Adding upstream version 110.0.1.upstream/110.0.1upstream

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

20 files changed, 6141 insertions, 0 deletions

diff --git a/third_party/rust/flate2/src/bufreader.rs b/third_party/rust/flate2/src/bufreader.rs
new file mode 100644
index 0000000000..7e6f89d688
--- /dev/null
+++ b/third_party/rust/flate2/src/bufreader.rs
@@ -0,0 +1,104 @@
+// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// <https://github.com/rust-lang/rust/blob/HEAD/COPYRIGHT>.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::cmp;
+use std::io;
+use std::io::prelude::*;
+use std::mem;
+
+pub struct BufReader<R> {
+    inner: R,
+    buf: Box<[u8]>,
+    pos: usize,
+    cap: usize,
+}
+
+impl<R> ::std::fmt::Debug for BufReader<R>
+where
+    R: ::std::fmt::Debug,
+{
+    fn fmt(&self, fmt: &mut ::std::fmt::Formatter) -> Result<(), ::std::fmt::Error> {
+        fmt.debug_struct("BufReader")
+            .field("reader", &self.inner)
+            .field(
+                "buffer",
+                &format_args!("{}/{}", self.cap - self.pos, self.buf.len()),
+            )
+            .finish()
+    }
+}
+
+impl<R: Read> BufReader<R> {
+    pub fn new(inner: R) -> BufReader<R> {
+        BufReader::with_buf(vec![0; 32 * 1024], inner)
+    }
+
+    pub fn with_buf(buf: Vec<u8>, inner: R) -> BufReader<R> {
+        BufReader {
+            inner,
+            buf: buf.into_boxed_slice(),
+            pos: 0,
+            cap: 0,
+        }
+    }
+}
+
+impl<R> BufReader<R> {
+    pub fn get_ref(&self) -> &R {
+        &self.inner
+    }
+
+    pub fn get_mut(&mut self) -> &mut R {
+        &mut self.inner
+    }
+
+    pub fn into_inner(self) -> R {
+        self.inner
+    }
+
+    pub fn reset(&mut self, inner: R) -> R {
+        self.pos = 0;
+        self.cap = 0;
+        mem::replace(&mut self.inner, inner)
+    }
+}
+
+impl<R: Read> Read for BufReader<R> {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        // If we don't have any buffered data and we're doing a massive read
+        // (larger than our internal buffer), bypass our internal buffer
+        // entirely.
+        if self.pos == self.cap && buf.len() >= self.buf.len() {
+            return self.inner.read(buf);
+        }
+        let nread = {
+            let mut rem = self.fill_buf()?;
+            rem.read(buf)?
+        };
+        self.consume(nread);
+        Ok(nread)
+    }
+}
+
+impl<R: Read> BufRead for BufReader<R> {
+    fn fill_buf(&mut self) -> io::Result<&[u8]> {
+        // If we've reached the end of our internal buffer then we need to fetch
+        // some more data from the underlying reader.
+        if self.pos == self.cap {
+            self.cap = self.inner.read(&mut self.buf)?;
+            self.pos = 0;
+        }
+        Ok(&self.buf[self.pos..self.cap])
+    }
+
+    fn consume(&mut self, amt: usize) {
+        self.pos = cmp::min(self.pos + amt, self.cap);
+    }
+}
diff --git a/third_party/rust/flate2/src/crc.rs b/third_party/rust/flate2/src/crc.rs
new file mode 100644
index 0000000000..cd00cebe18
--- /dev/null
+++ b/third_party/rust/flate2/src/crc.rs
@@ -0,0 +1,184 @@
+//! Simple CRC bindings backed by miniz.c
+
+use std::io;
+use std::io::prelude::*;
+
+use crc32fast::Hasher;
+
+/// The CRC calculated by a [`CrcReader`].
+///
+/// [`CrcReader`]: struct.CrcReader.html
+#[derive(Debug)]
+pub struct Crc {
+    amt: u32,
+    hasher: Hasher,
+}
+
+/// A wrapper around a [`Read`] that calculates the CRC.
+///
+/// [`Read`]: https://doc.rust-lang.org/std/io/trait.Read.html
+#[derive(Debug)]
+pub struct CrcReader<R> {
+    inner: R,
+    crc: Crc,
+}
+
+impl Default for Crc {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl Crc {
+    /// Create a new CRC.
+    pub fn new() -> Crc {
+        Crc {
+            amt: 0,
+            hasher: Hasher::new(),
+        }
+    }
+
+    /// Returns the current crc32 checksum.
+    pub fn sum(&self) -> u32 {
+        self.hasher.clone().finalize()
+    }
+
+    /// The number of bytes that have been used to calculate the CRC.
+    /// This value is only accurate if the amount is lower than 2<sup>32</sup>.
+    pub fn amount(&self) -> u32 {
+        self.amt
+    }
+
+    /// Update the CRC with the bytes in `data`.
+    pub fn update(&mut self, data: &[u8]) {
+        self.amt = self.amt.wrapping_add(data.len() as u32);
+        self.hasher.update(data);
+    }
+
+    /// Reset the CRC.
+    pub fn reset(&mut self) {
+        self.amt = 0;
+        self.hasher.reset();
+    }
+
+    /// Combine the CRC with the CRC for the subsequent block of bytes.
+    pub fn combine(&mut self, additional_crc: &Crc) {
+        self.amt += additional_crc.amt;
+        self.hasher.combine(&additional_crc.hasher);
+    }
+}
+
+impl<R: Read> CrcReader<R> {
+    /// Create a new CrcReader.
+    pub fn new(r: R) -> CrcReader<R> {
+        CrcReader {
+            inner: r,
+            crc: Crc::new(),
+        }
+    }
+}
+
+impl<R> CrcReader<R> {
+    /// Get the Crc for this CrcReader.
+    pub fn crc(&self) -> &Crc {
+        &self.crc
+    }
+
+    /// Get the reader that is wrapped by this CrcReader.
+    pub fn into_inner(self) -> R {
+        self.inner
+    }
+
+    /// Get the reader that is wrapped by this CrcReader by reference.
+    pub fn get_ref(&self) -> &R {
+        &self.inner
+    }
+
+    /// Get a mutable reference to the reader that is wrapped by this CrcReader.
+    pub fn get_mut(&mut self) -> &mut R {
+        &mut self.inner
+    }
+
+    /// Reset the Crc in this CrcReader.
+    pub fn reset(&mut self) {
+        self.crc.reset();
+    }
+}
+
+impl<R: Read> Read for CrcReader<R> {
+    fn read(&mut self, into: &mut [u8]) -> io::Result<usize> {
+        let amt = self.inner.read(into)?;
+        self.crc.update(&into[..amt]);
+        Ok(amt)
+    }
+}
+
+impl<R: BufRead> BufRead for CrcReader<R> {
+    fn fill_buf(&mut self) -> io::Result<&[u8]> {
+        self.inner.fill_buf()
+    }
+    fn consume(&mut self, amt: usize) {
+        if let Ok(data) = self.inner.fill_buf() {
+            self.crc.update(&data[..amt]);
+        }
+        self.inner.consume(amt);
+    }
+}
+
+/// A wrapper around a [`Write`] that calculates the CRC.
+///
+/// [`Write`]: https://doc.rust-lang.org/std/io/trait.Write.html
+#[derive(Debug)]
+pub struct CrcWriter<W> {
+    inner: W,
+    crc: Crc,
+}
+
+impl<W> CrcWriter<W> {
+    /// Get the Crc for this CrcWriter.
+    pub fn crc(&self) -> &Crc {
+        &self.crc
+    }
+
+    /// Get the writer that is wrapped by this CrcWriter.
+    pub fn into_inner(self) -> W {
+        self.inner
+    }
+
+    /// Get the writer that is wrapped by this CrcWriter by reference.
+    pub fn get_ref(&self) -> &W {
+        &self.inner
+    }
+
+    /// Get a mutable reference to the writer that is wrapped by this CrcWriter.
+    pub fn get_mut(&mut self) -> &mut W {
+        &mut self.inner
+    }
+
+    /// Reset the Crc in this CrcWriter.
+    pub fn reset(&mut self) {
+        self.crc.reset();
+    }
+}
+
+impl<W: Write> CrcWriter<W> {
+    /// Create a new CrcWriter.
+    pub fn new(w: W) -> CrcWriter<W> {
+        CrcWriter {
+            inner: w,
+            crc: Crc::new(),
+        }
+    }
+}
+
+impl<W: Write> Write for CrcWriter<W> {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        let amt = self.inner.write(buf)?;
+        self.crc.update(&buf[..amt]);
+        Ok(amt)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        self.inner.flush()
+    }
+}
diff --git a/third_party/rust/flate2/src/deflate/bufread.rs b/third_party/rust/flate2/src/deflate/bufread.rs
new file mode 100644
index 0000000000..f0b29e0b4d
--- /dev/null
+++ b/third_party/rust/flate2/src/deflate/bufread.rs
@@ -0,0 +1,243 @@
+use std::io;
+use std::io::prelude::*;
+use std::mem;
+
+use crate::zio;
+use crate::{Compress, Decompress};
+
+/// A DEFLATE 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 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> {
+    obj: R,
+    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: crate::Compression) -> DeflateEncoder<R> {
+        DeflateEncoder {
+            obj: r,
+            data: Compress::new(level, false),
+        }
+    }
+}
+
+pub fn reset_encoder_data<R>(zlib: &mut DeflateEncoder<R>) {
+    zlib.data.reset();
+}
+
+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 {
+        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 DeflateEncoder<R> {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        zio::read(&mut self.obj, &mut self.data, buf)
+    }
+}
+
+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()
+    }
+}
+
+/// A DEFLATE 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::DeflateEncoder;
+/// use flate2::bufread::DeflateDecoder;
+///
+/// # fn main() {
+/// #    let mut e = DeflateEncoder::new(Vec::new(), Compression::default());
+/// #    e.write_all(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> {
+    obj: R,
+    data: Decompress,
+}
+
+pub fn reset_decoder_data<R>(zlib: &mut DeflateDecoder<R>) {
+    zlib.data = Decompress::new(false);
+}
+
+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 {
+        reset_decoder_data(self);
+        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) {
+        reset_decoder_data(self);
+    }
+
+    /// 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)
+    }
+}
+
+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()
+    }
+}
diff --git a/third_party/rust/flate2/src/deflate/mod.rs b/third_party/rust/flate2/src/deflate/mod.rs
new file mode 100644
index 0000000000..51758b30ae
--- /dev/null
+++ b/third_party/rust/flate2/src/deflate/mod.rs
@@ -0,0 +1,193 @@
+pub mod bufread;
+pub mod read;
+pub mod write;
+
+#[cfg(test)]
+mod tests {
+    use std::io::prelude::*;
+
+    use rand::{thread_rng, Rng};
+
+    use super::{read, write};
+    use crate::Compression;
+
+    #[test]
+    fn roundtrip() {
+        let mut real = Vec::new();
+        let mut w = write::DeflateEncoder::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::DeflateDecoder::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::DeflateEncoder::new(&mut data, Compression::default())
+            .write_all(b"foo")
+            .unwrap();
+        let mut r = read::DeflateDecoder::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::DeflateEncoder::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::DeflateDecoder::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::DeflateDecoder::new(read::DeflateEncoder::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::DeflateEncoder::new(
+            write::DeflateDecoder::new(Vec::new()),
+            Compression::default(),
+        );
+        w.write_all(&v).unwrap();
+        let w = w.finish().unwrap().finish().unwrap();
+        assert!(w == v);
+    }
+
+    #[test]
+    fn reset_writer() {
+        let v = crate::random_bytes().take(1024 * 1024).collect::<Vec<_>>();
+        let mut w = write::DeflateEncoder::new(Vec::new(), Compression::default());
+        w.write_all(&v).unwrap();
+        let a = w.reset(Vec::new()).unwrap();
+        w.write_all(&v).unwrap();
+        let b = w.finish().unwrap();
+
+        let mut w = write::DeflateEncoder::new(Vec::new(), Compression::default());
+        w.write_all(&v).unwrap();
+        let c = w.finish().unwrap();
+        assert!(a == b && b == c);
+    }
+
+    #[test]
+    fn reset_reader() {
+        let v = crate::random_bytes().take(1024 * 1024).collect::<Vec<_>>();
+        let (mut a, mut b, mut c) = (Vec::new(), Vec::new(), Vec::new());
+        let mut r = read::DeflateEncoder::new(&v[..], Compression::default());
+        r.read_to_end(&mut a).unwrap();
+        r.reset(&v[..]);
+        r.read_to_end(&mut b).unwrap();
+
+        let mut r = read::DeflateEncoder::new(&v[..], Compression::default());
+        r.read_to_end(&mut c).unwrap();
+        assert!(a == b && b == c);
+    }
+
+    #[test]
+    fn reset_decoder() {
+        let v = crate::random_bytes().take(1024 * 1024).collect::<Vec<_>>();
+        let mut w = write::DeflateEncoder::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::DeflateDecoder::new(&data[..]);
+            r.read_to_end(&mut a).unwrap();
+            r.reset(&data);
+            r.read_to_end(&mut b).unwrap();
+
+            let mut r = read::DeflateDecoder::new(&data[..]);
+            r.read_to_end(&mut c).unwrap();
+            assert!(a == b && b == c && c == v);
+        }
+
+        {
+            let mut w = write::DeflateDecoder::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::DeflateDecoder::new(Vec::new());
+            w.write_all(&data).unwrap();
+            let c = w.finish().unwrap();
+            assert!(a == b && b == c && c == v);
+        }
+    }
+
+    #[test]
+    fn zero_length_read_with_data() {
+        let m = vec![3u8; 128 * 1024 + 1];
+        let mut c = read::DeflateEncoder::new(&m[..], Compression::default());
+
+        let mut result = Vec::new();
+        c.read_to_end(&mut result).unwrap();
+
+        let mut d = read::DeflateDecoder::new(&result[..]);
+        let mut data = Vec::new();
+        assert!(d.read(&mut data).unwrap() == 0);
+    }
+
+    #[test]
+    fn qc_reader() {
+        ::quickcheck::quickcheck(test as fn(_) -> _);
+
+        fn test(v: Vec<u8>) -> bool {
+            let mut r = read::DeflateDecoder::new(read::DeflateEncoder::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::DeflateEncoder::new(
+                write::DeflateDecoder::new(Vec::new()),
+                Compression::default(),
+            );
+            w.write_all(&v).unwrap();
+            v == w.finish().unwrap().finish().unwrap()
+        }
+    }
+}
diff --git a/third_party/rust/flate2/src/deflate/read.rs b/third_party/rust/flate2/src/deflate/read.rs
new file mode 100644
index 0000000000..fd17a894af
--- /dev/null
+++ b/third_party/rust/flate2/src/deflate/read.rs
@@ -0,0 +1,241 @@
+use std::io;
+use std::io::prelude::*;
+
+use super::bufread;
+use crate::bufreader::BufReader;
+
+/// A DEFLATE 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 std::io;
+/// use flate2::Compression;
+/// use flate2::read::DeflateEncoder;
+///
+/// # fn main() {
+/// #    println!("{:?}", deflateencoder_read_hello_world().unwrap());
+/// # }
+/// #
+/// // Return a vector containing the Deflate compressed version of hello world
+/// fn deflateencoder_read_hello_world() -> io::Result<Vec<u8>> {
+///    let mut ret_vec = [0;100];
+///    let c = b"hello world";
+///    let mut deflater = DeflateEncoder::new(&c[..], Compression::fast());
+///    let count = deflater.read(&mut ret_vec)?;
+///    Ok(ret_vec[0..count].to_vec())
+/// }
+/// ```
+#[derive(Debug)]
+pub struct DeflateEncoder<R> {
+    inner: bufread::DeflateEncoder<BufReader<R>>,
+}
+
+impl<R: Read> 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: crate::Compression) -> DeflateEncoder<R> {
+        DeflateEncoder {
+            inner: bufread::DeflateEncoder::new(BufReader::new(r), level),
+        }
+    }
+}
+
+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.
+    ///
+    /// 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 reader
+    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 DeflateEncoder<R> {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.inner.read(buf)
+    }
+}
+
+impl<W: Read + 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()
+    }
+}
+
+/// A DEFLATE 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::DeflateEncoder;
+/// use flate2::read::DeflateDecoder;
+///
+/// # fn main() {
+/// #    let mut e = DeflateEncoder::new(Vec::new(), Compression::default());
+/// #    e.write_all(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> {
+    inner: bufread::DeflateDecoder<BufReader<R>>,
+}
+
+impl<R: Read> DeflateDecoder<R> {
+    /// Creates a new decoder which will decompress data read from the given
+    /// stream.
+    pub fn new(r: R) -> DeflateDecoder<R> {
+        DeflateDecoder::new_with_buf(r, vec![0; 32 * 1024])
+    }
+
+    /// Same as `new`, but the intermediate buffer for data is specified.
+    ///
+    /// Note that the capacity of the intermediate buffer is never increased,
+    /// and it is recommended for it to be large.
+    pub fn new_with_buf(r: R, buf: Vec<u8>) -> DeflateDecoder<R> {
+        DeflateDecoder {
+            inner: bufread::DeflateDecoder::new(BufReader::with_buf(buf, r)),
+        }
+    }
+}
+
+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.
+    ///
+    /// 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 DeflateDecoder<R> {
+    fn read(&mut self, into: &mut [u8]) -> io::Result<usize> {
+        self.inner.read(into)
+    }
+}
+
+impl<W: Read + 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()
+    }
+}
diff --git a/third_party/rust/flate2/src/deflate/write.rs b/third_party/rust/flate2/src/deflate/write.rs
new file mode 100644
index 0000000000..2c44556ac4
--- /dev/null
+++ b/third_party/rust/flate2/src/deflate/write.rs
@@ -0,0 +1,322 @@
+use std::io;
+use std::io::prelude::*;
+
+use crate::zio;
+use crate::{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_all(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: crate::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> {
+        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 DeflateEncoder<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 DeflateEncoder<W> {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.inner.get_mut().read(buf)
+    }
+}
+
+/// 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_all(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_all(&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> {
+        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> {
+        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()
+    }
+}
+
+impl<W: Read + Write> Read for DeflateDecoder<W> {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.inner.get_mut().read(buf)
+    }
+}
diff --git a/third_party/rust/flate2/src/ffi/c.rs b/third_party/rust/flate2/src/ffi/c.rs
new file mode 100644
index 0000000000..59e20118fb
--- /dev/null
+++ b/third_party/rust/flate2/src/ffi/c.rs
@@ -0,0 +1,421 @@
+//! Implementation for C backends.
