perf: avoid loading full node:stream module in internal modules - #27400
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Replace require('node:stream') with direct submodule requires:
- require('internal/streams/readable')
- require('internal/streams/writable')
- require('internal/streams/end-of-stream')
This avoids eagerly loading unused submodules (Transform, Duplex,
PassThrough, pipeline, operators, etc.) when accessing process.stdin,
fs.createReadStream, or fs.createWriteStream.
Benchmark shows ~0.5ms improvement in process.stdin startup cost.
Apply the same optimization to: - node/zlib.ts: Transform, finished - node/_http_server.ts: Duplex, Stream - node/_http2_upgrade.ts: Duplex - node/http2.ts: Readable, Duplex, Stream - thirdparty/undici.js: Readable - builtins/CompressionStream.ts: Readable, Writable - builtins/DecompressionStream.ts: Readable, Writable Each file now requires only the specific internal/streams/* submodules it needs instead of the full node:stream module.
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Updated 11:20 AM PT - Feb 27th, 2026
❌ @sosukesuzuki, your commit 2529997 has 6 failures in
🧪 To try this PR locally: bunx bun-pr 27400That installs a local version of the PR into your bun-27400 --bun |
end-of-stream exports the eos function as default export, not as
a named 'finished' export. Using { finished } destructuring caused
ERR_INVALID_ARG_TYPE because the callback was passed as options.
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Summary
Replace
require("node:stream")with direct submodule requires (internal/streams/readable,internal/streams/writable, etc.) in files that only use a subset of the stream module. This avoids eagerly loading unused submodules (Transform, Duplex, PassThrough, pipeline, operators, etc.) at startup.Changed files
src/js/internal/fs/streams.ts—Readable,Writable,finishedsrc/js/node/zlib.ts—Transform,finishedsrc/js/node/_http_server.ts—Duplex,Streamsrc/js/node/_http2_upgrade.ts—Duplexsrc/js/node/http2.ts—Readable,Duplex,Streamsrc/js/thirdparty/undici.js—Readablesrc/js/builtins/CompressionStream.ts—Readable,Writablesrc/js/builtins/DecompressionStream.ts—Readable,WritableBenchmark (
process.stdinstartup cost, release build, median of 50 runs × 3 rounds)process.stdinrequire("node:stream")fs.createReadStreamrequire("node:stream")itself is unchanged, confirming the improvement comes from avoiding unnecessary submodule loading.