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When computing revision ownership, cache some intermediate results for performance

Authored by epriestley on Feb 27 2017, 4:05 PM.



Ref T12319. With large datasets, the computation of which packages own paths in a revision is needlessly slow.

Improve performance through caching:

  • Cache which paths belong to each repository.
  • Cache the split fragments of each path.
  • Cache the path fragment counts.
  • Micro-optimize accessing $this->path.
Test Plan
  • Used bin/lipsum to generate 4,000 packages with 150,000 paths.
  • Created a revision affecting 100 paths in phabricator/ (these paths mostly overlap with bin/lipsum path rules, since Lipsum uses Phabricator-like rules to generate paths).
  • Before optimizations, this revision spent about 5.5 seconds computing paths.
  • After optimizations, it spends about 275ms.

Screen Shot 2017-02-27 at 8.01.39 AM.png (1×2 px, 375 KB)

Diff Detail

rP Phabricator
Automatic diff as part of commit; lint not applicable.
Automatic diff as part of commit; unit tests not applicable.