Package pyxb :: Package utils :: Module utility
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Source Code for Module pyxb.utils.utility

   1  # Copyright 2009, Peter A. Bigot 
   2  # 
   3  # Licensed under the Apache License, Version 2.0 (the "License"); you may 
   4  # not use this file except in compliance with the License. You may obtain a 
   5  # copy of the License at: 
   6  # 
   7  #            http://www.apache.org/licenses/LICENSE-2.0 
   8  # 
   9  # Unless required by applicable law or agreed to in writing, software 
  10  # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 
  11  # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 
  12  # License for the specific language governing permissions and limitations 
  13  # under the License. 
  14   
  15  """Utility functions and classes.""" 
  16   
  17  import re 
  18  import os 
  19  import errno 
  20  import pyxb 
  21   
22 -def QuotedEscaped (s):
23 """Convert a string into a literal value that can be used in Python source. 24 25 This just calls C{repr}. No point in getting all complex when the language 26 already gives us what we need. 27 28 @rtype: C{str} 29 """ 30 return repr(s)
31 32 _UnderscoreSubstitute_re = re.compile(r'[- .]') 33 _NonIdentifier_re = re.compile(r'[^a-zA-Z0-9_]') 34 _PrefixUnderscore_re = re.compile(r'^_+') 35 _PrefixDigit_re = re.compile(r'^\d+') 36
37 -def MakeIdentifier (s):
38 """Convert a string into something suitable to be a Python identifier. 39 40 The string is converted to unicode; spaces and periods replaced by 41 underscores; non-printables stripped. Furthermore, any leading 42 underscores are removed. If the result begins with a digit, the 43 character 'n' is prepended. If the result is the empty string, 44 the string 'emptyString' is substituted. 45 46 No check is made for L{conflicts with keywords <DeconflictKeyword>}. 47 48 @rtype: C{str} 49 """ 50 s = _PrefixUnderscore_re.sub('', _NonIdentifier_re.sub('',_UnderscoreSubstitute_re.sub('_', str(s)))) 51 if _PrefixDigit_re.match(s): 52 s = 'n' + s 53 if 0 == len(s): 54 s = 'emptyString' 55 return s
56 57 # Note that types like int and float are not keywords 58 _Keywords = frozenset( ( "and", "del", "from", "not", "while", "as", "elif", "global", 59 "or", "with", "assert", "else", "if", "pass", "yield", 60 "break", "except", "import", "print", "class", "exec", 61 "in", "raise", "continue", "finally", "is", "return", 62 "def", "for", "lambda", "try", 63 "None" ) ) 64 """The keywords reserved for Python.""" 65
66 -def DeconflictKeyword (s, aux_keywords=frozenset()):
67 """If the provided string C{s} matches a Python language keyword, 68 append an underscore to distinguish them. 69 70 See also L{MakeUnique}. 71 72 @param s: string to be deconflicted 73 74 @keyword aux_keywords: optional iterable of additional strings 75 that should be treated as keywords. 76 77 @rtype: C{str} 78 79 """ 80 if (s in _Keywords) or (s in aux_keywords): 81 return '%s_' % (s,) 82 return s
83
84 -def MakeUnique (s, in_use):
85 """Return an identifier based on C{s} that is not in the given set. 86 87 The returned identifier is made unique by appending an underscore 88 and, if necessary, a serial number. 89 90 The order is : C{x}, C{x_}, C{x_2}, C{x_3}, ... 91 92 @param in_use: The set of identifiers already in use in the 93 relevant scope. C{in_use} is updated to contain the returned 94 identifier. 95 96 @rtype: C{str} 97 """ 98 if s in in_use: 99 ctr = 2 100 s = s.rstrip('_') 101 candidate = '%s_' % (s,) 102 while candidate in in_use: 103 candidate = '%s_%d' % (s, ctr) 104 ctr += 1 105 s = candidate 106 in_use.add(s) 107 return s
108
109 -def PrepareIdentifier (s, in_use, aux_keywords=frozenset(), private=False, protected=False):
110 """Combine everything required to create a unique identifier. 111 112 Leading and trailing underscores are stripped from all 113 identifiers. 114 115 @param in_use: the set of already used identifiers. Upon return 116 from this function, it is updated to include the returned 117 identifier. 118 119 @keyword aux_keywords: an optional set of additional symbols that 120 are illegal in the given context; use this to prevent conflicts 121 with known method names. 122 123 @keyword private: if C{False} (default), all leading underscores 124 are stripped, guaranteeing the identifier will not be private. If 125 C{True}, the returned identifier has two leading underscores, 126 making it a private variable within a Python class. 127 128 @keyword protected: as for C{private}, but uses only one 129 underscore. 130 131 @rtype: C{str} 132 133 @note: Only module-level identifiers should be treated as 134 protected. The class-level L{_DeconflictSymbols_mixin} 135 infrastructure does not include protected symbols. All class and 136 instance members beginning with a single underscore are reserved 137 for the PyXB infrastructure.""" 138 s = DeconflictKeyword(MakeIdentifier(s).strip('_'), aux_keywords) 139 if private: 140 s = '__' + s 141 elif protected: 142 s = '_' + s 143 return MakeUnique(s, in_use)
