Remove redundant limit on LZWReader output length

This commit is contained in:
Jonathan Behrens committed 2022-04-15 10:02:33 -04:00
1 parent 1063d6dd27
commit c910ef8534
2 files changed
+4 -24

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+3 -12
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@@ -1036,8 +1036,6 @@ impl<R: Read + Seek> Decoder<R> {
&mut self.reader, &mut self.reader,
compression_method, compression_method,
length, length,
buffer.len(),
buffer.byte_len(),
)?; )?;
// Read into output buffer. // Read into output buffer.
@@ -1088,7 +1086,6 @@ impl<R: Read + Seek> Decoder<R> {
let tile_attrs = self.image().tile_attributes.as_ref().unwrap(); let tile_attrs = self.image().tile_attributes.as_ref().unwrap();
let (padding_right, padding_down) = tile_attrs.get_padding(tile); let (padding_right, padding_down) = tile_attrs.get_padding(tile);
let tile_samples = tile_attrs.tile_samples();
let tile_length = tile_attrs.tile_length; let tile_length = tile_attrs.tile_length;
let row_samples = tile_attrs.row_samples(); let row_samples = tile_attrs.row_samples();
let padding_right_samples = padding_right * self.image().bits_per_sample.len(); let padding_right_samples = padding_right * self.image().bits_per_sample.len();
@@ -1103,8 +1100,6 @@ impl<R: Read + Seek> Decoder<R> {
&mut self.reader, &mut self.reader,
compression_method, compression_method,
compressed_length, compressed_length,
tile_samples,
byte_len,
)?; )?;
for row in 0..(tile_length - padding_down) { for row in 0..(tile_length - padding_down) {
@@ -1147,16 +1142,12 @@ impl<R: Read + Seek> Decoder<R> {
reader: &'r mut SmartReader<R>, reader: &'r mut SmartReader<R>,
compression_method: CompressionMethod, compression_method: CompressionMethod,
compressed_length: u64, compressed_length: u64,
samples: usize, // Expected chunk length in samples
byte_len: usize, // Byte length of the samples in result buffer
) -> TiffResult<Box<dyn Read + 'r>> { ) -> TiffResult<Box<dyn Read + 'r>> {
Ok(match compression_method { Ok(match compression_method {
CompressionMethod::None => Box::new(reader), CompressionMethod::None => Box::new(reader),
CompressionMethod::LZW => Box::new(LZWReader::new( CompressionMethod::LZW => {
reader, Box::new(LZWReader::new(reader, usize::try_from(compressed_length)?))
usize::try_from(compressed_length)?, }
samples * byte_len,
)),
CompressionMethod::PackBits => { CompressionMethod::PackBits => {
Box::new(PackBitsReader::new(reader, usize::try_from(compressed_length)?)?.1) Box::new(PackBitsReader::new(reader, usize::try_from(compressed_length)?)?.1)
} }
+1 -12
View File
@@ -135,7 +135,6 @@ pub type DeflateReader<'r, R> = flate2::read::ZlibDecoder<&'r mut SmartReader<R>
pub struct LZWReader<R: Read> { pub struct LZWReader<R: Read> {
reader: BufReader<Take<R>>, reader: BufReader<Take<R>>,
decoder: weezl::decode::Decoder, decoder: weezl::decode::Decoder,
output_remaining: usize,
} }
impl<R: Read> LZWReader<R> { impl<R: Read> LZWReader<R> {
@@ -143,7 +142,6 @@ impl<R: Read> LZWReader<R> {
pub fn new( pub fn new(
reader: R, reader: R,
compressed_length: usize, compressed_length: usize,
max_uncompressed_length: usize,
) -> LZWReader<R> { ) -> LZWReader<R> {
Self { Self {
reader: BufReader::with_capacity( reader: BufReader::with_capacity(
@@ -151,25 +149,17 @@ impl<R: Read> LZWReader<R> {
reader.take(u64::try_from(compressed_length).unwrap()), reader.take(u64::try_from(compressed_length).unwrap()),
), ),
decoder: weezl::decode::Decoder::with_tiff_size_switch(weezl::BitOrder::Msb, 8), decoder: weezl::decode::Decoder::with_tiff_size_switch(weezl::BitOrder::Msb, 8),
output_remaining: max_uncompressed_length,
} }
} }
} }
impl<R: Read> Read for LZWReader<R> { impl<R: Read> Read for LZWReader<R> {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> { fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
if self.output_remaining == 0 {
return Ok(0);
}
loop { loop {
let max_output_length = self.output_remaining.min(buf.len());
let result = self let result = self
.decoder .decoder
.decode_bytes(self.reader.fill_buf()?, &mut buf[..max_output_length]); .decode_bytes(self.reader.fill_buf()?, buf);
self.reader.consume(result.consumed_in); self.reader.consume(result.consumed_in);
self.output_remaining -= result.consumed_out;
match result.status { match result.status {
Ok(weezl::LzwStatus::Ok) => { Ok(weezl::LzwStatus::Ok) => {
@@ -189,7 +179,6 @@ impl<R: Read> Read for LZWReader<R> {
)); ));
} }
Ok(weezl::LzwStatus::Done) => { Ok(weezl::LzwStatus::Done) => {
self.output_remaining = 0;
return Ok(result.consumed_out); return Ok(result.consumed_out);
} }
Err(err) => return Err(io::Error::new(io::ErrorKind::InvalidData, err)), Err(err) => return Err(io::Error::new(io::ErrorKind::InvalidData, err)),