Mercurial > hg
view mercurial/scmwindows.py @ 27895:2d6a89e79b48
scmutil: support background file closing
Closing files that have been appended to is relatively slow on
Windows/NTFS. This makes several Mercurial operations slower on
Windows.
The workaround to this issue is conceptually simple: use multiple
threads for I/O. Unfortunately, Python doesn't scale well to multiple
threads because of the GIL. And, refactoring our code to use threads
everywhere would be a huge undertaking. So, we decide to tackle this
problem by starting small: establishing a thread pool for closing
files.
This patch establishes a mechanism for closing file handles on separate
threads. The coordinator object is basically a queue of file handles to
operate on and a thread pool consuming from the queue.
When files are opened through the VFS layer, the caller can specify
that delay closing is allowed.
A proxy class for file handles has been added. We must use a proxy
because it isn't possible to modify __class__ on built-in types. This
adds some overhead. But as future patches will show, this overhead
is cancelled out by the benefit of closing file handles on background
threads.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Thu, 14 Jan 2016 13:34:59 -0800 |
parents | 029f02757c20 |
children | 3df9f780c90e |
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from __future__ import absolute_import import _winreg import os from . import ( osutil, util, ) def systemrcpath(): '''return default os-specific hgrc search path''' rcpath = [] filename = util.executablepath() # Use mercurial.ini found in directory with hg.exe progrc = os.path.join(os.path.dirname(filename), 'mercurial.ini') rcpath.append(progrc) # Use hgrc.d found in directory with hg.exe progrcd = os.path.join(os.path.dirname(filename), 'hgrc.d') if os.path.isdir(progrcd): for f, kind in osutil.listdir(progrcd): if f.endswith('.rc'): rcpath.append(os.path.join(progrcd, f)) # else look for a system rcpath in the registry value = util.lookupreg('SOFTWARE\\Mercurial', None, _winreg.HKEY_LOCAL_MACHINE) if not isinstance(value, str) or not value: return rcpath value = util.localpath(value) for p in value.split(os.pathsep): if p.lower().endswith('mercurial.ini'): rcpath.append(p) elif os.path.isdir(p): for f, kind in osutil.listdir(p): if f.endswith('.rc'): rcpath.append(os.path.join(p, f)) return rcpath def userrcpath(): '''return os-specific hgrc search path to the user dir''' home = os.path.expanduser('~') path = [os.path.join(home, 'mercurial.ini'), os.path.join(home, '.hgrc')] userprofile = os.environ.get('USERPROFILE') if userprofile and userprofile != home: path.append(os.path.join(userprofile, 'mercurial.ini')) path.append(os.path.join(userprofile, '.hgrc')) return path