Mercurial > hg
view mercurial/txnutil.py @ 45515:89f0d9f87701
branchmap: add a cache validation cache, avoid expensive re-hash on every use
In a pathological `hg log` case, we end up executing the branchmap validity
checking twice per commit displayed. Or maybe we always do, and I just noticed
because it's really slow in this repo for some reason.
Before:
```
Time (mean ± σ): 9.816 s ± 0.071 s [User: 9.435 s, System: 0.392 s]
Range (min … max): 9.709 s … 9.920 s
```
After:
```
Time (mean ± σ): 8.671 s ± 0.078 s [User: 8.309 s, System: 0.392 s]
Range (min … max): 8.594 s … 8.816 s
```
Differential Revision: https://phab.mercurial-scm.org/D9023
author | Kyle Lippincott <spectral@google.com> |
---|---|
date | Wed, 16 Sep 2020 12:13:46 -0700 |
parents | 687b865b95ad |
children | 89a2afe31e82 |
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# txnutil.py - transaction related utilities # # Copyright FUJIWARA Katsunori <foozy@lares.dti.ne.jp> and others # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import import errno from . import encoding def mayhavepending(root): '''return whether 'root' may have pending changes, which are visible to this process. ''' return root == encoding.environ.get(b'HG_PENDING') def trypending(root, vfs, filename, **kwargs): '''Open file to be read according to HG_PENDING environment variable This opens '.pending' of specified 'filename' only when HG_PENDING is equal to 'root'. This returns '(fp, is_pending_opened)' tuple. ''' if mayhavepending(root): try: return (vfs(b'%s.pending' % filename, **kwargs), True) except IOError as inst: if inst.errno != errno.ENOENT: raise return (vfs(filename, **kwargs), False)