arc::new(StringViewArray::from_iter([
4865            Some("tiny"),          // 4 (short)
4866            Some("thisisexact13"), // 13 (long)
4867            None,
4868            Some("short"), // 5 (short)
4869        ])) as ArrayRef;
4870
4871        let (unchecked_values_len, checked_values_len) = get_values_buffer_len(col);
4872        // Since there is single long string, len of values buffer is 13
4873        assert_eq!(unchecked_values_len, 13);
4874        assert!(checked_values_len > unchecked_values_len);
4875    }
4876
4877    #[test]
4878    fn test_sparse_union() {
4879        // create a sparse union with Int32 (type_id = 0) and Utf8 (type_id = 1)
4880        let int_array = Int32Array::from(vec![Some(1), None, Some(3), None, Some(5)]);
4881        let str_array = StringArray::from(vec![None, Some("b"), None, Some("d"), None]);
4882
4883        // [1, "b", 3, "d", 5]
4884        let type_ids = vec![0, 1, 0, 1, 0].into();
4885
4886        let union_fields = [
4887            (0, Arc::new(Field::new("int", DataType::Int32, false))),
4888            (1, Arc::new(Field::new("str", DataType::Utf8, false))),
4889        ]
4890        .into_iter()
4891        .collect();
4892
4893        let union_array = UnionArray::try_new(
4894            union_fields,
4895            type_ids,
4896            None,
4897            vec![Arc::new(int_array) as ArrayRef, Arc::new(str_array)],
4898        )
4899        .unwrap();
4900
4901        let union_type = union_array.data_type().clone();
4902        let converter = RowConverter::new(vec![SortField::new(union_type)]).unwrap();
4903
4904        let rows = converter
4905            .convert_columns(&[Arc::new(union_array.clone())])
4906            .unwrap();
4907
4908        // round trip
4909        let back = converter.convert_rows(&rows).unwrap();
4910        let back_union = back[0].as_any().downcast_ref::<UnionArray>().unwrap();
4911
4912        assert_eq!(union_array.len(), back_union.len());
4913        for i in 0..union_array.len() {
4914            assert_eq!(union_array.type_id(i), back_union.type_id(i));
4915        }
4916    }
4917
4918    #[test]
4919    fn test_sparse_union_with_nulls() {
4920        // create a sparse union with Int32 (type_id = 0) and Utf8 (type_id = 1)
4921        let int_array = Int32Array::from(vec![Some(1), None, Some(3), None, Some(5)]);
4922        let str_array = StringArray::from(vec![None::<&str>; 5]);
4923
4924        // [1, null (both children null), 3, null (both children null), 5]
4925        let type_ids = vec![0, 1, 0, 1, 0].into();
4926
4927        let union_fields = [
4928            (0, Arc::new(Field::new("int", DataType::Int32, true))),
4929            (1, Arc::new(Field::new("str", DataType::Utf8, true))),
4930        ]
4931        .into_iter()
4932        .collect();
4933
4934        let union_array = UnionArray::try_new(
4935            union_fields,
4936            type_ids,
4937            None,
4938            vec![Arc::new(int_array) as ArrayRef, Arc::new(str_array)],
4939        )
4940        .unwrap();
4941
4942        let union_type = union_array.data_type().clone();
4943        let converter = RowConverter::new(vec![SortField::new(union_type)]).unwrap();
4944
4945        let rows = converter
4946            .convert_columns(&[Arc::new(union_array.clone())])
4947            .unwrap();
4948
4949        // round trip
4950        let back = converter.convert_rows(&rows).unwrap();
4951        let back_union = back[0].as_any().downcast_ref::<UnionArray>().unwrap();
4952
4953        assert_eq!(union_array.len(), back_union.len());
4954        for i in 0..union_array.len() {
4955            let expected_null = union_array.is_null(i);
4956            let actual_null = back_union.is_null(i);
4957            assert_eq!(expected_null, actual_null, "Null mismatch at index {i}");
4958            if !expected_null {
4959                assert_eq!(union_array.type_id(i), back_union.type_id(i));
4960            }
4961        }
4962    }
4963
4964    #[test]