+use std::alloc::{self, Layout};
+use std::cmp;
+use std::convert::TryFrom;
+use std::fmt;
+use std::marker;
+use std::ops::{Deref, DerefMut};
+use std::os::raw::{c_int, c_uint, c_void};
+use std::ptr;
+
+use super::*;
+use crate::mem::{self, FlushDecompress, Status};
+
+#[derive(Default)]
+pub struct ErrorMessage(Option<&'static str>);
+
+impl ErrorMessage {
+    pub fn get(&self) -> Option<&str> {
+        self.0
+    }
+}
+
+pub struct StreamWrapper {
+    pub inner: Box<mz_stream>,
+}
+
+impl fmt::Debug for StreamWrapper {
+    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        write!(f, "StreamWrapper")
+    }
+}
+
+impl Default for StreamWrapper {
+    fn default() -> StreamWrapper {
+        StreamWrapper {
+            inner: Box::new(mz_stream {
+                next_in: ptr::null_mut(),
+                avail_in: 0,
+                total_in: 0,
+                next_out: ptr::null_mut(),
+                avail_out: 0,
+                total_out: 0,
+                msg: ptr::null_mut(),
+                adler: 0,
+                data_type: 0,
+                reserved: 0,
+                opaque: ptr::null_mut(),
+                state: ptr::null_mut(),
+                #[cfg(all(feature = "any_zlib", not(feature = "cloudflare-zlib-sys")))]
+                zalloc,
+                #[cfg(all(feature = "any_zlib", not(feature = "cloudflare-zlib-sys")))]
+                zfree,
+                #[cfg(not(all(feature = "any_zlib", not(feature = "cloudflare-zlib-sys"))))]
+                zalloc: Some(zalloc),
+                #[cfg(not(all(feature = "any_zlib", not(feature = "cloudflare-zlib-sys"))))]
+                zfree: Some(zfree),
+            }),
+        }
+    }
+}
+
+const ALIGN: usize = std::mem::align_of::<usize>();
+
+fn align_up(size: usize, align: usize) -> usize {
+    (size + align - 1) & !(align - 1)
+}
+
+extern "C" fn zalloc(_ptr: *mut c_void, items: AllocSize, item_size: AllocSize) -> *mut c_void {
+    // We need to multiply `items` and `item_size` to get the actual desired
+    // allocation size. Since `zfree` doesn't receive a size argument we
+    // also need to allocate space for a `usize` as a header so we can store
+    // how large the allocation is to deallocate later.
+    let size = match items
+        .checked_mul(item_size)
+        .and_then(|i| usize::try_from(i).ok())
+        .map(|size| align_up(size, ALIGN))
+        .and_then(|i| i.checked_add(std::mem::size_of::<usize>()))
+    {
+        Some(i) => i,
+        None => return ptr::null_mut(),
+    };
+
+    // Make sure the `size` isn't too big to fail `Layout`'s restrictions
+    let layout = match Layout::from_size_align(size, ALIGN) {
+        Ok(layout) => layout,
+        Err(_) => return ptr::null_mut(),
+    };
+
+    unsafe {
+        // Allocate the data, and if successful store the size we allocated
+        // at the beginning and then return an offset pointer.
+        let ptr = alloc::alloc(layout) as *mut usize;
+        if ptr.is_null() {
+            return ptr as *mut c_void;
+        }
+        *ptr = size;
+        ptr.add(1) as *mut c_void
+    }
+}
+
+extern "C" fn zfree(_ptr: *mut c_void, address: *mut c_void) {
+    unsafe {
+        // Move our address being freed back one pointer, read the size we
+        // stored in `zalloc`, and then free it using the standard Rust
+        // allocator.
+        let ptr = (address as *mut usize).offset(-1);
+        let size = *ptr;
+        let layout = Layout::from_size_align_unchecked(size, ALIGN);
+        alloc::dealloc(ptr as *mut u8, layout)
+    }
+}
+
+impl Deref for StreamWrapper {
+    type Target = mz_stream;
+
+    fn deref(&self) -> &Self::Target {
+        &*self.inner
+    }
+}
+
+impl DerefMut for StreamWrapper {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut *self.inner
+    }
+}
+
+unsafe impl<D: Direction> Send for Stream<D> {}
+unsafe impl<D: Direction> Sync for Stream<D> {}
+
+/// Trait used to call the right destroy/end function on the inner
+/// stream object on drop.
+pub trait Direction {
+    unsafe fn destroy(stream: *mut mz_stream) -> c_int;
+}
+
+#[derive(Debug)]
+pub enum DirCompress {}
+#[derive(Debug)]
+pub enum DirDecompress {}
+
+#[derive(Debug)]
+pub struct Stream<D: Direction> {
+    pub stream_wrapper: StreamWrapper,
+    pub total_in: u64,
+    pub total_out: u64,
+    pub _marker: marker::PhantomData<D>,
+}
+
+impl<D: Direction> Stream<D> {
+    pub fn msg(&self) -> ErrorMessage {
+        let msg = self.stream_wrapper.msg;
+        ErrorMessage(if msg.is_null() {
+            None
+        } else {
+            let s = unsafe { std::ffi::CStr::from_ptr(msg) };
+            std::str::from_utf8(s.to_bytes()).ok()
+        })
+    }
+}
+
+impl<D: Direction> Drop for Stream<D> {
+    fn drop(&mut self) {
+        unsafe {
+            let _ = D::destroy(&mut *self.stream_wrapper);
+        }
+    }
+}
+
+impl Direction for DirCompress {
+    unsafe fn destroy(stream: *mut mz_stream) -> c_int {
+        mz_deflateEnd(stream)
+    }
+}
+impl Direction for DirDecompress {
+    unsafe fn destroy(stream: *mut mz_stream) -> c_int {
+        mz_inflateEnd(stream)
+    }
+}
+
+#[derive(Debug)]
+pub struct Inflate {
+    pub inner: Stream<DirDecompress>,
+}
+
+impl InflateBackend for Inflate {
+    fn make(zlib_header: bool, window_bits: u8) -> Self {
+        unsafe {
+            let mut state = StreamWrapper::default();
+            let ret = mz_inflateInit2(
+                &mut *state,
+                if zlib_header {
+                    window_bits as c_int
+                } else {
+                    -(window_bits as c_int)
+                },
+            );
+            assert_eq!(ret, 0);
+            Inflate {
+                inner: Stream {
+                    stream_wrapper: state,
+                    total_in: 0,
+                    total_out: 0,
+                    _marker: marker::PhantomData,
+                },
+            }
+        }
+    }
+
+    fn decompress(
+        &mut self,
+        input: &[u8],
+        output: &mut [u8],
+        flush: FlushDecompress,
+    ) -> Result<Status, DecompressError> {
+        let raw = &mut *self.inner.stream_wrapper;
+        raw.msg = ptr::null_mut();
+        raw.next_in = input.as_ptr() as *mut u8;
+        raw.avail_in = cmp::min(input.len(), c_uint::max_value() as usize) as c_uint;
+        raw.next_out = output.as_mut_ptr();
+        raw.avail_out = cmp::min(output.len(), c_uint::max_value() as usize) as c_uint;
+
+        let rc = unsafe { mz_inflate(raw, flush as c_int) };
+
+        // Unfortunately the total counters provided by zlib might be only
+        // 32 bits wide and overflow while processing large amounts of data.
+        self.inner.total_in += (raw.next_in as usize - input.as_ptr() as usize) as u64;
+        self.inner.total_out += (raw.next_out as usize - output.as_ptr() as usize) as u64;
+
+        match rc {
+            MZ_DATA_ERROR | MZ_STREAM_ERROR => mem::decompress_failed(self.inner.msg()),
+            MZ_OK => Ok(Status::Ok),
+            MZ_BUF_ERROR => Ok(Status::BufError),
+            MZ_STREAM_END => Ok(Status::StreamEnd),
+            MZ_NEED_DICT => mem::decompress_need_dict(raw.adler as u32),
+            c => panic!("unknown return code: {}", c),
+        }
+    }
+
+    fn reset(&mut self, zlib_header: bool) {
+        let bits = if zlib_header {
+            MZ_DEFAULT_WINDOW_BITS
+        } else {
+            -MZ_DEFAULT_WINDOW_BITS
+        };
+        unsafe {
+            inflateReset2(&mut *self.inner.stream_wrapper, bits);
+        }
+        self.inner.total_out = 0;
+        self.inner.total_in = 0;
+    }
+}
+
+impl Backend for Inflate {
+    #[inline]
+    fn total_in(&self) -> u64 {
+        self.inner.total_in
+    }
+
+    #[inline]
+    fn total_out(&self) -> u64 {
+        self.inner.total_out
+    }
+}
+
+#[derive(Debug)]
+pub struct Deflate {
+    pub inner: Stream<DirCompress>,
+}
+
+impl DeflateBackend for Deflate {
+    fn make(level: Compression, zlib_header: bool, window_bits: u8) -> Self {
+        unsafe {
+            let mut state = StreamWrapper::default();
+            let ret = mz_deflateInit2(
+                &mut *state,
+                level.0 as c_int,
+                MZ_DEFLATED,
+                if zlib_header {
+                    window_bits as c_int
+                } else {
+                    -(window_bits as c_int)
+                },
+                8,
+                MZ_DEFAULT_STRATEGY,
+            );
+            assert_eq!(ret, 0);
+            Deflate {
+                inner: Stream {
+                    stream_wrapper: state,
+                    total_in: 0,
+                    total_out: 0,
+                    _marker: marker::PhantomData,
+                },
+            }
+        }
+    }
+    fn compress(
+        &mut self,
+        input: &[u8],
+        output: &mut [u8],
+        flush: FlushCompress,
+    ) -> Result<Status, CompressError> {
+        let raw = &mut *self.inner.stream_wrapper;
+        raw.msg = ptr::null_mut();
+        raw.next_in = input.as_ptr() as *mut _;
+        raw.avail_in = cmp::min(input.len(), c_uint::max_value() as usize) as c_uint;
+        raw.next_out = output.as_mut_ptr();
+        raw.avail_out = cmp::min(output.len(), c_uint::max_value() as usize) as c_uint;
+
+        let rc = unsafe { mz_deflate(raw, flush as c_int) };
+
+        // Unfortunately the total counters provided by zlib might be only
+        // 32 bits wide and overflow while processing large amounts of data.
+        self.inner.total_in += (raw.next_in as usize - input.as_ptr() as usize) as u64;
+        self.inner.total_out += (raw.next_out as usize - output.as_ptr() as usize) as u64;
+
+        match rc {
+            MZ_OK => Ok(Status::Ok),
+            MZ_BUF_ERROR => Ok(Status::BufError),
+            MZ_STREAM_END => Ok(Status::StreamEnd),
+            MZ_STREAM_ERROR => mem::compress_failed(self.inner.msg()),
+            c => panic!("unknown return code: {}", c),
+        }
+    }
+
+    fn reset(&mut self) {
+        self.inner.total_in = 0;
+        self.inner.total_out = 0;
+        let rc = unsafe { mz_deflateReset(&mut *self.inner.stream_wrapper) };
+        assert_eq!(rc, MZ_OK);
+    }
+}
+
+impl Backend for Deflate {
+    #[inline]
+    fn total_in(&self) -> u64 {
+        self.inner.total_in
+    }
+
+    #[inline]
+    fn total_out(&self) -> u64 {
+        self.inner.total_out
+    }
+}
+
+pub use self::c_backend::*;
+
+/// For backwards compatibility, we provide symbols as `mz_` to mimic the miniz API
+#[allow(bad_style)]
+mod c_backend {
+    use std::mem;
+    use std::os::raw::{c_char, c_int};
+
+    #[cfg(feature = "zlib-ng")]
+    use libz_ng_sys as libz;
+
+    #[cfg(all(not(feature = "zlib-ng"), feature = "cloudflare_zlib"))]
+    use cloudflare_zlib_sys as libz;
+
+    #[cfg(all(not(feature = "cloudflare_zlib"), not(feature = "zlib-ng")))]
+    use libz_sys as libz;
+
+    pub use libz::deflate as mz_deflate;
+    pub use libz::deflateEnd as mz_deflateEnd;
+    pub use libz::deflateReset as mz_deflateReset;
+    pub use libz::inflate as mz_inflate;
+    pub use libz::inflateEnd as mz_inflateEnd;
+    pub use libz::z_stream as mz_stream;
+    pub use libz::*;
+
+    pub use libz::Z_BLOCK as MZ_BLOCK;
+    pub use libz::Z_BUF_ERROR as MZ_BUF_ERROR;
+    pub use libz::Z_DATA_ERROR as MZ_DATA_ERROR;
+    pub use libz::Z_DEFAULT_STRATEGY as MZ_DEFAULT_STRATEGY;
+    pub use libz::Z_DEFLATED as MZ_DEFLATED;
+    pub use libz::Z_FINISH as MZ_FINISH;
+    pub use libz::Z_FULL_FLUSH as MZ_FULL_FLUSH;
+    pub use libz::Z_NEED_DICT as MZ_NEED_DICT;
+    pub use libz::Z_NO_FLUSH as MZ_NO_FLUSH;
+    pub use libz::Z_OK as MZ_OK;
+    pub use libz::Z_PARTIAL_FLUSH as MZ_PARTIAL_FLUSH;
+    pub use libz::Z_STREAM_END as MZ_STREAM_END;
+    pub use libz::Z_STREAM_ERROR as MZ_STREAM_ERROR;
+    pub use libz::Z_SYNC_FLUSH as MZ_SYNC_FLUSH;
+    pub type AllocSize = libz::uInt;
+
+    pub const MZ_DEFAULT_WINDOW_BITS: c_int = 15;
+
+    #[cfg(feature = "zlib-ng")]
+    const ZLIB_VERSION: &'static str = "2.1.0.devel\0";
+    #[cfg(not(feature = "zlib-ng"))]
+    const ZLIB_VERSION: &'static str = "1.2.8\0";
+
+    pub unsafe extern "C" fn mz_deflateInit2(
+        stream: *mut mz_stream,
+        level: c_int,
+        method: c_int,
+        window_bits: c_int,
+        mem_level: c_int,
+        strategy: c_int,
+    ) -> c_int {
+        libz::deflateInit2_(
+            stream,
+            level,
+            method,
+            window_bits,
+            mem_level,
+            strategy,
+            ZLIB_VERSION.as_ptr() as *const c_char,
+            mem::size_of::<mz_stream>() as c_int,
+        )
+    }
+    pub unsafe extern "C" fn mz_inflateInit2(stream: *mut mz_stream, window_bits: c_int) -> c_int {
+        libz::inflateInit2_(
+            stream,
+            window_bits,
+            ZLIB_VERSION.as_ptr() as *const c_char,
+            mem::size_of::<mz_stream>() as c_int,
+        )
+    }
+}
diff --git a/third_party/rust/flate2/src/ffi/mod.rs b/third_party/rust/flate2/src/ffi/mod.rs
new file mode 100644
index 0000000000..8bac6e4232
--- /dev/null
+++ b/third_party/rust/flate2/src/ffi/mod.rs
@@ -0,0 +1,52 @@
+//! This module contains backend-specific code.
+
+use crate::mem::{CompressError, DecompressError, FlushCompress, FlushDecompress, Status};
+use crate::Compression;
+
+/// Traits specifying the interface of the backends.
+///
+/// Sync + Send are added as a condition to ensure they are available
+/// for the frontend.
+pub trait Backend: Sync + Send {
+    fn total_in(&self) -> u64;
+    fn total_out(&self) -> u64;
+}
+
+pub trait InflateBackend: Backend {
+    fn make(zlib_header: bool, window_bits: u8) -> Self;
+    fn decompress(
+        &mut self,
+        input: &[u8],
+        output: &mut [u8],
+        flush: FlushDecompress,
+    ) -> Result<Status, DecompressError>;
+    fn reset(&mut self, zlib_header: bool);
+}
+
+pub trait DeflateBackend: Backend {
+    fn make(level: Compression, zlib_header: bool, window_bits: u8) -> Self;
+    fn compress(
+        &mut self,
+        input: &[u8],
+        output: &mut [u8],
+        flush: FlushCompress,
+    ) -> Result<Status, CompressError>;
+    fn reset(&mut self);
+}
+
+// Default to Rust implementation unless explicitly opted in to a different backend.
+#[cfg(feature = "any_zlib")]
+mod c;
+#[cfg(feature = "any_zlib")]
+pub use self::c::*;
+
+#[cfg(not(feature = "any_zlib"))]
+mod rust;
+#[cfg(not(feature = "any_zlib"))]
+pub use self::rust::*;
+
+impl std::fmt::Debug for ErrorMessage {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        self.get().fmt(f)
+    }
+}
diff --git a/third_party/rust/flate2/src/ffi/rust.rs b/third_party/rust/flate2/src/ffi/rust.rs
new file mode 100644
index 0000000000..eadd6ec187
--- /dev/null
+++ b/third_party/rust/flate2/src/ffi/rust.rs
@@ -0,0 +1,183 @@
+//! Implementation for miniz_oxide rust backend.
+
+use std::convert::TryInto;
+use std::fmt;
+
+use miniz_oxide::deflate::core::CompressorOxide;
+use miniz_oxide::inflate::stream::InflateState;
+pub use miniz_oxide::*;
+
+pub const MZ_NO_FLUSH: isize = MZFlush::None as isize;
+pub const MZ_PARTIAL_FLUSH: isize = MZFlush::Partial as isize;
+pub const MZ_SYNC_FLUSH: isize = MZFlush::Sync as isize;
+pub const MZ_FULL_FLUSH: isize = MZFlush::Full as isize;
+pub const MZ_FINISH: isize = MZFlush::Finish as isize;
+
+use super::*;
+use crate::mem;
+
+// miniz_oxide doesn't provide any error messages (yet?)
