scmutil: rename classes from "opener" to "vfs"
For backwards compatibility, aliases for the old names are added,
except for "abstractopener", "statichttpopener" and "_fncacheopener",
because these are not used in Mercurial core implementation after this
patch.
"_fncacheopener" was only referred in "fncachestore" constructor, so
this patch also renames from "_fncacheopener" to "_fncachevfs" there.
# scmutil.py - Mercurial core utility functions
#
# Copyright Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from i18n import _
import util, error, osutil, revset, similar, encoding, phases
import match as matchmod
import os, errno, re, stat, sys, glob
def nochangesfound(ui, repo, excluded=None):
'''Report no changes for push/pull, excluded is None or a list of
nodes excluded from the push/pull.
'''
secretlist = []
if excluded:
for n in excluded:
ctx = repo[n]
if ctx.phase() >= phases.secret and not ctx.extinct():
secretlist.append(n)
if secretlist:
ui.status(_("no changes found (ignored %d secret changesets)\n")
% len(secretlist))
else:
ui.status(_("no changes found\n"))
def checkfilename(f):
'''Check that the filename f is an acceptable filename for a tracked file'''
if '\r' in f or '\n' in f:
raise util.Abort(_("'\\n' and '\\r' disallowed in filenames: %r") % f)
def checkportable(ui, f):
'''Check if filename f is portable and warn or abort depending on config'''
checkfilename(f)
abort, warn = checkportabilityalert(ui)
if abort or warn:
msg = util.checkwinfilename(f)
if msg:
msg = "%s: %r" % (msg, f)
if abort:
raise util.Abort(msg)
ui.warn(_("warning: %s\n") % msg)
def checkportabilityalert(ui):
'''check if the user's config requests nothing, a warning, or abort for
non-portable filenames'''
val = ui.config('ui', 'portablefilenames', 'warn')
lval = val.lower()
bval = util.parsebool(val)
abort = os.name == 'nt' or lval == 'abort'
warn = bval or lval == 'warn'
if bval is None and not (warn or abort or lval == 'ignore'):
raise error.ConfigError(
_("ui.portablefilenames value is invalid ('%s')") % val)
return abort, warn
class casecollisionauditor(object):
def __init__(self, ui, abort, dirstate):
self._ui = ui
self._abort = abort
allfiles = '\0'.join(dirstate._map)
self._loweredfiles = set(encoding.lower(allfiles).split('\0'))
self._dirstate = dirstate
# The purpose of _newfiles is so that we don't complain about
# case collisions if someone were to call this object with the
# same filename twice.
self._newfiles = set()
def __call__(self, f):
fl = encoding.lower(f)
if (fl in self._loweredfiles and f not in self._dirstate and
f not in self._newfiles):
msg = _('possible case-folding collision for %s') % f
if self._abort:
raise util.Abort(msg)
self._ui.warn(_("warning: %s\n") % msg)
self._loweredfiles.add(fl)
self._newfiles.add(f)
class pathauditor(object):
'''ensure that a filesystem path contains no banned components.
the following properties of a path are checked:
- ends with a directory separator
- under top-level .hg
- starts at the root of a windows drive
- contains ".."
- traverses a symlink (e.g. a/symlink_here/b)
- inside a nested repository (a callback can be used to approve
some nested repositories, e.g., subrepositories)
'''
def __init__(self, root, callback=None):
self.audited = set()
self.auditeddir = set()
self.root = root
self.callback = callback
if os.path.lexists(root) and not util.checkcase(root):
self.normcase = util.normcase
else:
self.normcase = lambda x: x
def __call__(self, path):
'''Check the relative path.
path may contain a pattern (e.g. foodir/**.txt)'''
path = util.localpath(path)
normpath = self.normcase(path)
if normpath in self.audited:
return
# AIX ignores "/" at end of path, others raise EISDIR.
if util.endswithsep(path):
raise util.Abort(_("path ends in directory separator: %s") % path)
parts = util.splitpath(path)
if (os.path.splitdrive(path)[0]
or parts[0].lower() in ('.hg', '.hg.', '')
or os.pardir in parts):
raise util.Abort(_("path contains illegal component: %s") % path)
if '.hg' in path.lower():
lparts = [p.lower() for p in parts]
for p in '.hg', '.hg.':
if p in lparts[1:]:
pos = lparts.index(p)
base = os.path.join(*parts[:pos])
raise util.Abort(_("path '%s' is inside nested repo %r")
% (path, base))
normparts = util.splitpath(normpath)
assert len(parts) == len(normparts)
parts.pop()
normparts.pop()
prefixes = []
while parts:
prefix = os.sep.join(parts)
normprefix = os.sep.join(normparts)
if normprefix in self.auditeddir:
break
curpath = os.path.join(self.root, prefix)
try:
st = os.lstat(curpath)
except OSError, err:
# EINVAL can be raised as invalid path syntax under win32.
# They must be ignored for patterns can be checked too.
if err.errno not in (errno.ENOENT, errno.ENOTDIR, errno.EINVAL):
raise
else:
if stat.S_ISLNK(st.st_mode):
raise util.Abort(
_('path %r traverses symbolic link %r')
% (path, prefix))
elif (stat.S_ISDIR(st.st_mode) and
os.path.isdir(os.path.join(curpath, '.hg'))):
if not self.callback or not self.callback(curpath):
raise util.Abort(_("path '%s' is inside nested "
"repo %r")
% (path, prefix))
prefixes.append(normprefix)
parts.pop()
normparts.pop()
self.audited.add(normpath)
# only add prefixes to the cache after checking everything: we don't
# want to add "foo/bar/baz" before checking if there's a "foo/.hg"
self.auditeddir.update(prefixes)
class abstractvfs(object):
"""Abstract base class; cannot be instantiated"""
def __init__(self, *args, **kwargs):
'''Prevent instantiation; don't call this from subclasses.'''
raise NotImplementedError('attempted instantiating ' + str(type(self)))
def tryread(self, path):
'''gracefully return an empty string for missing files'''
try:
return self.read(path)
except IOError, inst:
if inst.errno != errno.ENOENT:
raise
return ""
def read(self, path):
fp = self(path, 'rb')
try:
return fp.read()
finally:
fp.close()
def write(self, path, data):
fp = self(path, 'wb')
try:
return fp.write(data)
finally:
fp.close()
def append(self, path, data):
fp = self(path, 'ab')
try:
return fp.write(data)
finally:
fp.close()
def mkdir(self, path=None):
return os.mkdir(self.join(path))
def exists(self, path=None):
return os.path.exists(self.join(path))
def isdir(self, path=None):
return os.path.isdir(self.join(path))
def makedir(self, path=None, notindexed=True):
return util.makedir(self.join(path), notindexed)
def makedirs(self, path=None, mode=None):
return util.makedirs(self.join(path), mode)
class vfs(abstractvfs):
'''Operate files relative to a base directory
This class is used to hide the details of COW semantics and
remote file access from higher level code.
'''
def __init__(self, base, audit=True, expand=False):
if expand:
base = os.path.realpath(util.expandpath(base))
self.base = base
self.basesep = self.base + os.sep
self._setmustaudit(audit)
self.createmode = None
self._trustnlink = None
def _getmustaudit(self):
return self._audit
def _setmustaudit(self, onoff):
self._audit = onoff
if onoff:
self.auditor = pathauditor(self.base)
else:
self.auditor = util.always
mustaudit = property(_getmustaudit, _setmustaudit)
@util.propertycache
def _cansymlink(self):
return util.checklink(self.base)
def _fixfilemode(self, name):
if self.createmode is None:
return
os.chmod(name, self.createmode & 0666)
def __call__(self, path, mode="r", text=False, atomictemp=False):
if self._audit:
r = util.checkosfilename(path)
if r:
raise util.Abort("%s: %r" % (r, path))
self.auditor(path)
f = self.join(path)
if not text and "b" not in mode:
mode += "b" # for that other OS
nlink = -1
dirname, basename = util.split(f)
# If basename is empty, then the path is malformed because it points
# to a directory. Let the posixfile() call below raise IOError.
if basename and mode not in ('r', 'rb'):
if atomictemp:
if not os.path.isdir(dirname):
util.makedirs(dirname, self.createmode)
return util.atomictempfile(f, mode, self.createmode)
try:
if 'w' in mode:
util.unlink(f)
nlink = 0
else:
