perf: scan lf text-block lines with indexOf#841
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He-Pin wants to merge 1 commit intodatabricks:masterfrom
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perf: scan lf text-block lines with indexOf#841He-Pin wants to merge 1 commit intodatabricks:masterfrom
He-Pin wants to merge 1 commit intodatabricks:masterfrom
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Motivation: Large text blocks spend visible parser time finding line boundaries with a Scala character loop. Modification: Use String.indexOf for single-character LF separators in the bulk text-block scanner while preserving the existing CRLF and multi-character separator path. Result: LF text-block parsing uses the platform string search fast path without changing text-block semantics.
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Motivation:
Large text blocks spend visible parser time finding line boundaries with a Scala character loop.
Key Design Decision:
Only single-character LF separators use
String.indexOf('\n'); CRLF and other multi-character separator paths keep the previous scanner to preserve behavior.Modification:
In the bulk
|||text-block body scanner, useString.indexOfto find LF line endings after indentation.Benchmark Results:
bench/resources/cpp_suite/large_string_template.jsonnet10.855 +/- 0.773 ms10.300 +/- 0.638 ms-5.12%11.191 ms10.373 ms-7.3%10.552 +/- 0.656 ms; jrsonnet5.611 +/- 0.826 ms1.88xAnalysis:
This is a narrow parser optimization with explicit CRLF fallback. Other larger text-block scanner rewrites were tested and rejected, so this PR keeps only the stable LF
indexOfwin.References:
Source exploration commit: He-Pin/sjsonnet
8f8ed59a.Result:
Local
./mill --no-server -j 1 __.reformatand./mill --no-server -j 1 __.testpassed on this split branch (2066/2066).