+#[derive(Default)]
+pub struct ErrorMessage;
+
+impl ErrorMessage {
+    pub fn get(&self) -> Option<&str> {
+        None
+    }
+}
+
+fn format_from_bool(zlib_header: bool) -> DataFormat {
+    if zlib_header {
+        DataFormat::Zlib
+    } else {
+        DataFormat::Raw
+    }
+}
+
+pub struct Inflate {
+    inner: Box<InflateState>,
+    total_in: u64,
+    total_out: u64,
+}
+
+impl fmt::Debug for Inflate {
+    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        write!(
+            f,
+            "miniz_oxide inflate internal state. total_in: {}, total_out: {}",
+            self.total_in, self.total_out,
+        )
+    }
+}
+
+impl InflateBackend for Inflate {
+    fn make(zlib_header: bool, _window_bits: u8) -> Self {
+        let format = format_from_bool(zlib_header);
+
+        Inflate {
+            inner: InflateState::new_boxed(format),
+            total_in: 0,
+            total_out: 0,
+        }
+    }
+
+    fn decompress(
+        &mut self,
+        input: &[u8],
+        output: &mut [u8],
+        flush: FlushDecompress,
+    ) -> Result<Status, DecompressError> {
+        let flush = MZFlush::new(flush as i32).unwrap();
+
+        let res = inflate::stream::inflate(&mut self.inner, input, output, flush);
+        self.total_in += res.bytes_consumed as u64;
+        self.total_out += res.bytes_written as u64;
+
+        match res.status {
+            Ok(status) => match status {
+                MZStatus::Ok => Ok(Status::Ok),
+                MZStatus::StreamEnd => Ok(Status::StreamEnd),
+                MZStatus::NeedDict => {
+                    mem::decompress_need_dict(self.inner.decompressor().adler32().unwrap_or(0))
+                }
+            },
+            Err(status) => match status {
+                MZError::Buf => Ok(Status::BufError),
+                _ => mem::decompress_failed(ErrorMessage),
+            },
+        }
+    }
+
+    fn reset(&mut self, zlib_header: bool) {
+        self.inner.reset(format_from_bool(zlib_header));
+        self.total_in = 0;
+        self.total_out = 0;
+    }
+}
+
+impl Backend for Inflate {
+    #[inline]
+    fn total_in(&self) -> u64 {
+        self.total_in
+    }
+
+    #[inline]
+    fn total_out(&self) -> u64 {
+        self.total_out
+    }
+}
+
+pub struct Deflate {
+    inner: Box<CompressorOxide>,
+    total_in: u64,
+    total_out: u64,
+}
+
+impl fmt::Debug for Deflate {
+    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        write!(
+            f,
+            "miniz_oxide deflate internal state. total_in: {}, total_out: {}",
+            self.total_in, self.total_out,
+        )
+    }
+}
+
+impl DeflateBackend for Deflate {
+    fn make(level: Compression, zlib_header: bool, _window_bits: u8) -> Self {
+        // Check in case the integer value changes at some point.
+        debug_assert!(level.level() <= 10);
+
+        let mut inner: Box<CompressorOxide> = Box::default();
+        let format = format_from_bool(zlib_header);
+        inner.set_format_and_level(format, level.level().try_into().unwrap_or(1));
+
+        Deflate {
+            inner,
+            total_in: 0,
+            total_out: 0,
+        }
+    }
+
+    fn compress(
+        &mut self,
+        input: &[u8],
+        output: &mut [u8],
+        flush: FlushCompress,
+    ) -> Result<Status, CompressError> {
+        let flush = MZFlush::new(flush as i32).unwrap();
+        let res = deflate::stream::deflate(&mut self.inner, input, output, flush);
+        self.total_in += res.bytes_consumed as u64;
+        self.total_out += res.bytes_written as u64;
+
+        match res.status {
+            Ok(status) => match status {
+                MZStatus::Ok => Ok(Status::Ok),
+                MZStatus::StreamEnd => Ok(Status::StreamEnd),
+                MZStatus::NeedDict => mem::compress_failed(ErrorMessage),
+            },
+            Err(status) => match status {
+                MZError::Buf => Ok(Status::BufError),
+                _ => mem::compress_failed(ErrorMessage),
+            },
+        }
+    }
+
+    fn reset(&mut self) {
+        self.total_in = 0;
+        self.total_out = 0;
+        self.inner.reset();
+    }
+}
+
+impl Backend for Deflate {
+    #[inline]
+    fn total_in(&self) -> u64 {
+        self.total_in
+    }
+
+    #[inline]
+    fn total_out(&self) -> u64 {
+        self.total_out
+    }
+}
diff --git a/third_party/rust/flate2/src/gz/bufread.rs b/third_party/rust/flate2/src/gz/bufread.rs
new file mode 100644
index 0000000000..6be144d0c8
--- /dev/null
+++ b/third_party/rust/flate2/src/gz/bufread.rs
@@ -0,0 +1,852 @@
+use std::cmp;
+use std::io;
+use std::io::prelude::*;
+use std::mem;
+
+use super::{GzBuilder, GzHeader};
+use super::{FCOMMENT, FEXTRA, FHCRC, FNAME};
+use crate::crc::{Crc, CrcReader};
+use crate::deflate;
+use crate::Compression;
+
+fn copy(into: &mut [u8], from: &[u8], pos: &mut usize) -> usize {
+    let min = cmp::min(into.len(), from.len() - *pos);
+    for (slot, val) in into.iter_mut().zip(from[*pos..*pos + min].iter()) {
+        *slot = *val;
+    }
+    *pos += min;
+    min
+}
+
+pub(crate) fn corrupt() -> io::Error {
+    io::Error::new(
+        io::ErrorKind::InvalidInput,
+        "corrupt gzip stream does not have a matching checksum",
+    )
+}
+
+fn bad_header() -> io::Error {
+    io::Error::new(io::ErrorKind::InvalidInput, "invalid gzip header")
+}
+
+fn read_le_u16<R: Read>(r: &mut Buffer<R>) -> io::Result<u16> {
+    let mut b = [0; 2];
+    r.read_and_forget(&mut b)?;
+    Ok((b[0] as u16) | ((b[1] as u16) << 8))
+}
+
+fn read_gz_header_part<'a, R: Read>(r: &'a mut Buffer<'a, R>) -> io::Result<()> {
+    loop {
+        match r.part.state {
+            GzHeaderParsingState::Start => {
+                let mut header = [0; 10];
+                r.read_and_forget(&mut header)?;
+
+                if header[0] != 0x1f || header[1] != 0x8b {
+                    return Err(bad_header());
+                }
+                if header[2] != 8 {
+                    return Err(bad_header());
+                }
+
+                r.part.flg = header[3];
+                r.part.header.mtime = ((header[4] as u32) << 0)
+                    | ((header[5] as u32) << 8)
+                    | ((header[6] as u32) << 16)
+                    | ((header[7] as u32) << 24);
+                let _xfl = header[8];
+                r.part.header.operating_system = header[9];
+                r.part.state = GzHeaderParsingState::Xlen;
+            }
+            GzHeaderParsingState::Xlen => {
+                if r.part.flg & FEXTRA != 0 {
+                    r.part.xlen = read_le_u16(r)?;
+                }
+                r.part.state = GzHeaderParsingState::Extra;
+            }
+            GzHeaderParsingState::Extra => {
+                if r.part.flg & FEXTRA != 0 {
+                    let mut extra = vec![0; r.part.xlen as usize];
+                    r.read_and_forget(&mut extra)?;
+                    r.part.header.extra = Some(extra);
+                }
+                r.part.state = GzHeaderParsingState::Filename;
+            }
+            GzHeaderParsingState::Filename => {
+                if r.part.flg & FNAME != 0 {
+                    if None == r.part.header.filename {
+                        r.part.header.filename = Some(Vec::new());
+                    };
+                    for byte in r.bytes() {
+                        let byte = byte?;
+                        if byte == 0 {
+                            break;
+                        }
+                    }
+                }
+                r.part.state = GzHeaderParsingState::Comment;
+            }
+            GzHeaderParsingState::Comment => {
+                if r.part.flg & FCOMMENT != 0 {
+                    if None == r.part.header.comment {
+                        r.part.header.comment = Some(Vec::new());
+                    };
+                    for byte in r.bytes() {
+                        let byte = byte?;
+                        if byte == 0 {
+                            break;
+                        }
+                    }
+                }
+                r.part.state = GzHeaderParsingState::Crc;
+            }
+            GzHeaderParsingState::Crc => {
+                if r.part.flg & FHCRC != 0 {
+                    let stored_crc = read_le_u16(r)?;
+                    let calced_crc = r.part.crc.sum() as u16;
+                    if stored_crc != calced_crc {
+                        return Err(corrupt());
+                    }
+                }
+                return Ok(());
+            }
+        }
+    }
+}
+
+pub(crate) fn read_gz_header<R: Read>(r: &mut R) -> io::Result<GzHeader> {
+    let mut part = GzHeaderPartial::new();
+
+    let result = {
+        let mut reader = Buffer::new(&mut part, r);
+        read_gz_header_part(&mut reader)
+    };
+    result.map(|()| part.take_header())
+}
+
+/// A gzip streaming encoder
+///
+/// This structure exposes a [`BufRead`] interface that will read uncompressed data
+/// from the underlying reader and expose the compressed version as a [`BufRead`]
+/// interface.
+///
+/// [`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::GzEncoder;
+/// use std::fs::File;
+/// use std::io::BufReader;
+///
+/// // Opens sample file, compresses the contents and returns a Vector or error
+/// // File wrapped in a BufReader implements BufRead
+///
+/// fn open_hello_world() -> io::Result<Vec<u8>> {
+///     let f = File::open("examples/hello_world.txt")?;
+///     let b = BufReader::new(f);
+///     let mut gz = GzEncoder::new(b, Compression::fast());
+///     let mut buffer = Vec::new();
+///     gz.read_to_end(&mut buffer)?;
+///     Ok(buffer)
+/// }
+/// ```
+#[derive(Debug)]
+pub struct GzEncoder<R> {
+    inner: deflate::bufread::DeflateEncoder<CrcReader<R>>,
+    header: Vec<u8>,
+    pos: usize,
+    eof: bool,
+}
+
+pub fn gz_encoder<R: BufRead>(header: Vec<u8>, r: R, lvl: Compression) -> GzEncoder<R> {
+    let crc = CrcReader::new(r);
+    GzEncoder {
+        inner: deflate::bufread::DeflateEncoder::new(crc, lvl),
+        header,
+        pos: 0,
+        eof: false,
+    }
+}
+
+impl<R: BufRead> GzEncoder<R> {
+    /// Creates a new encoder which will use the given compression level.
+    ///
+    /// The encoder is not configured specially for the emitted header. For
+    /// header configuration, see the `GzBuilder` type.
+    ///
+    /// The data read from the stream `r` will be compressed and available
+    /// through the returned reader.
+    pub fn new(r: R, level: Compression) -> GzEncoder<R> {
+        GzBuilder::new().buf_read(r, level)
+    }
+
+    fn read_footer(&mut self, into: &mut [u8]) -> io::Result<usize> {
+        if self.pos == 8 {
+            return Ok(0);
+        }
+        let crc = self.inner.get_ref().crc();
+        let ref arr = [
+            (crc.sum() >> 0) as u8,
+            (crc.sum() >> 8) as u8,
+            (crc.sum() >> 16) as u8,
+            (crc.sum() >> 24) as u8,
+            (crc.amount() >> 0) as u8,
+            (crc.amount() >> 8) as u8,
+            (crc.amount() >> 16) as u8,
+            (crc.amount() >> 24) as u8,
+        ];
+        Ok(copy(into, arr, &mut self.pos))
+    }
+}
+
+impl<R> GzEncoder<R> {
+    /// Acquires a reference to the underlying reader.
+    pub fn get_ref(&self) -> &R {
+        self.inner.get_ref().get_ref()
+    }
+
+    /// Acquires a mutable reference to the underlying reader.
+    ///
+    /// Note that mutation of the reader 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()
+    }
+
+    /// Returns the underlying stream, consuming this encoder
+    pub fn into_inner(self) -> R {
+        self.inner.into_inner().into_inner()
+    }
+}
+
+#[inline]
+fn finish(buf: &[u8; 8]) -> (u32, u32) {
+    let crc = ((buf[0] as u32) << 0)
+        | ((buf[1] as u32) << 8)
+        | ((buf[2] as u32) << 16)
+        | ((buf[3] as u32) << 24);
+    let amt = ((buf[4] as u32) << 0)
+        | ((buf[5] as u32) << 8)
+        | ((buf[6] as u32) << 16)
+        | ((buf[7] as u32) << 24);
+    (crc, amt)
+}
+
+impl<R: BufRead> Read for GzEncoder<R> {
+    fn read(&mut self, mut into: &mut [u8]) -> io::Result<usize> {
+        let mut amt = 0;
+        if self.eof {
+            return self.read_footer(into);
+        } else if self.pos < self.header.len() {
+            amt += copy(into, &self.header, &mut self.pos);
+            if amt == into.len() {
+                return Ok(amt);
+            }
+            let tmp = into;
+            into = &mut tmp[amt..];
+        }
+        match self.inner.read(into)? {
+            0 => {
+                self.eof = true;
+                self.pos = 0;
+                self.read_footer(into)
+            }
+            n => Ok(amt + n),
+        }
+    }
+}
+
+impl<R: BufRead + Write> Write for GzEncoder<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 gzip streaming decoder
+///
+/// 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::GzEncoder;
+/// use flate2::bufread::GzDecoder;
+///
+/// # fn main() {
+/// #   let mut e = GzEncoder::new(Vec::new(), Compression::default());
+/// #   e.write_all(b"Hello World").unwrap();
+/// #   let bytes = e.finish().unwrap();
+/// #   println!("{}", decode_reader(bytes).unwrap());
+/// # }
+/// #
+/// // Uncompresses a Gz Encoded vector of bytes and returns a string or error
+/// // Here &[u8] implements BufRead
+///
+/// fn decode_reader(bytes: Vec<u8>) -> io::Result<String> {
+///    let mut gz = GzDecoder::new(&bytes[..]);
+///    let mut s = String::new();
+///    gz.read_to_string(&mut s)?;
+///    Ok(s)
+/// }
+/// ```
+#[derive(Debug)]
+pub struct GzDecoder<R> {
+    inner: GzState,
+    header: Option<GzHeader>,
+    reader: CrcReader<deflate::bufread::DeflateDecoder<R>>,
+    multi: bool,
+}
+
+#[derive(Debug)]
+pub enum GzHeaderParsingState {
+    Start,
+    Xlen,
+    Extra,
+    Filename,
+    Comment,
+    Crc,
+}
+
+#[derive(Debug)]
+pub struct GzHeaderPartial {
+    buf: Vec<u8>,
+    state: GzHeaderParsingState,
+    flg: u8,
+    xlen: u16,
+    crc: Crc,
+    header: GzHeader,
+}
+
+impl GzHeaderPartial {
+    fn new() -> GzHeaderPartial {
+        GzHeaderPartial {
+            buf: Vec::with_capacity(10), // minimum header length
+            state: GzHeaderParsingState::Start,
+            flg: 0,
+            xlen: 0,
+            crc: Crc::new(),
+            header: GzHeader {
+                extra: None,
+                filename: None,
+                comment: None,
+                operating_system: 0,
+                mtime: 0,
+            },
+        }
+    }
+
+    pub fn take_header(self) -> GzHeader {
+        self.header
+    }
+}
+
+#[derive(Debug)]
+enum GzState {
+    Header(GzHeaderPartial),
+    Body,
+    Finished(usize, [u8; 8]),
+    Err(io::Error),
+    End,
+}
+
+/// A small adapter which reads data originally from `buf` and then reads all
+/// further data from `reader`. This will also buffer all data read from
+/// `reader` into `buf` for reuse on a further call.
+struct Buffer<'a, T: 'a> {
+    part: &'a mut GzHeaderPartial,
+    buf_cur: usize,
+    buf_max: usize,
+    reader: &'a mut T,
+}
+
+impl<'a, T> Buffer<'a, T> {
+    fn new(part: &'a mut GzHeaderPartial, reader: &'a mut T) -> Buffer<'a, T> {
+        Buffer {
+            reader,
+            buf_cur: 0,
+            buf_max: part.buf.len(),
+            part,
+        }
+    }
+}
+
+impl<'a, T: Read> Read for Buffer<'a, T> {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        let mut bufref = match self.part.state {
+            GzHeaderParsingState::Filename => self.part.header.filename.as_mut(),
+            GzHeaderParsingState::Comment => self.part.header.comment.as_mut(),
+            _ => None,
+        };
+        if let Some(ref mut b) = bufref {
+            // we have a direct reference to a buffer where to write
+            let len = self.reader.read(buf)?;
+            if len > 0 && buf[len - 1] == 0 {
+                // we do not append the final 0
+                b.extend_from_slice(&buf[..len - 1]);
+            } else {
+                b.extend_from_slice(&buf[..len]);
+            }
+            self.part.crc.update(&buf[..len]);
+            Ok(len)
+        } else if self.buf_cur == self.buf_max {
+            // we read new bytes and also save them in self.part.buf
+            let len = self.reader.read(buf)?;
+            self.part.buf.extend_from_slice(&buf[..len]);
+            self.part.crc.update(&buf[..len]);
+            Ok(len)
+        } else {
+            // we first read the previously saved bytes
+            let len = (&self.part.buf[self.buf_cur..self.buf_max]).read(buf)?;
+            self.buf_cur += len;
+            Ok(len)
+        }
+    }
+}
+
+impl<'a, T> Buffer<'a, T>
+where
+    T: std::io::Read,
+{
+    // If we manage to read all the bytes, we reset the buffer
+    fn read_and_forget(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.read_exact(buf)?;
+        // we managed to read the whole buf
+        // we will no longer need the previously saved bytes in self.part.buf
+        let rlen = buf.len();
+        self.part.buf.truncate(0);
+        self.buf_cur = 0;
+        self.buf_max = 0;
+        Ok(rlen)
+    }
+}
+
+impl<R: BufRead> GzDecoder<R> {
+    /// Creates a new decoder from the given reader, immediately parsing the
+    /// gzip header.
