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Diffstat (limited to 'vendor/flate2/src/gz/read.rs')
| -rw-r--r-- | vendor/flate2/src/gz/read.rs | 378 |
1 files changed, 378 insertions, 0 deletions
diff --git a/vendor/flate2/src/gz/read.rs b/vendor/flate2/src/gz/read.rs new file mode 100644 index 0000000..9dbadbd --- /dev/null +++ b/vendor/flate2/src/gz/read.rs @@ -0,0 +1,378 @@ +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 implements a [`Read`] interface. When read from, it reads +/// uncompressed data from the underlying [`Read`] and provides the 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::GzEncoder; +/// +/// // Return a vector containing the GZ compressed version of hello world +/// +/// fn gzencode_hello_world() -> io::Result<Vec<u8>> { +/// let mut ret_vec = Vec::new(); +/// let bytestring = b"hello world"; +/// let mut gz = GzEncoder::new(&bytestring[..], Compression::fast()); +/// gz.read_to_end(&mut ret_vec)?; +/// Ok(ret_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 decoder for a single member of a [gzip file]. +/// +/// This structure implements a [`Read`] interface. When read from, it reads +/// compressed data from the underlying [`Read`] and provides the uncompressed data. +/// +/// After reading a single member of the gzip data this reader will return +/// Ok(0) even if there are more bytes available in the underlying reader. +/// `GzDecoder` may have read additional bytes past the end of the gzip data. +/// If you need the following bytes, wrap the `Reader` in a `std::io::BufReader` +/// and use `bufread::GzDecoder` instead. +/// +/// To handle gzip files that may have multiple members, see [`MultiGzDecoder`] +/// or read more +/// [in the introduction](../index.html#about-multi-member-gzip-files). +/// +/// [gzip file]: https://www.rfc-editor.org/rfc/rfc1952#page-5 +/// +/// # 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. + /// + /// Note that the decoder may have read past the end of the gzip data. + /// To prevent this use [`bufread::GzDecoder`] instead. + 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 decoder continues to be used. + /// + /// Note that the decoder may have read past the end of the gzip data. + /// To prevent this use [`bufread::GzDecoder`] instead. + pub fn get_mut(&mut self) -> &mut R { + self.inner.get_mut().get_mut() + } + + /// Consumes this decoder, returning the underlying reader. + /// + /// Note that the decoder may have read past the end of the gzip data. + /// Subsequent reads will skip those bytes. To prevent this use + /// [`bufread::GzDecoder`] instead. + 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 a [gzip file] that may have multiple members. +/// +/// This structure implements a [`Read`] interface. When read from, it reads +/// compressed data from the underlying [`Read`] and provides the uncompressed +/// data. +/// +/// A gzip file consists of a series of *members* concatenated one after another. +/// MultiGzDecoder decodes all members of a file and returns Ok(0) once the +/// underlying reader does. +/// +/// To handle members seperately, see [GzDecoder] or read more +/// [in the introduction](../index.html#about-multi-member-gzip-files). +/// +/// [gzip file]: https://www.rfc-editor.org/rfc/rfc1952#page-5 +/// +/// # 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 decoder 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() + } +} + +#[cfg(test)] +mod tests { + use std::io::{Cursor, ErrorKind, Read, Result, Write}; + + use super::GzDecoder; + + //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); + } + } + + impl Write for BlockingCursor { + fn write(&mut self, buf: &[u8]) -> Result<usize> { + return self.cursor.write(buf); + } + fn flush(&mut self) -> Result<()> { + return self.cursor.flush(); + } + } + + impl Read for BlockingCursor { + fn read(&mut self, buf: &mut [u8]) -> 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() == ErrorKind::UnexpectedEof { + return Err(ErrorKind::WouldBlock.into()); + } + } + Ok(0) => { + //regular EOF turned into blocking error + return Err(ErrorKind::WouldBlock.into()); + } + Ok(_n) => {} + } + return r; + } + } + + #[test] + 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 = GzDecoder::new(r); + let mut out = Vec::with_capacity(7); + match decoder.read(&mut out) { + Err(e) => { + assert_eq!(e.kind(), ErrorKind::WouldBlock); + } + _ => { + panic!("Unexpected result for decoder.read"); + } + } + } +} |