# nlinks() may behave differently for files on Windows
# shares if the file is open.
fd = util.posixfile(f)
nlink = util.nlinks(f)
if nlink < 1:
nlink = 2 # force mktempcopy (issue1922)
fd.close()
except (OSError, IOError), e:
if e.errno != errno.ENOENT:
raise
nlink = 0
if not os.path.isdir(dirname):
util.makedirs(dirname, self.createmode)
if nlink > 0:
if self._trustnlink is None:
self._trustnlink = nlink > 1 or util.checknlink(f)
if nlink > 1 or not self._trustnlink:
util.rename(util.mktempcopy(f), f)
fp = util.posixfile(f, mode)
if nlink == 0:
self._fixfilemode(f)
return fp
def symlink(self, src, dst):
self.auditor(dst)
linkname = self.join(dst)
try:
os.unlink(linkname)
except OSError:
pass
dirname = os.path.dirname(linkname)
if not os.path.exists(dirname):
util.makedirs(dirname, self.createmode)
if self._cansymlink:
try:
os.symlink(src, linkname)
except OSError, err:
raise OSError(err.errno, _('could not symlink to %r: %s') %
(src, err.strerror), linkname)
else:
f = self(dst, "w")
f.write(src)
f.close()
self._fixfilemode(dst)
def audit(self, path):
self.auditor(path)
def join(self, path):
if path:
return path.startswith('/') and path or (self.basesep + path)
return self.base
opener = vfs
class filtervfs(abstractvfs):
'''Wrapper vfs for filtering filenames with a function.'''
def __init__(self, opener, filter):
self._filter = filter
self._orig = opener
def __call__(self, path, *args, **kwargs):
return self._orig(self._filter(path), *args, **kwargs)
filteropener = filtervfs
def canonpath(root, cwd, myname, auditor=None):
'''return the canonical path of myname, given cwd and root'''
if util.endswithsep(root):
rootsep = root
else:
rootsep = root + os.sep
name = myname
if not os.path.isabs(name):
name = os.path.join(root, cwd, name)
name = os.path.normpath(name)
if auditor is None:
auditor = pathauditor(root)
if name != rootsep and name.startswith(rootsep):
name = name[len(rootsep):]
auditor(name)
return util.pconvert(name)
elif name == root:
return ''
else:
# Determine whether `name' is in the hierarchy at or beneath `root',
# by iterating name=dirname(name) until that causes no change (can't
# check name == '/', because that doesn't work on windows). The list
# `rel' holds the reversed list of components making up the relative
# file name we want.
rel = []
while True:
try:
s = util.samefile(name, root)
except OSError:
s = False
if s:
if not rel:
# name was actually the same as root (maybe a symlink)
return ''
rel.reverse()
name = os.path.join(*rel)
auditor(name)
return util.pconvert(name)
dirname, basename = util.split(name)
rel.append(basename)
if dirname == name:
break
name = dirname
raise util.Abort('%s not under root' % myname)
def walkrepos(path, followsym=False, seen_dirs=None, recurse=False):
'''yield every hg repository under path, always recursively.
The recurse flag will only control recursion into repo working dirs'''
def errhandler(err):
if err.filename == path:
raise err
samestat = getattr(os.path, 'samestat', None)
if followsym and samestat is not None:
def adddir(dirlst, dirname):
match = False
dirstat = os.stat(dirname)
for lstdirstat in dirlst:
if samestat(dirstat, lstdirstat):
match = True
break
if not match:
dirlst.append(dirstat)
return not match
else:
followsym = False
if (seen_dirs is None) and followsym:
seen_dirs = []
adddir(seen_dirs, path)
for root, dirs, files in os.walk(path, topdown=True, onerror=errhandler):
dirs.sort()
if '.hg' in dirs:
yield root # found a repository
qroot = os.path.join(root, '.hg', 'patches')
if os.path.isdir(os.path.join(qroot, '.hg')):
yield qroot # we have a patch queue repo here
if recurse:
# avoid recursing inside the .hg directory
dirs.remove('.hg')
else:
dirs[:] = [] # don't descend further
elif followsym:
newdirs = []
for d in dirs:
fname = os.path.join(root, d)
if adddir(seen_dirs, fname):
if os.path.islink(fname):
for hgname in walkrepos(fname, True, seen_dirs):
yield hgname
else:
newdirs.append(d)
dirs[:] = newdirs
def osrcpath():
'''return default os-specific hgrc search path'''
path = systemrcpath()
path.extend(userrcpath())
path = [os.path.normpath(f) for f in path]
return path
_rcpath = None
def rcpath():
'''return hgrc search path. if env var HGRCPATH is set, use it.