+    pub fn new(mut r: R) -> GzDecoder<R> {
+        let mut part = GzHeaderPartial::new();
+        let mut header = None;
+
+        let result = {
+            let mut reader = Buffer::new(&mut part, &mut r);
+            read_gz_header_part(&mut reader)
+        };
+
+        let state = match result {
+            Ok(()) => {
+                header = Some(part.take_header());
+                GzState::Body
+            }
+            Err(ref err) if io::ErrorKind::WouldBlock == err.kind() => GzState::Header(part),
+            Err(err) => GzState::Err(err),
+        };
+
+        GzDecoder {
+            inner: state,
+            reader: CrcReader::new(deflate::bufread::DeflateDecoder::new(r)),
+            multi: false,
+            header,
+        }
+    }
+
+    fn multi(mut self, flag: bool) -> GzDecoder<R> {
+        self.multi = flag;
+        self
+    }
+}
+
+impl<R> GzDecoder<R> {
+    /// Returns the header associated with this stream, if it was valid
+    pub fn header(&self) -> Option<&GzHeader> {
+        self.header.as_ref()
+    }
+
+    /// Acquires a reference to the underlying reader.
+    pub fn get_ref(&self) -> &R {
+        self.reader.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.reader.get_mut().get_mut()
+    }
+
+    /// Consumes this decoder, returning the underlying reader.
+    pub fn into_inner(self) -> R {
+        self.reader.into_inner().into_inner()
+    }
+}
+
+impl<R: BufRead> Read for GzDecoder<R> {
+    fn read(&mut self, into: &mut [u8]) -> io::Result<usize> {
+        let GzDecoder {
+            inner,
+            header,
+            reader,
+            multi,
+        } = self;
+
+        loop {
+            *inner = match mem::replace(inner, GzState::End) {
+                GzState::Header(mut part) => {
+                    let result = {
+                        let mut reader = Buffer::new(&mut part, reader.get_mut().get_mut());
+                        read_gz_header_part(&mut reader)
+                    };
+                    match result {
+                        Ok(()) => {
+                            *header = Some(part.take_header());
+                            GzState::Body
+                        }
+                        Err(err) if io::ErrorKind::WouldBlock == err.kind() => {
+                            *inner = GzState::Header(part);
+                            return Err(err);
+                        }
+                        Err(err) => return Err(err),
+                    }
+                }
+                GzState::Body => {
+                    if into.is_empty() {
+                        *inner = GzState::Body;
+                        return Ok(0);
+                    }
+
+                    let n = reader.read(into).map_err(|err| {
+                        if io::ErrorKind::WouldBlock == err.kind() {
+                            *inner = GzState::Body;
+                        }
+
+                        err
+                    })?;
+
+                    match n {
+                        0 => GzState::Finished(0, [0; 8]),
+                        n => {
+                            *inner = GzState::Body;
+                            return Ok(n);
+                        }
+                    }
+                }
+                GzState::Finished(pos, mut buf) => {
+                    if pos < buf.len() {
+                        let n = reader
+                            .get_mut()
+                            .get_mut()
+                            .read(&mut buf[pos..])
+                            .and_then(|n| {
+                                if n == 0 {
+                                    Err(io::ErrorKind::UnexpectedEof.into())
+                                } else {
+                                    Ok(n)
+                                }
+                            })
+                            .map_err(|err| {
+                                if io::ErrorKind::WouldBlock == err.kind() {
+                                    *inner = GzState::Finished(pos, buf);
+                                }
+
+                                err
+                            })?;
+
+                        GzState::Finished(pos + n, buf)
+                    } else {
+                        let (crc, amt) = finish(&buf);
+
+                        if crc != reader.crc().sum() || amt != reader.crc().amount() {
+                            return Err(corrupt());
+                        } else if *multi {
+                            let is_eof = reader
+                                .get_mut()
+                                .get_mut()
+                                .fill_buf()
+                                .map(|buf| buf.is_empty())
+                                .map_err(|err| {
+                                    if io::ErrorKind::WouldBlock == err.kind() {
+                                        *inner = GzState::Finished(pos, buf);
+                                    }
+
+                                    err
+                                })?;
+
+                            if is_eof {
+                                GzState::End
+                            } else {
+                                reader.reset();
+                                reader.get_mut().reset_data();
+                                header.take();
+                                GzState::Header(GzHeaderPartial::new())
+                            }
+                        } else {
+                            GzState::End
+                        }
+                    }
+                }
+                GzState::Err(err) => return Err(err),
+                GzState::End => return Ok(0),
+            };
+        }
+    }
+}
+
+impl<R: BufRead + Write> Write for GzDecoder<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 gzip streaming decoder that decodes all members of a multistream
+///
+/// A gzip member consists of a header, compressed data and a trailer. The [gzip
+/// specification](https://tools.ietf.org/html/rfc1952), however, allows multiple
+/// gzip members to be joined in a single stream. `MultiGzDecoder` will
+/// decode all consecutive members while `GzDecoder` will only decompress
+/// the first gzip member. The multistream format is commonly used in
+/// bioinformatics, for example when using the BGZF compressed data.
+///
+/// This structure exposes a [`BufRead`] interface that will consume all gzip members
+/// from the underlying reader and emit 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::GzEncoder;
+/// use flate2::bufread::MultiGzDecoder;
+///
+/// # fn main() {
+/// #   let mut e = GzEncoder::new(Vec::new(), Compression::default());
+/// #   e.write_all(b"Hello World").unwrap();
+/// #   let bytes = e.finish().unwrap();
+/// #   println!("{}", decode_reader(bytes).unwrap());
+/// # }
+/// #
+/// // Uncompresses a Gz Encoded vector of bytes and returns a string or error
+/// // Here &[u8] implements BufRead
+///
+/// fn decode_reader(bytes: Vec<u8>) -> io::Result<String> {
+///    let mut gz = MultiGzDecoder::new(&bytes[..]);
+///    let mut s = String::new();
+///    gz.read_to_string(&mut s)?;
+///    Ok(s)
+/// }
+/// ```
+#[derive(Debug)]
+pub struct MultiGzDecoder<R>(GzDecoder<R>);
+
+impl<R: BufRead> MultiGzDecoder<R> {
+    /// Creates a new decoder from the given reader, immediately parsing the
+    /// (first) gzip header. If the gzip stream contains multiple members all will
+    /// be decoded.
+    pub fn new(r: R) -> MultiGzDecoder<R> {
+        MultiGzDecoder(GzDecoder::new(r).multi(true))
+    }
+}
+
+impl<R> MultiGzDecoder<R> {
+    /// Returns the current header associated with this stream, if it's valid
+    pub fn header(&self) -> Option<&GzHeader> {
+        self.0.header()
+    }
+
+    /// Acquires a reference to the underlying reader.
+    pub fn get_ref(&self) -> &R {
+        self.0.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.0.get_mut()
+    }
+
+    /// Consumes this decoder, returning the underlying reader.
+    pub fn into_inner(self) -> R {
+        self.0.into_inner()
+    }
+}
+
+impl<R: BufRead> Read for MultiGzDecoder<R> {
+    fn read(&mut self, into: &mut [u8]) -> io::Result<usize> {
+        self.0.read(into)
+    }
+}
+
+#[cfg(test)]
+pub mod tests {
+    use crate::gz::bufread::*;
+    use std::io;
+    use std::io::{Cursor, Read, Write};
+
+    //a cursor turning EOF into blocking errors
+    #[derive(Debug)]
+    pub struct BlockingCursor {
+        pub cursor: Cursor<Vec<u8>>,
+    }
+
+    impl BlockingCursor {
+        pub fn new() -> BlockingCursor {
+            BlockingCursor {
+                cursor: Cursor::new(Vec::new()),
+            }
+        }
+
+        pub fn set_position(&mut self, pos: u64) {
+            return self.cursor.set_position(pos);
+        }
+
+        pub fn position(&mut self) -> u64 {
+            return self.cursor.position();
+        }
+    }
+
+    impl Write for BlockingCursor {
+        fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+            return self.cursor.write(buf);
+        }
+        fn flush(&mut self) -> io::Result<()> {
+            return self.cursor.flush();
+        }
+    }
+
+    impl Read for BlockingCursor {
+        fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+            //use the cursor, except it turns eof into blocking error
+            let r = self.cursor.read(buf);
+            match r {
+                Err(ref err) => {
+                    if err.kind() == io::ErrorKind::UnexpectedEof {
+                        return Err(io::ErrorKind::WouldBlock.into());
+                    }
+                }
+                Ok(0) => {
+                    //regular EOF turned into blocking error
+                    return Err(io::ErrorKind::WouldBlock.into());
+                }
+                Ok(_n) => {}
+            }
+            return r;
+        }
+    }
+    #[test]
+    // test function read_and_forget of Buffer
+    fn buffer_read_and_forget() {
+        // this is unused except for the buffering
+        let mut part = GzHeaderPartial::new();
+        // this is a reader which receives data afterwards
+        let mut r = BlockingCursor::new();
+        let data = vec![1, 2, 3];
+        let mut out = Vec::with_capacity(7);
+
+        match r.write_all(&data) {
+            Ok(()) => {}
+            _ => {
+                panic!("Unexpected result for write_all");
+            }
+        }
+        r.set_position(0);
+
+        // First read : successful for one byte
+        let mut reader = Buffer::new(&mut part, &mut r);
+        out.resize(1, 0);
+        match reader.read_and_forget(&mut out) {
+            Ok(1) => {}
+            _ => {
+                panic!("Unexpected result for read_and_forget with data");
+            }
+        }
+
+        // Second read : incomplete for 7 bytes (we have only 2)
+        out.resize(7, 0);
+        match reader.read_and_forget(&mut out) {
+            Err(ref err) => {
+                assert_eq!(io::ErrorKind::WouldBlock, err.kind());
+            }
+            _ => {
+                panic!("Unexpected result for read_and_forget with incomplete");
+            }
+        }
+
+        // 3 more data bytes have arrived
+        let pos = r.position();
+        let data2 = vec![4, 5, 6];
+        match r.write_all(&data2) {
+            Ok(()) => {}
+            _ => {
+                panic!("Unexpected result for write_all");
+            }
+        }
+        r.set_position(pos);
+
+        // Third read : still incomplete for 7 bytes (we have 5)
+        let mut reader2 = Buffer::new(&mut part, &mut r);
+        match reader2.read_and_forget(&mut out) {
+            Err(ref err) => {
+                assert_eq!(io::ErrorKind::WouldBlock, err.kind());
+            }
+            _ => {
+                panic!("Unexpected result for read_and_forget with more incomplete");
+            }
+        }
+
+        // 3 more data bytes have arrived again
+        let pos2 = r.position();
+        let data3 = vec![7, 8, 9];
+        match r.write_all(&data3) {
+            Ok(()) => {}
+            _ => {
+                panic!("Unexpected result for write_all");
+            }
+        }
+        r.set_position(pos2);
+
+        // Fourth read : now successful for 7 bytes
+        let mut reader3 = Buffer::new(&mut part, &mut r);
+        match reader3.read_and_forget(&mut out) {
+            Ok(7) => {
+                assert_eq!(out[0], 2);
+                assert_eq!(out[6], 8);
+            }
+            _ => {
+                panic!("Unexpected result for read_and_forget with data");
+            }
+        }
+
+        // Fifth read : successful for one more byte
+        out.resize(1, 0);
+        match reader3.read_and_forget(&mut out) {
+            Ok(1) => {
+                assert_eq!(out[0], 9);
+            }
+            _ => {
+                panic!("Unexpected result for read_and_forget with data");
+            }
+        }
+    }
+}
diff --git a/third_party/rust/flate2/src/gz/mod.rs b/third_party/rust/flate2/src/gz/mod.rs
new file mode 100644
index 0000000000..505450e3e9
--- /dev/null
+++ b/third_party/rust/flate2/src/gz/mod.rs
@@ -0,0 +1,385 @@
+use std::ffi::CString;
+use std::io::prelude::*;
+use std::time;
+
+use crate::bufreader::BufReader;
+use crate::Compression;
+
+pub static FHCRC: u8 = 1 << 1;
+pub static FEXTRA: u8 = 1 << 2;
+pub static FNAME: u8 = 1 << 3;
+pub static FCOMMENT: u8 = 1 << 4;
+
+pub mod bufread;
+pub mod read;
+pub mod write;
+
+/// A structure representing the header of a gzip stream.
+///
+/// The header can contain metadata about the file that was compressed, if
+/// present.
+#[derive(PartialEq, Clone, Debug, Default)]
+pub struct GzHeader {
+    extra: Option<Vec<u8>>,
+    filename: Option<Vec<u8>>,
+    comment: Option<Vec<u8>>,
+    operating_system: u8,
+    mtime: u32,
+}
+
+impl GzHeader {
+    /// Returns the `filename` field of this gzip stream's header, if present.
+    pub fn filename(&self) -> Option<&[u8]> {
+        self.filename.as_ref().map(|s| &s[..])
+    }
+
+    /// Returns the `extra` field of this gzip stream's header, if present.
+    pub fn extra(&self) -> Option<&[u8]> {
+        self.extra.as_ref().map(|s| &s[..])
+    }
+
+    /// Returns the `comment` field of this gzip stream's header, if present.
+    pub fn comment(&self) -> Option<&[u8]> {
+        self.comment.as_ref().map(|s| &s[..])
+    }
+
+    /// Returns the `operating_system` field of this gzip stream's header.
+    ///
+    /// There are predefined values for various operating systems.
+    /// 255 means that the value is unknown.
+    pub fn operating_system(&self) -> u8 {
+        self.operating_system
+    }
+
+    /// This gives the most recent modification time of the original file being compressed.
+    ///
+    /// The time is in Unix format, i.e., seconds since 00:00:00 GMT, Jan. 1, 1970.
+    /// (Note that this may cause problems for MS-DOS and other systems that use local
+    /// rather than Universal time.) If the compressed data did not come from a file,
+    /// `mtime` is set to the time at which compression started.
+    /// `mtime` = 0 means no time stamp is available.
+    ///
+    /// The usage of `mtime` is discouraged because of Year 2038 problem.
+    pub fn mtime(&self) -> u32 {
+        self.mtime
+    }
+
+    /// Returns the most recent modification time represented by a date-time type.
+    /// Returns `None` if the value of the underlying counter is 0,
+    /// indicating no time stamp is available.
+    ///
+    ///
+    /// The time is measured as seconds since 00:00:00 GMT, Jan. 1 1970.
+    /// See [`mtime`](#method.mtime) for more detail.
+    pub fn mtime_as_datetime(&self) -> Option<time::SystemTime> {
+        if self.mtime == 0 {
+            None
+        } else {
+            let duration = time::Duration::new(u64::from(self.mtime), 0);
+            let datetime = time::UNIX_EPOCH + duration;
+            Some(datetime)
+        }
+    }
+}
+
+/// A builder structure to create a new gzip Encoder.
+///
+/// This structure controls header configuration options such as the filename.
+///
+/// # Examples
+///
+/// ```
+/// use std::io::prelude::*;
+/// # use std::io;
+/// use std::fs::File;
+/// use flate2::GzBuilder;
+/// use flate2::Compression;
+///
+/// // GzBuilder opens a file and writes a sample string using GzBuilder pattern
+///
+/// # fn sample_builder() -> Result<(), io::Error> {
+/// let f = File::create("examples/hello_world.gz")?;
+/// let mut gz = GzBuilder::new()
+///                 .filename("hello_world.txt")
+///                 .comment("test file, please delete")
+///                 .write(f, Compression::default());
+/// gz.write_all(b"hello world")?;
+/// gz.finish()?;
+/// # Ok(())
+/// # }
+/// ```
+#[derive(Debug)]
+pub struct GzBuilder {
+    extra: Option<Vec<u8>>,
+    filename: Option<CString>,
+    comment: Option<CString>,
+    operating_system: Option<u8>,
+    mtime: u32,
+}
+
+impl Default for GzBuilder {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl GzBuilder {
+    /// Create a new blank builder with no header by default.
+    pub fn new() -> GzBuilder {
+        GzBuilder {
+            extra: None,
+            filename: None,
+            comment: None,
+            operating_system: None,
+            mtime: 0,
+        }
+    }
+
+    /// Configure the `mtime` field in the gzip header.
+    pub fn mtime(mut self, mtime: u32) -> GzBuilder {
+        self.mtime = mtime;
+        self
+    }
+
+    /// Configure the `operating_system` field in the gzip header.
+    pub fn operating_system(mut self, os: u8) -> GzBuilder {
+        self.operating_system = Some(os);
+        self
+    }
+
+    /// Configure the `extra` field in the gzip header.
+    pub fn extra<T: Into<Vec<u8>>>(mut self, extra: T) -> GzBuilder {
+        self.extra = Some(extra.into());
+        self
+    }
+
+    /// Configure the `filename` field in the gzip header.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the `filename` slice contains a zero.
+    pub fn filename<T: Into<Vec<u8>>>(mut self, filename: T) -> GzBuilder {
+        self.filename = Some(CString::new(filename.into()).unwrap());
+        self
+    }
+
+    /// Configure the `comment` field in the gzip header.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the `comment` slice contains a zero.
+    pub fn comment<T: Into<Vec<u8>>>(mut self, comment: T) -> GzBuilder {
+        self.comment = Some(CString::new(comment.into()).unwrap());
+        self
+    }
+
+    /// Consume this builder, creating a writer encoder in the process.
+    ///
+    /// The data written to the returned encoder will be compressed and then
+    /// written out to the supplied parameter `w`.
+    pub fn write<W: Write>(self, w: W, lvl: Compression) -> write::GzEncoder<W> {
+        write::gz_encoder(self.into_header(lvl), w, lvl)
+    }
+
+    /// Consume this builder, creating a reader encoder in the process.
+    ///
+    /// Data read from the returned encoder will be the compressed version of
+    /// the data read from the given reader.