4965    fn test_dense_union() {
4966        // create a dense union with Int32 (type_id = 0) and use Utf8 (type_id = 1)
4967        let int_array = Int32Array::from(vec![1, 3, 5]);
4968        let str_array = StringArray::from(vec!["a", "b"]);
4969
4970        let type_ids = vec![0, 1, 0, 1, 0].into();
4971
4972        // [1, "a", 3, "b", 5]
4973        let offsets = vec![0, 0, 1, 1, 2].into();
4974
4975        let union_fields = [
4976            (0, Arc::new(Field::new("int", DataType::Int32, false))),
4977            (1, Arc::new(Field::new("str", DataType::Utf8, false))),
4978        ]
4979        .into_iter()
4980        .collect();
4981
4982        let union_array = UnionArray::try_new(
4983            union_fields,
4984            type_ids,
4985            Some(offsets), // Dense mode
4986            vec![Arc::new(int_array) as ArrayRef, Arc::new(str_array)],
4987        )
4988        .unwrap();
4989
4990        let union_type = union_array.data_type().clone();
4991        let converter = RowConverter::new(vec![SortField::new(union_type)]).unwrap();
4992
4993        let rows = converter
4994            .convert_columns(&[Arc::new(union_array.clone())])
4995            .unwrap();
4996
4997        // round trip
4998        let back = converter.convert_rows(&rows).unwrap();
4999        let back_union = back[0].as_any().downcast_ref::<UnionArray>().unwrap();
5000
5001        assert_eq!(union_array.len(), back_union.len());
5002        for i in 0..union_array.len() {
5003            assert_eq!(union_array.type_id(i), back_union.type_id(i));
5004        }
5005    }
5006
5007    #[test]
5008    fn test_dense_union_with_nulls() {
5009        // create a dense union with Int32 (type_id = 0) and Utf8 (type_id = 1)
5010        let int_array = Int32Array::from(vec![Some(1), None, Some(5)]);
5011        let str_array = StringArray::from(vec![Some("a"), None]);
5012
5013        // [1, "a", 5, null (str null), null (int null)]
5014        let type_ids = vec![0, 1, 0, 1, 0].into();
5015        let offsets = vec![0, 0, 1, 1, 2].into();
5016
5017        let union_fields = [
5018            (0, Arc::new(Field::new("int", DataType::Int32, true))),
5019            (1, Arc::new(Field::new("str", DataType::Utf8, true))),
5020        ]
5021        .into_iter()
5022        .collect();
5023
5024        let union_array = UnionArray::try_new(
5025            union_fields,
5026            type_ids,
5027            Some(offsets),
5028            vec![Arc::new(int_array) as ArrayRef, Arc::new(str_array)],
5029        )
5030        .unwrap();
5031
5032        let union_type = union_array.data_type().clone();
5033        let converter = RowConverter::new(vec![SortField::new(union_type)]).unwrap();
5034
5035        let rows = converter
5036            .convert_columns(&[Arc::new(union_array.clone())])
5037            .unwrap();
5038
5039        // round trip
5040        let back = converter.convert_rows(&rows).unwrap();
5041        let back_union = back[0].as_any().downcast_ref::<UnionArray>().unwrap();
5042
5043        assert_eq!(union_array.len(), back_union.len());
5044        for i in 0..union_array.len() {
5045            let expected_null = union_array.is_null(i);
5046            let actual_null = back_union.is_null(i);
5047            assert_eq!(expected_null, actual_null, "Null mismatch at index {i}");
5048            if !expected_null {
5049                assert_eq!(union_array.type_id(i), back_union.type_id(i));
5050            }
5051        }
5052    }
5053
5054    #[test]
5055    fn test_union_ordering() {
5056        let int_array = Int32Array::from(vec![100, 5, 20]);
5057        let str_array = StringArray::from(vec!["z", "a"]);
5058
5059        // [100, "z", 5, "a", 20]
5060        let type_ids = vec![0, 1, 0, 1, 0].into();
5061        let offsets = vec![0, 0, 1, 1, 2].into();
5062
5063        let union_fields = [
5064            (0, Arc::new(Field::new("int", DataType::Int32, false))),
5065            (1, Arc::new(Field::new("str", DataType::Utf8, false))),
