perf(cpp): skip LZ4 frame checksums (XXH32) for a measurable throughp… - #1742
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…ut gain Profiling a point-cloud-heavy MCAP showed LZ4_XXH32_update consuming more CPU than the decompression itself (~12% vs ~9% of total application CPU on a GUI thread). Skipping the frame-level block and content checksum via LZ4F_decompressOptions_t.skipChecksums eliminates that cost — roughly a 41% reduction in total LZ4 decode CPU. Structural corruption is still caught by the size/consumption checks already present in decompressAll(): wrong output size (dstSize != uncompressedSize), partial consumption (srcSize != compressedSize), and LZ4F_isError on the return code. The XXH32 integrity hash is therefore redundant for callers that trust the source (local files, verified network transports). Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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I think this makes sense to control via an option on the MCAP library, but might be unexpected as a default behavior.
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…ut gain
Profiling a point-cloud-heavy MCAP showed LZ4_XXH32_update consuming more CPU than the decompression itself (~12% vs ~9% of total application CPU on a GUI thread). Skipping the frame-level block and content checksum via LZ4F_decompressOptions_t.skipChecksums eliminates that cost — roughly a 41% reduction in total LZ4 decode CPU.
Structural corruption is still caught by the size/consumption checks already present in decompressAll(): wrong output size (dstSize != uncompressedSize), partial consumption (srcSize != compressedSize), and LZ4F_isError on the return code. The XXH32 integrity hash is therefore redundant for callers that trust the source (local files, verified network transports).
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