compression_codecs/xz2/
decoder.rs

1use crate::{lzma::params::LzmaDecoderParams, xz2::process_stream, DecodeV2, DecodedSize};
2use compression_core::util::{PartialBuffer, WriteBuffer};
3use liblzma::stream::{Action, Stream};
4use std::{
5    convert::TryFrom,
6    fmt,
7    io::{self, Cursor},
8};
9
10/// Xz2 decoding stream
11pub struct Xz2Decoder {
12    stream: Stream,
13    params: LzmaDecoderParams,
14}
15
16impl fmt::Debug for Xz2Decoder {
17    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
18        f.debug_struct("Xz2Decoder").finish_non_exhaustive()
19    }
20}
21
22impl TryFrom<LzmaDecoderParams> for Xz2Decoder {
23    type Error = liblzma::stream::Error;
24
25    fn try_from(params: LzmaDecoderParams) -> Result<Self, Self::Error> {
26        let stream = Stream::try_from(&params)?;
27        Ok(Self { stream, params })
28    }
29}
30
31impl Xz2Decoder {
32    pub fn new(mem_limit: u64) -> Self {
33        let params = LzmaDecoderParams::Auto {
34            mem_limit,
35            flags: 0,
36        };
37        Self::try_from(params).unwrap()
38    }
39
40    #[cfg(feature = "xz-parallel")]
41    pub fn parallel(threads: std::num::NonZeroU32, mem_limit: u64) -> Self {
42        use crate::lzma::params::MtStreamBuilder;
43
44        let mut builder = MtStreamBuilder::default();
45
46        builder
47            .threads(threads)
48            .timeout_ms(300)
49            .mem_limit_stop(mem_limit);
50
51        let params = LzmaDecoderParams::MultiThread { builder };
52
53        Self::try_from(params).unwrap()
54    }
55}
56
57impl DecodeV2 for Xz2Decoder {
58    fn reinit(&mut self) -> io::Result<()> {
59        *self = Self::try_from(self.params.clone())?;
60        Ok(())
61    }
62
63    fn decode(
64        &mut self,
65        input: &mut PartialBuffer<&[u8]>,
66        output: &mut WriteBuffer<'_>,
67    ) -> io::Result<bool> {
68        process_stream(&mut self.stream, input, output, Action::Run)
69    }
70
71    fn flush(&mut self, _output: &mut WriteBuffer<'_>) -> io::Result<bool> {
72        // While decoding flush is a noop
73        Ok(true)
74    }
75
76    fn finish(&mut self, output: &mut WriteBuffer<'_>) -> io::Result<bool> {
77        process_stream(
78            &mut self.stream,
79            &mut PartialBuffer::new(&[]),
80            output,
81            Action::Finish,
82        )
83    }
84}
85
86impl DecodedSize for Xz2Decoder {
87    fn decoded_size(input: &[u8]) -> io::Result<u64> {
88        let cursor = Cursor::new(input);
89        liblzma::uncompressed_size(cursor)
90    }
91}
92
93#[cfg(test)]
94mod tests {
95    use std::convert::TryFrom;
96
97    use crate::{
98        lzma::params::{LzmaDecoderParams, LzmaFilter, LzmaFilters, LzmaOptions},
99        Xz2Decoder,
100    };
101
102    #[test]
103    fn test_lzma_decoder_from_params() {
104        let filters = LzmaFilters::default().add_filter(LzmaFilter::Lzma2(LzmaOptions::default()));
105        let params = LzmaDecoderParams::Raw { filters };
106        Xz2Decoder::try_from(params).unwrap();
107    }
108}
compression_codecs/xz2/decoder.rs

compression_codecs/xz2/
decoder.rs
