changeset 30758:76104a4899ad

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.
author Gregory Szorc <gregory.szorc@gmail.com>
date Tue, 10 Jan 2017 11:20:32 -0800
parents 511a4bf52754
children 3f5f0c98cd18
files mercurial/commands.py tests/test-bundle-type.t
diffstat 2 files changed, 42 insertions(+), 1 deletions(-) [+]
line wrap: on
line diff
--- a/mercurial/commands.py	Tue Jan 10 11:19:37 2017 -0800
+++ b/mercurial/commands.py	Tue Jan 10 11:20:32 2017 -0800
@@ -1383,7 +1383,17 @@
         assert cgversion == '02'
         bversion = 'HG20'
 
-    bundle2.writebundle(ui, cg, fname, bversion, compression=bcompression)
+    # TODO compression options should be derived from bundlespec parsing.
+    # This is a temporary hack to allow adjusting bundle compression
+    # level without a) formalizing the bundlespec changes to declare it
+    # b) introducing a command flag.
+    compopts = {}
+    complevel = ui.configint('experimental', 'bundlecomplevel')
+    if complevel is not None:
+        compopts['level'] = complevel
+
+    bundle2.writebundle(ui, cg, fname, bversion, compression=bcompression,
+                        compopts=compopts)
 
 @command('cat',
     [('o', 'output', '',
--- a/tests/test-bundle-type.t	Tue Jan 10 11:19:37 2017 -0800
+++ b/tests/test-bundle-type.t	Tue Jan 10 11:20:32 2017 -0800
@@ -110,6 +110,37 @@
   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