arrow_select/coalesce/
primitive.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
3// distributed with this work for additional information
4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License.  You may obtain a copy of the License at
8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
12// software distributed under the License is distributed on an
13// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18use crate::coalesce::InProgressArray;
19use arrow_array::cast::AsArray;
20use arrow_array::{Array, ArrayRef, ArrowPrimitiveType, PrimitiveArray};
21use arrow_buffer::{NullBufferBuilder, ScalarBuffer};
22use arrow_schema::{ArrowError, DataType};
23use std::fmt::Debug;
24use std::sync::Arc;
25
26/// InProgressArray for [`PrimitiveArray`]
27#[derive(Debug)]
28pub(crate) struct InProgressPrimitiveArray<T: ArrowPrimitiveType> {
29    /// Data type of the array
30    data_type: DataType,
31    /// The current source, if any
32    source: Option<ArrayRef>,
33    /// the target batch size (and thus size for views allocation)
34    batch_size: usize,
35    /// In progress nulls
36    nulls: NullBufferBuilder,
37    /// The currently in progress array
38    current: Vec<T::Native>,
39}
40
41impl<T: ArrowPrimitiveType> InProgressPrimitiveArray<T> {
42    /// Create a new `InProgressPrimitiveArray`
43    pub(crate) fn new(batch_size: usize, data_type: DataType) -> Self {
44        Self {
45            data_type,
46            batch_size,
47            source: None,
48            nulls: NullBufferBuilder::new(batch_size),
49            current: vec![],
50        }
51    }
52
53    /// Allocate space for output values if necessary.
54    ///
55    /// This is done on write (when we know it is necessary) rather than
56    /// eagerly to avoid allocations that are not used.
57    fn ensure_capacity(&mut self) {
58        if self.current.capacity() == 0 {
59            self.current.reserve(self.batch_size);
60        }
61    }
62}
63
64impl<T: ArrowPrimitiveType + Debug> InProgressArray for InProgressPrimitiveArray<T> {
65    fn set_source(&mut self, source: Option<ArrayRef>) {
66        self.source = source;
67    }
68
69    fn copy_rows(&mut self, offset: usize, len: usize) -> Result<(), ArrowError> {
70        self.ensure_capacity();
71
72        let s = self
73            .source
74            .as_ref()
75            .ok_or_else(|| {
76                ArrowError::InvalidArgumentError(
77                    "Internal Error: InProgressPrimitiveArray: source not set".to_string(),
78                )
79            })?
80            .as_primitive::<T>();
81
82        // add nulls if necessary
83        if let Some(nulls) = s.nulls().as_ref() {
84            let nulls = nulls.slice(offset, len);
85            self.nulls.append_buffer(&nulls);
86        } else {
87            self.nulls.append_n_non_nulls(len);
88        };
89
90        // Copy the values
91        self.current
92            .extend_from_slice(&s.values()[offset..offset + len]);
93
94        Ok(())
95    }
96
97    fn finish(&mut self) -> Result<ArrayRef, ArrowError> {
98        // take and reset the current values and nulls
99        let values = std::mem::take(&mut self.current);
100        let nulls = self.nulls.finish();
101        self.nulls = NullBufferBuilder::new(self.batch_size);
102
103        let array = PrimitiveArray::<T>::try_new(ScalarBuffer::from(values), nulls)?
104            // preserve timezone / precision+scale if applicable
105            .with_data_type(self.data_type.clone());
106        Ok(Arc::new(array))
107    }
108}
arrow_select/coalesce/primitive.rs

arrow_select/coalesce/
primitive.rs
