discovery-helper: use reflink copy if available
A reflink copy will copy the files "as usual" but keep using the same data block
underneath. This is only supported by "copy on write" file system like btrfs or
zfs.
This will achieve similar performance that the existing hardlink clone that
Mercurial performs with the same initial space saving. However, it will behave
better on revlogs start being touch by strip. Instead of duplicating all data in
the touched revlogs, only the block actually affected by the strip will be
duplicated. This save a lot of space when building many variants of large
repositories.
The --reflink=always flag make sure the `cp` call fails if reflink copies are
not supported. Falling back to local clone.
#require cvs112
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 | egrep '^(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