Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

4 files changed, 953 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()
+    }
+}
diff --git a/third_party/rust/flate2/src/zlib/mod.rs b/third_party/rust/flate2/src/zlib/mod.rs
new file mode 100644
index 0000000000..9d3de95c54
--- /dev/null
+++ b/third_party/rust/flate2/src/zlib/mod.rs
@@ -0,0 +1,159 @@
+pub mod bufread;
+pub mod read;
+pub mod write;
+
+#[cfg(test)]
+mod tests {
+    use std::io;
+    use std::io::prelude::*;
+
+    use rand::{thread_rng, Rng};
+
+    use crate::zlib::{read, write};
+    use crate::Compression;
+
+    #[test]
+    fn roundtrip() {
+        let mut real = Vec::new();
+        let mut w = write::ZlibEncoder::new(Vec::new(), Compression::default());
+        let v = crate::random_bytes().take(1024).collect::<Vec<_>>();
+        for _ in 0..200 {
+            let to_write = &v[..thread_rng().gen_range(0..v.len())];
+            real.extend(to_write.iter().map(|x| *x));
+            w.write_all(to_write).unwrap();
+        }
+        let result = w.finish().unwrap();
+        let mut r = read::ZlibDecoder::new(&result[..]);
+        let mut ret = Vec::new();
+        r.read_to_end(&mut ret).unwrap();
+        assert!(ret == real);
+    }
+
+    #[test]
+    fn drop_writes() {
+        let mut data = Vec::new();
+        write::ZlibEncoder::new(&mut data, Compression::default())
+            .write_all(b"foo")
+            .unwrap();
+        let mut r = read::ZlibDecoder::new(&data[..]);
+        let mut ret = Vec::new();
+        r.read_to_end(&mut ret).unwrap();
+        assert!(ret == b"foo");
+    }
+
+    #[test]
+    fn total_in() {
+        let mut real = Vec::new();
+        let mut w = write::ZlibEncoder::new(Vec::new(), Compression::default());
+        let v = crate::random_bytes().take(1024).collect::<Vec<_>>();
+        for _ in 0..200 {
+            let to_write = &v[..thread_rng().gen_range(0..v.len())];
+            real.extend(to_write.iter().map(|x| *x));
+            w.write_all(to_write).unwrap();
+        }
+        let mut result = w.finish().unwrap();
+
+        let result_len = result.len();
+
+        for _ in 0..200 {
+            result.extend(v.iter().map(|x| *x));
+        }
+
+        let mut r = read::ZlibDecoder::new(&result[..]);
+        let mut ret = Vec::new();
+        r.read_to_end(&mut ret).unwrap();
+        assert!(ret == real);
+        assert_eq!(r.total_in(), result_len as u64);
+    }
+
+    #[test]
+    fn roundtrip2() {
+        let v = crate::random_bytes().take(1024 * 1024).collect::<Vec<_>>();
+        let mut r = read::ZlibDecoder::new(read::ZlibEncoder::new(&v[..], Compression::default()));
+        let mut ret = Vec::new();
+        r.read_to_end(&mut ret).unwrap();
+        assert_eq!(ret, v);
+    }
+
+    #[test]
+    fn roundtrip3() {
+        let v = crate::random_bytes().take(1024 * 1024).collect::<Vec<_>>();
+        let mut w =
+            write::ZlibEncoder::new(write::ZlibDecoder::new(Vec::new()), Compression::default());
+        w.write_all(&v).unwrap();
+        let w = w.finish().unwrap().finish().unwrap();
+        assert!(w == v);
+    }
+
+    #[test]
+    fn reset_decoder() {
+        let v = crate::random_bytes().take(1024 * 1024).collect::<Vec<_>>();
+        let mut w = write::ZlibEncoder::new(Vec::new(), Compression::default());
+        w.write_all(&v).unwrap();
+        let data = w.finish().unwrap();
+
+        {
+            let (mut a, mut b, mut c) = (Vec::new(), Vec::new(), Vec::new());
+            let mut r = read::ZlibDecoder::new(&data[..]);
+            r.read_to_end(&mut a).unwrap();
+            r.reset(&data);
+            r.read_to_end(&mut b).unwrap();
+
+            let mut r = read::ZlibDecoder::new(&data[..]);
+            r.read_to_end(&mut c).unwrap();
+            assert!(a == b && b == c && c == v);
+        }
+
+        {
+            let mut w = write::ZlibDecoder::new(Vec::new());
+            w.write_all(&data).unwrap();
+            let a = w.reset(Vec::new()).unwrap();
+            w.write_all(&data).unwrap();
+            let b = w.finish().unwrap();
+
+            let mut w = write::ZlibDecoder::new(Vec::new());
+            w.write_all(&data).unwrap();
+            let c = w.finish().unwrap();
+            assert!(a == b && b == c && c == v);
+        }
+    }
+
+    #[test]
+    fn bad_input() {
+        // regress tests: previously caused a panic on drop
+        let mut out: Vec<u8> = Vec::new();
+        let data: Vec<u8> = (0..255).cycle().take(1024).collect();
+        let mut w = write::ZlibDecoder::new(&mut out);
+        match w.write_all(&data[..]) {
+            Ok(_) => panic!("Expected an error to be returned!"),
+            Err(e) => assert_eq!(e.kind(), io::ErrorKind::InvalidInput),
+        }
+    }
+
+    #[test]
+    fn qc_reader() {
