52 lines
1.5 KiB
Rust
52 lines
1.5 KiB
Rust
use lzma_rs::decompress::{Options, Stream, UnpackedSize};
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use std::collections::VecDeque;
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use std::io::{copy, Error, Read, Result, Write};
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const COMPRESSED_BYTES_TO_BUFFER: usize = 4096;
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const OPTIONS: Options = Options {
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unpacked_size: UnpackedSize::ReadFromHeader,
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memlimit: None,
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allow_incomplete: true,
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};
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#[derive(Debug)]
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pub struct LzmaDecoder<R> {
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compressed_reader: R,
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stream: Stream<VecDeque<u8>>,
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}
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impl<R: Read> LzmaDecoder<R> {
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pub fn new(inner: R) -> Self {
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LzmaDecoder {
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compressed_reader: inner,
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stream: Stream::new_with_options(&OPTIONS, VecDeque::new()),
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}
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}
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pub fn finish(mut self) -> Result<VecDeque<u8>> {
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copy(&mut self.compressed_reader, &mut self.stream)?;
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self.stream.finish().map_err(Error::from)
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}
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}
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impl<R: Read> Read for LzmaDecoder<R> {
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fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
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let mut bytes_read = self.stream.get_output_mut().unwrap().read(buf)?;
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while bytes_read < buf.len() {
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let mut next_compressed = [0u8; COMPRESSED_BYTES_TO_BUFFER];
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let compressed_bytes_read = self.compressed_reader.read(&mut next_compressed)?;
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if compressed_bytes_read == 0 {
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break;
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}
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self.stream
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.write_all(&next_compressed[..compressed_bytes_read])?;
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bytes_read += self
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.stream
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.get_output_mut()
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.unwrap()
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.read(&mut buf[bytes_read..])?;
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}
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Ok(bytes_read)
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}
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}
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