5066        ]
5067        .into_iter()
5068        .collect();
5069
5070        let union_array = UnionArray::try_new(
5071            union_fields,
5072            type_ids,
5073            Some(offsets),
5074            vec![Arc::new(int_array) as ArrayRef, Arc::new(str_array)],
5075        )
5076        .unwrap();
5077
5078        let union_type = union_array.data_type().clone();
5079        let converter = RowConverter::new(vec![SortField::new(union_type)]).unwrap();
5080
5081        let rows = converter.convert_columns(&[Arc::new(union_array)]).unwrap();
5082
5083        /*
5084        expected ordering
5085
5086        row 2: 5    - type_id 0
5087        row 4: 20   - type_id 0
5088        row 0: 100  - type id 0
5089        row 3: "a"  - type id 1
5090        row 1: "z"  - type id 1
5091        */
5092
5093        // 5 < "z"
5094        assert!(rows.row(2) < rows.row(1));
5095
5096        // 100 < "a"
5097        assert!(rows.row(0) < rows.row(3));
5098
5099        // among ints
5100        // 5 < 20
5101        assert!(rows.row(2) < rows.row(4));
5102        // 20 < 100
5103        assert!(rows.row(4) < rows.row(0));
5104
5105        // among strigns
5106        // "a" < "z"
5107        assert!(rows.row(3) < rows.row(1));
5108    }
5109
5110    #[test]
5111    fn test_row_converter_roundtrip_with_many_union_columns() {
5112        // col 1: Union(Int32, Utf8) [67, "hello"]
5113        let fields1 = UnionFields::try_new(
5114            vec![0, 1],
5115            vec![
5116                Field::new("int", DataType::Int32, true),
5117                Field::new("string", DataType::Utf8, true),
5118            ],
5119        )
5120        .unwrap();
5121
5122        let int_array1 = Int32Array::from(vec![Some(67), None]);
5123        let string_array1 = StringArray::from(vec![None::<&str>, Some("hello")]);
5124        let type_ids1 = vec![0i8, 1].into();
5125
5126        let union_array1 = UnionArray::try_new(
5127            fields1.clone(),
5128            type_ids1,
5129            None,
5130            vec![
5131                Arc::new(int_array1) as ArrayRef,
5132                Arc::new(string_array1) as ArrayRef,
5133            ],
5134        )
5135        .unwrap();
5136
5137        // col 2: Union(Int32, Utf8) [100, "world"]
5138        let fields2 = UnionFields::try_new(
5139            vec![0, 1],
5140            vec![
5141                Field::new("int", DataType::Int32, true),
5142                Field::new("string", DataType::Utf8, true),
5143            ],
5144        )
5145        .unwrap();
5146
5147        let int_array2 = Int32Array::from(vec![Some(100), None]);
5148        let string_array2 = StringArray::from(vec![None::<&str>, Some("world")]);
5149        let type_ids2 = vec![0i8, 1].into();
5150
5151        let union_array2 = UnionArray::try_new(
5152            fields2.clone(),
5153            type_ids2,
5154            None,
5155            vec![
5156                Arc::new(int_array2) as ArrayRef,
5157                Arc::new(string_array2) as ArrayRef,
5158            ],
5159        )
5160        .unwrap();
5161
5162        // create a row converter with 2 union columns
5163        let field1 = Field::new("col1", DataType::Union(fields1, UnionMode::Sparse), true);
5164        let field2 = Field::new("col2", DataType::Union(fields2, UnionMode::Sparse), true);
5165
5166        let sort_field1 = SortField::new(field1.data_type().clone());
5167        let sort_field2 = SortField::new(field2.data_type().clone());
5168
5169        let converter = RowConverter::new(vec![sort_field1, sort_field2]).unwrap();
5170
5171        let rows = converter
5172            .convert_columns(&[
5173                Arc::new(union_array1.clone()) as ArrayRef,
5174                Arc::new(union_array2.clone()) as ArrayRef,
5175            ])
5176            .unwrap();
5177
5178        // roundtrip
5179        let out = converter.convert_rows(&rows).unwrap();
5180
5181        let [col1, col2] = out.as_slice() else {
5182            panic!("expected 2 columns")
