bisect: avoid copying ancestor list for non-merge commits
During a bisection, hg needs to compute a list of all ancestors for every
candidate commit. This is accomplished via a bottom-up traversal of the set of
candidates, during which each revision's ancestor list is populated using the
ancestor list of its parent(s). Previously, this involved copying the entire
list, which could be very long in if the bisection range was large.
To help improve this, we can observe that each candidate commit is visited
exactly once, at which point its ancestor list is copied into its children's
lists and then dropped. In the case of non-merge commits, a commit's ancestor
list consists exactly of its parent's list plus itself. This means that we can
trivially reuse the parent's existing list for one of its non-merge children,
which avoids copying entirely if that commit is the parent's only child. This
makes bisections over linear ranges of commits much faster.
During some informal testing in the large publicly-available `mozilla-central`
repository, this noticeably sped up bisections over large ranges of history:
Setup:
$ cd mozilla-central
$ hg bisect --reset
$ hg bisect --good 0
$ hg log -r tip -T '{rev}\n'
628417
Test:
$ time hg bisect --bad tip --noupdate
Before:
real 3m35.927s
user 3m35.553s
sys 0m0.319s
After:
real 1m41.142s
user 1m40.810s
sys 0m0.285s
#require serve
$ hg init test
$ cd test
$ for i in 0 1 2 3 4 5 6 7 8; do
> echo $i >> foo
> hg commit -A -m $i
> done
adding foo
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 9 changesets with 9 changes to 1 files
$ hg serve -p $HGPORT -d --pid-file=hg.pid
$ cat hg.pid >> $DAEMON_PIDS
$ cd ..
$ hg init new
http incoming
$ hg -R new incoming http://localhost:$HGPORT/
comparing with http://localhost:$HGPORT/
changeset: 0:00a43fa82f62
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 0
changeset: 1:5460a410df01
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 1
changeset: 2:d9f42cd1a1ec
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 2
changeset: 3:376476025137
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 3
changeset: 4:70d7eb252d49
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 4
changeset: 5:ad284ee3b5ee
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 5
changeset: 6:e9229f2de384
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 6
changeset: 7:d152815bb8db
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 7
changeset: 8:e4feb4ac9035
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 8
$ hg -R new incoming -r 4 http://localhost:$HGPORT/
comparing with http://localhost:$HGPORT/
changeset: 0:00a43fa82f62
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 0
changeset: 1:5460a410df01
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 1
changeset: 2:d9f42cd1a1ec
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 2
changeset: 3:376476025137
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 3
changeset: 4:70d7eb252d49
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 4
local incoming
$ hg -R new incoming test
comparing with test
changeset: 0:00a43fa82f62
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 0
changeset: 1:5460a410df01
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 1
changeset: 2:d9f42cd1a1ec
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 2
changeset: 3:376476025137
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 3
changeset: 4:70d7eb252d49
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 4
changeset: 5:ad284ee3b5ee
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 5
changeset: 6:e9229f2de384
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 6
changeset: 7:d152815bb8db
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 7
changeset: 8:e4feb4ac9035
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 8
$ hg -R new incoming -r 4 test
comparing with test
changeset: 0:00a43fa82f62
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 0
changeset: 1:5460a410df01
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 1
changeset: 2:d9f42cd1a1ec
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 2
changeset: 3:376476025137
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 3
changeset: 4:70d7eb252d49
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 4
limit to 2 changesets
$ hg -R new incoming -l 2 test
comparing with test
changeset: 0:00a43fa82f62
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 0
changeset: 1:5460a410df01
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 1
limit to 2 changesets, test with -p --git
$ hg -R new incoming -l 2 -p --git test
comparing with test
changeset: 0:00a43fa82f62
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 0
diff --git a/foo b/foo
new file mode 100644
--- /dev/null
+++ b/foo
@@ -0,0 +1,1 @@
+0
changeset: 1:5460a410df01
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 1
diff --git a/foo b/foo
--- a/foo
+++ b/foo
@@ -1,1 +1,2 @@
0
+1
test with --bundle
$ hg -R new incoming --bundle test.hg http://localhost:$HGPORT/
comparing with http://localhost:$HGPORT/
changeset: 0:00a43fa82f62
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 0
changeset: 1:5460a410df01
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 1
changeset: 2:d9f42cd1a1ec
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 2
changeset: 3:376476025137
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 3
changeset: 4:70d7eb252d49
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 4
