Mercurial > hg
view mercurial/pycompat.py @ 33278:87bca10a06ed
transaction: avoid file stat ambiguity only for files in blacklist
Advancing mtime by os.utime() fails for EPERM, if the target file is
owned by another. bff5ccbe5ead and related changes made some code
paths give advancing mtime up in such case, to fix issue5418.
This causes file stat ambiguity (again), if it is owned by another.
https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan
To avoid file stat ambiguity in such case, especially for
.hg/dirstate, ed66ec39933f made vfs.rename() copy the target file, and
advance mtime of renamed one again, if EPERM (see issue5584 for detail).
But straightforward "copy if EPERM" isn't reasonable for truncation of
append-only files at rollbacking, because rollbacking might cost much
for truncation of many filelogs, even though filelogs aren't
filecache-ed.
Therefore, this patch introduces blacklist "checkambigfiles", and
avoids file stat ambiguity only for files specified in this blacklist.
This patch consists of two parts below, which should be applied at
once in order to avoid regression.
- specify 'checkambig=True' at vfs.open(mode='a') in _playback()
according to checkambigfiles
- invoke _playback() with checkambigfiles
- add transaction.__init__() checkambigfiles argument, for _abort()
- make localrepo instantiate transaction with _cachedfiles
- add rollback() checkambigfiles argument, for "hg rollback/recover"
- make localrepo invoke rollback() with _cachedfiles
After this patch, straightforward "copy if EPERM" will be reasonable
at closing the file opened with checkambig=True, because this policy
is applied only on files, which are listed in blacklist
"checkambigfiles".
author | FUJIWARA Katsunori <foozy@lares.dti.ne.jp> |
---|---|
date | Tue, 04 Jul 2017 23:13:46 +0900 |
parents | 6e38b4212661 |
children | 524b13fc711f |
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# pycompat.py - portability shim for python 3 # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. """Mercurial portability shim for python 3. This contains aliases to hide python version-specific details from the core. """ from __future__ import absolute_import import getopt import os import shlex import sys ispy3 = (sys.version_info[0] >= 3) if not ispy3: import cookielib import cPickle as pickle import httplib import Queue as _queue import SocketServer as socketserver import xmlrpclib else: import http.cookiejar as cookielib import http.client as httplib import pickle import queue as _queue import socketserver import xmlrpc.client as xmlrpclib empty = _queue.Empty queue = _queue.Queue def identity(a): return a if ispy3: import builtins import functools import io import struct fsencode = os.fsencode fsdecode = os.fsdecode oslinesep = os.linesep.encode('ascii') osname = os.name.encode('ascii') ospathsep = os.pathsep.encode('ascii') ossep = os.sep.encode('ascii') osaltsep = os.altsep if osaltsep: osaltsep = osaltsep.encode('ascii') # os.getcwd() on Python 3 returns string, but it has os.getcwdb() which # returns bytes. getcwd = os.getcwdb sysplatform = sys.platform.encode('ascii') sysexecutable = sys.executable if sysexecutable: sysexecutable = os.fsencode(sysexecutable) stringio = io.BytesIO maplist = lambda *args: list(map(*args)) # TODO: .buffer might not exist if std streams were replaced; we'll need # a silly wrapper to make a bytes stream backed by a unicode one. stdin = sys.stdin.buffer stdout = sys.stdout.buffer stderr = sys.stderr.buffer # Since Python 3 converts argv to wchar_t type by Py_DecodeLocale() on Unix, # we can use os.fsencode() to get back bytes argv. # # https://hg.python.org/cpython/file/v3.5.1/Programs/python.c#l55 # # TODO: On Windows, the native argv is wchar_t, so we'll need a different # workaround to simulate the Python 2 (i.e. ANSI Win32 API) behavior. if getattr(sys, 'argv', None) is not None: sysargv = list(map(os.fsencode, sys.argv)) bytechr = struct.Struct('>B').pack class bytestr(bytes): """A bytes which mostly acts as a Python 2 str >>> bytestr(), bytestr(bytearray(b'foo')), bytestr(u'ascii'), bytestr(1) (b'', b'foo', b'ascii', b'1') >>> s = bytestr(b'foo') >>> assert s is bytestr(s) __bytes__() should be called if provided: >>> class bytesable(object): ... def __bytes__(self): ... return b'bytes' >>> bytestr(bytesable()) b'bytes' There's no implicit conversion from