[Perf]: ~1.9x faster parse via fast-paths and manual scanning#552
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homanp wants to merge 2 commits into
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[Perf]: ~1.9x faster parse via fast-paths and manual scanning#552homanp wants to merge 2 commits into
homanp wants to merge 2 commits into
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homanp
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ljharb
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Apr 27, 2026
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This will need a rebase; it conflicts with some bugfixes i merged.
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| if (cleanStr.indexOf('%5') !== -1) { | ||
| cleanStr = cleanStr.replace(/%5B/gi, '[').replace(/%5D/gi, ']'); | ||
| } |
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i'm surprised "indexOf + 2 replaces" being slower doesn't outweigh the benefit of the other branch being "indexOf instead of 2 replaced". it might be a good idea to do each change in a separate commit, and put the benchmark results in each commit message.
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Ageee, Will make it clearer. Ty for feedback.
…parts Hoist decoder/defaultDecoder lookups out of the per-part loop. Check whether each part actually contains '%' or '+' before calling the decoder; plain ASCII key=value pairs are sliced directly without entering the decode path. Benchmark (weighted ops/sec): 540,502 → 696,526 (+28.9%) flat: 745,039 → 1,010,337 nested: 394,463 → 481,302 arrays: 356,643 → 534,676 encoded: 846,351 → 859,280 search: 332,500 → 492,732
When a key has no '[' (and no '.' when allowDots is set), assign directly instead of going through parseKeys/splitKeyIntoSegments/ parseObject/merge. Also track whether any key needed the full path to skip the compact() pass when it is unnecessary. Benchmark (weighted ops/sec): 696,526 → 861,226 (+23.6%) flat: 1,010,337 → 1,430,967 nested: 481,302 → 461,549 arrays: 534,676 → 536,818 encoded: 859,280 → 1,067,296 search: 492,732 → 580,142
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@ljharb Rebased and split into separate commits with benchmarks in each. After testing each optimization in isolation I ended up dropping two of them:
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Summary
~1.9x faster
qs.parsevia fast-paths for common cases and manual scanning to replace split/regex in hot loops. No behavior changes, no new deps. All 893 tests pass.Benchmarks
Weighted throughput across 5 representative query string shapes, 3 fresh node processes (Node 23, macOS):
a=1&b=2&c=3&d=4&e=5)user[name]=alice&...)ids[]=1&ids[]=2&...)q=hello%20world&...)Bench script in
bench/workload.jsfor reproduction.What changed
[, skip bracket-parsing entirely.indexOf('%')+indexOf('+')up front — if neither present, return input unchanged.&), in-place scan instead ofsplit().compact()only needed when bracket parsing created sparse arrays.indexOfinsplitKeyIntoSegments.Correctness
All 893 tape tests pass. Equivalence also verified on 25 additional adversarial inputs (empty strings, bare keys, duplicates, deep nesting, percent-encoded specials,
+as space, mixed bracket styles).Happy to split into separate commits per optimization if that helps review.