+    pub fn read<R: Read>(self, r: R, lvl: Compression) -> read::GzEncoder<R> {
+        read::gz_encoder(self.buf_read(BufReader::new(r), lvl))
+    }
+
+    /// Consume this builder, creating a reader encoder in the process.
+    ///
+    /// Data read from the returned encoder will be the compressed version of
+    /// the data read from the given reader.
+    pub fn buf_read<R>(self, r: R, lvl: Compression) -> bufread::GzEncoder<R>
+    where
+        R: BufRead,
+    {
+        bufread::gz_encoder(self.into_header(lvl), r, lvl)
+    }
+
+    fn into_header(self, lvl: Compression) -> Vec<u8> {
+        let GzBuilder {
+            extra,
+            filename,
+            comment,
+            operating_system,
+            mtime,
+        } = self;
+        let mut flg = 0;
+        let mut header = vec![0u8; 10];
+        if let Some(v) = extra {
+            flg |= FEXTRA;
+            header.push((v.len() >> 0) as u8);
+            header.push((v.len() >> 8) as u8);
+            header.extend(v);
+        }
+        if let Some(filename) = filename {
+            flg |= FNAME;
+            header.extend(filename.as_bytes_with_nul().iter().map(|x| *x));
+        }
+        if let Some(comment) = comment {
+            flg |= FCOMMENT;
+            header.extend(comment.as_bytes_with_nul().iter().map(|x| *x));
+        }
+        header[0] = 0x1f;
+        header[1] = 0x8b;
+        header[2] = 8;
+        header[3] = flg;
+        header[4] = (mtime >> 0) as u8;
+        header[5] = (mtime >> 8) as u8;
+        header[6] = (mtime >> 16) as u8;
+        header[7] = (mtime >> 24) as u8;
+        header[8] = if lvl.0 >= Compression::best().0 {
+            2
+        } else if lvl.0 <= Compression::fast().0 {
+            4
+        } else {
+            0
+        };
+
+        // Typically this byte indicates what OS the gz stream was created on,
+        // but in an effort to have cross-platform reproducible streams just
+        // default this value to 255. I'm not sure that if we "correctly" set
+        // this it'd do anything anyway...
+        header[9] = operating_system.unwrap_or(255);
+        header
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::io::prelude::*;
+
+    use super::{read, write, GzBuilder};
+    use crate::Compression;
+    use rand::{thread_rng, Rng};
+
+    #[test]
+    fn roundtrip() {
+        let mut e = write::GzEncoder::new(Vec::new(), Compression::default());
+        e.write_all(b"foo bar baz").unwrap();
+        let inner = e.finish().unwrap();
+        let mut d = read::GzDecoder::new(&inner[..]);
+        let mut s = String::new();
+        d.read_to_string(&mut s).unwrap();
+        assert_eq!(s, "foo bar baz");
+    }
+
+    #[test]
+    fn roundtrip_zero() {
+        let e = write::GzEncoder::new(Vec::new(), Compression::default());
+        let inner = e.finish().unwrap();
+        let mut d = read::GzDecoder::new(&inner[..]);
+        let mut s = String::new();
+        d.read_to_string(&mut s).unwrap();
+        assert_eq!(s, "");
+    }
+
+    #[test]
+    fn roundtrip_big() {
+        let mut real = Vec::new();
+        let mut w = write::GzEncoder::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::GzDecoder::new(&result[..]);
+        let mut v = Vec::new();
+        r.read_to_end(&mut v).unwrap();
+        assert!(v == real);
+    }
+
+    #[test]
+    fn roundtrip_big2() {
+        let v = crate::random_bytes().take(1024 * 1024).collect::<Vec<_>>();
+        let mut r = read::GzDecoder::new(read::GzEncoder::new(&v[..], Compression::default()));
+        let mut res = Vec::new();
+        r.read_to_end(&mut res).unwrap();
+        assert!(res == v);
+    }
+
+    #[test]
+    fn fields() {
+        let r = vec![0, 2, 4, 6];
+        let e = GzBuilder::new()
+            .filename("foo.rs")
+            .comment("bar")
+            .extra(vec![0, 1, 2, 3])
+            .read(&r[..], Compression::default());
+        let mut d = read::GzDecoder::new(e);
+        assert_eq!(d.header().unwrap().filename(), Some(&b"foo.rs"[..]));
+        assert_eq!(d.header().unwrap().comment(), Some(&b"bar"[..]));
+        assert_eq!(d.header().unwrap().extra(), Some(&b"\x00\x01\x02\x03"[..]));
+        let mut res = Vec::new();
+        d.read_to_end(&mut res).unwrap();
+        assert_eq!(res, vec![0, 2, 4, 6]);
+    }
+
+    #[test]
+    fn keep_reading_after_end() {
+        let mut e = write::GzEncoder::new(Vec::new(), Compression::default());
+        e.write_all(b"foo bar baz").unwrap();
+        let inner = e.finish().unwrap();
+        let mut d = read::GzDecoder::new(&inner[..]);
+        let mut s = String::new();
+        d.read_to_string(&mut s).unwrap();
+        assert_eq!(s, "foo bar baz");
+        d.read_to_string(&mut s).unwrap();
+        assert_eq!(s, "foo bar baz");
+    }
+
+    #[test]
+    fn qc_reader() {
+        ::quickcheck::quickcheck(test as fn(_) -> _);
+
+        fn test(v: Vec<u8>) -> bool {
+            let r = read::GzEncoder::new(&v[..], Compression::default());
+            let mut r = read::GzDecoder::new(r);
+            let mut v2 = Vec::new();
+            r.read_to_end(&mut v2).unwrap();
+            v == v2
+        }
+    }
+
+    #[test]
+    fn flush_after_write() {
+        let mut f = write::GzEncoder::new(Vec::new(), Compression::default());
+        write!(f, "Hello world").unwrap();
+        f.flush().unwrap();
+    }
+
+    use crate::gz::bufread::tests::BlockingCursor;
+    #[test]
+    // test function read_and_forget of Buffer
+    fn blocked_partial_header_read() {
+        // this is a reader which receives data afterwards
+        let mut r = BlockingCursor::new();
+        let data = vec![1, 2, 3];
+
+        match r.write_all(&data) {
+            Ok(()) => {}
+            _ => {
+                panic!("Unexpected result for write_all");
+            }
+        }
+        r.set_position(0);
+
+        // this is unused except for the buffering
+        let mut decoder = read::GzDecoder::new(r);
+        let mut out = Vec::with_capacity(7);
+        match decoder.read(&mut out) {
+            Err(e) => {
+                assert_eq!(e.kind(), std::io::ErrorKind::WouldBlock);
+            }
+            _ => {
+                panic!("Unexpected result for decoder.read");
+            }
+        }
+    }
+}
diff --git a/third_party/rust/flate2/src/gz/read.rs b/third_party/rust/flate2/src/gz/read.rs
new file mode 100644
index 0000000000..dbbe632829
--- /dev/null
+++ b/third_party/rust/flate2/src/gz/read.rs
@@ -0,0 +1,278 @@
+use std::io;
+use std::io::prelude::*;
+
+use super::bufread;
+use super::{GzBuilder, GzHeader};
+use crate::bufreader::BufReader;
+use crate::Compression;
+
+/// A gzip streaming encoder
+///
+/// This structure exposes a [`Read`] interface that will read uncompressed data
+/// from the underlying reader and expose the compressed version as a [`Read`]
+/// interface.
+///
+/// [`Read`]: https://doc.rust-lang.org/std/io/trait.Read.html
+///
+/// # Examples
+///
+/// ```
+/// use std::io::prelude::*;
+/// use std::io;
+/// use flate2::Compression;
+/// use flate2::read::GzEncoder;
+///
+/// // Return a vector containing the GZ compressed version of hello world
+///
+/// fn gzencode_hello_world() -> io::Result<Vec<u8>> {
+///     let mut ret_vec = [0;100];
+///     let bytestring = b"hello world";
+///     let mut gz = GzEncoder::new(&bytestring[..], Compression::fast());
+///     let count = gz.read(&mut ret_vec)?;
+///     Ok(ret_vec[0..count].to_vec())
+/// }
+/// ```
+#[derive(Debug)]
+pub struct GzEncoder<R> {
+    inner: bufread::GzEncoder<BufReader<R>>,
+}
+
+pub fn gz_encoder<R: Read>(inner: bufread::GzEncoder<BufReader<R>>) -> GzEncoder<R> {
+    GzEncoder { inner }
+}
+
+impl<R: Read> GzEncoder<R> {
+    /// Creates a new encoder which will use the given compression level.
+    ///
+    /// The encoder is not configured specially for the emitted header. For
+    /// header configuration, see the `GzBuilder` type.
+    ///
+    /// The data read from the stream `r` will be compressed and available
+    /// through the returned reader.
+    pub fn new(r: R, level: Compression) -> GzEncoder<R> {
+        GzBuilder::new().read(r, level)
+    }
+}
+
+impl<R> GzEncoder<R> {
+    /// Acquires a reference to the underlying reader.
+    pub fn get_ref(&self) -> &R {
+        self.inner.get_ref().get_ref()
+    }
+
+    /// Acquires a mutable reference to the underlying reader.
+    ///
+    /// Note that mutation of the reader 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()
+    }
+
+    /// Returns the underlying stream, consuming this encoder
+    pub fn into_inner(self) -> R {
+        self.inner.into_inner().into_inner()
+    }
+}
+
+impl<R: Read> Read for GzEncoder<R> {
+    fn read(&mut self, into: &mut [u8]) -> io::Result<usize> {
+        self.inner.read(into)
+    }
+}
+
+impl<R: Read + Write> Write for GzEncoder<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 gzip streaming decoder
+///
+/// This structure exposes a [`Read`] interface that will consume compressed
+/// data from the underlying reader and emit uncompressed data.
+///
+/// [`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::GzEncoder;
+/// use flate2::read::GzDecoder;
+///
+/// # fn main() {
+/// #    let mut e = GzEncoder::new(Vec::new(), Compression::default());
+/// #    e.write_all(b"Hello World").unwrap();
+/// #    let bytes = e.finish().unwrap();
+/// #    println!("{}", decode_reader(bytes).unwrap());
+/// # }
+/// #
+/// // Uncompresses a Gz 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 gz = GzDecoder::new(&bytes[..]);
+///    let mut s = String::new();
+///    gz.read_to_string(&mut s)?;
+///    Ok(s)
+/// }
+/// ```
+#[derive(Debug)]
+pub struct GzDecoder<R> {
+    inner: bufread::GzDecoder<BufReader<R>>,
+}
+
+impl<R: Read> GzDecoder<R> {
+    /// Creates a new decoder from the given reader, immediately parsing the
+    /// gzip header.
+    pub fn new(r: R) -> GzDecoder<R> {
+        GzDecoder {
+            inner: bufread::GzDecoder::new(BufReader::new(r)),
+        }
+    }
+}
+
+impl<R> GzDecoder<R> {
+    /// Returns the header associated with this stream, if it was valid.
+    pub fn header(&self) -> Option<&GzHeader> {
+        self.inner.header()
+    }
+
+    /// Acquires a reference to the underlying reader.
+    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.
+    pub fn into_inner(self) -> R {
+        self.inner.into_inner().into_inner()
+    }
+}
+
+impl<R: Read> Read for GzDecoder<R> {
+    fn read(&mut self, into: &mut [u8]) -> io::Result<usize> {
+        self.inner.read(into)
+    }
+}
+
+impl<R: Read + Write> Write for GzDecoder<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 gzip streaming decoder that decodes all members of a multistream
+///
+/// A gzip member consists of a header, compressed data and a trailer. The [gzip
+/// specification](https://tools.ietf.org/html/rfc1952), however, allows multiple
+/// gzip members to be joined in a single stream.  `MultiGzDecoder` will
+/// decode all consecutive members while `GzDecoder` will only decompress the
+/// first gzip member. The multistream format is commonly used in bioinformatics,
+/// for example when using the BGZF compressed data.
+///
+/// This structure exposes a [`Read`] interface that will consume all gzip members
+/// from the underlying reader and emit uncompressed data.
+///
+/// [`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::GzEncoder;
+/// use flate2::read::MultiGzDecoder;
+///
+/// # fn main() {
+/// #    let mut e = GzEncoder::new(Vec::new(), Compression::default());
+/// #    e.write_all(b"Hello World").unwrap();
+/// #    let bytes = e.finish().unwrap();
+/// #    println!("{}", decode_reader(bytes).unwrap());
+/// # }
+/// #
+/// // Uncompresses a Gz 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 gz = MultiGzDecoder::new(&bytes[..]);
+///    let mut s = String::new();
+///    gz.read_to_string(&mut s)?;
+///    Ok(s)
+/// }
+/// ```
+#[derive(Debug)]
+pub struct MultiGzDecoder<R> {
+    inner: bufread::MultiGzDecoder<BufReader<R>>,
+}
+
+impl<R: Read> MultiGzDecoder<R> {
+    /// Creates a new decoder from the given reader, immediately parsing the
+    /// (first) gzip header. If the gzip stream contains multiple members all will
+    /// be decoded.
+    pub fn new(r: R) -> MultiGzDecoder<R> {
+        MultiGzDecoder {
+            inner: bufread::MultiGzDecoder::new(BufReader::new(r)),
+        }
+    }
+}
+
+impl<R> MultiGzDecoder<R> {
+    /// Returns the current header associated with this stream, if it's valid.
+    pub fn header(&self) -> Option<&GzHeader> {
+        self.inner.header()
+    }
+
+    /// Acquires a reference to the underlying reader.
+    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.
+    pub fn into_inner(self) -> R {
+        self.inner.into_inner().into_inner()
+    }
+}
+
+impl<R: Read> Read for MultiGzDecoder<R> {
+    fn read(&mut self, into: &mut [u8]) -> io::Result<usize> {
+        self.inner.read(into)
+    }
+}
+
+impl<R: Read + Write> Write for MultiGzDecoder<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/gz/write.rs b/third_party/rust/flate2/src/gz/write.rs
new file mode 100644
index 0000000000..7cf1a7cd41
--- /dev/null
+++ b/third_party/rust/flate2/src/gz/write.rs
@@ -0,0 +1,450 @@
+use std::cmp;
+use std::io;
+use std::io::prelude::*;
+
+use super::bufread::{corrupt, read_gz_header};
+use super::{GzBuilder, GzHeader};
+use crate::crc::{Crc, CrcWriter};
+use crate::zio;
+use crate::{Compress, Compression, Decompress, Status};
+
+/// A gzip streaming encoder
+///
+/// This structure exposes a [`Write`] interface that will emit compressed data
+/// to the underlying writer `W`.
+///
+/// [`Write`]: https://doc.rust-lang.org/std/io/trait.Write.html
+///
+/// # Examples
+///
+/// ```
+/// use std::io::prelude::*;
+/// use flate2::Compression;
+/// use flate2::write::GzEncoder;
+///
+/// // Vec<u8> implements Write to print the compressed bytes of sample string
+/// # fn main() {
+///
+/// let mut e = GzEncoder::new(Vec::new(), Compression::default());
+/// e.write_all(b"Hello World").unwrap();
+/// println!("{:?}", e.finish().unwrap());
+/// # }
+/// ```
+#[derive(Debug)]
+pub struct GzEncoder<W: Write> {
+    inner: zio::Writer<W, Compress>,
+    crc: Crc,
+    crc_bytes_written: usize,
+    header: Vec<u8>,
+}
+
+pub fn gz_encoder<W: Write>(header: Vec<u8>, w: W, lvl: Compression) -> GzEncoder<W> {
+    GzEncoder {
+        inner: zio::Writer::new(w, Compress::new(lvl, false)),
+        crc: Crc::new(),
+        header,
+        crc_bytes_written: 0,
+    }
+}
+
+impl<W: Write> GzEncoder<W> {
+    /// Creates a new encoder which will use the given compression level.
+    ///
+    /// The encoder is not configured specially for the emitted header. For
+    /// header configuration, see the `GzBuilder` type.
+    ///
+    /// The data written to the returned encoder will be compressed and then
+    /// written to the stream `w`.
+    pub fn new(w: W, level: Compression) -> GzEncoder<W> {
+        GzBuilder::new().write(w, level)
+    }
+
+    /// 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 mutation of the writer may result in surprising results if
+    /// this encoder is continued to be used.
+    pub fn get_mut(&mut self) -> &mut W {
+        self.inner.get_mut()
+    }
+
+    /// 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.write_header()?;
+        self.inner.finish()?;
+
+        while self.crc_bytes_written < 8 {
+            let (sum, amt) = (self.crc.sum() as u32, self.crc.amount());
+            let buf = [
+                (sum >> 0) as u8,
+                (sum >> 8) as u8,
+                (sum >> 16) as u8,
+                (sum >> 24) as u8,
+                (amt >> 0) as u8,
+                (amt >> 8) as u8,
+                (amt >> 16) as u8,
+                (amt >> 24) as u8,
+            ];
+            let inner = self.inner.get_mut();
+            let n = inner.write(&buf[self.crc_bytes_written..])?;
+            self.crc_bytes_written += n;
+        }
+        Ok(())
+    }
+
+    /// Finish encoding this stream, returning the underlying writer once the
+    /// encoding is done.
+    ///
+    /// 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.try_finish()?;
+        Ok(self.inner.take_inner())
+    }
+
+    fn write_header(&mut self) -> io::Result<()> {
+        while !self.header.is_empty() {
+            let n = self.inner.get_mut().write(&self.header)?;
+            self.header.drain(..n);
+        }
+        Ok(())
+    }
+}
+
+impl<W: Write> Write for GzEncoder<W> {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        assert_eq!(self.crc_bytes_written, 0);
+        self.write_header()?;
+        let n = self.inner.write(buf)?;
+        self.crc.update(&buf[..n]);
+        Ok(n)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        assert_eq!(self.crc_bytes_written, 0);
+        self.write_header()?;
+        self.inner.flush()
+    }
+}
+
+impl<R: Read + Write> Read for GzEncoder<R> {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.get_mut().read(buf)
+    }
+}
+
+impl<W: Write> Drop for GzEncoder<W> {
+    fn drop(&mut self) {
+        if self.inner.is_present() {
+            let _ = self.try_finish();
+        }
+    }
+}
+
+/// A gzip streaming decoder
+///
+/// This structure exposes a [`Write`] interface that will emit compressed data
+/// to the underlying writer `W`.
