refactor the deflate, gz and zlib modules

Author: sbstp

src/deflate.rs

@@ -0,0 +1,262 @@
+use std::io::prelude::*;
+use std::io;
+use std::mem;
+
+#[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 [`BufRead`] interface and will read uncompressed
+/// data from an underlying stream and emit a stream of compressed 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::bufread::DeflateEncoder;
+/// use std::fs::File;
+/// use std::io::BufReader;
+///
+/// # fn main() {
+/// #    println!("{:?}", open_hello_world().unwrap());
+/// # }
+/// #
+/// // Opens sample file, compresses the contents and returns a Vector
+/// fn open_hello_world() -> io::Result<Vec<u8>> {
+///    let f = File::open("examples/hello_world.txt")?;
+///    let b = BufReader::new(f);
+///    let mut deflater = DeflateEncoder::new(b, Compression::Fast);
+///    let mut buffer = Vec::new();
+///    deflater.read_to_end(&mut buffer)?;
+///    Ok(buffer)
+/// }
+/// ```
+#[derive(Debug)]
+pub struct DeflateEncoder<R> {
+    pub(crate) obj: R,
+    pub(crate) data: Compress,
+}
+
+
+impl<R: BufRead> DeflateEncoder<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: ::Compression) -> DeflateEncoder<R> {
+        DeflateEncoder {
+            obj: r,
+            data: Compress::new(level, false),
+        }
+    }
+}
+
+impl<R> DeflateEncoder<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 {
+        self.data.reset();
+        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 DeflateEncoder<R> {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        zio::read(&mut self.obj, &mut self.data, buf)
+    }
+}
+
+#[cfg(feature = "tokio")]
+impl<R: AsyncRead + BufRead> AsyncRead for DeflateEncoder<R> {}
+
+impl<W: BufRead + Write> Write for DeflateEncoder<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()
+    }
+}
+
+#[cfg(feature = "tokio")]
+impl<R: AsyncWrite + BufRead> AsyncWrite for DeflateEncoder<R> {
+    fn shutdown(&mut self) -> Poll<(), io::Error> {
+        self.get_mut().shutdown()
+    }
+}
+
+/// A DEFLATE decoder, or decompressor.
+///
+/// This structure implements a [`BufRead`] interface and takes a stream of
+/// compressed data as input, providing the decompressed data when read from.
+///
+/// [`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::DeflateEncoder;
+/// use flate2::bufread::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_reader(bytes).unwrap());
+/// # }
+/// // Uncompresses a Deflate 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 deflater = DeflateDecoder::new(&bytes[..]);
+///    let mut s = String::new();
+///    deflater.read_to_string(&mut s)?;
+///    Ok(s)
+/// }
+/// ```
+#[derive(Debug)]
+pub struct DeflateDecoder<R> {
+    pub(crate) obj: R,
+    pub(crate) data: Decompress,
+}
+
+
+impl<R: BufRead> DeflateDecoder<R> {
+    /// Creates a new decoder which will decompress data read from the given
+    /// stream.
+    pub fn new(r: R) -> DeflateDecoder<R> {
+        DeflateDecoder {
+            obj: r,
+            data: Decompress::new(false),
+        }
+    }
+}
+
+impl<R> DeflateDecoder<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 {
+        self.data = Decompress::new(false);
+        mem::replace(&mut self.obj, r)
+    }
+
+    /// Resets the state of this decoder's data
+    ///
+    /// This will reset the internal state of this decoder. It will continue
+    /// reading from the same stream.
+    pub fn reset_data(&mut self) {
+        self.data = Decompress::new(false);
+    }
+
+    /// 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 DeflateDecoder<R> {
+    fn read(&mut self, into: &mut [u8]) -> io::Result<usize> {
+        zio::read(&mut self.obj, &mut self.data, into)
+    }
+}
+
+#[cfg(feature = "tokio")]
+impl<R: AsyncRead + BufRead> AsyncRead for DeflateDecoder<R> {}
+
+impl<W: BufRead + Write> Write for DeflateDecoder<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()
+    }
+}
+
+#[cfg(feature = "tokio")]
+impl<R: AsyncWrite + BufRead> AsyncWrite for DeflateDecoder<R> {
+    fn shutdown(&mut self) -> Poll<(), io::Error> {
+        self.get_mut().shutdown()
+    }
+}