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Diffstat (limited to 'vendor/flate2/src/zio.rs')
| -rw-r--r-- | vendor/flate2/src/zio.rs | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/vendor/flate2/src/zio.rs b/vendor/flate2/src/zio.rs new file mode 100644 index 000000000..50beacbd0 --- /dev/null +++ b/vendor/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(); + } + } +} |