perf: add MarshalAppend APIs and increase buffer capacity#12
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Lunkers merged 3 commits intoEyevinn:mainfrom Apr 17, 2026
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Add MarshalVmapAppend and MarshalVastAppend functions that accept a caller-provided buffer, enabling buffer reuse via sync.Pool for reduced GC pressure in high-throughput scenarios. Also increase initial buffer capacity from 8KB/4KB to 256KB/128KB to better match typical VMAP/VAST document sizes and reduce intermediate growth allocations. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Summary
MarshalVmapAppendandMarshalVastAppendfunctions that accept a caller-provided[]bytebuffer and return the extended buffer. This enables callers to reuse buffers (e.g. viasync.Pool) for reduced GC pressure in high-throughput scenarios.MarshalVmap(8 KB → 256 KB) andMarshalVast(4 KB → 128 KB) to better match typical document sizes and reduce intermediate growth allocations during marshaling.Motivation
Profiling the ad-normalizer service showed
escTextaccounting for ~43% of all cumulative allocations (73.8 GB). The allocations were not from the escaping logic itself (which is already efficient) but from repeated[]bytebuffer growth — starting at 8 KB and doubling through many intermediate sizes for typical 100KB+ VMAP documents.Test plan
MarshalVmapAppend,MarshalVastAppend, and prefix preservationMarshalVmap/MarshalVast🤖 Generated with Claude Code