arrow_json/reader/
decimal_array.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 std::marker::PhantomData;
19use std::sync::Arc;
20
21use arrow_array::ArrayRef;
22use arrow_array::builder::PrimitiveBuilder;
23use arrow_array::types::DecimalType;
24use arrow_cast::parse::parse_decimal;
25use arrow_schema::ArrowError;
26
27use crate::reader::tape::{Tape, TapeElement};
28use crate::reader::{ArrayDecoder, DecoderContext};
29
30pub struct DecimalArrayDecoder<D: DecimalType> {
31    precision: u8,
32    scale: i8,
33    ignore_type_conflicts: bool,
34    // Invariant and Send
35    phantom: PhantomData<fn(D) -> D>,
36}
37
38impl<D: DecimalType> DecimalArrayDecoder<D> {
39    pub fn new(ctx: &DecoderContext, precision: u8, scale: i8) -> Self {
40        Self {
41            precision,
42            scale,
43            ignore_type_conflicts: ctx.ignore_type_conflicts(),
44            phantom: PhantomData,
45        }
46    }
47}
48
49impl<D> ArrayDecoder for DecimalArrayDecoder<D>
50where
51    D: DecimalType,
52{
53    fn decode(&mut self, tape: &Tape<'_>, pos: &[u32]) -> Result<ArrayRef, ArrowError> {
54        let mut builder = PrimitiveBuilder::<D>::with_capacity(pos.len());
55
56        #[allow(unused)] // initial value overwritten without ever being read
57        let mut anchor = String::default();
58        for p in pos {
59            let value = match tape.get(*p) {
60                TapeElement::Null => {
61                    builder.append_null();
62                    continue;
63                }
64                TapeElement::String(idx) | TapeElement::Number(idx) => tape.get_string(idx),
65                TapeElement::I64(high) => match tape.get(*p + 1) {
66                    TapeElement::I32(low) => {
67                        anchor = (((high as i64) << 32) | (low as u32) as i64).to_string();
68                        anchor.as_str()
69                    }
70                    _ => unreachable!(),
71                },
72                TapeElement::I32(val) => {
73                    anchor = val.to_string();
74                    anchor.as_str()
75                }
76                TapeElement::F64(high) => match tape.get(*p + 1) {
77                    TapeElement::F32(low) => {
78                        anchor = f64::from_bits(((high as u64) << 32) | low as u64).to_string();
79                        anchor.as_str()
80                    }
81                    _ => unreachable!(),
82                },
83                TapeElement::F32(val) => {
84                    anchor = f32::from_bits(val).to_string();
85                    anchor.as_str()
86                }
87                _ if self.ignore_type_conflicts => {
88                    builder.append_null();
89                    continue;
90                }
91                _ => return Err(tape.error(*p, "decimal")),
92            };
93
94            match parse_decimal::<D>(value, self.precision, self.scale) {
95                Ok(value) => builder.append_value(value),
96                Err(_) if self.ignore_type_conflicts => builder.append_null(),
97                Err(e) => return Err(e),
98            }
99        }
100
101        Ok(Arc::new(
102            builder
103                .finish()
104                .with_precision_and_scale(self.precision, self.scale)?,
105        ))
106    }
107}
arrow_json/reader/decimal_array.rs

arrow_json/reader/
decimal_array.rs