5183        };
5184
5185        let col1 = col1.as_any().downcast_ref::<UnionArray>().unwrap();
5186        let col2 = col2.as_any().downcast_ref::<UnionArray>().unwrap();
5187
5188        for (expected, got) in [union_array1, union_array2].iter().zip([col1, col2]) {
5189            assert_eq!(expected.len(), got.len());
5190            assert_eq!(expected.type_ids(), got.type_ids());
5191
5192            for i in 0..expected.len() {
5193                assert_eq!(expected.value(i).as_ref(), got.value(i).as_ref());
5194            }
5195        }
5196    }
5197
5198    #[test]
5199    fn test_row_converter_roundtrip_with_one_union_column() {
5200        let fields = UnionFields::try_new(
5201            vec![0, 1],
5202            vec![
5203                Field::new("int", DataType::Int32, true),
5204                Field::new("string", DataType::Utf8, true),
5205            ],
5206        )
5207        .unwrap();
5208
5209        let int_array = Int32Array::from(vec![Some(67), None]);
5210        let string_array = StringArray::from(vec![None::<&str>, Some("hello")]);
5211        let type_ids = vec![0i8, 1].into();
5212
5213        let union_array = UnionArray::try_new(
5214            fields.clone(),
5215            type_ids,
5216            None,
5217            vec![
5218                Arc::new(int_array) as ArrayRef,
5219                Arc::new(string_array) as ArrayRef,
5220            ],
5221        )
5222        .unwrap();
5223
5224        let field = Field::new("col", DataType::Union(fields, UnionMode::Sparse), true);
5225        let sort_field = SortField::new(field.data_type().clone());
5226        let converter = RowConverter::new(vec![sort_field]).unwrap();
5227
5228        let rows = converter
5229            .convert_columns(&[Arc::new(union_array.clone()) as ArrayRef])
5230            .unwrap();
5231
5232        // roundtrip
5233        let out = converter.convert_rows(&rows).unwrap();
5234
5235        let [col1] = out.as_slice() else {
5236            panic!("expected 1 column")
5237        };
5238
5239        let col = col1.as_any().downcast_ref::<UnionArray>().unwrap();
5240        assert_eq!(col.len(), union_array.len());
5241        assert_eq!(col.type_ids(), union_array.type_ids());
5242
5243        for i in 0..col.len() {
5244            assert_eq!(col.value(i).as_ref(), union_array.value(i).as_ref());
5245        }
5246    }
5247
5248    #[test]
5249    fn test_row_converter_roundtrip_with_non_default_union_type_ids() {
5250        // test with non-sequential type IDs (70, 85) instead of (0, 1)
5251        let fields = UnionFields::try_new(
5252            vec![70, 85],
5253            vec![
5254                Field::new("int", DataType::Int32, true),
5255                Field::new("string", DataType::Utf8, true),
5256            ],
5257        )
5258        .unwrap();
5259
5260        let int_array = Int32Array::from(vec![Some(67), None]);
5261        let string_array = StringArray::from(vec![None::<&str>, Some("hello")]);
5262        let type_ids = vec![70i8, 85].into();
5263
5264        let union_array = UnionArray::try_new(
5265            fields.clone(),
5266            type_ids,
5267            None,
5268            vec![
5269                Arc::new(int_array) as ArrayRef,
5270                Arc::new(string_array) as ArrayRef,
5271            ],
5272        )
5273        .unwrap();
5274
5275        let field = Field::new("col", DataType::Union(fields, UnionMode::Sparse), true);
5276        let sort_field = SortField::new(field.data_type().clone());
5277        let converter = RowConverter::new(vec![sort_field]).unwrap();
5278
5279        let rows = converter
5280            .convert_columns(&[Arc::new(union_array.clone()) as ArrayRef])
5281            .unwrap();
5282
5283        // roundtrip
5284        let out = converter.convert_rows(&rows).unwrap();
5285
5286        let [col1] = out.as_slice() else {
5287            panic!("expected 1 column")
5288        };
5289
