blob: 596450348ab293a53278e26172469142f19de385 [file] [log] [blame]
use std::io::prelude::*;
use std::io;
#[cfg(feature = "tokio")]
use futures::Poll;
#[cfg(feature = "tokio")]
use tokio_io::{AsyncRead, AsyncWrite};
use zio;
use {Compress, Decompress};
/// A DEFLATE encoder, or compressor.
///
/// This structure implements a [`Write`] interface and takes a stream of
/// uncompressed data, writing the compressed data to the wrapped writer.
///
/// [`Write`]: https://doc.rust-lang.org/std/io/trait.Write.html
///
/// # Examples
///
/// ```
/// use std::io::prelude::*;
/// use flate2::Compression;
/// use flate2::write::DeflateEncoder;
///
/// // Vec<u8> implements Write to print the compressed bytes of sample string
/// # fn main() {
///
/// let mut e = DeflateEncoder::new(Vec::new(), Compression::Default);
/// e.write(b"Hello World").unwrap();
/// println!("{:?}", e.finish().unwrap());
/// # }
/// ```
#[derive(Debug)]
pub struct DeflateEncoder<W: Write> {
inner: zio::Writer<W, Compress>,
}
impl<W: Write> DeflateEncoder<W> {
/// Creates a new encoder which will write compressed data to the stream
/// given at the given compression level.
///
/// When this encoder is dropped or unwrapped the final pieces of data will
/// be flushed.
pub fn new(w: W, level: ::Compression) -> DeflateEncoder<W> {
DeflateEncoder {
inner: zio::Writer::new(w, Compress::new(level, false)),
}
}
/// Acquires a reference to the underlying writer.
pub fn get_ref(&self) -> &W {
self.inner.get_ref()
}
/// Acquires a mutable reference to the underlying writer.
///
/// Note that mutating the output/input state of the stream may corrupt this
/// object, so care must be taken when using this method.
pub fn get_mut(&mut self) -> &mut W {
self.inner.get_mut()
}
/// Resets the state of this encoder entirely, swapping out the output
/// stream for another.
///
/// This function will finish encoding the current stream into the current
/// output stream before swapping out the two output streams. If the stream
/// cannot be finished an error is returned.
///
/// After the current stream has been finished, this will reset the internal
/// state of this encoder and replace the output stream with the one
/// provided, returning the previous output stream. Future data written to
/// this encoder will be the compressed into the stream `w` provided.
///
/// # Errors
///
/// This function will perform I/O to complete this stream, and any I/O
/// errors which occur will be returned from this function.
pub fn reset(&mut self, w: W) -> io::Result<W> {
try!(self.inner.finish());
self.inner.data.reset();
Ok(self.inner.replace(w))
}
/// Attempt to finish this output stream, writing out final chunks of data.
///
/// Note that this function can only be used once data has finished being
/// written to the output stream. After this function is called then further
/// calls to `write` may result in a panic.
///
/// # Panics
///
/// Attempts to write data to this stream may result in a panic after this
/// function is called.
///
/// # Errors
///
/// This function will perform I/O to complete this stream, and any I/O
/// errors which occur will be returned from this function.
pub fn try_finish(&mut self) -> io::Result<()> {
self.inner.finish()
}
/// Consumes this encoder, flushing the output stream.
///
/// This will flush the underlying data stream, close off the compressed
/// stream and, if successful, return the contained writer.
///
/// Note that this function may not be suitable to call in a situation where
/// the underlying stream is an asynchronous I/O stream. To finish a stream
/// the `try_finish` (or `shutdown`) method should be used instead. To
/// re-acquire ownership of a stream it is safe to call this method after
/// `try_finish` or `shutdown` has returned `Ok`.
///
/// # Errors
///
/// This function will perform I/O to complete this stream, and any I/O
/// errors which occur will be returned from this function.
pub fn finish(mut self) -> io::Result<W> {
try!(self.inner.finish());
Ok(self.inner.take_inner())
}
/// Consumes this encoder, flushing the output stream.
///
/// This will flush the underlying data stream and then return the contained
/// writer if the flush succeeded.
/// The compressed stream will not closed but only flushed. This
/// means that obtained byte array can by extended by another deflated
/// stream. To close the stream add the two bytes 0x3 and 0x0.
///
/// # Errors
///
/// This function will perform I/O to complete this stream, and any I/O
/// errors which occur will be returned from this function.
pub fn flush_finish(mut self) -> io::Result<W> {
try!(self.inner.flush());
Ok(self.inner.take_inner())
}
/// Returns the number of bytes that have been written to this compresor.
///
/// Note that not all bytes written to this object may be accounted for,
/// there may still be some active buffering.
pub fn total_in(&self) -> u64 {
self.inner.data.total_in()
}
/// Returns the number of bytes that the compressor has produced.
///
/// Note that not all bytes may have been written yet, some may still be
/// buffered.
pub fn total_out(&self) -> u64 {
self.inner.data.total_out()
}
}
impl<W: Write> Write for DeflateEncoder<W> {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.inner.write(buf)
}
fn flush(&mut self) -> io::Result<()> {
self.inner.flush()
}
}
#[cfg(feature = "tokio")]
impl<W: AsyncWrite> AsyncWrite for DeflateEncoder<W> {
fn shutdown(&mut self) -> Poll<(), io::Error> {
try_nb!(self.inner.finish());
self.inner.get_mut().shutdown()
}
}
impl<W: Read + Write> Read for DeflateEncoder<W> {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
self.inner.get_mut().read(buf)
}
}
#[cfg(feature = "tokio")]
impl<W: AsyncRead + AsyncWrite> AsyncRead for DeflateEncoder<W> {}
/// A DEFLATE decoder, or decompressor.
