Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

fix ability to disable block checksumming #55

Merged
merged 3 commits into from
Sep 26, 2024
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
50 changes: 46 additions & 4 deletions src/decoder.rs
Original file line number Diff line number Diff line change
Expand Up @@ -69,13 +69,13 @@ impl<R: Read> Read for Decoder<R> {
self.next
};
self.len = self.r.read(&mut self.buf[0..need])?;
if self.len == 0 {
break;
}
// NOTE: we do not exit here if there was nothing read
// The lz4 context may still have more bytes to emit.

self.pos = 0;
self.next -= self.len;
}
while (dst_offset < buf.len()) && (self.pos < self.len) {
while (dst_offset < buf.len()) && ((self.pos < self.len) || self.len == 0) {
let mut src_size = (self.len - self.pos) as size_t;
let mut dst_size = (buf.len() - dst_offset) as size_t;
let len = check_error(unsafe {
Expand All @@ -90,6 +90,14 @@ impl<R: Read> Read for Decoder<R> {
})?;
self.pos += src_size as usize;
dst_offset += dst_size as usize;

// We need to keep trying to read bytes from the decompressor
// until it is no longer emitting them, even after it
// has finished reading bytes.
if dst_size == 0 && src_size == 0 {
return Ok(dst_offset);
}

if len == 0 {
self.next = 0;
return Ok(dst_offset);
Expand Down Expand Up @@ -290,6 +298,40 @@ mod test {
finish_decode(decoder);
}

/// Ensure that we emit the full decompressed stream even if we're
/// using a very small output buffer.
#[test]
fn issue_45() {
// create an encoder
let mut enc = crate::EncoderBuilder::new().build(Vec::new()).unwrap();

// write 'a' 100 times to the encoder
let text: Vec<u8> = vec!['a' as u8; 100];
enc.write_all(&text[..]).unwrap();

// flush the encoder
enc.flush().unwrap();

// read from the decoder, buf_size bytes at a time
for buf_size in [5, 10, 15, 20, 25] {
let mut buf = vec![0; buf_size];

let mut total_bytes_read = 0;

// create a decoder wrapping the backing buffer
let mut dec = crate::Decoder::new(&enc.writer()[..]).unwrap();
while let Ok(n) = dec.read(&mut buf[..]) {
if n == 0 {
break;
}

total_bytes_read += n;
}

assert_eq!(total_bytes_read, text.len());
}
}

fn random() -> StdRng {
let seed: [u8; 32] = [
157, 164, 190, 237, 231, 103, 60, 22, 197, 108, 51, 176, 30, 170, 155, 21, 163, 249,
Expand Down
4 changes: 2 additions & 2 deletions src/encoder.rs
Original file line number Diff line number Diff line change
Expand Up @@ -39,7 +39,7 @@ impl EncoderBuilder {
block_size: BlockSize::Default,
block_mode: BlockMode::Linked,
checksum: ContentChecksum::ChecksumEnabled,
block_checksum: BlockChecksum::NoBlockChecksum,
block_checksum: BlockChecksum::BlockChecksumEnabled,
level: 0,
auto_flush: false,
favor_dec_speed: false,
Expand Down Expand Up @@ -99,7 +99,7 @@ impl EncoderBuilder {
content_size: self.content_size.clone(),
frame_type: FrameType::Frame,
dict_id: 0,
block_checksum_flag: BlockChecksum::BlockChecksumEnabled,
block_checksum_flag: self.block_checksum.clone(),
},
compression_level: self.level,
auto_flush: if self.auto_flush { 1 } else { 0 },
Expand Down
Loading