144 145 # @todo: descend from pyxb.cscRoot, if we import pyxb
146 -class _DeconflictSymbols_mixin (object):
147 """Mix-in used to deconflict public symbols in classes that may be 148 inherited by generated binding classes. 149 150 Some classes, like the L{pyxb.binding.basis.element} or 151 L{pyxb.binding.basis.simpleTypeDefinition} classes in 152 L{pyxb.binding.basis}, have public symbols associated with 153 functions and variables. It is possible that an XML schema might 154 include tags and attribute names that match these symbols. To 155 avoid conflict, the reserved symbols marked in this class are 156 added to the pre-defined identifier set. 157 158 Subclasses should create a class-level variable 159 C{_ReservedSymbols} that contains a set of strings denoting the 160 symbols reserved in this class, combined with those from any 161 superclasses that also have reserved symbols. Code like the 162 following is suggested:: 163 164 # For base classes (direct mix-in): 165 _ReservedSymbols = set([ 'one', 'two' ]) 166 # For subclasses: 167 _ReservedSymbols = SuperClass._ReservedSymbols.union(set([ 'three' ])) 168 169 Only public symbols (those with no underscores) are currently 170 supported. (Private symbols can't be deconflicted that easily, 171 and no protected symbols that derive from the XML are created by 172 the binding generator.) 173 """ 174 175 _ReservedSymbols = set() 176 """There are no reserved symbols in the base class."""
177 178 # Regular expression detecting tabs, carriage returns, and line feeds 179 __TabCRLF_re = re.compile("[\t\n\r]") 180 # Regular expressoin detecting sequences of two or more spaces 181 __MultiSpace_re = re.compile(" +") 182
183 -def NormalizeWhitespace (text, preserve=False, replace=False, collapse=False):
184 """Normalize the given string. 185 186 Exactly one of the C{preserve}, C{replace}, and C{collapse} keyword 187 parameters must be assigned the value C{True} by the caller. 188 189 - C{preserve}: the text is returned unchanged. 190 191 - C{replace}: all tabs, newlines, and carriage returns are 192 replaced with ASCII spaces. 193 194 - C{collapse}: the C{replace} normalization is done, then 195 sequences of two or more spaces are replaced by a single space. 196 197 See the U{whiteSpace facet<http://www.w3.org/TR/xmlschema-2/#rf-whiteSpace>}. 198 199 @rtype: C{str} 200 """ 201 if preserve: 202 return text 203 text = __TabCRLF_re.sub(' ', text) 204 if replace: 205 return text 206 if collapse: 207 return __MultiSpace_re.sub(' ', text).strip() 208 # pyxb not imported here; could be. 209 raise Exception('NormalizeWhitespace: No normalization specified')
210
211 -class Graph:
212 """Represent a directed graph with arbitrary objects as nodes. 213 214 This is used in the L{code 215 generator<pyxb.binding.generate.Generator>} to determine order 216 dependencies among components within a namespace, and schema that 217 comprise various namespaces. An edge from C{source} to C{target} 218 indicates that some aspect of C{source} requires that some aspect 219 of C{target} already be available. 220 """ 221
222 - def __init__ (self, root=None):
223 self.__roots = None 224 if root is not None: 225 self.__roots = set([root]) 226 self.__edges = set() 227 self.__edgeMap = { } 228 self.__reverseMap = { } 229 self.__nodes = set()
230 231 __scc = None 232 __sccMap = None 233 __dfsOrder = None 234
235 - def addEdge (self, source, target):
236 """Add a directed edge from the C{source} to the C{target}. 237 238 The nodes are added to the graph if necessary. 239 """ 240 self.__edges.add( (source, target) ) 241 self.__edgeMap.setdefault(source, set()).add(target) 242 if source != target: 243 self.__reverseMap.setdefault(target, set()).add(source) 244 self.__nodes.add(source) 245 self.__nodes.add(target)