5290        let col = col1.as_any().downcast_ref::<UnionArray>().unwrap();
5291        assert_eq!(col.len(), union_array.len());
5292        assert_eq!(col.type_ids(), union_array.type_ids());
5293
5294        for i in 0..col.len() {
5295            assert_eq!(col.value(i).as_ref(), union_array.value(i).as_ref());
5296        }
5297    }
5298
5299    #[test]
5300    fn rows_size_should_count_for_capacity() {
5301        let row_converter = RowConverter::new(vec![SortField::new(DataType::UInt8)]).unwrap();
5302
5303        let empty_rows_size_with_preallocate_rows_and_data = {
5304            let rows = row_converter.empty_rows(1000, 1000);
5305
5306            rows.size()
5307        };
5308        let empty_rows_size_with_preallocate_rows = {
5309            let rows = row_converter.empty_rows(1000, 0);
5310
5311            rows.size()
5312        };
5313        let empty_rows_size_with_preallocate_data = {
5314            let rows = row_converter.empty_rows(0, 1000);
5315
5316            rows.size()
5317        };
5318        let empty_rows_size_without_preallocate = {
5319            let rows = row_converter.empty_rows(0, 0);
5320
5321            rows.size()
5322        };
5323
5324        assert!(
5325            empty_rows_size_with_preallocate_rows_and_data > empty_rows_size_with_preallocate_rows,
5326            "{empty_rows_size_with_preallocate_rows_and_data} should be larger than {empty_rows_size_with_preallocate_rows}"
5327        );
5328        assert!(
5329            empty_rows_size_with_preallocate_rows_and_data > empty_rows_size_with_preallocate_data,
5330            "{empty_rows_size_with_preallocate_rows_and_data} should be larger than {empty_rows_size_with_preallocate_data}"
5331        );
5332        assert!(
5333            empty_rows_size_with_preallocate_rows > empty_rows_size_without_preallocate,
5334            "{empty_rows_size_with_preallocate_rows} should be larger than {empty_rows_size_without_preallocate}"
5335        );
5336        assert!(
5337            empty_rows_size_with_preallocate_data > empty_rows_size_without_preallocate,
5338            "{empty_rows_size_with_preallocate_data} should be larger than {empty_rows_size_without_preallocate}"
5339        );
5340    }
5341
5342    #[test]
5343    fn test_struct_no_child_fields() {
5344        fn run_test(array: ArrayRef) {
5345            let sort_fields = vec![SortField::new(array.data_type().clone())];
5346            let converter = RowConverter::new(sort_fields).unwrap();
5347            let r = converter.convert_columns(&[Arc::clone(&array)]).unwrap();
5348
5349            let back = converter.convert_rows(&r).unwrap();
5350            assert_eq!(back.len(), 1);
5351            assert_eq!(&back[0], &array);
5352        }
5353
5354        let s = Arc::new(StructArray::new_empty_fields(5, None)) as ArrayRef;
5355        run_test(s);
5356
5357        let s = Arc::new(StructArray::new_empty_fields(
5358            5,
5359            Some(vec![true, false, true, false, false].into()),
5360        )) as ArrayRef;
5361        run_test(s);
5362    }
5363
5364    #[test]
5365    fn reserve_should_increase_capacity_to_the_requested_size() {
5366        let row_converter = RowConverter::new(vec![SortField::new(DataType::UInt8)]).unwrap();
5367        let mut empty_rows = row_converter.empty_rows(0, 0);
5368        empty_rows.reserve(50, 50);
5369        let before_size = empty_rows.size();
5370        empty_rows.reserve(50, 50);
5371        assert_eq!(
5372            empty_rows.size(),
5373            before_size,
5374            "Size should not change when reserving already reserved space"
5375        );
5376        empty_rows.reserve(10, 20);
5377        assert_eq!(
5378            empty_rows.size(),
5379            before_size,
5380            "Size should not change when already have space for the expected reserved data"
5381        );
5382
5383        empty_rows.reserve(100, 20);
5384        assert!(
5385            empty_rows.size() > before_size,
5386            "Size should increase when reserving more space than previously reserved"
