perf(markdown): cache syntax highlighting results for code blocks#2119
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dgageot merged 1 commit intodocker:mainfrom Mar 16, 2026
Merged
perf(markdown): cache syntax highlighting results for code blocks#2119dgageot merged 1 commit intodocker:mainfrom
dgageot merged 1 commit intodocker:mainfrom
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During streaming, the FastRenderer re-renders the full accumulated content on every incoming chunk. Code blocks that were already fully received were being re-tokenized through chroma's expensive regex engine on every render, causing O(n²) performance degradation. Add a package-level cache keyed by (lang, code) for syntax highlighting token results. Once a code block has been tokenized, subsequent renders reuse the cached tokens. The cache is cleared on theme changes via ResetStyles(). Streaming benchmark results (BenchmarkStreamingFastRenderer): Time: 3,311ms → ~350ms (~10x faster) Allocs: 26M → ~2.3M (~11x fewer) Memory: 2,497MB → ~906MB (~2.8x less) Assisted-By: docker-agent
gtardif
approved these changes
Mar 16, 2026
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During streaming, the FastRenderer re-renders the full accumulated content on every incoming chunk. Code blocks that were already fully received were being re-tokenized through chroma's expensive regex engine on every render, causing O(n²) performance degradation.
Add a package-level cache keyed by (lang, code) for syntax highlighting token results. Once a code block has been tokenized, subsequent renders reuse the cached tokens. The cache is cleared on theme changes via ResetStyles().
Streaming benchmark results (BenchmarkStreamingFastRenderer):
Time: 3,311ms → ~350ms (~10x faster)
Allocs: 26M → ~2.3M (~11x fewer)
Memory: 2,497MB → ~906MB (~2.8x less)
Assisted-By: docker-agent