perf(engine,producer): worker-offload JPEG encode for drawElement fast capture#1444
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perf(engine,producer): worker-offload JPEG encode for drawElement fast capture#1444vanceingalls wants to merge 3 commits into
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…t capture Moves per-frame JPEG encode (~7.4ms, 57% of frame cost) off the page main thread into an in-page OffscreenCanvas Worker, then pipelines so frame N encodes while frame N+1 seeks+paints. Target ~1.65× (1 worker) wall-time speedup on macOS hardware-GPU drawElement renders. New machinery: - EngineConfig.enableDrawElementWorkerEncode (default false, env HF_DE_WORKER_ENCODE) - drawElementService: WorkerEncodeState, initDrawElementWorkerEncode, cleanupDrawElementWorkerEncode, produceDrawElementFrame - frameCapture: CaptureSession.workerEncodeEnabled, captureFrameToBufferPipelined - captureStreamingStage: runWorkerEncodePipelineLoop helper + depth-2 dispatch Gated off by default. No effect on BeginFrame/Linux, SwiftShader, PNG, or any render without useDrawElement+enableDrawElementWorkerEncode=true. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Liveness/correctness:
- Worker encode failures now propagate: the in-page worker wraps encode in
try/catch + null-checks getContext and posts {id,error} on failure; its
onerror posts a fatal signal (id=-1). The node binding rejects the matching
pending promise (or all of them on fatal) instead of leaving encodeResult
pending forever — previously any worker throw hung the render to timeout.
- Pipeline loop attaches a no-op catch to the orphaned in-flight encode on
abort/throw so cleanup's rejection is not an unhandled promise rejection.
- drainPrev checks assertNotAborted before awaiting so aborts are observed
while parked on the encode wait, not one frame later.
- captureFrameToBufferPipelined wraps capture in captureFrameErrorDiagnostics,
restoring per-frame frame-error PNG/HTML/JSON the serial path produced.
Lifecycle/efficiency:
- __hfFrameReady binding tracked via a separate workerEncodeBoundPages WeakSet
so a re-init after cleanup doesn't call exposeFunction twice ('already exists').
- URL.revokeObjectURL after Worker construction (was leaked per init).
- Drop the unconditional setTimeout(0) around createImageBitmap (~1-4ms/frame
of macrotask latency on the produce critical path; encode runs in the worker).
- Reset nextId on session reuse; remove the unreachable BeginFrame branch from
the pipelined path (gated to beginFrameTimeTicks===0).
Base64 stays in the worker (off the main thread) by design; a binary
side-channel to node is a follow-up. Gated off by default.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Co-authored-by: Miguel Ángel <miguel07alm@protonmail.com>
… (re-review) Re-review found the prior orphan-rejection fix attached to the wrong promise. - Unhandled-rejection guard moved to source: produceDrawElementFrame attaches a no-op .catch to every encodeResult at creation, covering the depth-2 loop's orphaned in-flight frame. Removed the ineffective loop-level prev.catch. - Per-frame encode watchdog (30s): a lost worker message no longer hangs the render to the protocol timeout (onerror->id=-1 only covered crashes). - Empty-frame guard: payload-less worker success rejects instead of resolving a 0-byte Buffer ffmpeg would write as a corrupt frame. - Worker reuses one OffscreenCanvas across frames (was per-frame alloc). - Close the ImageBitmap on the worker-missing reject path (GPU leak). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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