push: rework the computation of fallbackheads to be correct
The previous computation tried to be smart but ended up being wrong. This was
caught by phase movement test while reworking the phase discovery logic to be
faster.
The previous logic was failing to catch case where the pushed set was not based
on a common heads (i.e. when the discovery seemed to have "over discovered"
content, outside the pushed set)
In the following graph, `e` is a common head and we `hg push -r f`. We need to
detect `c` as a fallback heads and we previous failed to do so::
e
|
d f
|/
c
|
b
|
a
The performance impact of the change seems minimal. On the most impacted
repository at hand (mozilla-try), the slowdown seems mostly mixed in the
overall noise `hg push` but seems to be in the hundred of milliseconds order of
magnitude. When using rust, we seems to be a bit faster, probably because we
leverage more accelaratd internals.
I added a couple of performance related common for further investigation later
on.
#require cvs112 no-root
This feature requires use of builtin cvsps!
$ echo "[extensions]" >> $HGRCPATH
$ echo "convert = " >> $HGRCPATH
create cvs repository with one project
$ mkdir cvsrepo
$ cd cvsrepo
$ CVSROOT=`pwd`
$ export CVSROOT
$ CVS_OPTIONS=-f
$ export CVS_OPTIONS
$ cd ..
$ rmdir cvsrepo
$ cvscall()
> {
> cvs -f "$@"
> }
output of 'cvs ci' varies unpredictably, so just discard it
$ cvsci()
> {
> sleep 1
> cvs -f ci "$@" >/dev/null
> }
$ cvscall -d "$CVSROOT" init
$ mkdir cvsrepo/proj
$ cvscall -q co proj
create file1 on the trunk
$ cd proj
$ touch file1
$ cvscall -Q add file1
$ cvsci -m"add file1 on trunk" file1
create two branches
$ cvscall -q tag -b v1_0
T file1
$ cvscall -q tag -b v1_1
T file1
create file2 on branch v1_0
$ cvscall -Q up -rv1_0
$ touch file2
$ cvscall -Q add file2
$ cvsci -m"add file2" file2
create file3, file4 on branch v1_1
$ cvscall -Q up -rv1_1
$ touch file3
$ touch file4
$ cvscall -Q add file3 file4
$ cvsci -m"add file3, file4 on branch v1_1" file3 file4
merge file2 from v1_0 to v1_1
$ cvscall -Q up -jv1_0
$ cvsci -m"MERGE from v1_0: add file2"
cvs commit: Examining .
Step things up a notch: now we make the history really hairy, with
changes bouncing back and forth between trunk and v1_2 and merges
going both ways. (I.e., try to model the real world.)
create branch v1_2
$ cvscall -Q up -A
$ cvscall -q tag -b v1_2
T file1
create file5 on branch v1_2
$ cvscall -Q up -rv1_2
$ touch file5
$ cvs -Q add file5
$ cvsci -m"add file5 on v1_2"
cvs commit: Examining .
create file6 on trunk post-v1_2
$ cvscall -Q up -A
$ touch file6
$ cvscall -Q add file6
$ cvsci -m"add file6 on trunk post-v1_2"
cvs commit: Examining .
merge file5 from v1_2 to trunk
$ cvscall -Q up -A
$ cvscall -Q up -jv1_2 file5
$ cvsci -m"MERGE from v1_2: add file5"
cvs commit: Examining .
merge file6 from trunk to v1_2
$ cvscall -Q up -rv1_2
$ cvscall up -jHEAD file6
U file6
$ cvsci -m"MERGE from HEAD: add file6"
cvs commit: Examining .
cvs rlog output
$ cvscall -q rlog proj | grep -E '^(RCS file|revision)'
RCS file: $TESTTMP/cvsrepo/proj/file1,v
revision 1.1
RCS file: $TESTTMP/cvsrepo/proj/Attic/file2,v
revision 1.1
revision 1.1.4.2
revision 1.1.4.1
revision 1.1.2.1
RCS file: $TESTTMP/cvsrepo/proj/Attic/file3,v
revision 1.1
revision 1.1.2.1
RCS file: $TESTTMP/cvsrepo/proj/Attic/file4,v
revision 1.1
revision 1.1.2.1
RCS file: $TESTTMP/cvsrepo/proj/file5,v
revision 1.2
revision 1.1
revision 1.1.2.1
RCS file: $TESTTMP/cvsrepo/proj/file6,v
revision 1.1
revision 1.1.2.2
revision 1.1.2.1
convert to hg (#1)
$ cd ..
$ hg convert --datesort proj proj.hg
initializing destination proj.hg repository
connecting to $TESTTMP/cvsrepo
scanning source...
collecting CVS rlog
15 log entries
creating changesets
9 changeset entries
sorting...
converting...
8 add file1 on trunk
7 add file2
6 MERGE from v1_0: add file2
5 file file3 was initially added on branch v1_1.
4 add file3, file4 on branch v1_1
3 add file5 on v1_2
2 add file6 on trunk post-v1_2
1 MERGE from HEAD: add file6
0 MERGE from v1_2: add file5
hg log -G output (#1)
$ hg -R proj.hg log -G --template "{rev} {desc}\n"
o 8 MERGE from v1_2: add file5
|
| o 7 MERGE from HEAD: add file6
| |
o | 6 add file6 on trunk post-v1_2
| |
| o 5 add file5 on v1_2
| |
| | o 4 add file3, file4 on branch v1_1
| | |
o | | 3 file file3 was initially added on branch v1_1.
|/ /
| o 2 MERGE from v1_0: add file2
|/
| o 1 add file2
|/
o 0 add file1 on trunk
convert to hg (#2: with merge detection)
$ hg convert \
> --config convert.cvsps.mergefrom='"^MERGE from (\S+):"' \
> --datesort \
> proj proj.hg2
initializing destination proj.hg2 repository
connecting to $TESTTMP/cvsrepo
scanning source...
collecting CVS rlog
15 log entries
creating changesets
9 changeset entries
sorting...
converting...
8 add file1 on trunk
7 add file2
6 MERGE from v1_0: add file2
5 file file3 was initially added on branch v1_1.
4 add file3, file4 on branch v1_1
3 add file5 on v1_2
2 add file6 on trunk post-v1_2
1 MERGE from HEAD: add file6
0 MERGE from v1_2: add file5
hg log -G output (#2)
$ hg -R proj.hg2 log -G --template "{rev} {desc}\n"
o 8 MERGE from v1_2: add file5
|
| o 7 MERGE from HEAD: add file6
| |
o | 6 add file6 on trunk post-v1_2
| |
| o 5 add file5 on v1_2
| |
| | o 4 add file3, file4 on branch v1_1
| | |
o | | 3 file file3 was initially added on branch v1_1.
|/ /
| o 2 MERGE from v1_0: add file2
|/
| o 1 add file2
|/
o 0 add file1 on trunk