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Diffstat (limited to 'third_party/rust/flate2/src/zlib/bufread.rs')
| -rw-r--r-- | third_party/rust/flate2/src/zlib/bufread.rs | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/third_party/rust/flate2/src/zlib/bufread.rs b/third_party/rust/flate2/src/zlib/bufread.rs new file mode 100644 index 0000000000..f1d3231651 --- /dev/null +++ b/third_party/rust/flate2/src/zlib/bufread.rs @@ -0,0 +1,233 @@ +use std::io; +use std::io::prelude::*; +use std::mem; + +use crate::zio; +use crate::{Compress, Decompress}; + +/// A ZLIB encoder, or compressor. +/// +/// This structure consumes a [`BufRead`] interface, reading uncompressed data +/// from the underlying reader, and emitting compressed data. +/// +/// [`BufRead`]: https://doc.rust-lang.org/std/io/trait.BufRead.html +/// +/// # Examples +/// +/// ``` +/// use std::io::prelude::*; +/// use flate2::Compression; +/// use flate2::bufread::ZlibEncoder; +/// use std::fs::File; +/// use std::io::BufReader; +/// +/// // Use a buffered file to compress contents into a Vec<u8> +/// +/// # fn open_hello_world() -> std::io::Result<Vec<u8>> { +/// let f = File::open("examples/hello_world.txt")?; +/// let b = BufReader::new(f); +/// let mut z = ZlibEncoder::new(b, Compression::fast()); +/// let mut buffer = Vec::new(); +/// z.read_to_end(&mut buffer)?; +/// # Ok(buffer) +/// # } +/// ``` +#[derive(Debug)] +pub struct ZlibEncoder<R> { + obj: R, + data: Compress, +} + +impl<R: BufRead> ZlibEncoder<R> { + /// Creates a new encoder which will read uncompressed data from the given + /// stream and emit the compressed stream. + pub fn new(r: R, level: crate::Compression) -> ZlibEncoder<R> { + ZlibEncoder { + obj: r, + data: Compress::new(level, true), + } + } +} + +pub fn reset_encoder_data<R>(zlib: &mut ZlibEncoder<R>) { + zlib.data.reset() +} + +impl<R> ZlibEncoder<R> { + /// Resets the state of this encoder entirely, swapping out the input + /// stream for another. + /// + /// This function will reset the internal state of this encoder and replace + /// the input stream with the one provided, returning the previous input + /// stream. Future data read from this encoder will be the compressed + /// version of `r`'s data. + pub fn reset(&mut self, r: R) -> R { + reset_encoder_data(self); + mem::replace(&mut self.obj, r) + } + + /// Acquires a reference to the underlying reader + pub fn get_ref(&self) -> &R { + &self.obj + } + + /// Acquires a mutable reference to the underlying stream + /// + /// Note that mutation of the stream may result in surprising results if + /// this encoder is continued to be used. + pub fn get_mut(&mut self) -> &mut R { + &mut self.obj + } + + /// Consumes this encoder, returning the underlying reader. + pub fn into_inner(self) -> R { + self.obj + } + + /// Returns the number of bytes that have been read into this compressor. + /// + /// Note that not all bytes read from the underlying object may be accounted + /// for, there may still be some active buffering. + pub fn total_in(&self) -> u64 { + self.data.total_in() + } + + /// Returns the number of bytes that the compressor has produced. + /// + /// Note that not all bytes may have been read yet, some may still be + /// buffered. + pub fn total_out(&self) -> u64 { + self.data.total_out() + } +} + +impl<R: BufRead> Read for ZlibEncoder<R> { + fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> { + zio::read(&mut self.obj, &mut self.data, buf) + } +} + +impl<R: BufRead + Write> Write for ZlibEncoder<R> { + fn write(&mut self, buf: &[u8]) -> io::Result<usize> { + self.get_mut().write(buf) + } + + fn flush(&mut self) -> io::Result<()> { + self.get_mut().flush() + } +} + +/// A ZLIB decoder, or decompressor. +/// +/// This structure consumes a [`BufRead`] interface, reading compressed data +/// from the underlying reader, and emitting uncompressed data. +/// +/// [`BufRead`]: https://doc.rust-lang.org/std/io/trait.BufRead.html +/// +/// # Examples +/// +/// ``` +/// use std::io::prelude::*; +/// use std::io; +/// # use flate2::Compression; +/// # use flate2::write::ZlibEncoder; +/// use flate2::bufread::ZlibDecoder; +/// +/// # fn main() { +/// # let mut e = ZlibEncoder::new(Vec::new(), Compression::default()); +/// # e.write_all(b"Hello World").unwrap(); +/// # let bytes = e.finish().unwrap(); +/// # println!("{}", decode_bufreader(bytes).unwrap()); +/// # } +/// # +/// // Uncompresses a Zlib Encoded vector of bytes and returns a string or error +/// // Here &[u8] implements BufRead +/// +/// fn decode_bufreader(bytes: Vec<u8>) -> io::Result<String> { +/// let mut z = ZlibDecoder::new(&bytes[..]); +/// let mut s = String::new(); +/// z.read_to_string(&mut s)?; +/// Ok(s) +/// } +/// ``` +#[derive(Debug)] +pub struct ZlibDecoder<R> { + obj: R, + data: Decompress, +} + +impl<R: BufRead> ZlibDecoder<R> { + /// Creates a new decoder which will decompress data read from the given + /// stream. + pub fn new(r: R) -> ZlibDecoder<R> { + ZlibDecoder { + obj: r, + data: Decompress::new(true), + } + } +} + +pub fn reset_decoder_data<R>(zlib: &mut ZlibDecoder<R>) { + zlib.data = Decompress::new(true); +} + +impl<R> ZlibDecoder<R> { + /// Resets the state of this decoder entirely, swapping out the input + /// stream for another. + /// + /// This will reset the internal state of this decoder and replace the + /// input stream with the one provided, returning the previous input + /// stream. Future data read from this decoder will be the decompressed + /// version of `r`'s data. + pub fn reset(&mut self, r: R) -> R { + reset_decoder_data(self); + mem::replace(&mut self.obj, r) + } + + /// Acquires a reference to the underlying stream + pub fn get_ref(&self) -> &R { + &self.obj + } + + /// Acquires a mutable reference to the underlying stream + /// + /// Note that mutation of the stream may result in surprising results if + /// this encoder is continued to be used. + pub fn get_mut(&mut self) -> &mut R { + &mut self.obj + } + + /// Consumes this decoder, returning the underlying reader. + pub fn into_inner(self) -> R { + self.obj + } + + /// Returns the number of bytes that the decompressor has consumed. + /// + /// Note that this will likely be smaller than what the decompressor + /// actually read from the underlying stream due to buffering. + pub fn total_in(&self) -> u64 { + self.data.total_in() + } + + /// Returns the number of bytes that the decompressor has produced. + pub fn total_out(&self) -> u64 { + self.data.total_out() + } +} + +impl<R: BufRead> Read for ZlibDecoder<R> { + fn read(&mut self, into: &mut [u8]) -> io::Result<usize> { + zio::read(&mut self.obj, &mut self.data, into) + } +} + +impl<R: BufRead + Write> Write for ZlibDecoder<R> { + fn write(&mut self, buf: &[u8]) -> io::Result<usize> { + self.get_mut().write(buf) + } + + fn flush(&mut self) -> io::Result<()> { + self.get_mut().flush() + } +} |