5387        );
5388
5389        let before_size = empty_rows.size();
5390
5391        empty_rows.reserve(20, 100);
5392        assert!(
5393            empty_rows.size() > before_size,
5394            "Size should increase when reserving more space than previously reserved"
5395        );
5396    }
5397
5398    #[test]
5399    fn empty_rows_should_return_empty_lengths_iterator() {
5400        let rows = RowConverter::new(vec![SortField::new(DataType::UInt8)])
5401            .unwrap()
5402            .empty_rows(0, 0);
5403        let mut lengths_iter = rows.lengths();
5404        assert_eq!(lengths_iter.next(), None);
5405    }
5406
5407    #[test]
5408    fn test_nested_null_list() {
5409        let null_array = Arc::new(NullArray::new(3));
5410        // [[NULL], [], [NULL, NULL]]
5411        let list: ArrayRef = Arc::new(ListArray::new(
5412            Field::new_list_field(DataType::Null, true).into(),
5413            OffsetBuffer::from_lengths(vec![1, 0, 2]),
5414            null_array,
5415            None,
5416        ));
5417
5418        let converter = RowConverter::new(vec![SortField::new(list.data_type().clone())]).unwrap();
5419        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
5420        let back = converter.convert_rows(&rows).unwrap();
5421
5422        assert_eq!(&list, &back[0]);
5423    }
5424
5425    // Test case from original issue #9227: [[NULL]] - double nested List with Null
5426    #[test]
5427    fn test_double_nested_null_list() {
5428        let null_array = Arc::new(NullArray::new(1));
5429        // [NULL]
5430        let nested_field = Arc::new(Field::new_list_field(DataType::Null, true));
5431        let nested_list = Arc::new(ListArray::new(
5432            nested_field.clone(),
5433            OffsetBuffer::from_lengths(vec![1]),
5434            null_array,
5435            None,
5436        ));
5437        // [[NULL]]
5438        let list = Arc::new(ListArray::new(
5439            Field::new_list_field(DataType::List(nested_field), true).into(),
5440            OffsetBuffer::from_lengths(vec![1]),
5441            nested_list,
5442            None,
5443        )) as ArrayRef;
5444
5445        let converter = RowConverter::new(vec![SortField::new(list.data_type().clone())]).unwrap();
5446        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
5447        let back = converter.convert_rows(&rows).unwrap();
5448
5449        assert_eq!(&list, &back[0]);
5450    }
5451
5452    // Test LargeList<Null>
5453    #[test]
5454    fn test_large_list_null() {
5455        let null_array = Arc::new(NullArray::new(3));
5456        // [[NULL], [], [NULL, NULL]] as LargeList
5457        let list: ArrayRef = Arc::new(LargeListArray::new(
5458            Field::new_list_field(DataType::Null, true).into(),
5459            OffsetBuffer::from_lengths(vec![1, 0, 2]),
5460            null_array,
5461            None,
5462        ));
5463
5464        let converter = RowConverter::new(vec![SortField::new(list.data_type().clone())]).unwrap();
5465        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
5466        let back = converter.convert_rows(&rows).unwrap();
5467
5468        assert_eq!(&list, &back[0]);
5469    }
5470
5471    // Test FixedSizeList<Null>
5472    #[test]
5473    fn test_fixed_size_list_null() {
5474        let null_array = Arc::new(NullArray::new(6));
5475        // [[NULL, NULL], [NULL, NULL], [NULL, NULL]] as FixedSizeList
5476        let list: ArrayRef = Arc::new(FixedSizeListArray::new(
5477            Arc::new(Field::new_list_field(DataType::Null, true)),
5478            2,
5479            null_array,
5480            None,
5481        ));
5482
5483        let converter = RowConverter::new(vec![SortField::new(list.data_type().clone())]).unwrap();
5484        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
5485        let back = converter.convert_rows(&rows).unwrap();
5486
5487        assert_eq!(&list, &back[0]);
5488    }
5489