+        ::quickcheck::quickcheck(test as fn(_) -> _);
+
+        fn test(v: Vec<u8>) -> bool {
+            let mut r =
+                read::ZlibDecoder::new(read::ZlibEncoder::new(&v[..], Compression::default()));
+            let mut v2 = Vec::new();
+            r.read_to_end(&mut v2).unwrap();
+            v == v2
+        }
+    }
+
+    #[test]
+    fn qc_writer() {
+        ::quickcheck::quickcheck(test as fn(_) -> _);
+
+        fn test(v: Vec<u8>) -> bool {
+            let mut w = write::ZlibEncoder::new(
+                write::ZlibDecoder::new(Vec::new()),
+                Compression::default(),
+            );
+            w.write_all(&v).unwrap();
+            v == w.finish().unwrap().finish().unwrap()
+        }
+    }
+}
diff --git a/third_party/rust/flate2/src/zlib/read.rs b/third_party/rust/flate2/src/zlib/read.rs
new file mode 100644
index 0000000000..5094931665
--- /dev/null
+++ b/third_party/rust/flate2/src/zlib/read.rs
@@ -0,0 +1,240 @@
+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()
+    }
+}
diff --git a/third_party/rust/flate2/src/zlib/write.rs b/third_party/rust/flate2/src/zlib/write.rs
new file mode 100644
index 0000000000..c67181402b
--- /dev/null
+++ b/third_party/rust/flate2/src/zlib/write.rs
@@ -0,0 +1,321 @@
+use std::io;
+use std::io::prelude::*;
+
+use crate::zio;
+use crate::{Compress, Decompress};
+
+/// A ZLIB 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::ZlibEncoder;
+///
+/// // Vec<u8> implements Write, assigning the compressed bytes of sample string
+///
+/// # fn zlib_encoding() -> std::io::Result<()> {
+/// let mut e = ZlibEncoder::new(Vec::new(), Compression::default());
+/// e.write_all(b"Hello World")?;
+/// let compressed = e.finish()?;
+/// # Ok(())
+/// # }
+/// ```
+#[derive(Debug)]
+pub struct ZlibEncoder<W: Write> {
+    inner: zio::Writer<W, Compress>,
+}
+
+impl<W: Write> ZlibEncoder<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: crate::Compression) -> ZlibEncoder<W> {
+        ZlibEncoder {
+            inner: zio::Writer::new(w, Compress::new(level, true)),
+        }
+    }
+
+    /// 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.
+    ///
+    /// 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> {
+        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> {
+        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> {
+        self.inner.flush()?;
+        Ok(self.inner.take_inner())
+    }
+
+    /// Returns the number of bytes that have been written to this compressor.
+    ///
+    /// 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 ZlibEncoder<W> {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        self.inner.write(buf)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        self.inner.flush()
+    }
+}
+
+impl<W: Read + Write> Read for ZlibEncoder<W> {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.get_mut().read(buf)
+    }
+}
+
+/// A ZLIB 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.Write.html
+///
+/// # Examples
+///
+/// ```
+/// use std::io::prelude::*;
+/// use std::io;
+/// # use flate2::Compression;
+/// # use flate2::write::ZlibEncoder;
+/// use flate2::write::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 Vec<u8> implements Write
+///
+/// fn decode_reader(bytes: Vec<u8>) -> io::Result<String> {
+///    let mut writer = Vec::new();
+///    let mut z = ZlibDecoder::new(writer);
+///    z.write_all(&bytes[..])?;
+///    writer = z.finish()?;
+///    let return_string = String::from_utf8(writer).expect("String parsing error");
+///    Ok(return_string)
+/// }
+/// ```
+#[derive(Debug)]
+pub struct ZlibDecoder<W: Write> {
+    inner: zio::Writer<W, Decompress>,
+}
+
+impl<W: Write> ZlibDecoder<W> {
+    /// Creates a new decoder which will write uncompressed data to the stream.
+    ///
+    /// When this decoder is dropped or unwrapped the final pieces of data will
+    /// be flushed.
+    pub fn new(w: W) -> ZlibDecoder<W> {
+        ZlibDecoder {
+            inner: zio::Writer::new(w, Decompress::new(true)),
+        }
+    }
+
+    /// 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 will 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 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> {
+        self.inner.finish()?;
+        self.inner.data = Decompress::new(true);
+        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 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> {
+        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 ZlibDecoder<W> {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        self.inner.write(buf)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        self.inner.flush()
+    }
+}
+
+impl<W: Read + Write> Read for ZlibDecoder<W> {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.inner.get_mut().read(buf)
+    }
+}