Mercurial > public > mercurial-scm > hg-stable
comparison mercurial/revset.py @ 20894:04e1596d5dbd
revset: improve _descendants performance
Previously revset._descendants would iterate over the entire subset (which is
often the entire repo) and test if each rev was in the descendants list. This is
really slow on large repos (3+ seconds).
Now we iterate over the descendants and test if they're in the subset.
This affects advancing and retracting the phase boundary (3.5 seconds down to
0.8 seconds, which is even faster than it was in 2.9). Also affects commands
that move the phase boundary (commit and rebase, presumably).
The new revsetbenchmark indicates an improvement from 0.2 to 0.12 seconds. So
future revset changes should be able to notice regressions.
I removed a bad test. It was recently added and tested '1:: and reverse(all())',
which has an amibiguous output direction. Previously it printed in reverse order,
because we iterated over the subset (the reverse part). Now it prints in normal
order because we iterate over the 1:: . Since the revset itself doesn't imply an
order, I removed the test.
author | Durham Goode <durham@fb.com> |
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date | Tue, 25 Mar 2014 14:10:01 -0700 |
parents | 876c17336b4e |
children | f52e4ca93529 |
comparison
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20893:b5de9dde181c | 20894:04e1596d5dbd |
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659 def _descendants(repo, subset, x, followfirst=False): | 659 def _descendants(repo, subset, x, followfirst=False): |
660 args = getset(repo, spanset(repo), x) | 660 args = getset(repo, spanset(repo), x) |
661 if not args: | 661 if not args: |
662 return baseset([]) | 662 return baseset([]) |
663 s = _revdescendants(repo, args, followfirst) | 663 s = _revdescendants(repo, args, followfirst) |
664 a = set(args) | 664 |
665 return subset.filter(lambda r: r in s or r in a) | 665 # Both sets need to be ascending in order to lazily return the union |
666 # in the correct order. | |
667 args.ascending() | |
668 | |
669 subsetset = subset.set() | |
670 result = (orderedlazyset(s, subsetset.__contains__, ascending=True) + | |
671 orderedlazyset(args, subsetset.__contains__, ascending=True)) | |
672 | |
673 # Wrap result in a lazyset since it's an _addset, which doesn't implement | |
674 # all the necessary functions to be consumed by callers. | |
675 return orderedlazyset(result, lambda r: True, ascending=True) | |
666 | 676 |
667 def descendants(repo, subset, x): | 677 def descendants(repo, subset, x): |
668 """``descendants(set)`` | 678 """``descendants(set)`` |
669 Changesets which are descendants of changesets in set. | 679 Changesets which are descendants of changesets in set. |
670 """ | 680 """ |