5490    // Test List<Null> with various combinations of nulls and empty lists
5491    #[test]
5492    fn test_list_null_variations() {
5493        // Test case: [[NULL], [], [NULL, NULL]]
5494        let null_array = Arc::new(NullArray::new(3));
5495        let list: ArrayRef = Arc::new(ListArray::new(
5496            Field::new_list_field(DataType::Null, true).into(),
5497            OffsetBuffer::from_lengths(vec![1, 0, 2]),
5498            null_array,
5499            None,
5500        ));
5501
5502        let converter = RowConverter::new(vec![SortField::new(list.data_type().clone())]).unwrap();
5503        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
5504        let back = converter.convert_rows(&rows).unwrap();
5505        assert_eq!(&list, &back[0]);
5506
5507        // Test case: [[NULL], null, [NULL, NULL]] - middle element is null
5508        let null_array = Arc::new(NullArray::new(3));
5509        let list: ArrayRef = Arc::new(ListArray::new(
5510            Field::new_list_field(DataType::Null, true).into(),
5511            OffsetBuffer::from_lengths(vec![1, 0, 2]),
5512            null_array,
5513            Some(vec![true, false, true].into()),
5514        ));
5515
5516        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
5517        let back = converter.convert_rows(&rows).unwrap();
5518        assert_eq!(&list, &back[0]);
5519
5520        // Test case: [] - empty list
5521        let null_array = Arc::new(NullArray::new(0));
5522        let list: ArrayRef = Arc::new(ListArray::new(
5523            Field::new_list_field(DataType::Null, true).into(),
5524            OffsetBuffer::from_lengths(vec![]),
5525            null_array,
5526            None,
5527        ));
5528
5529        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
5530        let back = converter.convert_rows(&rows).unwrap();
5531        assert_eq!(&list, &back[0]);
5532
5533        // Test case: [[], [], []] - all empty sublists
5534        let null_array = Arc::new(NullArray::new(0));
5535        let list: ArrayRef = Arc::new(ListArray::new(
5536            Field::new_list_field(DataType::Null, true).into(),
5537            OffsetBuffer::from_lengths(vec![0, 0, 0]),
5538            null_array,
5539            None,
5540        ));
5541
5542        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
5543        let back = converter.convert_rows(&rows).unwrap();
5544        assert_eq!(&list, &back[0]);
5545    }
5546
5547    // Test List<Null> with descending order
5548    #[test]
5549    fn test_list_null_descending() {
5550        let null_array = Arc::new(NullArray::new(3));
5551        // [[NULL], [], [NULL, NULL]]
5552        let list: ArrayRef = Arc::new(ListArray::new(
5553            Field::new_list_field(DataType::Null, true).into(),
5554            OffsetBuffer::from_lengths(vec![1, 0, 2]),
5555            null_array,
5556            None,
5557        ));
5558
5559        let options = SortOptions::default().with_descending(true);
5560        let field = SortField::new_with_options(list.data_type().clone(), options);
5561        let converter = RowConverter::new(vec![field]).unwrap();
5562        let rows = converter.convert_columns(&[Arc::clone(&list)]).unwrap();
5563        let back = converter.convert_rows(&rows).unwrap();
5564
5565        assert_eq!(&list, &back[0]);
5566    }
5567
5568    // Test Struct with Null field
5569    #[test]
5570    fn test_struct_with_null_field() {
5571        // Struct { a: Null, b: Int32 }
5572        let null_array = Arc::new(NullArray::new(3));
5573        let int_array = Arc::new(Int32Array::from(vec![1, 2, 3]));
5574
5575        let struct_array: ArrayRef = Arc::new(StructArray::new(
5576            vec![
5577                Arc::new(Field::new("a", DataType::Null, true)),
5578                Arc::new(Field::new("b", DataType::Int32, true)),
5579            ]
5580            .into(),
5581            vec![null_array, int_array],
5582            Some(vec![true, true, false].into()), // validity bitmap
5583        ));
5584
