/usr/share/pyshared/checkbox/contrib/persist.py is in checkbox 0.13.7.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 | # Copyright (c) 2006 Canonical
# Copyright (c) 2004 Conectiva, Inc.
#
# Written by Gustavo Niemeyer <gustavo@niemeyer.net>
#
# This Python module is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as published
# by the Free Software Foundation; either version 2 of the License, or (at
# your option) any later version.
#
# This Python module is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this Python module; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
import os
import sys
import copy
import re
import posixpath
from checkbox.lib.safe import safe_close
__all__ = ["Persist", "MemoryBackend", "PickleBackend", "BPickleBackend",
"path_string_to_tuple", "path_tuple_to_string", "RootedPersist",
"PersistError", "PersistReadOnlyError"]
NOTHING = object()
class PersistError(Exception):
pass
class PersistReadOnlyError(PersistError):
pass
class Persist(object):
"""Persistence handler.
There are three different kinds of opition maps, regarding the
persistence and priority that maps are queried.
hard - Options are persistent.
soft - Options are not persistent, and have a higher priority
than persistent options.
weak - Options are not persistent, and have a lower priority
than persistent options.
@ivar filename: The name of the file where persist data is saved
or None if not filename is available.
"""
def __init__(self, filename=None, backend=None):
"""
@param backend: The backend to use. If none is specified,
L{BPickleBackend} will be used.
@param filename: The default filename to save to and load from. If
specified, and the file exists, it will be immediately
loaded. Specifying this will also allow L{save} to be called
without any arguments to save the persist.
"""
if backend is None:
backend = BPickleBackend()
self._backend = backend
self._hardmap = backend.new()
self._softmap = {}
self._weakmap = {}
self._readonly = False
self._modified = False
self.filename = filename
if filename is not None and posixpath.exists(filename):
self.load(filename)
def _get_readonly(self):
return self._readonly
def _set_readonly(self, flag):
self._readonly = bool(flag)
def _get_modified(self):
return self._modified
readonly = property(_get_readonly, _set_readonly)
modified = property(_get_modified)
def reset_modified(self):
self._modified = False
def assert_writable(self):
if self._readonly:
raise PersistReadOnlyError("Configuration is in readonly mode.")
def load(self, filepath):
filepath = posixpath.expanduser(filepath)
if not posixpath.isfile(filepath):
raise PersistError("File not found: %s" % filepath)
if posixpath.getsize(filepath) == 0:
return
try:
self._hardmap = self._backend.load(filepath)
except:
filepathold = filepath+".old"
if (posixpath.isfile(filepathold) and
posixpath.getsize(filepathold) > 0):
# warning("Broken configuration file at %s" % filepath)
# warning("Trying backup at %s" % filepathold)
try:
self._hardmap = self._backend.load(filepathold)
except:
raise PersistError("Broken configuration file at %s" %
filepathold)
else:
raise PersistError("Broken configuration file at %s" %
filepath)
def save(self, filepath=None):
"""Save the persist to the given C{filepath}.
If None is specified, then the filename passed during construction will
be used.
"""
if filepath is None:
if self.filename is None:
return
filepath = self.filename
filepath = posixpath.expanduser(filepath)
if posixpath.isfile(filepath):
os.rename(filepath, filepath+".old")
dirname = posixpath.dirname(filepath)
if dirname and not posixpath.isdir(dirname):
os.makedirs(dirname)
self._backend.save(filepath, self._hardmap)
def _traverse(self, obj, path, default=NOTHING, setvalue=NOTHING):
if setvalue is not NOTHING:
setvalue = self._backend.copy(setvalue)
queue = list(path)
marker = NOTHING
newobj = obj
while queue:
obj = newobj
elem = queue.pop(0)
newobj = self._backend.get(obj, elem)
if newobj is NotImplemented:
if queue:
path = path[:-len(queue)]
raise PersistError("Can't traverse %r (%r): %r" %
(type(obj), path_tuple_to_string(path),
str(obj)))
if newobj is marker:
break
if newobj is not marker:
if setvalue is not marker:
newobj = self._backend.set(obj, elem, setvalue)
else:
if setvalue is marker:
newobj = default
else:
while True:
if len(queue) > 0:
if type(queue[0]) is int:
newvalue = []
else:
newvalue = {}
else:
newvalue = setvalue
newobj = self._backend.set(obj, elem, newvalue)
if newobj is NotImplemented:
raise PersistError("Can't traverse %r with %r" %
(type(obj), type(elem)))
if not queue:
break
obj = newobj
elem = queue.pop(0)
return newobj
def _getvalue(self, path, soft=False, hard=False, weak=False):
if type(path) is str:
path = path_string_to_tuple(path)
marker = NOTHING
if soft:
value = self._traverse(self._softmap, path, marker)
elif hard:
value = self._traverse(self._hardmap, path, marker)
elif weak:
value = self._traverse(self._weakmap, path, marker)
else:
value = self._traverse(self._softmap, path, marker)
if value is marker:
value = self._traverse(self._hardmap, path, marker)
if value is marker:
value = self._traverse(self._weakmap, path, marker)
return value
def has(self, path, value=NOTHING, soft=False, hard=False, weak=False):
obj = self._getvalue(path, soft, hard, weak)
marker = NOTHING
if obj is marker:
return False
elif value is marker:
return True
result = self._backend.has(obj, value)
if result is NotImplemented:
raise PersistError("Can't check %r for containment" % type(obj))
return result
def keys(self, path, soft=False, hard=False, weak=False):
obj = self._getvalue(path, soft, hard, weak)
if obj is NOTHING:
return []
result = self._backend.keys(obj)
if result is NotImplemented:
raise PersistError("Can't return keys for %s" % type(obj))
return result
def get(self, path, default=None, soft=False, hard=False, weak=False):
value = self._getvalue(path, soft, hard, weak)
if value is NOTHING:
return default
return self._backend.copy(value)
def set(self, path, value, soft=False, weak=False):
assert path
if type(path) is str:
path = path_string_to_tuple(path)
if soft:
map = self._softmap
elif weak:
map = self._weakmap
else:
self.assert_writable()
self._modified = True
map = self._hardmap
self._traverse(map, path, setvalue=value)
def add(self, path, value, unique=False, soft=False, weak=False):
assert path
if type(path) is str:
path = path_string_to_tuple(path)
if soft:
map = self._softmap
elif weak:
map = self._weakmap
else:
self.assert_writable()
self._modified = True
map = self._hardmap
if unique:
current = self._traverse(map, path)
if type(current) is list and value in current:
return
path = path+(sys.maxint,)
self._traverse(map, path, setvalue=value)
def remove(self, path, value=NOTHING, soft=False, weak=False):
assert path
if type(path) is str:
path = path_string_to_tuple(path)
if soft:
map = self._softmap
elif weak:
map = self._weakmap
else:
self.assert_writable()
self._modified = True
map = self._hardmap
marker = NOTHING
while path:
if value is marker:
obj = self._traverse(map, path[:-1])
elem = path[-1]
isvalue = False
else:
obj = self._traverse(map, path)
elem = value
isvalue = True
result = False
if obj is not marker:
result = self._backend.remove(obj, elem, isvalue)
if result is NotImplemented:
raise PersistError("Can't remove %r from %r" %
(elem, type(obj)))
if self._backend.empty(obj):
if value is not marker:
value = marker
else:
path = path[:-1]
else:
break
return result
def move(self, oldpath, newpath, soft=False, weak=False):
if not (soft or weak):
self.assert_writable()
if type(oldpath) is str:
oldpath = path_string_to_tuple(oldpath)
if type(newpath) is str:
newpath = path_string_to_tuple(newpath)
result = False
marker = NOTHING
value = self._getvalue(oldpath, soft, not (soft or weak), weak)
if value is not marker:
self.remove(oldpath, soft=soft, weak=weak)
self.set(newpath, value, weak, soft)
result = True
return result
def root_at(self, path):
return RootedPersist(self, path)
class RootedPersist(object):
def __init__(self, parent, root):
self.parent = parent
if type(root) is str:
self.root = path_string_to_tuple(root)
else:
self.root = root
readonly = property(lambda self: self.parent.readonly)
modified = property(lambda self: self.parent.modified)
def assert_writable(self):
self.parent.assert_writable()
def save(self):
self.parent.save()
def has(self, path, value=NOTHING, soft=False, hard=False, weak=False):
if type(path) is str:
path = path_string_to_tuple(path)
return self.parent.has(self.root+path, value, soft, hard, weak)
def keys(self, path, soft=False, hard=False, weak=False):
if type(path) is str:
path = path_string_to_tuple(path)
return self.parent.keys(self.root+path, soft, hard, weak)
