Fix for incremental reader chunk-drop#259
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MaxHeimbrock merged 2 commits intomainfrom Apr 27, 2026
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Exercise ReadIncrementalInstructionBase<T>.OnChunk with several chunks arriving before the consumer drains, simulating multiple ChunkReceived events delivered on the same sync-context flush. The base keeps only a single _latestChunk, so earlier chunks are silently overwritten; the test pins this down ahead of the queue-backed fix on a follow-up branch. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
ReadIncrementalInstructionBase<T> previously stored each incoming chunk in a single _latestChunk field. When several ChunkReceived FFI events were dispatched on the same sync-context flush (routine between Unity frames), OnChunk overwrote the field before the consumer coroutine could resume from its yield, silently dropping earlier chunks. Queue chunks that arrive while a prior read is still pending. Reset() advances _latestChunk to the next queued chunk and keeps IsCurrentReadDone true so the next yield completes immediately, draining the buffer before waiting for more FFI events. Flips DataStreamIncrementalReadTests from failing to passing. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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ladvoc
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Apr 27, 2026
| [Test] | ||
| public void OnChunk_MultipleChunksBeforeConsumerDrains_AllChunksAreObserved() | ||
| { | ||
| using var handle = new FfiHandle(IntPtr.Zero); |
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question: I'm probably missing something obvious, but how does creating a zero FfiHandle work here?
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It is a null pointer and we just need it to satisfy the constructor. In the TestIncrementalReader we can push chunks to mock callbacks without needing any native stuff, so the null handle is never used. Does that answer your question?
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And on cleanup we check if the handle is valid, so it would also not be released.
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Summary
ReadIncrementalInstructionBase<T>.OnChunkcall into a single_latestChunkfield, so when severalChunkReceivedFFI events are dispatched on the same sync-context flush (common: multiple chunks arriving between Unity frames), earlier chunks are silently overwritten before the consumer coroutine can resume from its yield.Test plan
Add just the new unit test without the fix and see the CI tests fail:
https://github.com/livekit/client-sdk-unity/actions/runs/24781354985?pr=259
Fix bug in 2nd commit will make this test go green without changing the test itself.