246
247 - def addNode (self, node):
248 """Add the given node to the graph.""" 249 self.__nodes.add(node)
250 251 __roots = None
252 - def roots (self, reset=False):
253 """Return the set of nodes calculated to be roots (i.e., those that have no incoming edges). 254 255 This caches the roots calculated in a previous invocation 256 unless the C{reset} keyword is given the value C{True}. 257 258 @note: Upon reset, any notes that had been manually added 259 using L{addNode} will no longer be in the set. 260 261 @keyword reset: If C{True}, any cached value is discarded and 262 recomputed. No effect if C{False} (defalut). 263 264 @rtype: C{set} 265 """ 266 if reset or (self.__roots is None): 267 self.__roots = set() 268 for n in self.__nodes: 269 if not (n in self.__reverseMap): 270 self.__roots.add(n) 271 return self.__roots
272 - def addRoot (self, root):
273 """Add the provided node as a root node, even if it has incoming edges. 274 275 The node need not be present in the graph (if necessary, it is added). 276 277 Note that roots added in this way do not survive a reset using 278 L{roots}. 279 280 @return: C{self} 281 """ 282 if self.__roots is None: 283 self.__roots = set() 284 self.__nodes.add(root) 285 self.__roots.add(root) 286 return self
287
288 - def edgeMap (self):
289 """Return the edges in the graph. 290 291 The edge data structure is a map from the source node to the 292 set of nodes that can be reached in a single step from the 293 source. 294 """ 295 return self.__edgeMap
296 __edgeMap = None 297
298 - def edges (self):
299 """Return the edges in the graph. 300 301 The edge data structure is a set of node pairs represented as C{( source, target )}. 302 """ 303 return self.__edges
304
305 - def nodes (self):
306 """Return the set of nodes in the graph. 307 308 The node collection data structure is a set containing node 309 objects, whatever they may be.""" 310 return self.__nodes
311
312 - def tarjan (self, reset=False):
313 """Execute Tarjan's algorithm on the graph. 314 315 U{Tarjan's 316 algorithm<http://en.wikipedia.org/wiki/Tarjan%27s_strongly_connected_components_algorithm>} 317 computes the U{strongly-connected 318 components<http://en.wikipedia.org/wiki/Strongly_connected_component>} 319 of the graph: i.e., the sets of nodes that form a minimal 320 closed set under edge transition. In essence, the loops. We 321 use this to detect groups of components that have a dependency 322 cycle. 323 324 @keyword reset: If C{True}, any cached component set is erased 325 and recomputed. If C{True}, an existing previous result is 326 left unchanged.""" 327 328 if (self.__scc is not None) and (not reset): 329 return 330 self.__sccMap = { } 331 self.__stack = [] 332 self.__sccOrder = [] 333 self.__scc = [] 334 self.__index = 0 335 self.__tarjanIndex = { } 336 self.__tarjanLowLink = { } 337 for v in self.__nodes: 338 self.__tarjanIndex[v] = None 339 roots = self.roots() 340 if (0 == len(roots)) and (0 < len(self.__nodes)): 341 raise Exception('TARJAN: No roots found in graph with %d nodes' % (len(self.__nodes),)) 342 for r in roots: 343 self._tarjan(r) 344 self.__didTarjan = True
345
346 - def _tarjan (self, v):
347 """Do the work of Tarjan's algorithm for a given root node.""" 348 if self.__tarjanIndex.get(v) is not None: 349 # "Root" was already reached. 350 return 351 self.__tarjanIndex[v] = self.__tarjanLowLink[v] = self.__index 352 self.__index += 1 353 self.__stack.append(v) 354 source = v 355 for target in self.__edgeMap.get(source, []): 356 if self.__tarjanIndex[target] is None: 357 #print "Target %s not found in processed" % (target,) 358 self._tarjan(target) 359 self.__tarjanLowLink[v] = min(self.__tarjanLowLink[v], self.__tarjanLowLink[target]) 360 elif target in self.__stack: 361 #print "Found %s in stack" % (target,) 362 self.__tarjanLowLink[v] = min(self.__tarjanLowLink[v], self.__tarjanLowLink[target]) 363 else: 364 #print "No %s in stack" % (target,) 365 pass 366 367 if self.__tarjanLowLink[v] == self.__tarjanIndex[v]: 368 scc = [] 369 while True: 370 scc.append(self.__stack.pop()) 371 if v == scc[-1]: 372 break; 373 self.__sccOrder.append(scc) 374 if 1 < len(scc): 375 self.__scc.append(scc) 376 [ self.__sccMap.setdefault(_v, scc) for _v in scc ]
377 #print 'SCC at %s' % (' '.join( [str(_s) for _s in scc ]),) 378
379 - def scc (self, reset=False):
