Mercurial > hg
changeset 30437:64d7275445d0
util: expose an "available" API on compression engines
When the zstd compression engine is introduced, it won't work in all
installations, namely pure Python installs. So, we need a mechanism to
declare whether a compression engine is available. We don't want to
conditionally register the compression engine because it is sometimes
useful to know when a compression engine name or encountered data is
valid but just not available versus unknown.
| author | Gregory Szorc <gregory.szorc@gmail.com> |
|---|---|
| date | Thu, 10 Nov 2016 23:03:48 -0800 |
| parents | 788ea4ac4388 |
| children | 90933e4e44fd |
| files | mercurial/util.py |
| diffstat | 1 files changed, 9 insertions(+), 0 deletions(-) [+] |
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--- a/mercurial/util.py Thu Nov 10 22:26:35 2016 -0800 +++ b/mercurial/util.py Thu Nov 10 23:03:48 2016 -0800 @@ -3047,6 +3047,15 @@ """ raise NotImplementedError() + def available(self): + """Whether the compression engine is available. + + The intent of this method is to allow optional compression engines + that may not be available in all installations (such as engines relying + on C extensions that may not be present). + """ + return True + def bundletype(self): """Describes bundle identifiers for this engine.