Mercurial > public > mercurial-scm > hg-stable
diff contrib/perf.py @ 16414:e8d37b78acfb
parsers: use base-16 trie for faster node->rev mapping
This greatly speeds up node->rev lookups, with results that are
often user-perceptible: for instance, "hg --time log" of the node
associated with rev 1000 on a linux-2.6 repo improves from 0.3
seconds to 0.03. I have not found any instances of slowdowns.
The new perfnodelookup command in contrib/perf.py demonstrates the
speedup more dramatically, since it performs no I/O. For a single
lookup, the new code is about 40x faster.
These changes also prepare the ground for the possibility of further
improving the performance of prefix-based node lookups.
| author | Bryan O'Sullivan <bryano@fb.com> |
|---|---|
| date | Thu, 12 Apr 2012 14:05:59 -0700 |
| parents | efae1fea4bbd |
| children | 525fdb738975 |
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--- a/contrib/perf.py Thu Apr 12 20:22:18 2012 -0500 +++ b/contrib/perf.py Thu Apr 12 14:05:59 2012 -0700 @@ -1,7 +1,7 @@ # perf.py - performance test routines '''helper extension to measure performance''' -from mercurial import cmdutil, scmutil, match, commands +from mercurial import cmdutil, scmutil, util, match, commands import time, os, sys def timer(func, title=None): @@ -120,6 +120,27 @@ cl.rev(n) timer(d) +def perfnodelookup(ui, repo, rev): + import mercurial.revlog + mercurial.revlog._prereadsize = 2**24 # disable lazy parser in old hg + n = repo[rev].node() + cl = mercurial.revlog.revlog(repo.sopener, "00changelog.i") + # behave somewhat consistently across internal API changes + if util.safehasattr(cl, 'clearcaches'): + clearcaches = cl.clearcaches + elif util.safehasattr(cl, '_nodecache'): + from mercurial.node import nullid, nullrev + def clearcaches(): + cl._nodecache = {nullid: nullrev} + cl._nodepos = None + else: + def clearcaches(): + pass + def d(): + cl.rev(n) + clearcaches() + timer(d) + def perflog(ui, repo, **opts): ui.pushbuffer() timer(lambda: commands.log(ui, repo, rev=[], date='', user='',