380 """Return the strongly-connected components of the graph. 381 382 The data structure is a set, each element of which is itself a 383 set containing one or more nodes from the graph. 384 385 @see: L{tarjan}. 386 """ 387 if reset or (self.__scc is None): 388 self.tarjan(reset) 389 return self.__scc
390 __scc = None 391
392 - def sccMap (self, reset=False):
393 """Return a map from nodes to the strongly-connected component 394 to which the node belongs. 395 396 @keyword reset: If C{True}, the L{tarjan} method will be 397 re-invoked, propagating the C{reset} value. If C{False} 398 (default), a cached value will be returned if available. 399 400 @see: L{tarjan}. 401 """ 402 if reset or (self.__sccMap is None): 403 self.tarjan(reset) 404 return self.__sccMap
405 __sccMap = None 406
407 - def sccOrder (self, reset=False):
408 """Return the strongly-connected components in order. 409 410 The data structure is a list, in dependency order, of strongly 411 connected components (which can be single nodes). Appearance 412 of a node in a set earlier in the list indicates that it has 413 no dependencies on any node that appears in a subsequent set. 414 This order is preferred over L{dfsOrder} for code generation, 415 since it detects loops. 416 417 @see: L{tarjan}. 418 """ 419 if reset or (self.__sccOrder is None): 420 self.tarjan(reset) 421 return self.__sccOrder
422 __sccOrder = None 423
424 - def sccForNode (self, node, **kw):
425 """Return the strongly-connected component to which the given 426 node belongs. 427 428 Any keywords suppliend when invoking this method are passed to 429 the L{sccMap} method. 430 431 @return: The SCC set, or C{None} if the node is not present in 432 the results of Tarjan's algorithm.""" 433 434 return self.sccMap(**kw).get(node, None)
435
436 - def cyclomaticComplexity (self):
437 """Return the cyclomatic complexity of the graph.""" 438 self.tarjan() 439 return len(self.__edges) - len(self.__nodes) + 2 * len(self.__scc)
440
441 - def __dfsWalk (self, source):
442 assert not (source in self.__dfsWalked) 443 self.__dfsWalked.add(source) 444 for target in self.__edgeMap.get(source, []): 445 if not (target in self.__dfsWalked): 446 self.__dfsWalk(target) 447 self.__dfsOrder.append(source)
448
449 - def _generateDOT (self, title='UNKNOWN', labeller=None):
450 node_map = { } 451 idx = 1 452 for n in self.__nodes: 453 node_map[n] = idx 454 idx += 1 455 text = [] 456 text.append('digraph "%s" {' % (title,)) 457 for n in self.__nodes: 458 if labeller is not None: 459 nn = labeller(n) 460 else: 461 nn = str(n) 462 text.append('%s [shape=box,label="%s"];' % (node_map[n], nn)) 463 for s in self.__nodes: 464 for d in self.__edgeMap.get(s, []): 465 if s != d: 466 text.append('%s -> %s;' % (node_map[s], node_map[d])) 467 text.append("};") 468 return "\n".join(text)
469
470 - def dfsOrder (self, reset=False):
471 """Return the nodes of the graph in U{depth-first-search 472 order<http://en.wikipedia.org/wiki/Depth-first_search>}. 473 474 The data structure is a list. Calculated lists are retained 475 and returned on future invocations, subject to the C{reset} 476 keyword. 477 478 @keyword reset: If C{True}, discard cached results and recompute the order.""" 479 if reset or (self.__dfsOrder is None): 480 self.__dfsWalked = set() 481 self.__dfsOrder = [] 482 for root in self.roots(reset=reset): 483 self.__dfsWalk(root) 484 self.__dfsWalked = None 485 if len(self.__dfsOrder) != len(self.__nodes): 486 raise Exception('DFS walk did not cover all nodes (walk %d versus nodes %d)' % (len(self.__dfsOrder), len(self.__nodes))) 487 return self.__dfsOrder
488
489 -def NormalizeLocation (uri, parent_uri=None):
490 """Normalize a URI against an optional parent_uri in the way that is 491 done for C{schemaLocation} attribute values. 492 493 If no URI schema is present, this will normalize a file system 494 path.""" 495 import urlparse 496 import os 497 498 if uri is None: 499 return uri 500 if parent_uri is None: 501 abs_uri = uri 502 else: 503 #if (0 > parent_uri.find(':')) and (not parent_uri.endswith(os.sep)): 504 # parent_uri = parent_uri + os.sep 505 abs_uri = urlparse.urljoin(parent_uri, uri) 506 if 0 > abs_uri.find(':'): 507 abs_uri = os.path.realpath(abs_uri) 508 return abs_uri
509 510 import urlparse 511
512 -def TextFromURI (uri, archive_directory=None):