+///
+/// [`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::{GzEncoder, GzDecoder};
+///
+/// # fn main() {
+/// #    let mut e = GzEncoder::new(Vec::new(), Compression::default());
+/// #    e.write(b"Hello World").unwrap();
+/// #    let bytes = e.finish().unwrap();
+/// #    assert_eq!("Hello World", decode_writer(bytes).unwrap());
+/// # }
+/// // Uncompresses a gzip 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 decoder = GzDecoder::new(writer);
+///    decoder.write_all(&bytes[..])?;
+///    writer = decoder.finish()?;
+///    let return_string = String::from_utf8(writer).expect("String parsing error");
+///    Ok(return_string)
+/// }
+/// ```
+#[derive(Debug)]
+pub struct GzDecoder<W: Write> {
+    inner: zio::Writer<CrcWriter<W>, Decompress>,
+    crc_bytes: Vec<u8>,
+    header: Option<GzHeader>,
+    header_buf: Vec<u8>,
+}
+
+const CRC_BYTES_LEN: usize = 8;
+
+impl<W: Write> GzDecoder<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) -> GzDecoder<W> {
+        GzDecoder {
+            inner: zio::Writer::new(CrcWriter::new(w), Decompress::new(false)),
+            crc_bytes: Vec::with_capacity(CRC_BYTES_LEN),
+            header: None,
+            header_buf: Vec::new(),
+        }
+    }
+
+    /// Returns the header associated with this stream.
+    pub fn header(&self) -> Option<&GzHeader> {
+        self.header.as_ref()
+    }
+
+    /// Acquires a reference to the underlying writer.
+    pub fn get_ref(&self) -> &W {
+        self.inner.get_ref().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().get_mut()
+    }
+
+    /// 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.finish_and_check_crc()?;
+        Ok(())
+    }
+
+    /// Consumes this decoder, 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.finish_and_check_crc()?;
+        Ok(self.inner.take_inner().into_inner())
+    }
+
+    fn finish_and_check_crc(&mut self) -> io::Result<()> {
+        self.inner.finish()?;
+
+        if self.crc_bytes.len() != 8 {
+            return Err(corrupt());
+        }
+
+        let crc = ((self.crc_bytes[0] as u32) << 0)
+            | ((self.crc_bytes[1] as u32) << 8)
+            | ((self.crc_bytes[2] as u32) << 16)
+            | ((self.crc_bytes[3] as u32) << 24);
+        let amt = ((self.crc_bytes[4] as u32) << 0)
+            | ((self.crc_bytes[5] as u32) << 8)
+            | ((self.crc_bytes[6] as u32) << 16)
+            | ((self.crc_bytes[7] as u32) << 24);
+        if crc != self.inner.get_ref().crc().sum() as u32 {
+            return Err(corrupt());
+        }
+        if amt != self.inner.get_ref().crc().amount() {
+            return Err(corrupt());
+        }
+        Ok(())
+    }
+}
+
+struct Counter<T: Read> {
+    inner: T,
+    pos: usize,
+}
+
+impl<T: Read> Read for Counter<T> {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        let pos = self.inner.read(buf)?;
+        self.pos += pos;
+        Ok(pos)
+    }
+}
+
+impl<W: Write> Write for GzDecoder<W> {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        if self.header.is_none() {
+            // trying to avoid buffer usage
+            let (res, pos) = {
+                let mut counter = Counter {
+                    inner: self.header_buf.chain(buf),
+                    pos: 0,
+                };
+                let res = read_gz_header(&mut counter);
+                (res, counter.pos)
+            };
+
+            match res {
+                Err(err) => {
+                    if err.kind() == io::ErrorKind::UnexpectedEof {
+                        // not enough data for header, save to the buffer
+                        self.header_buf.extend(buf);
+                        Ok(buf.len())
+                    } else {
+                        Err(err)
+                    }
+                }
+                Ok(header) => {
+                    self.header = Some(header);
+                    let pos = pos - self.header_buf.len();
+                    self.header_buf.truncate(0);
+                    Ok(pos)
+                }
+            }
+        } else {
+            let (n, status) = self.inner.write_with_status(buf)?;
+
+            if status == Status::StreamEnd && n < buf.len() && self.crc_bytes.len() < 8 {
+                let remaining = buf.len() - n;
+                let crc_bytes = cmp::min(remaining, CRC_BYTES_LEN - self.crc_bytes.len());
+                self.crc_bytes.extend(&buf[n..n + crc_bytes]);
+                return Ok(n + crc_bytes);
+            }
+            Ok(n)
+        }
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        self.inner.flush()
+    }
+}
+
+impl<W: Read + Write> Read for GzDecoder<W> {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.inner.get_mut().get_mut().read(buf)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const STR: &'static str = "Hello World Hello World Hello World Hello World Hello World \
+                               Hello World Hello World Hello World Hello World Hello World \
+                               Hello World Hello World Hello World Hello World Hello World \
+                               Hello World Hello World Hello World Hello World Hello World \
+                               Hello World Hello World Hello World Hello World Hello World";
+
+    #[test]
+    fn decode_writer_one_chunk() {
+        let mut e = GzEncoder::new(Vec::new(), Compression::default());
+        e.write(STR.as_ref()).unwrap();
+        let bytes = e.finish().unwrap();
+
+        let mut writer = Vec::new();
+        let mut decoder = GzDecoder::new(writer);
+        let n = decoder.write(&bytes[..]).unwrap();
+        decoder.write(&bytes[n..]).unwrap();
+        decoder.try_finish().unwrap();
+        writer = decoder.finish().unwrap();
+        let return_string = String::from_utf8(writer).expect("String parsing error");
+        assert_eq!(return_string, STR);
+    }
+
+    #[test]
+    fn decode_writer_partial_header() {
+        let mut e = GzEncoder::new(Vec::new(), Compression::default());
+        e.write(STR.as_ref()).unwrap();
+        let bytes = e.finish().unwrap();
+
+        let mut writer = Vec::new();
+        let mut decoder = GzDecoder::new(writer);
+        assert_eq!(decoder.write(&bytes[..5]).unwrap(), 5);
+        let n = decoder.write(&bytes[5..]).unwrap();
+        if n < bytes.len() - 5 {
+            decoder.write(&bytes[n + 5..]).unwrap();
+        }
+        writer = decoder.finish().unwrap();
+        let return_string = String::from_utf8(writer).expect("String parsing error");
+        assert_eq!(return_string, STR);
+    }
+
+    #[test]
+    fn decode_writer_exact_header() {
+        let mut e = GzEncoder::new(Vec::new(), Compression::default());
+        e.write(STR.as_ref()).unwrap();
+        let bytes = e.finish().unwrap();
+
+        let mut writer = Vec::new();
+        let mut decoder = GzDecoder::new(writer);
+        assert_eq!(decoder.write(&bytes[..10]).unwrap(), 10);
+        decoder.write(&bytes[10..]).unwrap();
+        writer = decoder.finish().unwrap();
+        let return_string = String::from_utf8(writer).expect("String parsing error");
+        assert_eq!(return_string, STR);
+    }
+
+    #[test]
+    fn decode_writer_partial_crc() {
+        let mut e = GzEncoder::new(Vec::new(), Compression::default());
+        e.write(STR.as_ref()).unwrap();
+        let bytes = e.finish().unwrap();
+
+        let mut writer = Vec::new();
+        let mut decoder = GzDecoder::new(writer);
+        let l = bytes.len() - 5;
+        let n = decoder.write(&bytes[..l]).unwrap();
+        decoder.write(&bytes[n..]).unwrap();
+        writer = decoder.finish().unwrap();
+        let return_string = String::from_utf8(writer).expect("String parsing error");
+        assert_eq!(return_string, STR);
+    }
+}
diff --git a/third_party/rust/flate2/src/lib.rs b/third_party/rust/flate2/src/lib.rs
new file mode 100644
index 0000000000..23a783e559
--- /dev/null
+++ b/third_party/rust/flate2/src/lib.rs
@@ -0,0 +1,204 @@
+//! A DEFLATE-based stream compression/decompression library
+//!
+//! This library provides support for compression and decompression of
+//! DEFLATE-based streams:
+//!
+//! * the DEFLATE format itself
+//! * the zlib format
+//! * gzip
+//!
+//! These three formats are all closely related and largely only differ in their
+//! headers/footers. This crate has three types in each submodule for dealing
+//! with these three formats.
+//!
+//! # Implementation
+//!
+//! In addition to supporting three formats, this crate supports several different
+//! backends, controlled through this crate's features:
+//!
+//! * `default`, or `rust_backend` - this implementation uses the `miniz_oxide`
+//!   crate which is a port of `miniz.c` (below) to Rust. This feature does not
+//!   require a C compiler and only requires Rust code.
+//!
+//! * `zlib` - this feature will enable linking against the `libz` library, typically found on most
+//!   Linux systems by default. If the library isn't found to already be on the system it will be
+//!   compiled from source (this is a C library).
+//!
+//! There's various tradeoffs associated with each implementation, but in general you probably
+//! won't have to tweak the defaults. The default choice is selected to avoid the need for a C
+//! compiler at build time. `zlib-ng-compat` is useful if you're using zlib for compatibility but
+//! want performance via zlib-ng's zlib-compat mode. `zlib` is useful if something else in your
+//! dependencies links the original zlib so you cannot use zlib-ng-compat. The compression ratios
+//! and performance of each of these feature should be roughly comparable, but you'll likely want
+//! to run your own tests if you're curious about the performance.
+//!
+//! # Organization
+//!
+//! This crate consists mainly of three modules, [`read`], [`write`], and
+//! [`bufread`]. Each module contains a number of types used to encode and
+//! decode various streams of data.
+//!
+//! All types in the [`write`] module work on instances of [`Write`][write],
+//! whereas all types in the [`read`] module work on instances of
+//! [`Read`][read] and [`bufread`] works with [`BufRead`][bufread]. If you
+//! are decoding directly from a `&[u8]`, use the [`bufread`] types.
+//!
+//! ```
+//! use flate2::write::GzEncoder;
+//! use flate2::Compression;
+//! use std::io;
+//! use std::io::prelude::*;
+//!
+//! # fn main() { let _ = run(); }
+//! # fn run() -> io::Result<()> {
+//! let mut encoder = GzEncoder::new(Vec::new(), Compression::default());
+//! encoder.write_all(b"Example")?;
+//! # Ok(())
+//! # }
+//! ```
+//!
+//!
+//! Other various types are provided at the top-level of the crate for
+//! management and dealing with encoders/decoders. Also note that types which
+//! operate over a specific trait often implement the mirroring trait as well.
+//! For example a `flate2::read::DeflateDecoder<T>` *also* implements the
+//! `Write` trait if `T: Write`. That is, the "dual trait" is forwarded directly
+//! to the underlying object if available.
+//!
+//! [`read`]: read/index.html
+//! [`bufread`]: bufread/index.html
+//! [`write`]: write/index.html
+//! [read]: https://doc.rust-lang.org/std/io/trait.Read.html
+//! [write]: https://doc.rust-lang.org/std/io/trait.Write.html
+//! [bufread]: https://doc.rust-lang.org/std/io/trait.BufRead.html
+#![doc(html_root_url = "https://docs.rs/flate2/0.2")]
+#![deny(missing_docs)]
+#![deny(missing_debug_implementations)]
+#![allow(trivial_numeric_casts)]
+#![cfg_attr(test, deny(warnings))]
+
+pub use crate::crc::{Crc, CrcReader, CrcWriter};
+pub use crate::gz::GzBuilder;
+pub use crate::gz::GzHeader;
+pub use crate::mem::{Compress, CompressError, Decompress, DecompressError, Status};
+pub use crate::mem::{FlushCompress, FlushDecompress};
+
+mod bufreader;
+mod crc;
+mod deflate;
+mod ffi;
+mod gz;
+mod mem;
+mod zio;
+mod zlib;
+
+/// Types which operate over [`Read`] streams, both encoders and decoders for
+/// various formats.
+///
+/// [`Read`]: https://doc.rust-lang.org/std/io/trait.Read.html
+pub mod read {
+    pub use crate::deflate::read::DeflateDecoder;
+    pub use crate::deflate::read::DeflateEncoder;
+    pub use crate::gz::read::GzDecoder;
+    pub use crate::gz::read::GzEncoder;
+    pub use crate::gz::read::MultiGzDecoder;
+    pub use crate::zlib::read::ZlibDecoder;
+    pub use crate::zlib::read::ZlibEncoder;
+}
+
+/// Types which operate over [`Write`] streams, both encoders and decoders for
+/// various formats.
+///
+/// [`Write`]: https://doc.rust-lang.org/std/io/trait.Write.html
+pub mod write {
+    pub use crate::deflate::write::DeflateDecoder;
+    pub use crate::deflate::write::DeflateEncoder;
+    pub use crate::gz::write::GzDecoder;
+    pub use crate::gz::write::GzEncoder;
+    pub use crate::zlib::write::ZlibDecoder;
+    pub use crate::zlib::write::ZlibEncoder;
+}
+
+/// Types which operate over [`BufRead`] streams, both encoders and decoders for
+/// various formats.
+///
+/// [`BufRead`]: https://doc.rust-lang.org/std/io/trait.BufRead.html
+pub mod bufread {
+    pub use crate::deflate::bufread::DeflateDecoder;
+    pub use crate::deflate::bufread::DeflateEncoder;
+    pub use crate::gz::bufread::GzDecoder;
+    pub use crate::gz::bufread::GzEncoder;
+    pub use crate::gz::bufread::MultiGzDecoder;
+    pub use crate::zlib::bufread::ZlibDecoder;
+    pub use crate::zlib::bufread::ZlibEncoder;
+}
+
+fn _assert_send_sync() {
+    fn _assert_send_sync<T: Send + Sync>() {}
+
+    _assert_send_sync::<read::DeflateEncoder<&[u8]>>();
+    _assert_send_sync::<read::DeflateDecoder<&[u8]>>();
+    _assert_send_sync::<read::ZlibEncoder<&[u8]>>();
+    _assert_send_sync::<read::ZlibDecoder<&[u8]>>();
+    _assert_send_sync::<read::GzEncoder<&[u8]>>();
+    _assert_send_sync::<read::GzDecoder<&[u8]>>();
+    _assert_send_sync::<read::MultiGzDecoder<&[u8]>>();
+    _assert_send_sync::<write::DeflateEncoder<Vec<u8>>>();
+    _assert_send_sync::<write::DeflateDecoder<Vec<u8>>>();
+    _assert_send_sync::<write::ZlibEncoder<Vec<u8>>>();
+    _assert_send_sync::<write::ZlibDecoder<Vec<u8>>>();
+    _assert_send_sync::<write::GzEncoder<Vec<u8>>>();
+    _assert_send_sync::<write::GzDecoder<Vec<u8>>>();
+}
+
+/// When compressing data, the compression level can be specified by a value in
+/// this enum.
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+pub struct Compression(u32);
+
+impl Compression {
+    /// Creates a new description of the compression level with an explicitly
+    /// specified integer.
+    ///
+    /// The integer here is typically on a scale of 0-9 where 0 means "no
+    /// compression" and 9 means "take as long as you'd like".
+    pub const fn new(level: u32) -> Compression {
+        Compression(level)
+    }
+
+    /// No compression is to be performed, this may actually inflate data
+    /// slightly when encoding.
+    pub const fn none() -> Compression {
+        Compression(0)
+    }
+
+    /// Optimize for the best speed of encoding.
+    pub const fn fast() -> Compression {
+        Compression(1)
+    }
+
+    /// Optimize for the size of data being encoded.
+    pub const fn best() -> Compression {
+        Compression(9)
+    }
+
+    /// Returns an integer representing the compression level, typically on a
+    /// scale of 0-9
+    pub fn level(&self) -> u32 {
+        self.0
+    }
+}
+
+impl Default for Compression {
+    fn default() -> Compression {
+        Compression(6)
+    }
+}
+
+#[cfg(test)]
+fn random_bytes() -> impl Iterator<Item = u8> {
+    use rand::Rng;
+    use std::iter;
+
+    iter::repeat(()).map(|_| rand::thread_rng().gen())
+}
diff --git a/third_party/rust/flate2/src/mem.rs b/third_party/rust/flate2/src/mem.rs
new file mode 100644
index 0000000000..5f1d6d8c18
--- /dev/null
+++ b/third_party/rust/flate2/src/mem.rs
@@ -0,0 +1,788 @@
+use std::error::Error;
+use std::fmt;
+use std::io;
+use std::slice;
+
+use crate::ffi::{self, Backend, Deflate, DeflateBackend, ErrorMessage, Inflate, InflateBackend};
+use crate::Compression;
+
+/// Raw in-memory compression stream for blocks of data.
+///
+/// This type is the building block for the I/O streams in the rest of this
+/// crate. It requires more management than the [`Read`]/[`Write`] API but is
+/// maximally flexible in terms of accepting input from any source and being
+/// able to produce output to any memory location.
+///
+/// It is recommended to use the I/O stream adaptors over this type as they're
+/// easier to use.
+///
+/// [`Read`]: https://doc.rust-lang.org/std/io/trait.Read.html
+/// [`Write`]: https://doc.rust-lang.org/std/io/trait.Write.html
+#[derive(Debug)]
+pub struct Compress {
+    inner: Deflate,
+}
+
+/// Raw in-memory decompression stream for blocks of data.
+///
+/// This type is the building block for the I/O streams in the rest of this
+/// crate. It requires more management than the [`Read`]/[`Write`] API but is
+/// maximally flexible in terms of accepting input from any source and being
+/// able to produce output to any memory location.
+///
+/// It is recommended to use the I/O stream adaptors over this type as they're
+/// easier to use.
