Mercurial > hg
view tests/test-rebase-named-branches.t @ 17616:9535a0dc41f2
store: implement fncache basic path encoding in C
(This is not yet enabled; it will be turned on in a followup patch.)
The path encoding performed by fncache is complex and (perhaps
surprisingly) slow enough to negatively affect the overall performance
of Mercurial.
For a short path (< 120 bytes), the Python code can be reduced to a fairly
tractable state machine that either determines that nothing needs to be
done in a single pass, or performs the encoding in a second pass.
For longer paths, we avoid the more complicated hashed encoding scheme
for now, and fall back to Python.
Raw performance: I measured in a repo containing 150,000 files in its tip
manifest, with a median path name length of 57 bytes, and 95th percentile
of 96 bytes.
In this repo, the Python code takes 3.1 seconds to encode all path
names, while the hybrid C-and-Python code (called from Python) takes
0.21 seconds, for a speedup of about 14.
Across several other large repositories, I've measured the speedup from
the C code at between 26x and 40x.
For path names above 120 bytes where we must fall back to Python for
hashed encoding, the speedup is about 1.7x. Thus absolute performance
will depend strongly on the characteristics of a particular repository.
author | Bryan O'Sullivan <bryano@fb.com> |
---|---|
date | Tue, 18 Sep 2012 15:42:19 -0700 |
parents | 4f795f5fbb0b |
children | 9c78ed396075 |
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$ cat >> $HGRCPATH <<EOF > [extensions] > graphlog= > rebase= > > [phases] > publish=False > > [alias] > tglog = log -G --template "{rev}: '{desc}' {branches}\n" > EOF $ hg init a $ cd a $ hg unbundle "$TESTDIR/bundles/rebase.hg" adding changesets adding manifests adding file changes added 8 changesets with 7 changes to 7 files (+2 heads) (run 'hg heads' to see heads, 'hg merge' to merge) $ hg up tip 3 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cd .. $ hg clone -q -u . a a1 $ cd a1 $ hg update 3 3 files updated, 0 files merged, 2 files removed, 0 files unresolved $ hg branch dev-one marked working directory as branch dev-one (branches are permanent and global, did you want a bookmark?) $ hg ci -m 'dev-one named branch' $ hg update 7 2 files updated, 0 files merged, 3 files removed, 0 files unresolved $ hg branch dev-two marked working directory as branch dev-two (branches are permanent and global, did you want a bookmark?) $ echo x > x $ hg add x $ hg ci -m 'dev-two named branch' $ hg tglog @ 9: 'dev-two named branch' dev-two | | o 8: 'dev-one named branch' dev-one | | o | 7: 'H' | | +---o 6: 'G' | | | o | | 5: 'F' | | | +---o 4: 'E' | | | o 3: 'D' | | | o 2: 'C' | | | o 1: 'B' |/ o 0: 'A' Branch name containing a dash (issue3181) $ hg rebase -b dev-two -d dev-one --keepbranches saved backup bundle to $TESTTMP/a1/.hg/strip-backup/*-backup.hg (glob) $ hg tglog @ 9: 'dev-two named branch' dev-two | o 8: 'H' | | o 7: 'G' |/| o | 6: 'F' | | o | 5: 'dev-one named branch' dev-one | | | o 4: 'E' | | o | 3: 'D' | | o | 2: 'C' | | o | 1: 'B' |/ o 0: 'A' $ hg rebase -s dev-one -d 0 --keepbranches saved backup bundle to $TESTTMP/a1/.hg/strip-backup/*-backup.hg (glob) $ hg tglog @ 8: 'dev-two named branch' dev-two | o 7: 'H' | | o 6: 'G' |/| o | 5: 'F' | | | o 4: 'E' |/ | o 3: 'D' | | | o 2: 'C' | | | o 1: 'B' |/ o 0: 'A' $ hg update 3 3 files updated, 0 files merged, 3 files removed, 0 files unresolved $ hg branch dev-one marked working directory as branch dev-one (branches are permanent and global, did you want a bookmark?) $ hg ci -m 'dev-one named branch' $ hg tglog @ 9: 'dev-one named branch' dev-one | | o 8: 'dev-two named branch' dev-two | | | o 7: 'H' | | | | o 6: 'G' | |/| | o | 5: 'F' | | | | | o 4: 'E' | |/ o | 3: 'D' | | o | 2: 'C' | | o | 1: 'B' |/ o 0: 'A' $ hg rebase -b 'max(branch("dev-two"))' -d dev-one --keepbranches saved backup bundle to $TESTTMP/a1/.hg/strip-backup/*-backup.hg (glob) $ hg tglog @ 9: 'dev-two named branch' dev-two | o 8: 'H' | | o 7: 'G' |/| o | 6: 'F' | | o | 5: 'dev-one named branch' dev-one | | | o 4: 'E' | | o | 3: 'D' | | o | 2: 'C' | | o | 1: 'B' |/ o 0: 'A' $ hg rebase -s 'max(branch("dev-one"))' -d 0 --keepbranches saved backup bundle to $TESTTMP/a1/.hg/strip-backup/*-backup.hg (glob) $ hg tglog @ 8: 'dev-two named branch' dev-two | o 7: 'H' | | o 6: 'G' |/| o | 5: 'F' | | | o 4: 'E' |/ | o 3: 'D' | | | o 2: 'C' | | | o 1: 'B' |/ o 0: 'A' Rebasing descendant onto ancestor across different named branches $ hg rebase -s 1 -d 8 --keepbranches saved backup bundle to $TESTTMP/a1/.hg/strip-backup/*-backup.hg (glob) $ hg tglog @ 8: 'D' | o 7: 'C' | o 6: 'B' | o 5: 'dev-two named branch' dev-two | o 4: 'H' | | o 3: 'G' |/| o | 2: 'F' | | | o 1: 'E' |/ o 0: 'A' $ hg rebase -s 4 -d 5 abort: source is ancestor of destination [255] $ hg rebase -s 5 -d 4 saved backup bundle to $TESTTMP/a1/.hg/strip-backup/*-backup.hg (glob) $ hg tglog @ 8: 'D' | o 7: 'C' | o 6: 'B' | o 5: 'dev-two named branch' | o 4: 'H' | | o 3: 'G' |/| o | 2: 'F' | | | o 1: 'E' |/ o 0: 'A' $ cd ..