for each item in path, if directory, use files ending in .rc,
else use item.
make HGRCPATH empty to only look in .hg/hgrc of current repo.
if no HGRCPATH, use default os-specific path.'''
global _rcpath
if _rcpath is None:
if 'HGRCPATH' in os.environ:
_rcpath = []
for p in os.environ['HGRCPATH'].split(os.pathsep):
if not p:
continue
p = util.expandpath(p)
if os.path.isdir(p):
for f, kind in osutil.listdir(p):
if f.endswith('.rc'):
_rcpath.append(os.path.join(p, f))
else:
_rcpath.append(p)
else:
_rcpath = osrcpath()
return _rcpath
if os.name != 'nt':
def rcfiles(path):
rcs = [os.path.join(path, 'hgrc')]
rcdir = os.path.join(path, 'hgrc.d')
try:
rcs.extend([os.path.join(rcdir, f)
for f, kind in osutil.listdir(rcdir)
if f.endswith(".rc")])
except OSError:
pass
return rcs
def systemrcpath():
path = []
if sys.platform == 'plan9':
root = 'lib/mercurial'
else:
root = 'etc/mercurial'
# old mod_python does not set sys.argv
if len(getattr(sys, 'argv', [])) > 0:
p = os.path.dirname(os.path.dirname(sys.argv[0]))
path.extend(rcfiles(os.path.join(p, root)))
path.extend(rcfiles('/' + root))
return path
def userrcpath():
if sys.platform == 'plan9':
return [os.environ['home'] + '/lib/hgrc']
else:
return [os.path.expanduser('~/.hgrc')]
else:
import _winreg
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')
if os.path.isfile(progrc):
rcpath.append(progrc)
return rcpath
# 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))
return rcpath
# 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:
path.append(os.path.join(userprofile, 'mercurial.ini'))
path.append(os.path.join(userprofile, '.hgrc'))
return path
def revsingle(repo, revspec, default='.'):
if not revspec:
return repo[default]
l = revrange(repo, [revspec])
if len(l) < 1:
raise util.Abort(_('empty revision set'))
return repo[l[-1]]
def revpair(repo, revs):
if not revs:
return repo.dirstate.p1(), None
l = revrange(repo, revs)
if len(l) == 0:
if revs:
raise util.Abort(_('empty revision range'))
return repo.dirstate.p1(), None
if len(l) == 1 and len(revs) == 1 and _revrangesep not in revs[0]:
return repo.lookup(l[0]), None
return repo.lookup(l[0]), repo.lookup(l[-1])
_revrangesep = ':'
def revrange(repo, revs):
"""Yield revision as strings from a list of revision specifications."""
def revfix(repo, val, defval):
if not val and val != 0 and defval is not None:
return defval
return repo[val].rev()
seen, l = set(), []
for spec in revs:
if l and not seen:
seen = set(l)
# attempt to parse old-style ranges first to deal with
# things like old-tag which contain query metacharacters
try:
if isinstance(spec, int):
seen.add(spec)
l.append(spec)
continue
if _revrangesep in spec:
start, end = spec.split(_revrangesep, 1)
start = revfix(repo, start, 0)
end = revfix(repo, end, len(repo) - 1)
step = start > end and -1 or 1
if not seen and not l:
# by far the most common case: revs = ["-1:0"]
l = range(start, end + step, step)
# defer syncing seen until next iteration
continue
newrevs = set(xrange(start, end + step, step))
if seen:
newrevs.difference_update(seen)
seen.update(newrevs)
else:
seen = newrevs
l.extend(sorted(newrevs, reverse=start > end))
continue
elif spec and spec in repo: # single unquoted rev
rev = revfix(repo, spec, None)
if rev in seen:
continue
seen.add(rev)
l.append(rev)
continue
except error.RepoLookupError:
pass
# fall through to new-style queries if old-style fails
m = revset.match(repo.ui, spec)
dl = [r for r in m(repo, xrange(len(repo))) if r not in seen]
l.extend(dl)
seen.update(dl)
return l
def expandpats(pats):
if not util.expandglobs:
return list(pats)
ret = []
for p in pats:
kind, name = matchmod._patsplit(p, None)
if kind is None:
try:
globbed = glob.glob(name)
except re.error:
globbed = [name]
if globbed:
ret.extend(globbed)
continue
ret.append(p)
return ret
def matchandpats(ctx, pats=[], opts={}, globbed=False, default='relpath'):
if pats == ("",):
pats = []
if not globbed and default == 'relpath':
pats = expandpats(pats or [])
m = ctx.match(pats, opts.get('include'), opts.get('exclude'),
default)
def badfn(f, msg):
ctx._repo.ui.warn("%s: %s\n" % (m.rel(f), msg))
m.bad = badfn
return m, pats
def match(ctx, pats=[], opts={}, globbed=False, default='relpath'):
return matchandpats(ctx, pats, opts, globbed, default)[0]
def matchall(repo):
return matchmod.always(repo.root, repo.getcwd())
def matchfiles(repo, files):
return matchmod.exact(repo.root, repo.getcwd(), files)
def addremove(repo, pats=[], opts={}, dry_run=None, similarity=None):
if dry_run is None:
dry_run = opts.get('dry_run')
if similarity is None:
similarity = float(opts.get('similarity') or 0)
# we'd use status here, except handling of symlinks and ignore is tricky
added, unknown, deleted, removed = [], [], [], []
audit_path = pathauditor(repo.root)
m = match(repo[None], pats, opts)
rejected = []
m.bad = lambda x, y: rejected.append(x)
for abs in repo.walk(m):
target = repo.wjoin(abs)
good = True
try:
audit_path(abs)
except (OSError, util.Abort):
good = False
rel = m.rel(abs)
exact = m.exact(abs)
if good and abs not in repo.dirstate:
unknown.append(abs)
if repo.ui.verbose or not exact:
repo.ui.status(_('adding %s\n') % ((pats and rel) or abs))
elif (repo.dirstate[abs] != 'r' and
(not good or not os.path.lexists(target) or
(os.path.isdir(target) and not os.path.islink(target)))):
deleted.append(abs)
if repo.ui.verbose or not exact:
repo.ui.status(_('removing %s\n') % ((pats and rel) or abs))
# for finding renames
elif repo.dirstate[abs] == 'r':
removed.append(abs)
elif repo.dirstate[abs] == 'a':
added.append(abs)
copies = {}
if similarity > 0:
for old, new, score in similar.findrenames(repo,
added + unknown, removed + deleted, similarity):
if repo.ui.verbose or not m.exact(old) or not m.exact(new):
repo.ui.status(_('recording removal of %s as rename to %s '
'(%d%% similar)\n') %
(m.rel(old), m.rel(new), score * 100))
copies[new] = old
if not dry_run:
wctx = repo[None]
wlock = repo.wlock()
try:
wctx.forget(deleted)
wctx.add(unknown)
for new, old in copies.iteritems():
wctx.copy(old, new)
finally:
wlock.release()
for f in rejected:
if f in m.files():
return 1
return 0
def updatedir(ui, repo, patches, similarity=0):
'''Update dirstate after patch application according to metadata'''
if not patches:
return []
copies = []
removes = set()
cfiles = patches.keys()
cwd = repo.getcwd()
if cwd:
cfiles = [util.pathto(repo.root, cwd, f) for f in patches.keys()]
for f in patches:
gp = patches[f]
if not gp:
continue
if gp.op == 'RENAME':
copies.append((gp.oldpath, gp.path))
removes.add(gp.oldpath)
elif gp.op == 'COPY':
copies.append((gp.oldpath, gp.path))
elif gp.op == 'DELETE':
removes.add(gp.path)
wctx = repo[None]
for src, dst in copies:
dirstatecopy(ui, repo, wctx, src, dst, cwd=cwd)
if (not similarity) and removes:
wctx.remove(sorted(removes), True)
for f in patches:
gp = patches[f]
if gp and gp.mode:
islink, isexec = gp.mode
dst = repo.wjoin(gp.path)
# patch won't create empty files
if gp.op == 'ADD' and not os.path.lexists(dst):
flags = (isexec and 'x' or '') + (islink and 'l' or '')
repo.wwrite(gp.path, '', flags)
util.setflags(dst, islink, isexec)
addremove(repo, cfiles, similarity=similarity)
files = patches.keys()
files.extend([r for r in removes if r not in files])
return sorted(files)
def dirstatecopy(ui, repo, wctx, src, dst, dryrun=False, cwd=None):
"""Update the dirstate to reflect the intent of copying src to dst. For
different reasons it might not end with dst being marked as copied from src.
