rust/hg-core/src/revlog/revlog.rs

45597:48438e8968a2

            // header.
            b'\0' => Ok(Cow::Borrowed(self.bytes)),
            // Raw revision data follows.
            b'u' => Ok(Cow::Borrowed(&self.bytes[1..])),
            // zlib (RFC 1950) data.
            b'x' => Ok(Cow::Owned(self.uncompressed_zlib_data())),
            // zstd data.
            b'\x28' => Ok(Cow::Owned(self.uncompressed_zstd_data())),
            format_type => Err(RevlogError::UnknowDataFormat(format_type)),
        }
    }

    fn uncompressed_zlib_data(&self) -> Vec<u8> {
        let mut decoder = ZlibDecoder::new(self.bytes);
        if self.is_delta() {
            let mut buf = Vec::with_capacity(self.compressed_len);
            decoder.read_to_end(&mut buf).expect("corrupted zlib data");
            buf
        } else {
            let mut buf = vec![0; self.uncompressed_len];
            decoder.read_exact(&mut buf).expect("corrupted zlib data");
            buf
        }
    }

    fn uncompressed_zstd_data(&self) -> Vec<u8> {
        if self.is_delta() {
            let mut buf = Vec::with_capacity(self.compressed_len);
            zstd::stream::copy_decode(self.bytes, &mut buf)
                .expect("corrupted zstd data");
            buf
        } else {
            let mut buf = vec![0; self.uncompressed_len];
            let len = zstd::block::decompress_to_buffer(self.bytes, &mut buf)
                .expect("corrupted zstd data");
            assert_eq!(len, self.uncompressed_len, "corrupted zstd data");
            buf
        }
    }

    /// Tell if the entry is a snapshot or a delta
    /// (influences on decompression).

45598:497657895b54

            // header.
            b'\0' => Ok(Cow::Borrowed(self.bytes)),
            // Raw revision data follows.
            b'u' => Ok(Cow::Borrowed(&self.bytes[1..])),
            // zlib (RFC 1950) data.
            b'x' => Ok(Cow::Owned(self.uncompressed_zlib_data()?)),
            // zstd data.
            b'\x28' => Ok(Cow::Owned(self.uncompressed_zstd_data()?)),
            format_type => Err(RevlogError::UnknowDataFormat(format_type)),
        }
    }

    fn uncompressed_zlib_data(&self) -> Result<Vec<u8>, RevlogError> {
        let mut decoder = ZlibDecoder::new(self.bytes);
        if self.is_delta() {
            let mut buf = Vec::with_capacity(self.compressed_len);
            decoder
                .read_to_end(&mut buf)
                .or(Err(RevlogError::Corrupted))?;
            Ok(buf)
        } else {
            let mut buf = vec![0; self.uncompressed_len];
            decoder
                .read_exact(&mut buf)
                .or(Err(RevlogError::Corrupted))?;
            Ok(buf)
        }
    }

    fn uncompressed_zstd_data(&self) -> Result<Vec<u8>, RevlogError> {
        if self.is_delta() {
            let mut buf = Vec::with_capacity(self.compressed_len);
            zstd::stream::copy_decode(self.bytes, &mut buf)
                .or(Err(RevlogError::Corrupted))?;
            Ok(buf)
        } else {
            let mut buf = vec![0; self.uncompressed_len];
            let len = zstd::block::decompress_to_buffer(self.bytes, &mut buf)
                .or(Err(RevlogError::Corrupted))?;
            if len != self.uncompressed_len {
                Err(RevlogError::Corrupted)
            } else {
                Ok(buf)
            }
        }
    }

    /// Tell if the entry is a snapshot or a delta
    /// (influences on decompression).