changeset: 5:ad284ee3b5ee
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 5
changeset: 6:e9229f2de384
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 6
changeset: 7:d152815bb8db
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 7
changeset: 8:e4feb4ac9035
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 8
$ hg -R new incoming --bundle test2.hg test
comparing with test
changeset: 0:00a43fa82f62
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 0
changeset: 1:5460a410df01
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 1
changeset: 2:d9f42cd1a1ec
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 2
changeset: 3:376476025137
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 3
changeset: 4:70d7eb252d49
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 4
changeset: 5:ad284ee3b5ee
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 5
changeset: 6:e9229f2de384
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 6
changeset: 7:d152815bb8db
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 7
changeset: 8:e4feb4ac9035
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 8
test the resulting bundles
$ hg init temp
$ hg init temp2
$ hg -R temp unbundle test.hg
adding changesets
adding manifests
adding file changes
added 9 changesets with 9 changes to 1 files
new changesets 00a43fa82f62:e4feb4ac9035 (9 drafts)
(run 'hg update' to get a working copy)
$ hg -R temp2 unbundle test2.hg
adding changesets
adding manifests
adding file changes
added 9 changesets with 9 changes to 1 files
new changesets 00a43fa82f62:e4feb4ac9035 (9 drafts)
(run 'hg update' to get a working copy)
$ hg -R temp tip
changeset: 8:e4feb4ac9035
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 8
$ hg -R temp2 tip
changeset: 8:e4feb4ac9035
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 8
$ rm -r temp temp2 new
test outgoing
$ hg clone test test-dev
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd test-dev
$ for i in 9 10 11 12 13; do
> echo $i >> foo
> hg commit -A -m $i
> done
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 14 changesets with 14 changes to 1 files
$ cd ..
$ hg -R test-dev outgoing test
comparing with test
searching for changes
changeset: 9:d89d4abea5bc
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 9
changeset: 10:820095aa7158
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 10
changeset: 11:09ede2f3a638
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 11
changeset: 12:e576b1bed305
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 12
changeset: 13:96bbff09a7cc
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 13
test outgoing with secret changesets
$ hg -R test-dev phase --force --secret 9
$ hg -R test-dev outgoing test
comparing with test
searching for changes
no changes found (ignored 5 secret changesets)
[1]
$ hg -R test-dev phase --draft -r 'head()'
limit to 3 changesets
$ hg -R test-dev outgoing -l 3 test
comparing with test
searching for changes
changeset: 9:d89d4abea5bc
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 9
changeset: 10:820095aa7158
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 10
changeset: 11:09ede2f3a638
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 11
$ hg -R test-dev outgoing http://localhost:$HGPORT/
comparing with http://localhost:$HGPORT/
searching for changes
changeset: 9:d89d4abea5bc
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 9
changeset: 10:820095aa7158
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 10
changeset: 11:09ede2f3a638
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 11
changeset: 12:e576b1bed305
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 12
changeset: 13:96bbff09a7cc
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 13
$ hg -R test-dev outgoing -r 11 http://localhost:$HGPORT/
comparing with http://localhost:$HGPORT/
searching for changes
changeset: 9:d89d4abea5bc
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 9
changeset: 10:820095aa7158
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 10
changeset: 11:09ede2f3a638
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 11
incoming from empty remote repository
$ hg init r1
$ hg init r2
$ echo a > r1/foo
$ hg -R r1 ci -Ama
adding foo
$ hg -R r1 incoming r2 --bundle x.hg
comparing with r2
searching for changes
no changes found
[1]
Create a "split" repo that pulls from r1 and pushes to r2, using default-push
$ hg clone r1 split
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat > split/.hg/hgrc << EOF
> [paths]
> default = $TESTTMP/r3
> default-push = $TESTTMP/r2
> EOF
$ hg -R split outgoing
comparing with $TESTTMP/r2
searching for changes
changeset: 0:3e92d79f743a
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
Use default:pushurl instead of default-push
Windows needs a leading slash to make a URL that passes all of the checks
$ WD=`pwd`
#if windows
$ WD="/$WD"
#endif
$ cat > split/.hg/hgrc << EOF
> [paths]
> default = $WD/r3
> default:pushurl = file://$WD/r2
> EOF
$ hg -R split outgoing
comparing with file:/*/$TESTTMP/r2 (glob)
searching for changes
changeset: 0:3e92d79f743a
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
Push and then double-check outgoing
$ echo a >> split/foo
$ hg -R split commit -Ama
$ hg -R split push
pushing to file:/*/$TESTTMP/r2 (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
$ hg -R split outgoing
comparing with file:/*/$TESTTMP/r2 (glob)
searching for changes
no changes found
[1]