reed_solomon_simd/
decoder_result.rs

1use crate::rate::DecoderWork;
2
3// ======================================================================
4// DecoderResult - PUBLIC
5
6/// Result of decoding. Contains the restored original shards.
7///
8/// This struct is created by [`ReedSolomonDecoder::decode`]
9/// and [`RateDecoder::decode`].
10///
11/// [`RateDecoder::decode`]: crate::rate::RateDecoder::decode
12/// [`ReedSolomonDecoder::decode`]: crate::ReedSolomonDecoder::decode
13pub struct DecoderResult<'a> {
14    work: &'a mut DecoderWork,
15}
16
17impl DecoderResult<'_> {
18    /// Returns restored original shard with given `index`
19    /// or `None` if given `index` doesn't correspond to
20    /// a missing original shard.
21    pub fn restored_original(&self, index: usize) -> Option<&[u8]> {
22        self.work.restored_original(index)
23    }
24
25    /// Returns iterator over all restored original shards
26    /// and their indexes, ordered by indexes.
27    pub fn restored_original_iter(&self) -> RestoredOriginal {
28        RestoredOriginal::new(self.work)
29    }
30}
31
32// ======================================================================
33// DecoderResult - CRATE
34
35impl<'a> DecoderResult<'a> {
36    pub(crate) fn new(work: &'a mut DecoderWork) -> Self {
37        Self { work }
38    }
39}
40
41// ======================================================================
42// DecoderResult - IMPL DROP
43
44impl Drop for DecoderResult<'_> {
45    fn drop(&mut self) {
46        self.work.reset_received();
47    }
48}
49
50// ======================================================================
51// RestoredOriginal - PUBLIC
52
53/// Iterator over restored original shards and their indexes.
54///
55/// This struct is created by [`DecoderResult::restored_original_iter`].
56pub struct RestoredOriginal<'a> {
57    ended: bool,
58    next_index: usize,
59    work: &'a DecoderWork,
60}
61
62// ======================================================================
63// RestoredOriginal - IMPL Iterator
64
65impl<'a> Iterator for RestoredOriginal<'a> {
66    type Item = (usize, &'a [u8]);
67    fn next(&mut self) -> Option<(usize, &'a [u8])> {
68        if self.ended {
69            None
70        } else {
71            let mut index = self.next_index;
72            while index < self.work.original_count() {
73                if let Some(original) = self.work.restored_original(index) {
74                    self.next_index = index + 1;
75                    return Some((index, original));
76                }
77                index += 1;
78            }
79            self.ended = true;
80            None
81        }
82    }
83}
84
85// ======================================================================
86// RestoredOriginal - CRATE
87
88impl<'a> RestoredOriginal<'a> {
89    pub(crate) fn new(work: &'a DecoderWork) -> Self {
90        Self {
91            ended: false,
92            next_index: 0,
93            work,
94        }
95    }
96}
97
98// ======================================================================
99// TESTS
100
101#[cfg(test)]
102mod tests {
103    use super::*;
104    use crate::{test_util, ReedSolomonDecoder, ReedSolomonEncoder};
105
106    fn simple_roundtrip(shard_size: usize) {
107        let original = test_util::generate_original(3, shard_size, 0);
108
109        let mut encoder = ReedSolomonEncoder::new(3, 2, shard_size).unwrap();
110        let mut decoder = ReedSolomonDecoder::new(3, 2, shard_size).unwrap();
111
112        for original in &original {
113            encoder.add_original_shard(original).unwrap();
114        }
115
116        let result = encoder.encode().unwrap();
117        let recovery: Vec<_> = result.recovery_iter().collect();
118
119        assert!(recovery.iter().all(|slice| slice.len() == shard_size));
120
121        decoder.add_original_shard(1, &original[1]).unwrap();
122        decoder.add_recovery_shard(0, recovery[0]).unwrap();
123        decoder.add_recovery_shard(1, recovery[1]).unwrap();
124
125        let result: DecoderResult = decoder.decode().unwrap();
126
127        assert_eq!(result.restored_original(0).unwrap(), original[0]);
128        assert!(result.restored_original(1).is_none());
129        assert_eq!(result.restored_original(2).unwrap(), original[2]);
130        assert!(result.restored_original(3).is_none());
131
132        let mut iter: RestoredOriginal = result.restored_original_iter();
133        assert_eq!(iter.next(), Some((0, original[0].as_slice())));
134        assert_eq!(iter.next(), Some((2, original[2].as_slice())));
135        assert_eq!(iter.next(), None);
136        assert_eq!(iter.next(), None);
137    }
138
139    #[test]
140    // DecoderResult::restored_original
141    // DecoderResult::restored_original_iter
142    // RestoredOriginal
143    fn decoder_result() {
144        simple_roundtrip(1024);
145    }
146
147    #[test]
148    fn shard_size_not_divisible_by_64() {
149        for shard_size in [2, 4, 6, 30, 32, 34, 62, 64, 66, 126, 128, 130] {
150            simple_roundtrip(shard_size);
151        }
152    }
153}
reed_solomon_simd/decoder_result.rs

reed_solomon_simd/
decoder_result.rs
