hg/pyhgsh: mercurial/demandload.py annotate

annotate mercurial/demandload.py @ 2076:d007df6daf8e

Create an atomic opener that does not automatically rename on close The revlog.checkinlinesize() uses an atomic opener to replace the index file after converting it from inline to traditional .i and .d files. If this operation is interrupted, the atomic file class can overwrite a valid file with a partially written one. This patch introduces an atomic opener that does not automatically replace the destination file with the tempfile. This way an interrupted checkinlinesize() call turns into a noop.

author	mason@suse.com
date	Tue, 04 Apr 2006 16:38:44 -0400
parents	f3abe0bdccdd
children	d01eac5968c6

rev	line source
1826 f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	1 '''Demand load modules when used, not when imported.'''
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	2
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	3 __author__ = '''Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>.
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	4 This software may be used and distributed according to the terms
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	5 of the GNU General Public License, incorporated herein by reference.'''
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	6
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	7 # this is based on matt's original demandload module. it is a
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	8 # complete rewrite. some time, we may need to support syntax of
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	9 # "import foo as bar".
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	10
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	11 class _importer(object):
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	12 '''import a module. it is not imported until needed, and is
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	13 imported at most once per scope.'''
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	14
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	15 def __init__(self, scope, modname, fromlist):
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	16 '''scope is context (globals() or locals()) in which import
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	17 should be made. modname is name of module to import.
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	18 fromlist is list of modules for "from foo import ..."
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	19 emulation.'''
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	20
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	21 self.scope = scope
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	22 self.modname = modname
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	23 self.fromlist = fromlist
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	24 self.mod = None
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	25
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	26 def module(self):
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	27 '''import the module if needed, and return.'''
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	28 if self.mod is None:
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	29 self.mod = __import__(self.modname, self.scope, self.scope,
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	30 self.fromlist)
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	31 del self.modname, self.fromlist
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	32 return self.mod
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	33
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	34 class _replacer(object):
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	35 '''placeholder for a demand loaded module. demandload puts this in
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	36 a target scope. when an attribute of this object is looked up,
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	37 this object is replaced in the target scope with the actual
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	38 module.
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	39
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	40 we use __getattribute__ to avoid namespace clashes between
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	41 placeholder object and real module.'''
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	42
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	43 def __init__(self, importer, target):
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	44 self.importer = importer
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	45 self.target = target
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	46 # consider case where we do this:
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	47 # demandload(globals(), 'foo.bar foo.quux')
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	48 # foo will already exist in target scope when we get to
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	49 # foo.quux. so we remember that we will need to demandload
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	50 # quux into foo's scope when we really load it.
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	51 self.later = []
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	52
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	53 def module(self):
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	54 return object.__getattribute__(self, 'importer').module()
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	55
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	56 def __getattribute__(self, key):
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	57 '''look up an attribute in a module and return it. replace the
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	58 name of the module in the caller\'s dict with the actual
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	59 module.'''
262 3db700146536 implement demand loading hack mpm@selenic.com parents: diff changeset	60
1826 f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	61 module = object.__getattribute__(self, 'module')()
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	62 target = object.__getattribute__(self, 'target')
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	63 importer = object.__getattribute__(self, 'importer')
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	64 later = object.__getattribute__(self, 'later')
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	65
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	66 if later:
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	67 demandload(module.__dict__, ' '.join(later))
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	68
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	69 importer.scope[target] = module
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	70
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	71 return getattr(module, key)
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	72
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	73 class _replacer_from(_replacer):
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	74 '''placeholder for a demand loaded module. used for "from foo
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	75 import ..." emulation. semantics of this are different than
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	76 regular import, so different implementation needed.'''
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	77
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	78 def module(self):
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	79 importer = object.__getattribute__(self, 'importer')
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	80 target = object.__getattribute__(self, 'target')
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	81
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	82 return getattr(importer.module(), target)
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	83
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	84 def demandload(scope, modules):
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	85 '''import modules into scope when each is first used.
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	86
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	87 scope should be the value of globals() in the module calling this
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	88 function, or locals() in the calling function.
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	89
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	90 modules is a string listing module names, separated by white
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	91 space. names are handled like this:
262 3db700146536 implement demand loading hack mpm@selenic.com parents: diff changeset	92
1826 f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	93 foo import foo
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	94 foo bar import foo, bar
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	95 foo.bar import foo.bar
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	96 foo:bar from foo import bar
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	97 foo:bar,quux from foo import bar, quux
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	98 foo.bar:quux from foo.bar import quux'''
262 3db700146536 implement demand loading hack mpm@selenic.com parents: diff changeset	99
1826 f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	100 for mod in modules.split():
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	101 col = mod.find(':')
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	102 if col >= 0:
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	103 fromlist = mod[col+1:].split(',')
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	104 mod = mod[:col]
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	105 else:
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	106 fromlist = []
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	107 importer = _importer(scope, mod, fromlist)
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	108 if fromlist:
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	109 for name in fromlist:
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	110 scope[name] = _replacer_from(importer, name)
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	111 else:
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	112 dot = mod.find('.')
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	113 if dot >= 0:
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	114 basemod = mod[:dot]
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	115 val = scope.get(basemod)
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	116 # if base module has already been demandload()ed,
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	117 # remember to load this submodule into its namespace
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	118 # when needed.
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	119 if isinstance(val, _replacer):
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	120 later = object.__getattribute__(val, 'later')
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	121 later.append(mod[dot+1:])
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	122 continue
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	123 else:
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	124 basemod = mod
f3abe0bdccdd rewrite demandload module to be more flexible. Vadim Gelfer <vadim.gelger@gmail.com> parents: 262 diff changeset	125 scope[basemod] = _replacer(importer, basemod)

Mercurial > hg > pyhgsh

annotate mercurial/demandload.py @ 2076:d007df6daf8e