fix: cache esbuild transform results per VM to avoid repeated TTY syscalls - #25
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bflad merged 1 commit intoMar 9, 2026
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danielkov
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Mar 6, 2026
…calls Each call to esbuild.Transform() internally creates a new stderr logger that unconditionally calls GetTerminalInfo/IoctlGetTermios to check if stderr is a TTY. Since vm.compile() is called hundreds of times during generation (once per template rendered plus setup calls), and many calls receive the same source string, this accumulates significant CPU overhead. Cache esbuild.TransformResult per VM instance keyed by (name, src) to avoid redundant transform calls. The cache is bounded by the number of unique template sources and requires no eviction or synchronization since VMs are single-goroutine, where the number of template sources is not likely to be a concern in practice.
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Added RWMutex and rebased with main. 👍 |
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Summary
esbuild.TransformResultper VM instance to avoid redundantesbuild.Transform()calls invm.compile()esbuild.Transform()internally callsGetTerminalInfo/IoctlGetTermiosto check if stderr is a TTY, which accumulates significant CPU overhead when called hundreds of times during generation(name, src)using a struct key and requires no eviction or synchronization since VMs are single-goroutine