513 """Retrieve the contents of the uri as a text string. 514 515 If the uri does not include a scheme (e.g., C{http:}), it is 516 assumed to be a file path on the local system.""" 517 import urllib2 518 xmls = None 519 try: 520 if 0 <= uri.find(':'): 521 xmls = urllib2.urlopen(uri).read() 522 else: 523 xmls = file(uri).read() 524 archive_directory = None 525 except Exception, e: 526 print 'TextFromURI: open %s caught: %s' % (uri, e) 527 raise 528 if archive_directory: 529 base_name = os.path.basename(os.path.normpath(urlparse.urlparse(uri)[2])) 530 counter = 1 531 dest_file = os.path.join(archive_directory, base_name) 532 while os.path.isfile(dest_file): 533 dest_file = os.path.join(archive_directory, '%s.%d' % (base_name, counter)) 534 counter += 1 535 try: 536 OpenOrCreate(dest_file).write(xmls) 537 except OSError, e: 538 print 'WARNING: Unable to save %s in %s: %s' % (uri, dest_file, e) 539 return xmls
540
541 -def OpenOrCreate (file_name, tag=None, preserve_contents=False):
542 """Return a file object used to write the given file. 543 544 Use the C{tag} keyword to preserve the contents of existing files 545 that are not supposed to be overwritten. 546 547 To get a writable file but leaving any existing contents in place, 548 set the C{preserve_contents} keyword to C{True}. Normally, existing file 549 contents are erased. 550 551 The returned file pointer is positioned at the end of the file. 552 553 @keyword tag: If not C{None} and the file already exists, absence 554 of the given value in the first 4096 bytes of the file causes an 555 C{IOError} to be raised with C{errno} set to C{EEXIST}. I.e., 556 only files with this value in the first 4KB will be returned for 557 writing. 558 559 @keyword preserve_contents: This value controls whether existing 560 contents of the file will be erased (C{False}, default) or left in 561 place (C{True}). 562 """ 563 (path, leaf) = os.path.split(file_name) 564 if path: 565 try: 566 os.makedirs(path) 567 except Exception, e: 568 if not (isinstance(e, (OSError, IOError)) and (errno.EEXIST == e.errno)): 569 raise 570 fp = file(file_name, 'a+') 571 if (tag is not None) and (0 < os.fstat(fp.fileno()).st_size): 572 text = fp.read(4096) 573 if 0 > text.find(tag): 574 raise OSError(errno.EEXIST, os.strerror(errno.EEXIST)) 575 if not preserve_contents: 576 fp.seek(0) # os.SEEK_SET 577 fp.truncate() 578 else: 579 fp.seek(2) # os.SEEK_END 580 return fp
581 582 # hashlib didn't show up until 2.5, and sha is deprecated in 2.6. 583 __Hasher = None 584 try: 585 import hashlib 586 __Hasher = hashlib.sha1 587 except ImportError: 588 import sha 589 __Hasher = sha.new 590
591 -def HashForText (text):
592 """Calculate a cryptographic hash of the given string. 593 594 For example, this is used to verify that a given module file 595 contains bindings from a previous generation run for the same 596 namespace. See L{OpenOrCreate}. 597 598 @return: A C{str}, generally a sequence of hexadecimal "digit"s. 599 """ 600 return __Hasher(text).hexdigest()
601 602 # uuid didn't show up until 2.5 603 __HaveUUID = False 604 try: 605 import uuid 606 __HaveUUID = True 607 except ImportError: 608 import time 609 import random
610 -def _NewUUIDString ():
611 """Obtain a UUID using the best available method. On a version of 612 python that does not incorporate the C{uuid} class, this creates a 613 string combining the current date and time (to the second) with a 614 random number. 615 616 @rtype: C{str} 617 """ 618 if __HaveUUID: 619 return uuid.uuid1().urn 620 return '%s:%08.8x' % (time.strftime('%Y%m%d%H%M%S'), random.randint(0, 0xFFFFFFFFL))
621
622 -class UniqueIdentifier (object):
623 """Records a unique identifier, generally associated with a 624 binding generation action. 625 626 The identifier is a string, but gets wrapped in an instance of 627 this class to optimize comparisons and reduce memory footprint. 628 629 Invoking the constructor for this class on the same string 630 multiple times will return the same Python object. 631 632 An instance of this class compares equal to, and hashes equivalent 633 to, the uid string. When C{str}'d, the result is the uid; when 634 C{repr}'d, the result is a constructor call to 635 C{pyxb.utils.utility.UniqueIdentifier}. 636 """ 637 638 # A map from UID string to the instance that represents it 639 __ExistingUIDs = {} 640
641 - def uid (self):
642 """The string unique identifier""" 643 return self.__uid
644 __uid = None 645 646 # Support pickling, which is done using only the UID.
