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use std::io;
use std::io::prelude::*;
use super::bufread;
use crate::bufreader::BufReader;
/// A ZLIB encoder, or compressor.
///
/// This structure implements a [`Read`] interface and will read uncompressed
/// data from an underlying stream and emit a stream of compressed data.
///
/// [`Read`]: https://doc.rust-lang.org/std/io/trait.Read.html
///
/// # Examples
///
/// ```
/// use std::io::prelude::*;
/// use flate2::Compression;
/// use flate2::read::ZlibEncoder;
/// use std::fs::File;
///
/// // Open example file and compress the contents using Read interface
///
/// # fn open_hello_world() -> std::io::Result<Vec<u8>> {
/// let f = File::open("examples/hello_world.txt")?;
/// let mut z = ZlibEncoder::new(f, Compression::fast());
/// let mut buffer = [0;50];
/// let byte_count = z.read(&mut buffer)?;
/// # Ok(buffer[0..byte_count].to_vec())
/// # }
/// ```
#[derive(Debug)]
pub struct ZlibEncoder<R> {
inner: bufread::ZlibEncoder<BufReader<R>>,
}
impl<R: Read> 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 {
inner: bufread::ZlibEncoder::new(BufReader::new(r), level),
}
}
}
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.
///
/// Note that there may be currently buffered data when this function is
/// called, and in that case the buffered data is discarded.
pub fn reset(&mut self, r: R) -> R {
super::bufread::reset_encoder_data(&mut self.inner);
self.inner.get_mut().reset(r)
}
/// Acquires a reference to the underlying stream
pub fn get_ref(&self) -> &R {
self.inner.get_ref().get_ref()
}
/// 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 {
self.inner.get_mut().get_mut()
}
/// Consumes this encoder, returning the underlying reader.
///
/// Note that there may be buffered bytes which are not re-acquired as part
/// of this transition. It's recommended to only call this function after
/// EOF has been reached.
pub fn into_inner(self) -> R {
self.inner.into_inner().into_inner()
}
/// 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.inner.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.inner.total_out()
}
}
impl<R: Read> Read for ZlibEncoder<R> {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
self.inner.read(buf)
}
}
impl<W: Read + Write> Write for ZlibEncoder<W> {
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 implements a [`Read`] interface and takes a stream of
/// compressed data as input, providing the decompressed data when read from.
///
/// [`Read`]: https://doc.rust-lang.org/std/io/trait.Read.html
///
/// # Examples
///
/// ```
/// use std::io::prelude::*;
/// use std::io;
/// # use flate2::Compression;
/// # use flate2::write::ZlibEncoder;
/// use flate2::read::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_reader(bytes).unwrap());
/// # }
/// #
/// // Uncompresses a Zlib Encoded vector of bytes and returns a string or error
/// // Here &[u8] implements Read
///
/// fn decode_reader(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> {
inner: bufread::ZlibDecoder<BufReader<R>>,
}
impl<R: Read> ZlibDecoder<R> {
/// Creates a new decoder which will decompress data read from the given
/// stream.
pub fn new(r: R) -> ZlibDecoder<R> {
ZlibDecoder::new_with_buf(r, vec![0; 32 * 1024])
}
/// Same as `new`, but the intermediate buffer for data is specified.
///
/// Note that the specified buffer will only be used up to its current
/// length. The buffer's capacity will also not grow over time.
pub fn new_with_buf(r: R, buf: Vec<u8>) -> ZlibDecoder<R> {
ZlibDecoder {
inner: bufread::ZlibDecoder::new(BufReader::with_buf(buf, r)),
}
}
}
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.
///
/// Note that there may be currently buffered data when this function is
/// called, and in that case the buffered data is discarded.
pub fn reset(&mut self, r: R) -> R {
super::bufread::reset_decoder_data(&mut self.inner);
self.inner.get_mut().reset(r)
}
/// Acquires a reference to the underlying stream
pub fn get_ref(&self) -> &R {
self.inner.get_ref().get_ref()
}
/// 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 {
self.inner.get_mut().get_mut()
}
/// Consumes this decoder, returning the underlying reader.
///
/// Note that there may be buffered bytes which are not re-acquired as part
/// of this transition. It's recommended to only call this function after
/// EOF has been reached.
pub fn into_inner(self) -> R {
self.inner.into_inner().into_inner()
}
/// 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.inner.total_in()
}
/// Returns the number of bytes that the decompressor has produced.
pub fn total_out(&self) -> u64 {
self.inner.total_out()
}
}
impl<R: Read> Read for ZlibDecoder<R> {
fn read(&mut self, into: &mut [u8]) -> io::Result<usize> {
self.inner.read(into)
}
}
impl<R: Read + 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()
}
}
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