fn read_block_next()

in avro/src/reader.rs [136:170]

• 26 lines of code
• 3 McCabe index (conditional complexity)

    fn read_block_next(&mut self) -> AvroResult<()> {
        assert!(self.is_empty(), "Expected self to be empty!");
        match util::read_long(&mut self.reader) {
            Ok(block_len) => {
                self.message_count = block_len as usize;
                let block_bytes = util::read_long(&mut self.reader)?;
                self.fill_buf(block_bytes as usize)?;
                let mut marker = [0u8; 16];
                self.reader
                    .read_exact(&mut marker)
                    .map_err(Error::ReadBlockMarker)?;

                if marker != self.marker {
                    return Err(Error::GetBlockMarker);
                }

                // NOTE (JAB): This doesn't fit this Reader pattern very well.
                // `self.buf` is a growable buffer that is reused as the reader is iterated.
                // For non `Codec::Null` variants, `decompress` will allocate a new `Vec`
                // and replace `buf` with the new one, instead of reusing the same buffer.
                // We can address this by using some "limited read" type to decode directly
                // into the buffer. But this is fine, for now.
                self.codec.decompress(&mut self.buf)
            }
            Err(Error::ReadVariableIntegerBytes(io_err)) => {
                if let ErrorKind::UnexpectedEof = io_err.kind() {
                    // to not return any error in case we only finished to read cleanly from the stream
                    Ok(())
                } else {
                    Err(Error::ReadVariableIntegerBytes(io_err))
                }
            }
            Err(e) => Err(e),
        }
    }