⚡ perf(link): skip fragment regex when fragment marker absent#13987
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⚡ perf(link): skip fragment regex when fragment marker absent#13987gaborbernat wants to merge 1 commit into
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Every `Link` runs `_egg_fragment_re.search` and `_subdirectory_fragment_re.search` against `self._url` to find the matching fragment, even though Warehouse-served URLs (the bulk of links a Simple-API response carries) never include either fragment. Each regex search compiles a Boyer-Moore state and walks the full URL, which adds up across the ~65000 links a moderately sized cross-platform lock iterates per resolver pass. Guard each search with a literal `"egg=" not in self._url` (resp. `"subdirectory=" not in self._url`) pre-check. Python's substring search is C-implemented and runs an order of magnitude faster than the regex when the marker is absent; when the marker is present the existing regex still runs, so behaviour is preserved for VCS / direct-URL / `find-links` style URLs that carry it. A new `test_fragments_absent_for_typical_links` parametrize asserts both accessors return `None` for a representative spread of Simple-API URLs. The existing `test_fragments` and `test_invalid_egg_fragments` cases all carry explicit `#egg=…` / `&subdirectory=…` fragments and continue to exercise the slow path.
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Every
Linkruns_egg_fragment_re.searchand_subdirectory_fragment_re.searchagainstself._urlto find the matching fragment, even though Warehouse-served URLs (the bulk of links a Simple-API response carries) never include either fragment. Each regex search walks the full URL, which adds up across the ~65000 links a moderately sized cross-platform lock iterates per resolver pass. ⚡The patch guards each search with a literal
"egg=" not in self._url(resp."subdirectory=" not in self._url) pre-check. Python's substring search is C-implemented and runs roughly 8x faster than the regex when the marker is absent; when the marker is present the existing regex still runs, so behaviour is preserved byte-for-byte for VCS / direct-URL /find-linksstyle URLs that carry it.Function-level micro-bench against
https://files.pythonhosted.org/packages/12/34/foo-1.0-py3-none-any.whl#sha256=…(noegg=): the egg accessor drops from 535 ns/call to 69 ns/call, a 7.8x speedup. End-to-end against a cross-platform lock pipeline iterating ~65000 links across 8 resolver passes (n=8 paired runs alternatingupstream/mainvsupstream/main + this patch): user-CPU mean falls 2.8% (median 55 ms reduction), 7/8 paired runs faster.