5585        let converter =
5586            RowConverter::new(vec![SortField::new(struct_array.data_type().clone())]).unwrap();
5587        let rows = converter
5588            .convert_columns(&[Arc::clone(&struct_array)])
5589            .unwrap();
5590        let back = converter.convert_rows(&rows).unwrap();
5591
5592        assert_eq!(&struct_array, &back[0]);
5593    }
5594
5595    // Test nested Struct with Null
5596    #[test]
5597    fn test_nested_struct_with_null() {
5598        // Inner struct: { x: Null }
5599        let inner_null = Arc::new(NullArray::new(2));
5600        let inner_struct = Arc::new(StructArray::new(
5601            vec![Arc::new(Field::new("x", DataType::Null, true))].into(),
5602            vec![inner_null],
5603            None,
5604        ));
5605
5606        // Outer struct: { inner: Struct { x: Null }, y: Int32 }
5607        let y_array = Arc::new(Int32Array::from(vec![10, 20]));
5608        let outer_struct: ArrayRef = Arc::new(StructArray::new(
5609            vec![
5610                Arc::new(Field::new("inner", inner_struct.data_type().clone(), true)),
5611                Arc::new(Field::new("y", DataType::Int32, true)),
5612            ]
5613            .into(),
5614            vec![inner_struct, y_array],
5615            None,
5616        ));
5617
5618        let converter =
5619            RowConverter::new(vec![SortField::new(outer_struct.data_type().clone())]).unwrap();
5620        let rows = converter
5621            .convert_columns(&[Arc::clone(&outer_struct)])
5622            .unwrap();
5623        let back = converter.convert_rows(&rows).unwrap();
5624
5625        assert_eq!(&outer_struct, &back[0]);
5626    }
5627
5628    // Test Map<Null> - verify it's not supported (as per current implementation)
5629    // https://github.com/apache/arrow-rs/issues/7879
5630    #[test]
5631    fn test_map_null_not_supported() {
5632        // Map with Null values
5633        let map_data_type = Field::new_map(
5634            "map",
5635            "entries",
5636            Field::new("key", DataType::Utf8, false),
5637            Field::new("value", DataType::Null, true),
5638            false,
5639            true,
5640        )
5641        .data_type()
5642        .clone();
5643
5644        // Currently Map is not supported by RowConverter
5645        let result = RowConverter::new(vec![SortField::new(map_data_type)]);
5646        assert!(
5647            result.is_err(),
5648            "Map should not be supported by RowConverter"
5649        );
5650        assert!(
5651            result
5652                .unwrap_err()
5653                .to_string()
5654                .contains("not yet implemented")
5655        );
5656    }
5657
5658    #[test]
5659    fn empty_row_iter_next_back() {
5660        let rows = RowConverter::new(vec![SortField::new(DataType::UInt8)])
5661            .unwrap()
5662            .empty_rows(0, 0);
5663        let mut rows_iter = rows.iter();
5664        assert_eq!(rows_iter.next_back(), None);
5665        assert_eq!(rows_iter.next_back(), None);
5666        assert_eq!(rows_iter.next_back(), None);
5667    }
5668
5669    #[test]
5670    fn row_iter_next_back() {
5671        let row_converter = RowConverter::new(vec![SortField::new(DataType::UInt8)]).unwrap();
5672        let mut rng = StdRng::seed_from_u64(42);
5673        let array = generate_primitive_array::<UInt8Type>(&mut rng, 100, 0.8);
5674        let rows = row_converter.convert_columns(&[Arc::new(array)]).unwrap();
5675
5676        let mut rows_iter = rows.iter();
5677        let mut bytes: Vec<u8> = vec![];
5678
5679        while let Some(row) = rows_iter.next_back() {
5680            bytes.extend(row.data.iter().rev());
5681        }
5682
5683        bytes.reverse();
5684
5685        assert_eq!(
5686            bytes,
5687            &rows.buffer.as_slice()[..*rows.offsets.last().unwrap()]
5688        );
5689
5690        assert_eq!(rows_iter.next_back(), None);
5691        assert_eq!(rows_iter.next(), None);
5692    }
5693}