non-ascii str as its encoding is unknown: >>> bytestr(chr(0x80)) # doctest: +ELLIPSIS Traceback (most recent call last): ... UnicodeEncodeError: ... Comparison between bytestr and bytes should work: >>> assert bytestr(b'foo') == b'foo' >>> assert b'foo' == bytestr(b'foo') >>> assert b'f' in bytestr(b'foo') >>> assert bytestr(b'f') in b'foo' Sliced elements should be bytes, not integer: >>> s[1], s[:2] (b'o', b'fo') >>> list(s), list(reversed(s)) ([b'f', b'o', b'o'], [b'o', b'o', b'f']) As bytestr type isn't propagated across operations, you need to cast bytes to bytestr explicitly: >>> s = bytestr(b'foo').upper() >>> t = bytestr(s) >>> s[0], t[0] (70, b'F') Be careful to not pass a bytestr object to a function which expects bytearray-like behavior. >>> t = bytes(t) # cast to bytes >>> assert type(t) is bytes """ def __new__(cls, s=b''): if isinstance(s, bytestr): return s if (not isinstance(s, (bytes, bytearray)) and not hasattr(s, u'__bytes__')): # hasattr-py3-only s = str(s).encode(u'ascii') return bytes.__new__(cls, s) def __getitem__(self, key): s = bytes.__getitem__(self, key) if not isinstance(s, bytes): s = bytechr(s) return s def __iter__(self): return iterbytestr(bytes.__iter__(self)) def iterbytestr(s): """Iterate bytes as if it were a str object of Python 2""" return map(bytechr, s) def sysbytes(s): """Convert an internal str (e.g. keyword, __doc__) back to bytes This never raises UnicodeEncodeError, but only ASCII characters can be round-trip by sysstr(sysbytes(s)). """ return s.encode(u'utf-8') def sysstr(s): """Return a keyword str to be passed to Python functions such as getattr() and str.encode() This never raises UnicodeDecodeError. Non-ascii characters are considered invalid and mapped to arbitrary but unique code points such that 'sysstr(a) != sysstr(b)' for all 'a != b'. """ if isinstance(s, builtins.str): return s return s.decode(u'latin-1') def strurl(url): """Converts a bytes url back to str""" return url.decode(u'ascii') def bytesurl(url): """Converts a str url to bytes by encoding in ascii""" return url.encode(u'ascii') def raisewithtb(exc, tb): """Raise exception with the given traceback""" raise exc.with_traceback(tb) def getdoc(obj): """Get docstring as bytes; may be None so gettext() won't confuse it with _('')""" doc = getattr(obj, u'__doc__', None) if doc is None: return doc return sysbytes(doc) def _wrapattrfunc(f): @functools.wraps(f) def w(object, name, *args): return f(object, sysstr(name), *args) return w # these wrappers are automagically imported by hgloader delattr = _wrapattrfunc(builtins.delattr) getattr = _wrapattrfunc(builtins.getattr) hasattr = _wrapattrfunc(builtins.hasattr) setattr = _wrapattrfunc(builtins.setattr) xrange = builtins.range unicode = str def open(name, mode='r', buffering=-1): return builtins.open(name, sysstr(mode), buffering) def getoptb(args, shortlist, namelist): """ Takes bytes arguments, converts them to unicode, pass them to getopt.getopt(), convert the returned values back to bytes and then return them for Python 3 compatibility as getopt.getopt() don't accepts bytes on Python 3. """ args = [a.decode('latin-1') for a in args] shortlist = shortlist.decode('latin-1') namelist = [a.decode('latin-1') for a in namelist] opts, args = getopt.getopt(args, shortlist, namelist) opts = [(a[0].encode('latin-1'), a[1].encode('latin-1')) for a in opts] args = [a.encode('latin-1') for a in args] return opts, args def strkwargs(dic): """ Converts the keys of a python dictonary to str i.e. unicodes so that they can be passed as keyword arguments as dictonaries with bytes keys can't be passed as keyword arguments to functions on Python 3. """ dic = dict((k.decode('latin-1'), v) for k, v in dic.iteritems()) return dic def byteskwargs(dic): """ Converts keys of python dictonaries to bytes as they were converted to str to pass that dictonary as a keyword argument on Python 3. """ dic = dict((k.encode('latin-1'), v) for k, v in dic.iteritems()) return dic # TODO: handle shlex.shlex(). def shlexsplit(s): """ Takes bytes argument, convert it to str i.e. unicodes, pass that into shlex.split(), convert the returned value to bytes and return that for Python 3 compatibility as shelx.split() don't accept bytes on Python 3. """ ret = shlex.split(s.decode('latin-1')) return [a.encode('latin-1') for a in ret] else: import cStringIO bytechr = chr bytestr = str iterbytestr = iter sysbytes = identity sysstr = identity strurl = identity bytesurl = identity # this can't be parsed on Python 3 exec('def raisewithtb(exc, tb):\n' ' raise exc, None, tb\n') def fsencode(filename): """ Partial backport from os.py in Python 3, which only accepts bytes. In Python 2, our paths should only ever be bytes, a unicode path indicates a bug. """ if isinstance(filename, str): return filename else: raise TypeError( "expect str, not %s" % type(filename).