Mercurial > hg
view hgext/win32mbcs.py @ 30561:7c0c722d568d
bdiff: early pruning of common prefix before doing expensive computations
It seems quite common that files don't change completely. New lines are often
pretty much appended, and modifications will often only change a small section
of the file which on average will be in the middle.
There can thus be a big win by pruning a common prefix before starting the more
expensive search for longest common substrings.
Worst case, it will scan through a long sequence of similar bytes without
encountering a newline. Splitlines will then have to do the same again ...
twice for each side. If similar lines are found, splitlines will save the
double iteration and hashing of the lines ... plus there will be less lines to
find common substrings in.
This change might in some cases make the algorith pick shorter or less optimal
common substrings. We can't have the cake and eat it.
This make hg --time bundle --base null -r 4.0 go from 14.5 to 15 s - a 3%
increase.
On mozilla-unified:
perfbdiff -m 3041e4d59df2
! wall 0.053088 comb 0.060000 user 0.060000 sys 0.000000 (best of 100) to
! wall 0.024618 comb 0.020000 user 0.020000 sys 0.000000 (best of 116)
perfbdiff 0e9928989e9c --alldata --count 10
! wall 0.702075 comb 0.700000 user 0.700000 sys 0.000000 (best of 15) to
! wall 0.579235 comb 0.580000 user 0.580000 sys 0.000000 (best of 18)
author | Mads Kiilerich <madski@unity3d.com> |
---|---|
date | Wed, 16 Nov 2016 19:45:35 +0100 |
parents | 8a9681b963a3 |
children | 6f9fcd29e290 |
line wrap: on
line source
# win32mbcs.py -- MBCS filename support for Mercurial # # Copyright (c) 2008 Shun-ichi Goto <shunichi.goto@gmail.com> # # Version: 0.3 # Author: Shun-ichi Goto <shunichi.goto@gmail.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. # '''allow the use of MBCS paths with problematic encodings Some MBCS encodings are not good for some path operations (i.e. splitting path, case conversion, etc.) with its encoded bytes. We call such a encoding (i.e. shift_jis and big5) as "problematic encoding". This extension can be used to fix the issue with those encodings by wrapping some functions to convert to Unicode string before path operation. This extension is useful for: - Japanese Windows users using shift_jis encoding. - Chinese Windows users using big5 encoding. - All users who use a repository with one of problematic encodings on case-insensitive file system. This extension is not needed for: - Any user who use only ASCII chars in path. - Any user who do not use any of problematic encodings. Note that there are some limitations on using this extension: - You should use single encoding in one repository. - If the repository path ends with 0x5c, .hg/hgrc cannot be read. - win32mbcs is not compatible with fixutf8 extension. By default, win32mbcs uses encoding.encoding decided by Mercurial. You can specify the encoding by config option:: [win32mbcs] encoding = sjis It is useful for the users who want to commit with UTF-8 log message. ''' from __future__ import absolute_import import os import sys from mercurial.i18n import _ from mercurial import ( encoding, error, ) # Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for # extensions which SHIP WITH MERCURIAL. Non-mainline extensions should # be specifying the version(s) of Mercurial they are tested with, or # leave the attribute unspecified. testedwith = 'ships-with-hg-core' _encoding = None # see extsetup def decode(arg): if isinstance(arg, str): uarg = arg.decode(_encoding) if arg == uarg.encode(_encoding): return uarg raise UnicodeError("Not local encoding") elif isinstance(arg, tuple): return tuple(map(decode, arg)) elif isinstance(arg, list): return map(decode, arg) elif isinstance(arg, dict): for k, v in arg.items(): arg[k] = decode(v) return arg def encode(arg): if isinstance(arg, unicode): return arg.encode(_encoding) elif isinstance(arg, tuple): return tuple(map(encode, arg)) elif isinstance(arg, list): return map(encode, arg) elif isinstance(arg, dict): for k, v in arg.items(): arg[k] = encode(v) return arg def appendsep(s): # ensure the path ends with os.sep, appending it if necessary. try: us = decode(s) except UnicodeError: us = s if us and us[-1] not in ':/\\': s += os.sep return s def basewrapper(func, argtype, enc, dec, args, kwds): # check check already converted, then call original for arg in args: if isinstance(arg, argtype): return func(*args, **kwds) try: # convert string arguments, call func, then convert back the # return value. return enc(func(*dec(args), **dec(kwds))) except UnicodeError: raise error.Abort(_("[win32mbcs] filename conversion failed with" " %s encoding\n") % (_encoding)) def wrapper(func, args, kwds): return basewrapper(func, unicode, encode, decode, args, kwds) def reversewrapper(func, args, kwds): return basewrapper(func, str, decode, encode, args, kwds) def wrapperforlistdir(func, args, kwds): # Ensure 'path' argument ends with os.sep to avoids # misinterpreting last 0x5c of MBCS 2nd byte as path separator. if args: args = list(args) args[0] = appendsep(args[0]) if 'path' in kwds: kwds['path'] = appendsep(kwds['path']) return func(*args, **kwds) def wrapname(name, wrapper): module, name = name.rsplit('.', 1) module = sys.modules[module] func = getattr(module, name) def f(*args, **kwds): return wrapper(func, args, kwds) f.__name__ = func.__name__ setattr(module, name, f) # List of functions to be wrapped. # NOTE: os.path.dirname() and os.path.basename() are safe because # they use result of os.path.split() funcs = '''os.path.join os.path.split os.path.splitext os.path.normpath os.makedirs mercurial.util.endswithsep mercurial.util.splitpath mercurial.util.fscasesensitive mercurial.util.fspath mercurial.util.pconvert mercurial.util.normpath mercurial.util.checkwinfilename mercurial.util.checkosfilename mercurial.util.split''' # These functions are required to be called with local encoded string # because they expects argument is local encoded string and cause # problem with unicode string. rfuncs = '''mercurial.encoding.upper mercurial.encoding.lower''' # List of Windows specific functions to be wrapped. winfuncs = '''os.path.splitunc''' # codec and alias names of sjis and big5 to be faked. problematic_encodings = '''big5 big5-tw csbig5 big5hkscs big5-hkscs hkscs cp932 932 ms932 mskanji ms-kanji shift_jis csshiftjis shiftjis sjis s_jis shift_jis_2004 shiftjis2004 sjis_2004 sjis2004 shift_jisx0213 shiftjisx0213 sjisx0213 s_jisx0213 950 cp950 ms950 ''' def extsetup(ui): # TODO: decide use of config section for this extension if ((not os.path.supports_unicode_filenames) and (sys.platform != 'cygwin')): ui.warn(_("[win32mbcs] cannot activate on this platform.\n")) return # determine encoding for filename global _encoding _encoding = ui.config('win32mbcs', 'encoding', encoding.encoding) # fake is only for relevant environment. if _encoding.lower() in problematic_encodings.split(): for f in funcs.split(): wrapname(f, wrapper) if os.name == 'nt': for f in winfuncs.split(): wrapname(f, wrapper) wrapname("mercurial.osutil.listdir", wrapperforlistdir) # wrap functions to be called with local byte string arguments for f in rfuncs.split(): wrapname(f, reversewrapper) # Check sys.args manually instead of using ui.debug() because # command line options is not yet applied when # extensions.loadall() is called. if '--debug' in sys.argv: ui.write(("[win32mbcs] activated with encoding: %s\n") % _encoding)