647 - def __getnewargs__ (self):
648 return (self.__uid,)
649
650 - def __getstate__ (self):
651 return self.__uid
652
653 - def __setstate__ (self, state):
654 assert self.__uid == state
655 656 # Singleton-like
657 - def __new__ (cls, *args):
658 if 0 == len(args): 659 uid = _NewUUIDString() 660 else: 661 uid = args[0] 662 if isinstance(uid, UniqueIdentifier): 663 uid = uid.uid() 664 if not isinstance(uid, basestring): 665 raise TypeError('UniqueIdentifier uid must be a string') 666 rv = cls.__ExistingUIDs.get(uid) 667 if rv is None: 668 rv = super(UniqueIdentifier, cls).__new__(cls) 669 rv.__uid = uid 670 cls.__ExistingUIDs[uid] = rv 671 return rv
672
673 - def associateObject (self, obj):
674 """Associate the given object witth this identifier. 675 676 This is a one-way associatoin: the object is not provided with 677 a return path to this identifier instance.""" 678 self.__associatedObjects.add(obj)
679 - def associatedObjects (self):
680 """The set of objects that have been associated with this 681 identifier instance.""" 682 return self.__associatedObjects
683 __associatedObjects = None 684
685 - def __init__ (self, uid=None):
686 """Create a new UniqueIdentifier instance. 687 688 @param uid: The unique identifier string. If present, it is 689 the callers responsibility to ensure the value is universally 690 unique. If C{None}, one will be provided. 691 @type uid: C{str} or C{unicode} 692 """ 693 assert (uid is None) or (self.uid() == uid), 'UniqueIdentifier: ctor %s, actual %s' % (uid, self.uid()) 694 self.__associatedObjects = set()
695
696 - def __eq__ (self, other):
697 if other is None: 698 return False 699 elif isinstance(other, UniqueIdentifier): 700 other_uid = other.uid() 701 elif isinstance(other, basestring): 702 other_uid = other 703 else: 704 raise TypeError('UniqueIdentifier: Cannot compare with type %s' % (type(other),)) 705 return self.uid() == other_uid
706
707 - def __hash__ (self):
708 return hash(self.uid())
709
710 - def __str__ (self):
711 return self.uid()
712
713 - def __repr__ (self):
714 return 'pyxb.utils.utility.UniqueIdentifier(%s)' % (repr(self.uid()),)
715 716 import datetime 717 import calendar 718 import time
719 -class UTCOffsetTimeZone (datetime.tzinfo):
720 """A C{datetime.tzinfo} subclass that helps deal with UTC 721 conversions in an ISO8601 world. 722 723 This class only supports fixed offsets from UTC. 724 """ 725 726 # Regular expression that matches valid ISO8601 time zone suffixes 727 __Lexical_re = re.compile('^([-+])(\d\d):(\d\d)$') 728 729 # The offset in minutes east of UTC. 730 __utcOffset_min = 0 731 732 # Same as __utcOffset_min, but as a datetime.timedelta 733 __utcOffset_td = None 734 735 # A zero-length duration 736 __ZeroDuration = datetime.timedelta(0) 737
738 - def __init__ (self, spec=None, flip=False):
739 """Create a time zone instance with a fixed offset from UTC. 740 741 @param spec: Specifies the offset. Can be an integer counting 742 minutes east of UTC, the value C{None} (equal to 0 minutes 743 east), or a string that conform to the ISO8601 time zone 744 sequence (B{Z}, or B{[+-]HH:MM}). 745 746 @param flip: If C{False} (default), no adaptation is done. If 747 C{True}, the time zone offset is negated, resulting in the 748 conversion from localtime to UTC rather than the default of 749 UTC to localtime. 750 """ 751 752 if spec is not None: 753 if isinstance(spec, basestring): 754 if 'Z' == spec: 755 self.__utcOffset_min = 0 756 else: 757 match = self.__Lexical_re.match(spec) 758 if match is None: 759 raise ValueError('Bad time zone: %s' % (spec,)) 760 self.__utcOffset_min = int(match.group(2)) * 60 + int(match.group(3)) 761 if '-' == match.group(1): 762 self.__utcOffset_min = - self.__utcOffset_min 763 elif isinstance(spec, int): 764 self.__utcOffset_min = spec 765 elif isinstance(spec, datetime.timedelta): 766 self.__utcOffset_min = spec.seconds / 60 767 else: 768 raise TypeError('%s: unexpected type %s' % (type(self), type(spec))) 769 if flip: 770 self.__utcOffset_min = - self.__utcOffset_min 771 self.__utcOffset_td = datetime.timedelta(minutes=self.__utcOffset_min) 772 if 0 == self.__utcOffset_min: 773 self.__tzName = 'Z' 774 elif 0 > self.__utcOffset_min: 775 self.__tzName = '-%02d%02d' % divmod(-self.__utcOffset_min, 60) 776 else: 777 self.__tzName = '+%02d%02d' % divmod(self.__utcOffset_min, 60)
778
779 - def utcoffset (self, dt):
