compression_codecs/xz2/
decoder.rs

1use crate::{lzma::params::LzmaDecoderParams, Decode};
2use compression_core::util::PartialBuffer;
3use liblzma::stream::{Action, Status, Stream};
4use std::{convert::TryFrom, fmt, io};
5
6/// Xz2 decoding stream
7pub struct Xz2Decoder {
8    stream: Stream,
9    params: LzmaDecoderParams,
10}
11
12impl fmt::Debug for Xz2Decoder {
13    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
14        f.debug_struct("Xz2Decoder").finish_non_exhaustive()
15    }
16}
17
18impl TryFrom<LzmaDecoderParams> for Xz2Decoder {
19    type Error = liblzma::stream::Error;
20
21    fn try_from(params: LzmaDecoderParams) -> Result<Self, Self::Error> {
22        let stream = Stream::try_from(&params)?;
23        Ok(Self { stream, params })
24    }
25}
26
27impl Xz2Decoder {
28    pub fn new(mem_limit: u64) -> Self {
29        let params = LzmaDecoderParams::Auto {
30            mem_limit,
31            flags: 0,
32        };
33        Self::try_from(params).unwrap()
34    }
35
36    #[cfg(feature = "xz-parallel")]
37    pub fn parallel(threads: std::num::NonZeroU32, mem_limit: u64) -> Self {
38        use crate::lzma::params::MtStreamBuilder;
39
40        let mut builder = MtStreamBuilder::default();
41
42        builder
43            .threads(threads)
44            .timeout_ms(300)
45            .mem_limit_stop(mem_limit);
46
47        let params = LzmaDecoderParams::MultiThread { builder };
48
49        Self::try_from(params).unwrap()
50    }
51}
52
53impl Decode for Xz2Decoder {
54    fn reinit(&mut self) -> io::Result<()> {
55        *self = Self::try_from(self.params.clone())?;
56        Ok(())
57    }
58
59    fn decode(
60        &mut self,
61        input: &mut PartialBuffer<impl AsRef<[u8]>>,
62        output: &mut PartialBuffer<impl AsRef<[u8]> + AsMut<[u8]>>,
63    ) -> io::Result<bool> {
64        let previous_in = self.stream.total_in() as usize;
65        let previous_out = self.stream.total_out() as usize;
66
67        let status = self
68            .stream
69            .process(input.unwritten(), output.unwritten_mut(), Action::Run)?;
70
71        input.advance(self.stream.total_in() as usize - previous_in);
72        output.advance(self.stream.total_out() as usize - previous_out);
73
74        match status {
75            Status::Ok => Ok(false),
76            Status::StreamEnd => Ok(true),
77            Status::GetCheck => Err(io::Error::other("Unexpected lzma integrity check")),
78            Status::MemNeeded => Err(io::Error::other("More memory needed")),
79        }
80    }
81
82    fn flush(
83        &mut self,
84        _output: &mut PartialBuffer<impl AsRef<[u8]> + AsMut<[u8]>>,
85    ) -> io::Result<bool> {
86        // While decoding flush is a noop
87        Ok(true)
88    }
89
90    fn finish(
91        &mut self,
92        output: &mut PartialBuffer<impl AsRef<[u8]> + AsMut<[u8]>>,
93    ) -> io::Result<bool> {
94        let previous_out = self.stream.total_out() as usize;
95
96        let status = self
97            .stream
98            .process(&[], output.unwritten_mut(), Action::Finish)?;
99
100        output.advance(self.stream.total_out() as usize - previous_out);
101
102        match status {
103            Status::Ok => Ok(false),
104            Status::StreamEnd => Ok(true),
105            Status::GetCheck => Err(io::Error::other("Unexpected lzma integrity check")),
106            Status::MemNeeded => Err(io::Error::other("More memory needed")),
107        }
108    }
109}
110
111#[cfg(test)]
112mod tests {
113    use std::convert::TryFrom;
114
115    use crate::{
116        lzma::params::{LzmaDecoderParams, LzmaFilter, LzmaFilters, LzmaOptions},
117        Xz2Decoder,
118    };
119
120    #[test]
121    fn test_lzma_decoder_from_params() {
122        let filters = LzmaFilters::default().add_filter(LzmaFilter::Lzma2(LzmaOptions::default()));
123        let params = LzmaDecoderParams::Raw { filters };
124        Xz2Decoder::try_from(params).unwrap();
125    }
126}
compression_codecs/xz2/decoder.rs

compression_codecs/xz2/
decoder.rs
