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
Test character encoding
$ hg init t
$ cd t
we need a repo with some legacy latin-1 changesets
$ hg unbundle "$TESTDIR/bundles/legacy-encoding.hg"
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
new changesets 1e78a93102a3:0e5b7e3f9c4a (2 drafts)
(run 'hg update' to get a working copy)
$ hg co
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ "$PYTHON" << EOF
> f = open('latin-1', 'wb'); f.write(b"latin-1 e' encoded: \xe9"); f.close()
> f = open('utf-8', 'wb'); f.write(b"utf-8 e' encoded: \xc3\xa9"); f.close()
> f = open('latin-1-tag', 'wb'); f.write(b"\xe9"); f.close()
> EOF
should fail with encoding error
$ echo "plain old ascii" > a
$ hg st
M a
? latin-1
? latin-1-tag
? utf-8
$ HGENCODING=ascii hg ci -l latin-1
transaction abort!
rollback completed
abort: decoding near ' encoded: \xe9': 'ascii' codec can't decode byte 0xe9 in position 20: ordinal not in range(128)! (esc)
[255]
these should work
$ echo "latin-1" > a
$ HGENCODING=latin-1 hg ci -l latin-1
$ echo "utf-8" > a
$ HGENCODING=utf-8 hg ci -l utf-8
$ HGENCODING=latin-1 hg tag `cat latin-1-tag`
$ HGENCODING=latin-1 hg branch `cat latin-1-tag`
marked working directory as branch \xe9 (esc)
(branches are permanent and global, did you want a bookmark?)
$ HGENCODING=latin-1 hg ci -m 'latin1 branch'
$ hg -q rollback
$ HGENCODING=latin-1 hg branch
\xe9 (esc)
$ HGENCODING=latin-1 hg ci -m 'latin1 branch'
$ rm .hg/branch
hg log (ascii)
$ hg --encoding ascii log
changeset: 5:a52c0692f24a
branch: ?
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: latin1 branch
changeset: 4:94db611b4196
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Added tag ? for changeset ca661e7520de
changeset: 3:ca661e7520de
tag: ?
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: utf-8 e' encoded: ?
changeset: 2:650c6f3d55dd
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: latin-1 e' encoded: ?
changeset: 1:0e5b7e3f9c4a
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: koi8-r: ????? = u'\u0440\u0442\u0443\u0442\u044c'
changeset: 0:1e78a93102a3
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: latin-1 e': ? = u'\xe9'
hg log (latin-1)
$ hg --encoding latin-1 log
changeset: 5:a52c0692f24a
branch: \xe9 (esc)
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: latin1 branch
changeset: 4:94db611b4196
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Added tag \xe9 for changeset ca661e7520de (esc)
changeset: 3:ca661e7520de
tag: \xe9 (esc)
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: utf-8 e' encoded: \xe9 (esc)
changeset: 2:650c6f3d55dd
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: latin-1 e' encoded: \xe9 (esc)
changeset: 1:0e5b7e3f9c4a
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: koi8-r: \xd2\xd4\xd5\xd4\xd8 = u'\\u0440\\u0442\\u0443\\u0442\\u044c' (esc)
changeset: 0:1e78a93102a3
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: latin-1 e': \xe9 = u'\\xe9' (esc)
hg log (utf-8)
$ hg --encoding utf-8 log
changeset: 5:a52c0692f24a
branch: \xc3\xa9 (esc)
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: latin1 branch
changeset: 4:94db611b4196
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Added tag \xc3\xa9 for changeset ca661e7520de (esc)
changeset: 3:ca661e7520de
tag: \xc3\xa9 (esc)
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: utf-8 e' encoded: \xc3\xa9 (esc)
changeset: 2:650c6f3d55dd
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: latin-1 e' encoded: \xc3\xa9 (esc)
changeset: 1:0e5b7e3f9c4a
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: koi8-r: \xc3\x92\xc3\x94\xc3\x95\xc3\x94\xc3\x98 = u'\\u0440\\u0442\\u0443\\u0442\\u044c' (esc)
changeset: 0:1e78a93102a3
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: latin-1 e': \xc3\xa9 = u'\\xe9' (esc)
hg tags (ascii)
$ HGENCODING=ascii hg tags
tip 5:a52c0692f24a
? 3:ca661e7520de
hg tags (latin-1)
$ HGENCODING=latin-1 hg tags
tip 5:a52c0692f24a
\xe9 3:ca661e7520de (esc)
hg tags (utf-8)
$ HGENCODING=utf-8 hg tags
tip 5:a52c0692f24a
\xc3\xa9 3:ca661e7520de (esc)
hg tags (JSON)
$ hg tags -Tjson
[
{
"node": "a52c0692f24ad921c0a31e1736e7635a8b23b670",
"rev": 5,
"tag": "tip",
"type": ""
},
{
"node": "ca661e7520dec3f5438a63590c350bebadb04989",
"rev": 3,
"tag": "\xc3\xa9", (esc)
"type": ""
}
]
hg branches (ascii)
$ HGENCODING=ascii hg branches
? 5:a52c0692f24a
default 4:94db611b4196 (inactive)
hg branches (latin-1)
$ HGENCODING=latin-1 hg branches
\xe9 5:a52c0692f24a (esc)
default 4:94db611b4196 (inactive)
hg branches (utf-8)
$ HGENCODING=utf-8 hg branches
\xc3\xa9 5:a52c0692f24a (esc)
default 4:94db611b4196 (inactive)
$ echo '[ui]' >> .hg/hgrc
$ echo 'fallbackencoding = koi8-r' >> .hg/hgrc
hg log (utf-8)
$ HGENCODING=utf-8 hg log
changeset: 5:a52c0692f24a
branch: \xc3\xa9 (esc)
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: latin1 branch
changeset: 4:94db611b4196
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Added tag \xc3\xa9 for changeset ca661e7520de (esc)
changeset: 3:ca661e7520de
tag: \xc3\xa9 (esc)
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: utf-8 e' encoded: \xc3\xa9 (esc)
changeset: 2:650c6f3d55dd
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: latin-1 e' encoded: \xc3\xa9 (esc)
changeset: 1:0e5b7e3f9c4a
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: koi8-r: \xd1\x80\xd1\x82\xd1\x83\xd1\x82\xd1\x8c = u'\\u0440\\u0442\\u0443\\u0442\\u044c' (esc)
changeset: 0:1e78a93102a3
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: latin-1 e': \xd0\x98 = u'\\xe9' (esc)
hg log (dolphin)
$ HGENCODING=dolphin hg log
abort: unknown encoding: dolphin
(please check your locale settings)
[255]
$ HGENCODING=ascii hg branch `cat latin-1-tag`
abort: decoding near '\xe9': 'ascii' codec can't decode byte 0xe9 in position 0: ordinal not in range(128)! (esc)
[255]
$ cp latin-1-tag .hg/branch
$ HGENCODING=latin-1 hg ci -m 'auto-promote legacy name'
Test roundtrip encoding of lookup tables when not using UTF-8 (issue2763)
$ HGENCODING=latin-1 hg up `cat latin-1-tag`
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ cd ..
Test roundtrip encoding/decoding of utf8b for generated data
#if hypothesis
>>> import hypothesishelpers
>>> from mercurial import encoding
>>> hypothesishelpers.roundtrips(hypothesishelpers.st.binary(),
... encoding.fromutf8b, encoding.toutf8b)
Round trip OK
#endif