///
/// This structure implements a [`Write`] and will emit a stream of decompressed
/// data when fed a stream of compressed data.
///
/// [`Write`]: https://doc.rust-lang.org/std/io/trait.Read.html
///
/// # Examples
///
/// ```
/// use std::io::prelude::*;
/// use std::io;
/// # use flate2::Compression;
/// # use flate2::write::DeflateEncoder;
/// use flate2::write::DeflateDecoder;
///
/// # fn main() {
/// # let mut e = DeflateEncoder::new(Vec::new(), Compression::Default);
/// # e.write(b"Hello World").unwrap();
/// # let bytes = e.finish().unwrap();
/// # println!("{}", decode_writer(bytes).unwrap());
/// # }
/// // Uncompresses a Deflate Encoded vector of bytes and returns a string or error
/// // Here Vec<u8> implements Write
/// fn decode_writer(bytes: Vec<u8>) -> io::Result<String> {
/// let mut writer = Vec::new();
/// let mut deflater = DeflateDecoder::new(writer);
/// deflater.write(&bytes[..])?;
/// writer = deflater.finish()?;
/// let return_string = String::from_utf8(writer).expect("String parsing error");
/// Ok(return_string)
/// }
/// ```
#[derive(Debug)]
pub struct DeflateDecoder<W: Write> {
inner: zio::Writer<W, Decompress>,
}
impl<W: Write> DeflateDecoder<W> {
/// Creates a new decoder which will write uncompressed data to the stream.
///
/// When this encoder is dropped or unwrapped the final pieces of data will
/// be flushed.
pub fn new(w: W) -> DeflateDecoder<W> {
DeflateDecoder {
inner: zio::Writer::new(w, Decompress::new(false)),
}
}
/// Acquires a reference to the underlying writer.
pub fn get_ref(&self) -> &W {
self.inner.get_ref()
}
/// Acquires a mutable reference to the underlying writer.
///
/// Note that mutating the output/input state of the stream may corrupt this
/// object, so care must be taken when using this method.
pub fn get_mut(&mut self) -> &mut W {
self.inner.get_mut()
}
/// Resets the state of this decoder entirely, swapping out the output
/// stream for another.
///
/// This function will finish encoding the current stream into the current
/// output stream before swapping out the two output streams.
///
/// This will then reset the internal state of this decoder and replace the
/// output stream with the one provided, returning the previous output
/// stream. Future data written to this decoder will be decompressed into
/// the output stream `w`.
///
/// # Errors
///
/// This function will perform I/O to finish the stream, and if that I/O
/// returns an error then that will be returned from this function.
pub fn reset(&mut self, w: W) -> io::Result<W> {
try!(self.inner.finish());
self.inner.data = Decompress::new(false);
Ok(self.inner.replace(w))
}
/// Attempt to finish this output stream, writing out final chunks of data.
///
/// Note that this function can only be used once data has finished being
/// written to the output stream. After this function is called then further
/// calls to `write` may result in a panic.
///
/// # Panics
///
/// Attempts to write data to this stream may result in a panic after this
/// function is called.
///
/// # Errors
///
/// This function will perform I/O to finish the stream, returning any
/// errors which happen.
pub fn try_finish(&mut self) -> io::Result<()> {
self.inner.finish()
}
/// Consumes this encoder, flushing the output stream.
///
/// This will flush the underlying data stream and then return the contained
/// writer if the flush succeeded.
///
/// Note that this function may not be suitable to call in a situation where
/// the underlying stream is an asynchronous I/O stream. To finish a stream
/// the `try_finish` (or `shutdown`) method should be used instead. To
/// re-acquire ownership of a stream it is safe to call this method after
/// `try_finish` or `shutdown` has returned `Ok`.
///
/// # Errors
///
/// This function will perform I/O to complete this stream, and any I/O
/// errors which occur will be returned from this function.
pub fn finish(mut self) -> io::Result<W> {
try!(self.inner.finish());
Ok(self.inner.take_inner())
}
/// Returns the number of bytes that the decompressor has consumed for
/// decompression.
///
/// Note that this will likely be smaller than the number of bytes
/// successfully written to this stream due to internal buffering.
pub fn total_in(&self) -> u64 {
self.inner.data.total_in()
}
/// Returns the number of bytes that the decompressor has written to its
/// output stream.
pub fn total_out(&self) -> u64 {
self.inner.data.total_out()
}
}
impl<W: Write> Write for DeflateDecoder<W> {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.inner.write(buf)
}
fn flush(&mut self) -> io::Result<()> {
self.inner.flush()
}
}
#[cfg(feature = "tokio")]
impl<W: AsyncWrite> AsyncWrite for DeflateDecoder<W> {
fn shutdown(&mut self) -> Poll<(), io::Error> {
try_nb!(self.inner.finish());
self.inner.get_mut().shutdown()
}
}
impl<W: Read + Write> Read for DeflateDecoder<W> {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
self.inner.get_mut().read(buf)
}
}
#[cfg(feature = "tokio")]
impl<W: AsyncRead + AsyncWrite> AsyncRead for DeflateDecoder<W> {}