tests/test-ui-verbosity.py.out

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.

      hgrc settings    command line options      final result   
    quiet verbo debug   quiet verbo debug      quiet verbo debug
 0  False False False   False False False  ->  False False False
 1   True False False   False False False  ->   True False False
 2  False  True False   False False False  ->  False  True False
 3   True  True False   False False False  ->  False False False
 4  False False  True   False False False  ->  False  True  True
 5   True False  True   False False False  ->  False  True  True
 6  False  True  True   False False False  ->  False  True  True
 7   True  True  True   False False False  ->  False  True  True
 8  False False False    True False False  ->   True False False
 9   True False False    True False False  ->   True False False
10  False  True False    True False False  ->   True False False
11   True  True False    True False False  ->   True False False
12  False False  True    True False False  ->   True False False
13   True False  True    True False False  ->   True False False
14  False  True  True    True False False  ->   True False False
15   True  True  True    True False False  ->   True False False
16  False False False   False  True False  ->  False  True False
17   True False False   False  True False  ->  False  True False
18  False  True False   False  True False  ->  False  True False
19   True  True False   False  True False  ->  False  True False
20  False False  True   False  True False  ->  False  True False
21   True False  True   False  True False  ->  False  True False
22  False  True  True   False  True False  ->  False  True False
23   True  True  True   False  True False  ->  False  True False
24  False False False    True  True False  ->  False False False
25   True False False    True  True False  ->  False False False
26  False  True False    True  True False  ->  False False False
27   True  True False    True  True False  ->  False False False
28  False False  True    True  True False  ->  False False False
29   True False  True    True  True False  ->  False False False
30  False  True  True    True  True False  ->  False False False
31   True  True  True    True  True False  ->  False False False
32  False False False   False False  True  ->  False  True  True
33   True False False   False False  True  ->  False  True  True
34  False  True False   False False  True  ->  False  True  True
35   True  True False   False False  True  ->  False  True  True
36  False False  True   False False  True  ->  False  True  True
37   True False  True   False False  True  ->  False  True  True
38  False  True  True   False False  True  ->  False  True  True
39   True  True  True   False False  True  ->  False  True  True
40  False False False    True False  True  ->  False  True  True
41   True False False    True False  True  ->  False  True  True
42  False  True False    True False  True  ->  False  True  True
43   True  True False    True False  True  ->  False  True  True
44  False False  True    True False  True  ->  False  True  True
45   True False  True    True False  True  ->  False  True  True
46  False  True  True    True False  True  ->  False  True  True
47   True  True  True    True False  True  ->  False  True  True
48  False False False   False  True  True  ->  False  True  True
49   True False False   False  True  True  ->  False  True  True
50  False  True False   False  True  True  ->  False  True  True
51   True  True False   False  True  True  ->  False  True  True
52  False False  True   False  True  True  ->  False  True  True
53   True False  True   False  True  True  ->  False  True  True
54  False  True  True   False  True  True  ->  False  True  True
55   True  True  True   False  True  True  ->  False  True  True
56  False False False    True  True  True  ->  False  True  True
57   True False False    True  True  True  ->  False  True  True
58  False  True False    True  True  True  ->  False  True  True
59   True  True False    True  True  True  ->  False  True  True
60  False False  True    True  True  True  ->  False  True  True
61   True False  True    True  True  True  ->  False  True  True
62  False  True  True    True  True  True  ->  False  True  True
63   True  True  True    True  True  True  ->  False  True  True