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.
$ cat << EOF >> $HGRCPATH
> [format]
> usegeneraldelta=yes
> EOF
bundle w/o type option
$ hg init t1
$ hg init t2
$ cd t1
$ echo blablablablabla > file.txt
$ hg ci -Ama
adding file.txt
$ hg log | grep summary
summary: a
$ hg bundle ../b1 ../t2
searching for changes
1 changesets found
$ cd ../t2
$ hg pull ../b1
pulling from ../b1
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
(run 'hg update' to get a working copy)
$ hg up
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg log | grep summary
summary: a
$ cd ..
test bundle types
$ testbundle() {
> echo % test bundle type $1
> hg init t$1
> cd t1
> hg bundle -t $1 ../b$1 ../t$1
> f -q -B6 -D ../b$1; echo
> cd ../t$1
> hg debugbundle ../b$1
> hg debugbundle --spec ../b$1
> echo
> cd ..
> }
$ for t in "None" "bzip2" "gzip" "none-v2" "v2" "v1" "gzip-v1"; do
> testbundle $t
> done
% test bundle type None
searching for changes
1 changesets found
HG20\x00\x00 (esc)
Stream params: {}
changegroup -- "sortdict([('version', '02'), ('nbchanges', '1')])"
c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
none-v2
% test bundle type bzip2
searching for changes
1 changesets found
HG20\x00\x00 (esc)
Stream params: sortdict([('Compression', 'BZ')])
changegroup -- "sortdict([('version', '02'), ('nbchanges', '1')])"
c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
bzip2-v2
% test bundle type gzip
searching for changes
1 changesets found
HG20\x00\x00 (esc)
Stream params: sortdict([('Compression', 'GZ')])
changegroup -- "sortdict([('version', '02'), ('nbchanges', '1')])"
c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
gzip-v2
% test bundle type none-v2
searching for changes
1 changesets found
HG20\x00\x00 (esc)
Stream params: {}
changegroup -- "sortdict([('version', '02'), ('nbchanges', '1')])"
c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
none-v2
% test bundle type v2
searching for changes
1 changesets found
HG20\x00\x00 (esc)
Stream params: sortdict([('Compression', 'BZ')])
changegroup -- "sortdict([('version', '02'), ('nbchanges', '1')])"
c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
bzip2-v2
% test bundle type v1
searching for changes
1 changesets found
HG10BZ
c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
bzip2-v1
% test bundle type gzip-v1
searching for changes
1 changesets found
HG10GZ
c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
gzip-v1
Compression level can be adjusted for bundle2 bundles
$ hg init test-complevel
$ cd test-complevel
$ cat > file0 << EOF
> this is a file
> with some text
> and some more text
> and other content
> EOF
$ cat > file1 << EOF
> this is another file
> with some other content
> and repeated, repeated, repeated, repeated content
> EOF
$ hg -q commit -A -m initial
$ hg bundle -a -t gzip-v2 gzip-v2.hg
1 changesets found
$ f --size gzip-v2.hg
gzip-v2.hg: size=427
$ hg --config experimental.bundlecomplevel=1 bundle -a -t gzip-v2 gzip-v2-level1.hg
1 changesets found
$ f --size gzip-v2-level1.hg
gzip-v2-level1.hg: size=435
$ cd ..
#if zstd
$ for t in "zstd" "zstd-v2"; do
> testbundle $t
> done
% test bundle type zstd
searching for changes
1 changesets found
HG20\x00\x00 (esc)
Stream params: sortdict([('Compression', 'ZS')])
changegroup -- "sortdict([('version', '02'), ('nbchanges', '1')])"
c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
zstd-v2
% test bundle type zstd-v2
searching for changes
1 changesets found
HG20\x00\x00 (esc)
Stream params: sortdict([('Compression', 'ZS')])
changegroup -- "sortdict([('version', '02'), ('nbchanges', '1')])"
c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
zstd-v2
#else
zstd is a valid engine but isn't available
$ hg -R t1 bundle -a -t zstd irrelevant.hg
abort: compression engine zstd could not be loaded
[255]
#endif
test garbage file
$ echo garbage > bgarbage
$ hg init tgarbage
$ cd tgarbage
$ hg pull ../bgarbage
pulling from ../bgarbage
abort: ../bgarbage: not a Mercurial bundle
[255]
$ cd ..
test invalid bundle type
$ cd t1
$ hg bundle -a -t garbage ../bgarbage
abort: garbage is not a recognized bundle specification
(see 'hg help bundle' for supported values for --type)
[255]
$ cd ..