commands: config option to control bundle compression level
Currently, bundle compression uses the default compression level
for the active compression engine. The default compression level
is tuned as a compromise between speed and size.
Some scenarios may call for a different compression level. For
example, with clone bundles, bundles are generated once and used
several times. Since the cost to generate is paid infrequently,
server operators may wish to trade extra CPU time for better
compression ratios.
This patch introduces an experimental and undocumented config
option to control the bundle compression level. As the inline
comment says, this approach is a bit hacky. I'd prefer for
the compression level to be encoded in the bundle spec. e.g.
"zstd-v2;complevel=15." However, given that the 4.1 freeze is
imminent, I'm not comfortable implementing this user-facing
change without much time to test and consider the implications.
So, we're going with the quick and dirty solution for now.
Having this option in the 4.1 release will enable Mozilla to
easily produce and test zlib and zstd bundles with non-default
compression levels in production. This will help drive future
development of the feature and zstd integration with Mercurial.
#require bzr
N.B. bzr 1.13 has a bug that breaks this test. If you see this
test fail, check your bzr version. Upgrading to bzr 1.13.1
should fix it.
$ . "$TESTDIR/bzr-definitions"
test multiple merges at once
$ mkdir test-multimerge
$ cd test-multimerge
$ bzr init -q source
$ cd source
$ echo content > file
$ bzr add -q file
$ bzr commit -q -m 'Initial add'
$ cd ..
$ bzr branch -q source source-branch1
$ cd source-branch1
$ echo morecontent >> file
$ echo evenmorecontent > file-branch1
$ bzr add -q file-branch1
$ bzr commit -q -m 'Added branch1 file'
$ cd ../source
$ sleep 1
$ echo content > file-parent
$ bzr add -q file-parent
$ bzr commit -q -m 'Added parent file'
$ cd ..
$ bzr branch -q source source-branch2
$ cd source-branch2
$ echo somecontent > file-branch2
$ bzr add -q file-branch2
$ bzr commit -q -m 'Added brach2 file'
$ sleep 1
$ cd ../source
$ bzr merge -q ../source-branch1
$ bzr merge -q --force ../source-branch2
$ bzr commit -q -m 'Merged branches'
$ cd ..
$ hg convert --datesort source source-hg
initializing destination source-hg repository
scanning source...
sorting...
converting...
4 Initial add
3 Added branch1 file
2 Added parent file
1 Added brach2 file
0 Merged branches
$ glog -R source-hg
o 5@source "(octopus merge fixup)" files:
|\
| o 4@source "Merged branches" files: file-branch2
| |\
o---+ 3@source-branch2 "Added brach2 file" files: file-branch2
/ /
| o 2@source "Added parent file" files: file-parent
| |
o | 1@source-branch1 "Added branch1 file" files: file file-branch1
|/
o 0@source "Initial add" files: file
$ manifest source-hg tip
% manifest of tip
644 file
644 file-branch1
644 file-branch2
644 file-parent
$ cd ..