diff options
Diffstat (limited to 'third_party/rust/flate2/src/gz/bufread.rs')
| -rw-r--r-- | third_party/rust/flate2/src/gz/bufread.rs | 641 |
1 files changed, 641 insertions, 0 deletions
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..b66ab72f82 --- /dev/null +++ b/third_party/rust/flate2/src/gz/bufread.rs @@ -0,0 +1,641 @@ +use std::cmp; +use std::io; +use std::io::prelude::*; +use std::mem; + +#[cfg(feature = "tokio")] +use futures::Poll; +#[cfg(feature = "tokio")] +use tokio_io::{AsyncRead, AsyncWrite}; + +use super::{GzBuilder, GzHeader}; +use super::{FCOMMENT, FEXTRA, FHCRC, FNAME}; +use crate::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; + return 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 R) -> io::Result<u16> { + let mut b = [0; 2]; + r.read_exact(&mut b)?; + Ok((b[0] as u16) | ((b[1] as u16) << 8)) +} + +pub(crate) fn read_gz_header<R: Read>(r: &mut R) -> io::Result<GzHeader> { + let mut crc_reader = CrcReader::new(r); + let mut header = [0; 10]; + crc_reader.read_exact(&mut header)?; + + let id1 = header[0]; + let id2 = header[1]; + if id1 != 0x1f || id2 != 0x8b { + return Err(bad_header()); + } + let cm = header[2]; + if cm != 8 { + return Err(bad_header()); + } + + let flg = header[3]; + let 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]; + let os = header[9]; + + let extra = if flg & FEXTRA != 0 { + let xlen = read_le_u16(&mut crc_reader)?; + let mut extra = vec![0; xlen as usize]; + crc_reader.read_exact(&mut extra)?; + Some(extra) + } else { + None + }; + let filename = if flg & FNAME != 0 { + // wow this is slow + let mut b = Vec::new(); + for byte in crc_reader.by_ref().bytes() { + let byte = byte?; + if byte == 0 { + break; + } + b.push(byte); + } + Some(b) + } else { + None + }; + let comment = if flg & FCOMMENT != 0 { + // wow this is slow + let mut b = Vec::new(); + for byte in crc_reader.by_ref().bytes() { + let byte = byte?; + if byte == 0 { + break; + } + b.push(byte); + } + Some(b) + } else { + None + }; + + if flg & FHCRC != 0 { + let calced_crc = crc_reader.crc().sum() as u16; + let stored_crc = read_le_u16(&mut crc_reader)?; + if calced_crc != stored_crc { + return Err(corrupt()); + } + } + + Ok(GzHeader { + extra: extra, + filename: filename, + comment: comment, + operating_system: os, + mtime: mtime, + }) +} + +/// 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: 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)] +enum GzState { + Header(Vec<u8>), + 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> { + buf: &'a mut Vec<u8>, + buf_cur: usize, + buf_max: usize, + reader: &'a mut T, +} + +impl<'a, T> Buffer<'a, T> { + fn new(buf: &'a mut Vec<u8>, reader: &'a mut T) -> Buffer<'a, T> { + Buffer { + reader, + buf_cur: 0, + buf_max: buf.len(), + buf, + } + } +} + +impl<'a, T: Read> Read for Buffer<'a, T> { + fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> { + if self.buf_cur == self.buf_max { + let len = self.reader.read(buf)?; + self.buf.extend_from_slice(&buf[..len]); + Ok(len) + } else { + let len = (&self.buf[self.buf_cur..self.buf_max]).read(buf)?; + self.buf_cur += len; + Ok(len) + } + } +} + +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 buf = Vec::with_capacity(10); // minimum header length + let mut header = None; + + let result = { + let mut reader = Buffer::new(&mut buf, &mut r); + read_gz_header(&mut reader) + }; + + let state = match result { + Ok(hdr) => { + header = Some(hdr); + GzState::Body + } + Err(ref err) if io::ErrorKind::WouldBlock == err.kind() => GzState::Header(buf), + 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 buf) => { + let result = { + let mut reader = Buffer::new(&mut buf, reader.get_mut().get_mut()); + read_gz_header(&mut reader) + }; + let hdr = result.map_err(|err| { + if io::ErrorKind::WouldBlock == err.kind() { + *inner = GzState::Header(buf); + } + + err + })?; + *header = Some(hdr); + GzState::Body + } + 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(Vec::with_capacity(10)) + } + } else { + GzState::End + } + } + } + GzState::Err(err) => return Err(err), + GzState::End => return Ok(0), + }; + } + } +} + +#[cfg(feature = "tokio")] +impl<R: AsyncRead + BufRead> AsyncRead for GzDecoder<R> {} + +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() + } +} + +#[cfg(feature = "tokio")] +impl<R: AsyncWrite + BufRead> AsyncWrite for GzDecoder<R> { + fn shutdown(&mut self) -> Poll<(), io::Error> { + self.get_mut().shutdown() + } +} + +/// 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(feature = "tokio")] +impl<R: AsyncRead + BufRead> AsyncRead for MultiGzDecoder<R> {} + +impl<R: BufRead + 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() + } +} + +#[cfg(feature = "tokio")] +impl<R: AsyncWrite + BufRead> AsyncWrite for MultiGzDecoder<R> { + fn shutdown(&mut self) -> Poll<(), io::Error> { + self.get_mut().shutdown() + } +} |