fix: prevent frontend OOM on high-throughput SSE streams#945
Merged
mhordynski merged 2 commits intodevelopfrom Feb 26, 2026
Merged
fix: prevent frontend OOM on high-throughput SSE streams#945mhordynski merged 2 commits intodevelopfrom
mhordynski merged 2 commits intodevelopfrom
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…oduce - Add EventBuffer class to decouple SSE stream from store updates - Batch text events into single set() call with pre-built flat string - Wrap MarkdownContent in content-visibility: auto for Chrome renderer
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Code Coverage SummaryDetailsDiff against mainResults for commit: 1ee4b1f Minimum allowed coverage is ♻️ This comment has been updated with latest results |
mhordynski
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Feb 26, 2026
mkoruszowic
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Feb 27, 2026
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Problem
Streaming large SSE responses causes the browser to consume excessive memory and crash. Each incoming SSE event triggered 3 separate
immer.produce()calls via set(), and the flush loop applied them individually per event. With thousands of events batched at 100ms intervals, this created tens of thousands of immutable state snapshots in a tight synchronous loop, preventing GC from reclaiming intermediate copies.Chrome was particularly affected due to V8 cons-string chains from repeated
+=through immer's Proxy setter, and Blink's eager layout computation for large DOM trees.Changes
historyStore.ts
.map().join("")outside immer, then applied with a single set() call — collapsing N×3 snapshots into 1 per batchMarkdownContent.tsx
<Markdown>in a<div>withcontent-visibility: auto— tells Chrome to skip layout/paint for off-screen content (Firefox already does this implicitly)Testing