+///
+/// [`Read`]: https://doc.rust-lang.org/std/io/trait.Read.html
+/// [`Write`]: https://doc.rust-lang.org/std/io/trait.Write.html
+#[derive(Debug)]
+pub struct Decompress {
+    inner: Inflate,
+}
+
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+/// Values which indicate the form of flushing to be used when compressing
+/// in-memory data.
+pub enum FlushCompress {
+    /// A typical parameter for passing to compression/decompression functions,
+    /// this indicates that the underlying stream to decide how much data to
+    /// accumulate before producing output in order to maximize compression.
+    None = ffi::MZ_NO_FLUSH as isize,
+
+    /// All pending output is flushed to the output buffer and the output is
+    /// aligned on a byte boundary so that the decompressor can get all input
+    /// data available so far.
+    ///
+    /// Flushing may degrade compression for some compression algorithms and so
+    /// it should only be used when necessary. This will complete the current
+    /// deflate block and follow it with an empty stored block.
+    Sync = ffi::MZ_SYNC_FLUSH as isize,
+
+    /// All pending output is flushed to the output buffer, but the output is
+    /// not aligned to a byte boundary.
+    ///
+    /// All of the input data so far will be available to the decompressor (as
+    /// with `Flush::Sync`. This completes the current deflate block and follows
+    /// it with an empty fixed codes block that is 10 bites long, and it assures
+    /// that enough bytes are output in order for the decompressor to finish the
+    /// block before the empty fixed code block.
+    Partial = ffi::MZ_PARTIAL_FLUSH as isize,
+
+    /// All output is flushed as with `Flush::Sync` and the compression state is
+    /// reset so decompression can restart from this point if previous
+    /// compressed data has been damaged or if random access is desired.
+    ///
+    /// Using this option too often can seriously degrade compression.
+    Full = ffi::MZ_FULL_FLUSH as isize,
+
+    /// Pending input is processed and pending output is flushed.
+    ///
+    /// The return value may indicate that the stream is not yet done and more
+    /// data has yet to be processed.
+    Finish = ffi::MZ_FINISH as isize,
+
+    #[doc(hidden)]
+    _Nonexhaustive,
+}
+
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+/// Values which indicate the form of flushing to be used when
+/// decompressing in-memory data.
+pub enum FlushDecompress {
+    /// A typical parameter for passing to compression/decompression functions,
+    /// this indicates that the underlying stream to decide how much data to
+    /// accumulate before producing output in order to maximize compression.
+    None = ffi::MZ_NO_FLUSH as isize,
+
+    /// All pending output is flushed to the output buffer and the output is
+    /// aligned on a byte boundary so that the decompressor can get all input
+    /// data available so far.
+    ///
+    /// Flushing may degrade compression for some compression algorithms and so
+    /// it should only be used when necessary. This will complete the current
+    /// deflate block and follow it with an empty stored block.
+    Sync = ffi::MZ_SYNC_FLUSH as isize,
+
+    /// Pending input is processed and pending output is flushed.
+    ///
+    /// The return value may indicate that the stream is not yet done and more
+    /// data has yet to be processed.
+    Finish = ffi::MZ_FINISH as isize,
+
+    #[doc(hidden)]
+    _Nonexhaustive,
+}
+
+/// The inner state for an error when decompressing
+#[derive(Debug)]
+pub(crate) enum DecompressErrorInner {
+    General { msg: ErrorMessage },
+    NeedsDictionary(u32),
+}
+
+/// Error returned when a decompression object finds that the input stream of
+/// bytes was not a valid input stream of bytes.
+#[derive(Debug)]
+pub struct DecompressError(pub(crate) DecompressErrorInner);
+
+impl DecompressError {
+    /// Indicates whether decompression failed due to requiring a dictionary.
+    ///
+    /// The resulting integer is the Adler-32 checksum of the dictionary
+    /// required.
+    pub fn needs_dictionary(&self) -> Option<u32> {
+        match self.0 {
+            DecompressErrorInner::NeedsDictionary(adler) => Some(adler),
+            _ => None,
+        }
+    }
+}
+
+#[inline]
+pub(crate) fn decompress_failed<T>(msg: ErrorMessage) -> Result<T, DecompressError> {
+    Err(DecompressError(DecompressErrorInner::General { msg }))
+}
+
+#[inline]
+pub(crate) fn decompress_need_dict<T>(adler: u32) -> Result<T, DecompressError> {
+    Err(DecompressError(DecompressErrorInner::NeedsDictionary(
+        adler,
+    )))
+}
+
+/// Error returned when a compression object is used incorrectly or otherwise
+/// generates an error.
+#[derive(Debug)]
+pub struct CompressError {
+    pub(crate) msg: ErrorMessage,
+}
+
+#[inline]
+pub(crate) fn compress_failed<T>(msg: ErrorMessage) -> Result<T, CompressError> {
+    Err(CompressError { msg })
+}
+
+/// Possible status results of compressing some data or successfully
+/// decompressing a block of data.
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+pub enum Status {
+    /// Indicates success.
+    ///
+    /// Means that more input may be needed but isn't available
+    /// and/or there's more output to be written but the output buffer is full.
+    Ok,
+
+    /// Indicates that forward progress is not possible due to input or output
+    /// buffers being empty.
+    ///
+    /// For compression it means the input buffer needs some more data or the
+    /// output buffer needs to be freed up before trying again.
+    ///
+    /// For decompression this means that more input is needed to continue or
+    /// the output buffer isn't large enough to contain the result. The function
+    /// can be called again after fixing both.
+    BufError,
+
+    /// Indicates that all input has been consumed and all output bytes have
+    /// been written. Decompression/compression should not be called again.
+    ///
+    /// For decompression with zlib streams the adler-32 of the decompressed
+    /// data has also been verified.
+    StreamEnd,
+}
+
+impl Compress {
+    /// Creates a new object ready for compressing data that it's given.
+    ///
+    /// The `level` argument here indicates what level of compression is going
+    /// to be performed, and the `zlib_header` argument indicates whether the
+    /// output data should have a zlib header or not.
+    pub fn new(level: Compression, zlib_header: bool) -> Compress {
+        Compress {
+            inner: Deflate::make(level, zlib_header, ffi::MZ_DEFAULT_WINDOW_BITS as u8),
+        }
+    }
+
+    /// Creates a new object ready for compressing data that it's given.
+    ///
+    /// The `level` argument here indicates what level of compression is going
+    /// to be performed, and the `zlib_header` argument indicates whether the
+    /// output data should have a zlib header or not. The `window_bits` parameter
+    /// indicates the base-2 logarithm of the sliding window size and must be
+    /// between 9 and 15.
+    ///
+    /// # Panics
+    ///
+    /// If `window_bits` does not fall into the range 9 ..= 15,
+    /// `new_with_window_bits` will panic.
+    ///
+    /// # Note
+    ///
+    /// This constructor is only available when the `zlib` feature is used.
+    /// Other backends currently do not support custom window bits.
+    #[cfg(feature = "any_zlib")]
+    pub fn new_with_window_bits(
+        level: Compression,
+        zlib_header: bool,
+        window_bits: u8,
+    ) -> Compress {
+        assert!(
+            window_bits > 8 && window_bits < 16,
+            "window_bits must be within 9 ..= 15"
+        );
+        Compress {
+            inner: Deflate::make(level, zlib_header, window_bits),
+        }
+    }
+
+    /// Creates a new object ready for compressing data that it's given.
+    ///
+    /// The `level` argument here indicates what level of compression is going
+    /// to be performed.
+    ///
+    /// The Compress object produced by this constructor outputs gzip headers
+    /// for the compressed data.
+    ///
+    /// # Panics
+    ///
+    /// If `window_bits` does not fall into the range 9 ..= 15,
+    /// `new_with_window_bits` will panic.
+    ///
+    /// # Note
+    ///
+    /// This constructor is only available when the `zlib` feature is used.
+    /// Other backends currently do not support gzip headers for Compress.
+    #[cfg(feature = "any_zlib")]
+    pub fn new_gzip(level: Compression, window_bits: u8) -> Compress {
+        assert!(
+            window_bits > 8 && window_bits < 16,
+            "window_bits must be within 9 ..= 15"
+        );
+        Compress {
+            inner: Deflate::make(level, true, window_bits + 16),
+        }
+    }
+
+    /// Returns the total number of input bytes which have been processed by
+    /// this compression object.
+    pub fn total_in(&self) -> u64 {
+        self.inner.total_in()
+    }
+
+    /// Returns the total number of output bytes which have been produced by
+    /// this compression object.
+    pub fn total_out(&self) -> u64 {
+        self.inner.total_out()
+    }
+
+    /// Specifies the compression dictionary to use.
+    ///
+    /// Returns the Adler-32 checksum of the dictionary.
+    #[cfg(feature = "any_zlib")]
+    pub fn set_dictionary(&mut self, dictionary: &[u8]) -> Result<u32, CompressError> {
+        let stream = &mut *self.inner.inner.stream_wrapper;
+        stream.msg = std::ptr::null_mut();
+        let rc = unsafe {
+            assert!(dictionary.len() < ffi::uInt::MAX as usize);
+            ffi::deflateSetDictionary(stream, dictionary.as_ptr(), dictionary.len() as ffi::uInt)
+        };
+
+        match rc {
+            ffi::MZ_STREAM_ERROR => compress_failed(self.inner.inner.msg()),
+            ffi::MZ_OK => Ok(stream.adler as u32),
+            c => panic!("unknown return code: {}", c),
+        }
+    }
+
+    /// Quickly resets this compressor without having to reallocate anything.
+    ///
+    /// This is equivalent to dropping this object and then creating a new one.
+    pub fn reset(&mut self) {
+        self.inner.reset();
+    }
+
+    /// Dynamically updates the compression level.
+    ///
+    /// This can be used to switch between compression levels for different
+    /// kinds of data, or it can be used in conjunction with a call to reset
+    /// to reuse the compressor.
+    ///
+    /// This may return an error if there wasn't enough output space to complete
+    /// the compression of the available input data before changing the
+    /// compression level. Flushing the stream before calling this method
+    /// ensures that the function will succeed on the first call.
+    #[cfg(feature = "any_zlib")]
+    pub fn set_level(&mut self, level: Compression) -> Result<(), CompressError> {
+        use std::os::raw::c_int;
+        let stream = &mut *self.inner.inner.stream_wrapper;
+        stream.msg = std::ptr::null_mut();
+
+        let rc = unsafe { ffi::deflateParams(stream, level.0 as c_int, ffi::MZ_DEFAULT_STRATEGY) };
+
+        match rc {
+            ffi::MZ_OK => Ok(()),
+            ffi::MZ_BUF_ERROR => compress_failed(self.inner.inner.msg()),
+            c => panic!("unknown return code: {}", c),
+        }
+    }
+
+    /// Compresses the input data into the output, consuming only as much
+    /// input as needed and writing as much output as possible.
+    ///
+    /// The flush option can be any of the available `FlushCompress` parameters.
+    ///
+    /// To learn how much data was consumed or how much output was produced, use
+    /// the `total_in` and `total_out` functions before/after this is called.
+    pub fn compress(
+        &mut self,
+        input: &[u8],
+        output: &mut [u8],
+        flush: FlushCompress,
+    ) -> Result<Status, CompressError> {
+        self.inner.compress(input, output, flush)
+    }
+
+    /// Compresses the input data into the extra space of the output, consuming
+    /// only as much input as needed and writing as much output as possible.
+    ///
+    /// This function has the same semantics as `compress`, except that the
+    /// length of `vec` is managed by this function. This will not reallocate
+    /// the vector provided or attempt to grow it, so space for the output must
+    /// be reserved in the output vector by the caller before calling this
+    /// function.
+    pub fn compress_vec(
+        &mut self,
+        input: &[u8],
+        output: &mut Vec<u8>,
+        flush: FlushCompress,
+    ) -> Result<Status, CompressError> {
+        let cap = output.capacity();
+        let len = output.len();
+
+        unsafe {
+            let before = self.total_out();
+            let ret = {
+                let ptr = output.as_mut_ptr().offset(len as isize);
+                let out = slice::from_raw_parts_mut(ptr, cap - len);
+                self.compress(input, out, flush)
+            };
+            output.set_len((self.total_out() - before) as usize + len);
+            ret
+        }
+    }
+}
+
+impl Decompress {
+    /// Creates a new object ready for decompressing data that it's given.
+    ///
+    /// The `zlib_header` argument indicates whether the input data is expected
+    /// to have a zlib header or not.
+    pub fn new(zlib_header: bool) -> Decompress {
+        Decompress {
+            inner: Inflate::make(zlib_header, ffi::MZ_DEFAULT_WINDOW_BITS as u8),
+        }
+    }
+
+    /// Creates a new object ready for decompressing data that it's given.
+    ///
+    /// The `zlib_header` argument indicates whether the input data is expected
+    /// to have a zlib header or not. The `window_bits` parameter indicates the
+    /// base-2 logarithm of the sliding window size and must be between 9 and 15.
+    ///
+    /// # Panics
+    ///
+    /// If `window_bits` does not fall into the range 9 ..= 15,
+    /// `new_with_window_bits` will panic.
+    ///
+    /// # Note
+    ///
+    /// This constructor is only available when the `zlib` feature is used.
+    /// Other backends currently do not support custom window bits.
+    #[cfg(feature = "any_zlib")]
+    pub fn new_with_window_bits(zlib_header: bool, window_bits: u8) -> Decompress {
+        assert!(
+            window_bits > 8 && window_bits < 16,
+            "window_bits must be within 9 ..= 15"
+        );
+        Decompress {
+            inner: Inflate::make(zlib_header, window_bits),
+        }
+    }
+
+    /// Creates a new object ready for decompressing data that it's given.
+    ///
+    /// The Decompress object produced by this constructor expects gzip headers
+    /// for the compressed data.
+    ///
+    /// # Panics
+    ///
+    /// If `window_bits` does not fall into the range 9 ..= 15,
+    /// `new_with_window_bits` will panic.
+    ///
+    /// # Note
+    ///
+    /// This constructor is only available when the `zlib` feature is used.
+    /// Other backends currently do not support gzip headers for Decompress.
+    #[cfg(feature = "any_zlib")]
+    pub fn new_gzip(window_bits: u8) -> Decompress {
+        assert!(
+            window_bits > 8 && window_bits < 16,
+            "window_bits must be within 9 ..= 15"
+        );
+        Decompress {
+            inner: Inflate::make(true, window_bits + 16),
+        }
+    }
+
+    /// Returns the total number of input bytes which have been processed by
+    /// this decompression object.
+    pub fn total_in(&self) -> u64 {
+        self.inner.total_in()
+    }
+
+    /// Returns the total number of output bytes which have been produced by
+    /// this decompression object.
+    pub fn total_out(&self) -> u64 {
+        self.inner.total_out()
+    }
+
+    /// Decompresses the input data into the output, consuming only as much
+    /// input as needed and writing as much output as possible.
+    ///
+    /// The flush option can be any of the available `FlushDecompress` parameters.
+    ///
+    /// If the first call passes `FlushDecompress::Finish` it is assumed that
+    /// the input and output buffers are both sized large enough to decompress
+    /// the entire stream in a single call.
+    ///
+    /// A flush value of `FlushDecompress::Finish` indicates that there are no
+    /// more source bytes available beside what's already in the input buffer,
+    /// and the output buffer is large enough to hold the rest of the
+    /// decompressed data.
+    ///
+    /// To learn how much data was consumed or how much output was produced, use
+    /// the `total_in` and `total_out` functions before/after this is called.
+    ///
+    /// # Errors
+    ///
+    /// If the input data to this instance of `Decompress` is not a valid
+    /// zlib/deflate stream then this function may return an instance of
+    /// `DecompressError` to indicate that the stream of input bytes is corrupted.
+    pub fn decompress(
+        &mut self,
+        input: &[u8],
+        output: &mut [u8],
+        flush: FlushDecompress,
+    ) -> Result<Status, DecompressError> {
+        self.inner.decompress(input, output, flush)
+    }
+
+    /// Decompresses the input data into the extra space in the output vector
+    /// specified by `output`.
+    ///
+    /// This function has the same semantics as `decompress`, except that the
+    /// length of `vec` is managed by this function. This will not reallocate
+    /// the vector provided or attempt to grow it, so space for the output must
+    /// be reserved in the output vector by the caller before calling this
+    /// function.
+    ///
+    /// # Errors
+    ///
+    /// If the input data to this instance of `Decompress` is not a valid
+    /// zlib/deflate stream then this function may return an instance of
+    /// `DecompressError` to indicate that the stream of input bytes is corrupted.
+    pub fn decompress_vec(
+        &mut self,
+        input: &[u8],
+        output: &mut Vec<u8>,
+        flush: FlushDecompress,
+    ) -> Result<Status, DecompressError> {
+        let cap = output.capacity();
+        let len = output.len();
+
+        unsafe {
+            let before = self.total_out();
+            let ret = {
+                let ptr = output.as_mut_ptr().offset(len as isize);
+                let out = slice::from_raw_parts_mut(ptr, cap - len);
+                self.decompress(input, out, flush)
+            };
+            output.set_len((self.total_out() - before) as usize + len);
+            ret
+        }
+    }
+
+    /// Specifies the decompression dictionary to use.
+    #[cfg(feature = "any_zlib")]
+    pub fn set_dictionary(&mut self, dictionary: &[u8]) -> Result<u32, DecompressError> {
+        let stream = &mut *self.inner.inner.stream_wrapper;
+        stream.msg = std::ptr::null_mut();
+        let rc = unsafe {
+            assert!(dictionary.len() < ffi::uInt::MAX as usize);
+            ffi::inflateSetDictionary(stream, dictionary.as_ptr(), dictionary.len() as ffi::uInt)
+        };
+
+        match rc {
+            ffi::MZ_STREAM_ERROR => decompress_failed(self.inner.inner.msg()),
+            ffi::MZ_DATA_ERROR => decompress_need_dict(stream.adler as u32),
+            ffi::MZ_OK => Ok(stream.adler as u32),
+            c => panic!("unknown return code: {}", c),
+        }
+    }
+
+    /// Performs the equivalent of replacing this decompression state with a
+    /// freshly allocated copy.
+    ///
+    /// This function may not allocate memory, though, and attempts to reuse any
+    /// previously existing resources.