__name__) # In Python 2, fsdecode() has a very chance to receive bytes. So it's # better not to touch Python 2 part as it's already working fine. fsdecode = identity def getdoc(obj): return getattr(obj, '__doc__', None) def getoptb(args, shortlist, namelist): return getopt.getopt(args, shortlist, namelist) strkwargs = identity byteskwargs = identity oslinesep = os.linesep osname = os.name ospathsep = os.pathsep ossep = os.sep osaltsep = os.altsep stdin = sys.stdin stdout = sys.stdout stderr = sys.stderr if getattr(sys, 'argv', None) is not None: sysargv = sys.argv sysplatform = sys.platform getcwd = os.getcwd sysexecutable = sys.executable shlexsplit = shlex.split stringio = cStringIO.StringIO maplist = map class _pycompatstub(object): def __init__(self): self._aliases = {} def _registeraliases(self, origin, items): """Add items that will be populated at the first access""" items = map(sysstr, items) self._aliases.update( (item.replace(sysstr('_'), sysstr('')).lower(), (origin, item)) for item in items) def _registeralias(self, origin, attr, name): """Alias ``origin``.``attr`` as ``name``""" self._aliases[sysstr(name)] = (origin, sysstr(attr)) def __getattr__(self, name): try: origin, item = self._aliases[name] except KeyError: raise AttributeError(name) self.__dict__[name] = obj = getattr(origin, item) return obj httpserver = _pycompatstub() urlreq = _pycompatstub() urlerr = _pycompatstub() if not ispy3: import BaseHTTPServer import CGIHTTPServer import SimpleHTTPServer import urllib2 import urllib import urlparse urlreq._registeraliases(urllib, ( "addclosehook", "addinfourl", "ftpwrapper", "pathname2url", "quote", "splitattr", "splitpasswd", "splitport", "splituser", "unquote", "url2pathname", "urlencode", )) urlreq._registeraliases(urllib2, ( "AbstractHTTPHandler", "BaseHandler", "build_opener", "FileHandler", "FTPHandler", "HTTPBasicAuthHandler", "HTTPDigestAuthHandler", "HTTPHandler", "HTTPPasswordMgrWithDefaultRealm", "HTTPSHandler", "install_opener", "ProxyHandler", "Request", "urlopen", )) urlreq._registeraliases(urlparse, ( "urlparse", "urlunparse", )) urlerr._registeraliases(urllib2, ( "HTTPError", "URLError", )) httpserver._registeraliases(BaseHTTPServer, ( "HTTPServer", "BaseHTTPRequestHandler", )) httpserver._registeraliases(SimpleHTTPServer, ( "SimpleHTTPRequestHandler", )) httpserver._registeraliases(CGIHTTPServer, ( "CGIHTTPRequestHandler", )) else: import urllib.parse urlreq._registeraliases(urllib.parse, ( "splitattr", "splitpasswd", "splitport", "splituser", "urlparse", "urlunparse", )) urlreq._registeralias(urllib.parse, "unquote_to_bytes", "unquote") import urllib.request urlreq._registeraliases(urllib.request, ( "AbstractHTTPHandler", "BaseHandler", "build_opener", "FileHandler", "FTPHandler", "ftpwrapper", "HTTPHandler", "HTTPSHandler", "install_opener", "pathname2url", "HTTPBasicAuthHandler", "HTTPDigestAuthHandler", "HTTPPasswordMgrWithDefaultRealm", "ProxyHandler", "Request", "url2pathname", "urlopen", )) import urllib.response urlreq._registeraliases(urllib.response, ( "addclosehook", "addinfourl", )) import urllib.error urlerr._registeraliases(urllib.error, ( "HTTPError", "URLError", )) import http.server httpserver._registeraliases(http.server, ( "HTTPServer", "BaseHTTPRequestHandler", "SimpleHTTPRequestHandler", "CGIHTTPRequestHandler", )) # urllib.parse.quote() accepts both str and bytes, decodes bytes # (if necessary), and returns str. This is wonky. We provide a custom # implementation that only accepts bytes and emits bytes. def quote(s, safe=r'/'): s = urllib.parse.quote_from_bytes(s, safe=safe) return s.encode('ascii', 'strict') # urllib.parse.urlencode() returns str. We use this function to make # sure we return bytes. def urlencode(query, doseq=False): s = urllib.parse.urlencode(query, doseq=doseq) return s.encode('ascii') urlreq.quote = quote urlreq.urlencode = urlencode