"""
origsrc = repo.dirstate.copied(src) or src
if dst == origsrc: # copying back a copy?
if repo.dirstate[dst] not in 'mn' and not dryrun:
repo.dirstate.normallookup(dst)
else:
if repo.dirstate[origsrc] == 'a' and origsrc == src:
if not ui.quiet:
ui.warn(_("%s has not been committed yet, so no copy "
"data will be stored for %s.\n")
% (repo.pathto(origsrc, cwd), repo.pathto(dst, cwd)))
if repo.dirstate[dst] in '?r' and not dryrun:
wctx.add([dst])
elif not dryrun:
wctx.copy(origsrc, dst)
def readrequires(opener, supported):
'''Reads and parses .hg/requires and checks if all entries found
are in the list of supported features.'''
requirements = set(opener.read("requires").splitlines())
missings = []
for r in requirements:
if r not in supported:
if not r or not r[0].isalnum():
raise error.RequirementError(_(".hg/requires file is corrupt"))
missings.append(r)
missings.sort()
if missings:
raise error.RequirementError(
_("unknown repository format: requires features '%s' (upgrade "
"Mercurial)") % "', '".join(missings))
return requirements
class filecacheentry(object):
def __init__(self, path):
self.path = path
self.cachestat = filecacheentry.stat(self.path)
if self.cachestat:
self._cacheable = self.cachestat.cacheable()
else:
# None means we don't know yet
self._cacheable = None
def refresh(self):
if self.cacheable():
self.cachestat = filecacheentry.stat(self.path)
def cacheable(self):
if self._cacheable is not None:
return self._cacheable
# we don't know yet, assume it is for now
return True
def changed(self):
# no point in going further if we can't cache it
if not self.cacheable():
return True
newstat = filecacheentry.stat(self.path)
# we may not know if it's cacheable yet, check again now
if newstat and self._cacheable is None:
self._cacheable = newstat.cacheable()
# check again
if not self._cacheable:
return True
if self.cachestat != newstat:
self.cachestat = newstat
return True
else:
return False
@staticmethod
def stat(path):
try:
return util.cachestat(path)
except OSError, e:
if e.errno != errno.ENOENT:
raise
class filecache(object):
'''A property like decorator that tracks a file under .hg/ for updates.
Records stat info when called in _filecache.
On subsequent calls, compares old stat info with new info, and recreates
the object when needed, updating the new stat info in _filecache.
Mercurial either atomic renames or appends for files under .hg,
so to ensure the cache is reliable we need the filesystem to be able
to tell us if a file has been replaced. If it can't, we fallback to
recreating the object on every call (essentially the same behaviour as
propertycache).'''
def __init__(self, path):
self.path = path
def join(self, obj, fname):
"""Used to compute the runtime path of the cached file.
Users should subclass filecache and provide their own version of this
function to call the appropriate join function on 'obj' (an instance
of the class that its member function was decorated).
"""
return obj.join(fname)
def __call__(self, func):
self.func = func
self.name = func.__name__
return self
def __get__(self, obj, type=None):
# do we need to check if the file changed?
if self.name in obj.__dict__:
return obj.__dict__[self.name]
entry = obj._filecache.get(self.name)
if entry:
if entry.changed():
entry.obj = self.func(obj)
else:
path = self.join(obj, self.path)
# We stat -before- creating the object so our cache doesn't lie if
# a writer modified between the time we read and stat
entry = filecacheentry(path)
entry.obj = self.func(obj)
obj._filecache[self.name] = entry
obj.__dict__[self.name] = entry.obj
return entry.obj
def __set__(self, obj, value):
if self.name in obj._filecache:
obj._filecache[self.name].obj = value # update cached copy
obj.__dict__[self.name] = value # update copy returned by obj.x
def __delete__(self, obj):
try:
del obj.__dict__[self.name]
except KeyError:
raise AttributeError, self.name