Support configurable root cache compression

This patch adds configuration options that influence how is the root
cache compressed:

  config_opts['plugin_conf']['root_cache_opts']['compress_program'] = "gzip"
  config_opts['plugin_conf']['root_cache_opts']['extension'] = ".gz"

Motivation to do this was to be able to use lzma compression. While it
takes a long time to compress, for me it was more than two times faster
than gzip when decompressing. Since I only seldom regenerate the root cache
while doing a lot of builds, I was able to gain a considerable speed up.

1 files changed, 3 insertions, 1 deletions

diff --git a/py/mock.py b/py/mock.py
index dd5d1af..c5f057b 100755
--- a/py/mock.py
+++ b/py/mock.py
@@ -248,7 +248,9 @@ def setup_default_config_opts(config_opts, unprivUid):
             'root_cache_enable': True,
             'root_cache_opts': {
                 'max_age_days': 15,
-                'dir': "%(cache_topdir)s/%(root)s/root_cache/"},
+                'dir': "%(cache_topdir)s/%(root)s/root_cache/",
+                'compress_program': 'gzip',
+                'extension': '.gz'},
             'bind_mount_enable': True,
             'bind_mount_opts': {'dirs': [
                 # specify like this: