Support multiple concatenated streams #20
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Otherwise the number of bytes read is off by one which later leads to problems when consuming the input stream precisely to the last byte.
In addition to the per-block CRC sums, the stream ends with a checksum that combines all CRC sums; check that one as well. Also align the bit reader to the next byte boundary in the end to allow reading data that follows.
bzip2 can handle inputs that consist of multiple concatenated bzip2 streams. To support this functionality, the decoder needs to continue after seeing an EOS marker because it may be followed by another bzip2 stream.
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Looks good! |
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Merged and published as unbzip2-stream@1.3.0 Thanks, @sfriesel ! |
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Fixes #19
unbzip2-stream stops decoding as soon as it encounters an EOS marker, but bzip2 transparently supports concatenated streams like so:
cat <(echo -n a | bzip2) <(echo b | bzip2) | bunzip2The example file in #19 is such a case of concatenation.
To support this feature the current implementation needs to be more precise in consuming the correct number of bits/bytes up until the first stream ends, so that decoding for following bzip2 streams picks up at the right position again. If the input stream doesn't end after the first bzip2 stream, the decoder will now continue and expect additional bzip2 streams until the input stream ends.
As an intermediate step, this PR also validates the stream checksum that directly follows each EOS marker, to validate that all blocks were present and in the right order.