perf(cache): reuse a single SHA-256 hasher across blobToHash calls#128
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KodyJKing wants to merge 2 commits into
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perf(cache): reuse a single SHA-256 hasher across blobToHash calls#128KodyJKing wants to merge 2 commits into
KodyJKing wants to merge 2 commits into
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Previously blobToHash instantiated a fresh hash-wasm instance per call. Reuse one lazily-created global instance, using hash-wasm's resumable save()/load() so concurrent calls interleave at their stream reads without serializing or corrupting each other. Optimizes the I/O-bound case where blobs are often not fully in memory. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
KodyJKing
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Jun 23, 2026
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| hasher.load(state); | ||
| hasher.update(chunk.value); | ||
| state = hasher.save(); |
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The save and load are the only possible performance concession here.
The await reader.read() means concurrent hash calls can interleave and corrupt each other's state since the hasher is shared now.
…eads Adds a deterministic test that drives concurrent blobToHash calls through a gated fake Blob, forcing chunk reads to interleave round-robin and asserting results equal the serial digests. Fails on a shared hasher without save()/load(); passes with it. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
KodyJKing
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Jun 23, 2026
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| it("interleaved concurrent reads match serial hashes", async () => { |
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This has been verified to fail when save/load are omitted, so this is correctly testing interleaved reads.
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Description
See FFP PR #12270 for motivation.
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