def get(self, path, default=None, soft=False, hard=False, weak=False):
if type(path) is str:
path = path_string_to_tuple(path)
return self.parent.get(self.root+path, default, soft, hard, weak)
def set(self, path, value, soft=False, weak=False):
if type(path) is str:
path = path_string_to_tuple(path)
return self.parent.set(self.root+path, value, soft, weak)
def add(self, path, value, unique=False, soft=False, weak=False):
if type(path) is str:
path = path_string_to_tuple(path)
return self.parent.add(self.root+path, value, unique, soft, weak)
def remove(self, path, value=NOTHING, soft=False, weak=False):
if type(path) is str:
path = path_string_to_tuple(path)
return self.parent.remove(self.root+path, value, soft, weak)
def move(self, oldpath, newpath, soft=False, weak=False):
if type(oldpath) is str:
oldpath = path_string_to_tuple(oldpath)
if type(newpath) is str:
newpath = path_string_to_tuple(newpath)
return self.parent.move(self.root+oldpath, self.root+newpath,
soft, weak)
def root_at(self, path):
if type(path) is str:
path = path_string_to_tuple(path)
return self.parent.root_at(self.root+path)
_splitpath = re.compile(r"(\[-?\d+\])|(?<!\\)\.").split
def path_string_to_tuple(path):
if "." not in path and "[" not in path:
return (path,)
result = []
tokens = _splitpath(path)
for token in tokens:
if token:
if token[0] == "[" and token[-1] == "]":
try:
result.append(int(token[1:-1]))
except ValueError:
raise PersistError("Invalid path index: %r" % token)
else:
result.append(token.replace(r"\.", "."))
return tuple(result)
def path_tuple_to_string(path):
result = []
for elem in path:
if type(elem) is int:
result[-1] += "[%d]" % elem
else:
result.append(str(elem).replace(".", "\."))
return ".".join(result)
class Backend(object):
def new(self):
return {}
def load(self, filepath):
raise NotImplementedError
def save(self, filepath, map):
raise NotImplementedError
def get(self, obj, elem, _marker=NOTHING):
if type(obj) is dict:
newobj = obj.get(elem, _marker)
elif type(obj) in (tuple, list):
if type(elem) is int:
try:
newobj = obj[elem]
except IndexError:
newobj = _marker
elif elem in obj:
newobj = elem
else:
newobj = _marker
else:
newobj = NotImplemented
return newobj
def set(self, obj, elem, value):
if type(obj) is dict:
newobj = obj[elem] = value
elif type(obj) is list and type(elem) is int:
lenobj = len(obj)
if lenobj <= elem:
obj.append(None)
elem = lenobj
elif elem < 0 and abs(elem) > lenobj:
obj.insert(0, None)
elem = 0
newobj = obj[elem] = value
else:
newobj = NotImplemented
return newobj
def remove(self, obj, elem, isvalue):
result = False
if type(obj) is dict:
if elem in obj:
del obj[elem]
result = True
elif type(obj) is list:
if not isvalue and type(elem) is int:
try:
del obj[elem]
result = True
except IndexError:
pass
elif elem in obj:
obj[:] = [x for x in obj if x != elem]
result = True
else:
result = NotImplemented
return result
def copy(self, value):
if type(value) in (dict, list):
return copy.deepcopy(value)
return value
def empty(self, obj):
return (not obj)
def has(self, obj, elem):
contains = getattr(obj, "__contains__", None)
if contains:
return contains(elem)
return NotImplemented
def keys(self, obj):
keys = getattr(obj, "keys", None)
if keys:
return keys()
elif type(obj) is list:
return range(len(obj))
return NotImplemented
class MemoryBackend(Backend):
def __init__(self):
self._store = {}
def load(self, filepath):
return self._store.get(filepath)
def save(self, filepath, map):
self._store[filepath] = map
class DiskBackend(Backend):
safe_file_closing = True
class PickleBackend(DiskBackend):
def __init__(self):
import cPickle
self._pickle = cPickle
def load(self, filepath):
file = open(filepath)
try:
return self._pickle.load(file)
finally:
safe_close(file, self.safe_file_closing)
def save(self, filepath, map):
file = open(filepath, "w")
try:
self._pickle.dump(map, file, 2)
finally:
safe_close(file, self.safe_file_closing)
class BPickleBackend(DiskBackend):
def __init__(self):
from checkbox.contrib import bpickle
self._bpickle = bpickle
def load(self, filepath):
file = open(filepath)
try:
return self._bpickle.loads(file.read())
finally:
safe_close(file, self.safe_file_closing)
def save(self, filepath, map):
file = open(filepath, "w")
try:
file.write(self._bpickle.dumps(map))
finally:
safe_close(file, self.safe_file_closing)
|