+    ///
+    /// The argument provided here indicates whether the reset state will
+    /// attempt to decode a zlib header first or not.
+    pub fn reset(&mut self, zlib_header: bool) {
+        self.inner.reset(zlib_header);
+    }
+}
+
+impl Error for DecompressError {}
+
+impl DecompressError {
+    /// Retrieve the implementation's message about why the operation failed, if one exists.
+    pub fn message(&self) -> Option<&str> {
+        match &self.0 {
+            DecompressErrorInner::General { msg } => msg.get(),
+            _ => None,
+        }
+    }
+}
+
+impl From<DecompressError> for io::Error {
+    fn from(data: DecompressError) -> io::Error {
+        io::Error::new(io::ErrorKind::Other, data)
+    }
+}
+
+impl fmt::Display for DecompressError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let msg = match &self.0 {
+            DecompressErrorInner::General { msg } => msg.get(),
+            DecompressErrorInner::NeedsDictionary { .. } => Some("requires a dictionary"),
+        };
+        match msg {
+            Some(msg) => write!(f, "deflate decompression error: {}", msg),
+            None => write!(f, "deflate decompression error"),
+        }
+    }
+}
+
+impl Error for CompressError {}
+
+impl CompressError {
+    /// Retrieve the implementation's message about why the operation failed, if one exists.
+    pub fn message(&self) -> Option<&str> {
+        self.msg.get()
+    }
+}
+
+impl From<CompressError> for io::Error {
+    fn from(data: CompressError) -> io::Error {
+        io::Error::new(io::ErrorKind::Other, data)
+    }
+}
+
+impl fmt::Display for CompressError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self.msg.get() {
+            Some(msg) => write!(f, "deflate compression error: {}", msg),
+            None => write!(f, "deflate compression error"),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::io::Write;
+
+    use crate::write;
+    use crate::{Compression, Decompress, FlushDecompress};
+
+    #[cfg(feature = "any_zlib")]
+    use crate::{Compress, FlushCompress};
+
+    #[test]
+    fn issue51() {
+        let data = vec![
+            0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0xb3, 0xc9, 0x28, 0xc9,
+            0xcd, 0xb1, 0xe3, 0xe5, 0xb2, 0xc9, 0x48, 0x4d, 0x4c, 0xb1, 0xb3, 0x29, 0xc9, 0x2c,
+            0xc9, 0x49, 0xb5, 0x33, 0x31, 0x30, 0x51, 0xf0, 0xcb, 0x2f, 0x51, 0x70, 0xcb, 0x2f,
+            0xcd, 0x4b, 0xb1, 0xd1, 0x87, 0x08, 0xda, 0xe8, 0x83, 0x95, 0x00, 0x95, 0x26, 0xe5,
+            0xa7, 0x54, 0x2a, 0x24, 0xa5, 0x27, 0xe7, 0xe7, 0xe4, 0x17, 0xd9, 0x2a, 0x95, 0x67,
+            0x64, 0x96, 0xa4, 0x2a, 0x81, 0x8c, 0x48, 0x4e, 0xcd, 0x2b, 0x49, 0x2d, 0xb2, 0xb3,
+            0xc9, 0x30, 0x44, 0x37, 0x01, 0x28, 0x62, 0xa3, 0x0f, 0x95, 0x06, 0xd9, 0x05, 0x54,
+            0x04, 0xe5, 0xe5, 0xa5, 0x67, 0xe6, 0x55, 0xe8, 0x1b, 0xea, 0x99, 0xe9, 0x19, 0x21,
+            0xab, 0xd0, 0x07, 0xd9, 0x01, 0x32, 0x53, 0x1f, 0xea, 0x3e, 0x00, 0x94, 0x85, 0xeb,
+            0xe4, 0xa8, 0x00, 0x00, 0x00,
+        ];
+
+        let mut decoded = Vec::with_capacity(data.len() * 2);
+
+        let mut d = Decompress::new(false);
+        // decompressed whole deflate stream
+        assert!(d
+            .decompress_vec(&data[10..], &mut decoded, FlushDecompress::Finish)
+            .is_ok());
+
+        // decompress data that has nothing to do with the deflate stream (this
+        // used to panic)
+        drop(d.decompress_vec(&[0], &mut decoded, FlushDecompress::None));
+    }
+
+    #[test]
+    fn reset() {
+        let string = "hello world".as_bytes();
+        let mut zlib = Vec::new();
+        let mut deflate = Vec::new();
+
+        let comp = Compression::default();
+        write::ZlibEncoder::new(&mut zlib, comp)
+            .write_all(string)
+            .unwrap();
+        write::DeflateEncoder::new(&mut deflate, comp)
+            .write_all(string)
+            .unwrap();
+
+        let mut dst = [0; 1024];
+        let mut decoder = Decompress::new(true);
+        decoder
+            .decompress(&zlib, &mut dst, FlushDecompress::Finish)
+            .unwrap();
+        assert_eq!(decoder.total_out(), string.len() as u64);
+        assert!(dst.starts_with(string));
+
+        decoder.reset(false);
+        decoder
+            .decompress(&deflate, &mut dst, FlushDecompress::Finish)
+            .unwrap();
+        assert_eq!(decoder.total_out(), string.len() as u64);
+        assert!(dst.starts_with(string));
+    }
+
+    #[cfg(feature = "any_zlib")]
+    #[test]
+    fn set_dictionary_with_zlib_header() {
+        let string = "hello, hello!".as_bytes();
+        let dictionary = "hello".as_bytes();
+
+        let mut encoded = Vec::with_capacity(1024);
+
+        let mut encoder = Compress::new(Compression::default(), true);
+
+        let dictionary_adler = encoder.set_dictionary(&dictionary).unwrap();
+
+        encoder
+            .compress_vec(string, &mut encoded, FlushCompress::Finish)
+            .unwrap();
+
+        assert_eq!(encoder.total_in(), string.len() as u64);
+        assert_eq!(encoder.total_out(), encoded.len() as u64);
+
+        let mut decoder = Decompress::new(true);
+        let mut decoded = [0; 1024];
+        let decompress_error = decoder
+            .decompress(&encoded, &mut decoded, FlushDecompress::Finish)
+            .expect_err("decompression should fail due to requiring a dictionary");
+
+        let required_adler = decompress_error.needs_dictionary()
+            .expect("the first call to decompress should indicate a dictionary is required along with the required Adler-32 checksum");
+
+        assert_eq!(required_adler, dictionary_adler,
+            "the Adler-32 checksum should match the value when the dictionary was set on the compressor");
+
+        let actual_adler = decoder.set_dictionary(&dictionary).unwrap();
+
+        assert_eq!(required_adler, actual_adler);
+
+        // Decompress the rest of the input to the remainder of the output buffer
+        let total_in = decoder.total_in();
+        let total_out = decoder.total_out();
+
+        let decompress_result = decoder.decompress(
+            &encoded[total_in as usize..],
+            &mut decoded[total_out as usize..],
+            FlushDecompress::Finish,
+        );
+        assert!(decompress_result.is_ok());
+
+        assert_eq!(&decoded[..decoder.total_out() as usize], string);
+    }
+
+    #[cfg(feature = "any_zlib")]
+    #[test]
+    fn set_dictionary_raw() {
+        let string = "hello, hello!".as_bytes();
+        let dictionary = "hello".as_bytes();
+
+        let mut encoded = Vec::with_capacity(1024);
+
+        let mut encoder = Compress::new(Compression::default(), false);
+
+        encoder.set_dictionary(&dictionary).unwrap();
+
+        encoder
+            .compress_vec(string, &mut encoded, FlushCompress::Finish)
+            .unwrap();
+
+        assert_eq!(encoder.total_in(), string.len() as u64);
+        assert_eq!(encoder.total_out(), encoded.len() as u64);
+
+        let mut decoder = Decompress::new(false);
+
+        decoder.set_dictionary(&dictionary).unwrap();
+
+        let mut decoded = [0; 1024];
+        let decompress_result = decoder.decompress(&encoded, &mut decoded, FlushDecompress::Finish);
+
+        assert!(decompress_result.is_ok());
+
+        assert_eq!(&decoded[..decoder.total_out() as usize], string);
+    }
+
+    #[cfg(feature = "any_zlib")]
+    #[test]
+    fn test_gzip_flate() {
+        let string = "hello, hello!".as_bytes();
+
+        let mut encoded = Vec::with_capacity(1024);
+
+        let mut encoder = Compress::new_gzip(Compression::default(), 9);
+
+        encoder
+            .compress_vec(string, &mut encoded, FlushCompress::Finish)
+            .unwrap();
+
+        assert_eq!(encoder.total_in(), string.len() as u64);
+        assert_eq!(encoder.total_out(), encoded.len() as u64);
+
+        let mut decoder = Decompress::new_gzip(9);
+
+        let mut decoded = [0; 1024];
+        decoder
+            .decompress(&encoded, &mut decoded, FlushDecompress::Finish)
+            .unwrap();
+
+        assert_eq!(&decoded[..decoder.total_out() as usize], string);
+    }
+
+    #[cfg(feature = "any_zlib")]
+    #[test]
+    fn test_error_message() {
+        let mut decoder = Decompress::new(false);
+        let mut decoded = [0; 128];
+        let garbage = b"xbvxzi";
+
+        let err = decoder
+            .decompress(&*garbage, &mut decoded, FlushDecompress::Finish)
+            .unwrap_err();
+
+        assert_eq!(err.message(), Some("invalid stored block lengths"));
+    }
+}
diff --git a/third_party/rust/flate2/src/zio.rs b/third_party/rust/flate2/src/zio.rs
new file mode 100644
index 0000000000..50beacbd0f
--- /dev/null
+++ b/third_party/rust/flate2/src/zio.rs
@@ -0,0 +1,288 @@
+use std::io;
+use std::io::prelude::*;
+use std::mem;
+
+use crate::{Compress, Decompress, DecompressError, FlushCompress, FlushDecompress, Status};
+
+#[derive(Debug)]
+pub struct Writer<W: Write, D: Ops> {
+    obj: Option<W>,
+    pub data: D,
+    buf: Vec<u8>,
+}
+
+pub trait Ops {
+    type Flush: Flush;
+    fn total_in(&self) -> u64;
+    fn total_out(&self) -> u64;
+    fn run(
+        &mut self,
+        input: &[u8],
+        output: &mut [u8],
+        flush: Self::Flush,
+    ) -> Result<Status, DecompressError>;
+    fn run_vec(
+        &mut self,
+        input: &[u8],
+        output: &mut Vec<u8>,
+        flush: Self::Flush,
+    ) -> Result<Status, DecompressError>;
+}
+
+impl Ops for Compress {
+    type Flush = FlushCompress;
+    fn total_in(&self) -> u64 {
+        self.total_in()
+    }
+    fn total_out(&self) -> u64 {
+        self.total_out()
+    }
+    fn run(
+        &mut self,
+        input: &[u8],
+        output: &mut [u8],
+        flush: FlushCompress,
+    ) -> Result<Status, DecompressError> {
+        Ok(self.compress(input, output, flush).unwrap())
+    }
+    fn run_vec(
+        &mut self,
+        input: &[u8],
+        output: &mut Vec<u8>,
+        flush: FlushCompress,
+    ) -> Result<Status, DecompressError> {
+        Ok(self.compress_vec(input, output, flush).unwrap())
+    }
+}
+
+impl Ops for Decompress {
+    type Flush = FlushDecompress;
+    fn total_in(&self) -> u64 {
+        self.total_in()
+    }
+    fn total_out(&self) -> u64 {
+        self.total_out()
+    }
+    fn run(
+        &mut self,
+        input: &[u8],
+        output: &mut [u8],
+        flush: FlushDecompress,
+    ) -> Result<Status, DecompressError> {
+        self.decompress(input, output, flush)
+    }
+    fn run_vec(
+        &mut self,
+        input: &[u8],
+        output: &mut Vec<u8>,
+        flush: FlushDecompress,
+    ) -> Result<Status, DecompressError> {
+        self.decompress_vec(input, output, flush)
+    }
+}
+
+pub trait Flush {
+    fn none() -> Self;
+    fn sync() -> Self;
+    fn finish() -> Self;
+}
+
+impl Flush for FlushCompress {
+    fn none() -> Self {
+        FlushCompress::None
+    }
+
+    fn sync() -> Self {
+        FlushCompress::Sync
+    }
+
+    fn finish() -> Self {
+        FlushCompress::Finish
+    }
+}
+
+impl Flush for FlushDecompress {
+    fn none() -> Self {
+        FlushDecompress::None
+    }
+
+    fn sync() -> Self {
+        FlushDecompress::Sync
+    }
+
+    fn finish() -> Self {
+        FlushDecompress::Finish
+    }
+}
+
+pub fn read<R, D>(obj: &mut R, data: &mut D, dst: &mut [u8]) -> io::Result<usize>
+where
+    R: BufRead,
+    D: Ops,
+{
+    loop {
+        let (read, consumed, ret, eof);
+        {
+            let input = obj.fill_buf()?;
+            eof = input.is_empty();
+            let before_out = data.total_out();
+            let before_in = data.total_in();
+            let flush = if eof {
+                D::Flush::finish()
+            } else {
+                D::Flush::none()
+            };
+            ret = data.run(input, dst, flush);
+            read = (data.total_out() - before_out) as usize;
+            consumed = (data.total_in() - before_in) as usize;
+        }
+        obj.consume(consumed);
+
+        match ret {
+            // If we haven't ready any data and we haven't hit EOF yet,
+            // then we need to keep asking for more data because if we
+            // return that 0 bytes of data have been read then it will
+            // be interpreted as EOF.
+            Ok(Status::Ok) | Ok(Status::BufError) if read == 0 && !eof && !dst.is_empty() => {
+                continue
+            }
+            Ok(Status::Ok) | Ok(Status::BufError) | Ok(Status::StreamEnd) => return Ok(read),
+
+            Err(..) => {
+                return Err(io::Error::new(
+                    io::ErrorKind::InvalidInput,
+                    "corrupt deflate stream",
+                ))
+            }
+        }
+    }
+}
+
+impl<W: Write, D: Ops> Writer<W, D> {
+    pub fn new(w: W, d: D) -> Writer<W, D> {
+        Writer {
+            obj: Some(w),
+            data: d,
+            buf: Vec::with_capacity(32 * 1024),
+        }
+    }
+
+    pub fn finish(&mut self) -> io::Result<()> {
+        loop {
+            self.dump()?;
+
+            let before = self.data.total_out();
+            self.data.run_vec(&[], &mut self.buf, D::Flush::finish())?;
+            if before == self.data.total_out() {
+                return Ok(());
+            }
+        }
+    }
+
+    pub fn replace(&mut self, w: W) -> W {
+        self.buf.truncate(0);
+        mem::replace(self.get_mut(), w)
+    }
+
+    pub fn get_ref(&self) -> &W {
+        self.obj.as_ref().unwrap()
+    }
+
+    pub fn get_mut(&mut self) -> &mut W {
+        self.obj.as_mut().unwrap()
+    }
+
+    // Note that this should only be called if the outer object is just about
+    // to be consumed!
+    //
+    // (e.g. an implementation of `into_inner`)
+    pub fn take_inner(&mut self) -> W {
+        self.obj.take().unwrap()
+    }
+
+    pub fn is_present(&self) -> bool {
+        self.obj.is_some()
+    }
+
+    // Returns total written bytes and status of underlying codec
+    pub(crate) fn write_with_status(&mut self, buf: &[u8]) -> io::Result<(usize, Status)> {
+        // miniz isn't guaranteed to actually write any of the buffer provided,
+        // it may be in a flushing mode where it's just giving us data before
+        // we're actually giving it any data. We don't want to spuriously return
+        // `Ok(0)` when possible as it will cause calls to write_all() to fail.
+        // As a result we execute this in a loop to ensure that we try our
+        // darndest to write the data.
+        loop {
+            self.dump()?;
+
+            let before_in = self.data.total_in();
+            let ret = self.data.run_vec(buf, &mut self.buf, D::Flush::none());
+            let written = (self.data.total_in() - before_in) as usize;
+            let is_stream_end = matches!(ret, Ok(Status::StreamEnd));
+
+            if !buf.is_empty() && written == 0 && ret.is_ok() && !is_stream_end {
+                continue;
+            }
+            return match ret {
+                Ok(st) => match st {
+                    Status::Ok | Status::BufError | Status::StreamEnd => Ok((written, st)),
+                },
+                Err(..) => Err(io::Error::new(
+                    io::ErrorKind::InvalidInput,
+                    "corrupt deflate stream",
+                )),
+            };
+        }
+    }
+
+    fn dump(&mut self) -> io::Result<()> {
+        // TODO: should manage this buffer not with `drain` but probably more of
+        // a deque-like strategy.
+        while !self.buf.is_empty() {
+            let n = self.obj.as_mut().unwrap().write(&self.buf)?;
+            if n == 0 {
+                return Err(io::ErrorKind::WriteZero.into());
+            }
+            self.buf.drain(..n);
+        }
+        Ok(())
+    }
+}
+
+impl<W: Write, D: Ops> Write for Writer<W, D> {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        self.write_with_status(buf).map(|res| res.0)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        self.data
+            .run_vec(&[], &mut self.buf, D::Flush::sync())
+            .unwrap();
+
+        // Unfortunately miniz doesn't actually tell us when we're done with
+        // pulling out all the data from the internal stream. To remedy this we
+        // have to continually ask the stream for more memory until it doesn't
+        // give us a chunk of memory the same size as our own internal buffer,
+        // at which point we assume it's reached the end.
+        loop {
+            self.dump()?;
+            let before = self.data.total_out();
+            self.data
+                .run_vec(&[], &mut self.buf, D::Flush::none())
+                .unwrap();
+            if before == self.data.total_out() {
+                break;
+            }
+        }
+
+        self.obj.as_mut().unwrap().flush()
+    }
+}
+
+impl<W: Write, D: Ops> Drop for Writer<W, D> {
+    fn drop(&mut self) {
+        if self.obj.is_some() {
+            let _ = self.finish();
+        }
+    }
+}
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)
+    }
+}