780 """Returns the constant offset for this zone.""" 781 return self.__utcOffset_td
782
783 - def tzname (self, dt):
784 """Return the name of the timezone in ISO8601 format.""" 785 return self.__tzName
786
787 - def dst (self, dt):
788 """Returns a constant zero duration.""" 789 return self.__ZeroDuration
790
791 -class LocalTimeZone (datetime.tzinfo):
792 """A C{datetime.tzinfo} subclass for the local time zone. 793 794 Mostly pinched from the C{datetime.tzinfo} documentation in Python 2.5.1. 795 """ 796 797 __STDOffset = datetime.timedelta(seconds=-time.timezone) 798 __DSTOffset = __STDOffset 799 if time.daylight: 800 __DSTOffset = datetime.timedelta(seconds=-time.altzone) 801 __ZeroDelta = datetime.timedelta(0) 802 __DSTDelta = __DSTOffset - __STDOffset 803
804 - def utcoffset (self, dt):
805 if self.__isDST(dt): 806 return self.__DSTOffset 807 return self.__STDOffset
808
809 - def dst (self, dt):
810 if self.__isDST(dt): 811 return self.__DSTDelta 812 return self.__ZeroDelta
813
814 - def tzname (self, dt):
815 return time.tzname[self.__isDST(dt)]
816
817 - def __isDST (self, dt):
818 tt = (dt.year, dt.month, dt.day, 819 dt.hour, dt.minute, dt.second, 820 0, 0, -1) 821 tt = time.localtime(time.mktime(tt)) 822 return tt.tm_isdst > 0
823
824 -class PrivateTransient_mixin (pyxb.cscRoot):
825 """Emulate the B{transient} keyword from Java for private member 826 variables. 827 828 This class defines a C{__getstate__} method which returns a copy 829 of C{self.__dict__} with certain members removed. Specifically, 830 if a string "s" appears in a class member variable named 831 C{__PrivateTransient} defined in the "Class" class, then the 832 corresponding private variable "_Class__s" will be removed from 833 the state dictionary. This is used to eliminate unnecessary 834 fields from instances placed in L{namespace 835 archives<pyxb.namespace.archive.NamespaceArchive>} without having 836 to implement a C{__getstate__} method in every class in the 837 instance hierarchy. 838 839 For an example, see 840 L{pyxb.xmlschema.structures._SchemaComponent_mixin} 841 842 If you use this, it is your responsibility to define the 843 C{__PrivateTransient} class variable and add to it the required 844 variable names. 845 846 Classes that inherit from this are free to define their own 847 C{__getstate__} method, which may or may not invoke the superclass 848 one. If you do this, be sure that the class defining 849 C{__getstate__} lists L{PrivateTransient_mixin} as one of its 850 direct superclasses, lest the latter end up earlier in the mro and 851 consequently bypass the local override. 852 """ 853 854 # Suffix used when creating the class member variable in which the 855 # transient members are cached. 856 __Attribute = '__PrivateTransient' 857
858 - def __getstate__ (self):
859 state = self.__dict__.copy() 860 # Note that the aggregate set is stored in a class variable 861 # with a slightly different name than the class-level set. 862 attr = '_%s%s_' % (self.__class__.__name__, self.__Attribute) 863 skipped = getattr(self.__class__, attr, None) 864 if skipped is None: 865 skipped = set() 866 for cl in self.__class__.mro(): 867 for (k, v) in cl.__dict__.items(): 868 if k.endswith(self.__Attribute): 869 cl2 = k[:-len(self.__Attribute)] 870 skipped.update([ '%s__%s' % (cl2, _n) for _n in v ]) 871 setattr(self.__class__, attr, skipped) 872 #print 'Defined skipped for %s: %s' % (self.__class__, skipped) 873 for k in skipped: 874 if state.get(k) is not None: 875 #print 'Stripping %s from instance %x of %s' % (k, id(self), type(self)) 876 del state[k] 877 # Uncomment the following to test whether undesirable types 878 # are being pickled, generally by accidently leaving a 879 # reference to one in an instance private member. 880 #for (k, v) in state.items(): 881 # import pyxb.namespace 882 # import xml.dom 883 # import pyxb.xmlschema.structures 884 # if isinstance(v, (pyxb.namespace.resolution.NamespaceContext, xml.dom.Node, pyxb.xmlschema.structures.Schema)): 885 # raise pyxb.LogicError('Unexpected instance of %s key %s in %s' % (type(v), k, self)) 886 887 return state
888
889 -def GetMatchingFiles (path, pattern=None, default_path_wildcard=None, default_path=None, prefix_pattern=None, prefix_substituend=None):
