Since v0.7.3 'yams get' has requested compressed transfers
(acceptCompressed), and the daemon has answered with a framed payload: a
CompressionHeader followed by a Zstandard body. Only the MCP server
decoded it; 'yams get' wrote the frame itself to stdout or -o, so users
saw the 'CNRK' header and a zstd frame instead of the document. 'yams cat'
was unaffected because it does not request compression.
- Move the frame format into compression/framed_payload
(encodeFramedPayload/decodeFramedPayload). DocumentService encodes with
it; 'yams get' and MCP decode with it.
- The decoder checks the header, body size and CRC, and the decoded size
and CRC. A payload that fails is an error; MCP used to fall back to
returning the framed bytes as content.
Verified end to end: 'yams get' output (stdout and -o) is byte-identical
to the added file while the transfer stays compressed (51.75x).
Signed-off-by: trvon <me@trevon.dev>
lzma_compressor.cpp targets the 7-Zip LZMA SDK (LzmaEnc.h/Alloc.h), but
the build only finds xz/liblzma, which does not ship those headers, so
every build (release logs: 'Has header "LzmaEnc.h" ... NO') compiled it
out. No build could read or write LZMA blocks, and its decoder never
bounded output by the expected size.
The policy still chose LZMA for cold/archival and large inactive data;
compression then failed ('Compressor not available') and batch stores
kept those blocks uncompressed. Select Zstandard, which already uses the
archive level for old data.
Remove the compressor, its test, the enable-lzma option and the build
flags that passed it. The LZMA algorithm id stays in the header format,
and compression.lzma_level remains accepted in config (now unused).
decompress() trusted a caller-provided expected size (from the stored
block header, which has no checksum of its own) and allocated that many
bytes, up to 16 GB, before decoding. A corrupt size field could therefore
drive a huge allocation.
When the frame records its content size, the expected size must match
it. When it does not (streaming compressor output), decode incrementally
so the buffer grows with the real output and fail once it passes the
expected size.