890 """Provide a list of absolute paths to files present in any of a 891 set of directories and meeting certain criteria. 892 893 This is used, for example, to locate namespace archive files 894 within the archive path specified by the user. One could use:: 895 896 files = GetMatchingFiles('&bundles//:+', 897 pattern=re.compile('.*\.wxs$'), 898 default_path_wildcard='+', 899 default_path='/usr/local/pyxb/nsarchives', 900 prefix_pattern='&', 901 prefix_substituend='/opt/pyxb') 902 903 to obtain all files that can be recursively found within 904 C{/opt/pyxb/bundles}, or non-recursively within 905 C{/usr/local/pyxb/nsarchives}. 906 907 @param path: A colon separated list of directories in which the 908 search should be performed. If a path entry ends with C{//}, any 909 directory beneath it is scanned as well, recursively. 910 911 @keyword pattern: Optional regular expression object used to 912 determine whether a given directory entry should be returned. If 913 left as C{None}, all directory entries will be returned. 914 915 @keyword default_path_wildcard: An optional string which, if 916 present as a single directory in the path, is replaced by the 917 value of C{default-path}. 918 919 @keyword default_path: A system-defined directory which can be 920 restored to the path by placing the C{default_path_wildcard} in 921 the C{path}. 922 923 @keyword prefix_pattern: An optional string which, if present at 924 the start of a path element, is replaced by the value of 925 C{prefix_substituend}. 926 927 @keyword prefix_substituend: A system-defined string (path prefix) 928 which can be combined with the user-provided path information to 929 identify a file or subdirectory within an installation-specific 930 area. 931 """ 932 matching_files = [] 933 path_set = path.split(':') 934 while 0 < len(path_set): 935 path = path_set.pop(0) 936 if default_path_wildcard == path: 937 if default_path is not None: 938 path_set[0:0] = default_path.split(':') 939 continue 940 recursive = False 941 if (prefix_pattern is not None) and path.startswith(prefix_pattern): 942 path = os.path.join(prefix_substituend, path[len(prefix_pattern):]) 943 if path.endswith('//'): 944 recursive = True 945 path = path[:-2] 946 if os.path.isfile(path): 947 if (pattern is None) or (pattern.search(path) is not None): 948 matching_files.append(path) 949 else: 950 for (root, dirs, files) in os.walk(path): 951 for f in files: 952 if (pattern is None) or (pattern.search(f) is not None): 953 matching_files.append(os.path.join(root, f)) 954 if not recursive: 955 break 956 return matching_files
957
958 -class _LocationBase (object):
959 """Wrap a location. 960 961 This is probably a string, but might be a uri object or the like. 962 Really we only have this as a separate object so as to avoid 963 creating hundreds of copies of the same string.""" 964 965 __locationBase = None
966 - def locationBase (self):
967 return self.__locationBase
968
969 - def __init__ (self, location_base):
970 if isinstance(location_base, _LocationBase): 971 location_base = location_base.locationBase() 972 self.__locationBase = location_base
973
974 - def __str__ (self):
975 return str(self.__locationBase)
976
977 -class Location (object):
978 __locationBase = None 979 __lineNumber = None 980 __columnNumber = None 981
982 - def __init__ (self, location_base=None, line_number=None, column_number=None):
983 if not isinstance(location_base, _LocationBase): 984 location_base = _LocationBase(location_base) 985 self.__locationBase = location_base 986 self.__lineNumber = line_number 987 self.__columnNumber = column_number
988
989 - def newLocation (self, locator=None, line_number=None, column_number=None):
990 if locator is not None: 991 try: 992 line_number = locator.getLineNumber() 993 column_number = locator.getColumnNumber() 994 except: 995 pass 996 return Location(self.__locationBase, line_number, column_number)
997 998 locationBase = property(lambda _s: _s.__locationBase) 999 lineNumber = property(lambda _s: _s.__lineNumber) 1000 columnNumber = property(lambda _s: _s.__columnNumber) 1001
1002 - def __str__ (self):
1003 if self.locationBase is None: 1004 return '<unknownLocation>' 1005 return '%s[%s:%s]' % (self.locationBase, self.lineNumber, self.columnNumber)
1006
1007 -class Locatable_mixin (pyxb.cscRoot):
1008 __location = None 1009
1010 - def __init__ (self, *args, **kw):
1011 self.__location = kw.pop('location', None) 1012 super(Locatable_mixin, self).__init__(*args, **kw)
1013
1014 - def _setLocation (self, location):
1015 self.__location = location
1016
1017 - def _location (self):
1018 return self.__location
1019