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| 1 # Protocol Buffers - Google's data interchange format |
| 2 # Copyright 2008 Google Inc. All rights reserved. |
| 3 # http://code.google.com/p/protobuf/ |
| 4 # |
| 5 # Redistribution and use in source and binary forms, with or without |
| 6 # modification, are permitted provided that the following conditions are |
| 7 # met: |
| 8 # |
| 9 # * Redistributions of source code must retain the above copyright |
| 10 # notice, this list of conditions and the following disclaimer. |
| 11 # * Redistributions in binary form must reproduce the above |
| 12 # copyright notice, this list of conditions and the following disclaimer |
| 13 # in the documentation and/or other materials provided with the |
| 14 # distribution. |
| 15 # * Neither the name of Google Inc. nor the names of its |
| 16 # contributors may be used to endorse or promote products derived from |
| 17 # this software without specific prior written permission. |
| 18 # |
| 19 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 20 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 21 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 22 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 23 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 24 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 25 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 26 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 27 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 28 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 29 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 30 |
| 31 """Contains routines for printing protocol messages in text format.""" |
| 32 |
| 33 __author__ = 'kenton@google.com (Kenton Varda)' |
| 34 |
| 35 import cStringIO |
| 36 import re |
| 37 |
| 38 from collections import deque |
| 39 from google.protobuf.internal import type_checkers |
| 40 from google.protobuf import descriptor |
| 41 |
| 42 __all__ = [ 'MessageToString', 'PrintMessage', 'PrintField', |
| 43 'PrintFieldValue', 'Merge' ] |
| 44 |
| 45 |
| 46 _INTEGER_CHECKERS = (type_checkers.Uint32ValueChecker(), |
| 47 type_checkers.Int32ValueChecker(), |
| 48 type_checkers.Uint64ValueChecker(), |
| 49 type_checkers.Int64ValueChecker()) |
| 50 _FLOAT_INFINITY = re.compile('-?inf(?:inity)?f?', re.IGNORECASE) |
| 51 _FLOAT_NAN = re.compile('nanf?', re.IGNORECASE) |
| 52 |
| 53 |
| 54 class ParseError(Exception): |
| 55 """Thrown in case of ASCII parsing error.""" |
| 56 |
| 57 |
| 58 def MessageToString(message, as_utf8=False, as_one_line=False): |
| 59 out = cStringIO.StringIO() |
| 60 PrintMessage(message, out, as_utf8=as_utf8, as_one_line=as_one_line) |
| 61 result = out.getvalue() |
| 62 out.close() |
| 63 if as_one_line: |
| 64 return result.rstrip() |
| 65 return result |
| 66 |
| 67 |
| 68 def PrintMessage(message, out, indent=0, as_utf8=False, as_one_line=False): |
| 69 for field, value in message.ListFields(): |
| 70 if field.label == descriptor.FieldDescriptor.LABEL_REPEATED: |
| 71 for element in value: |
| 72 PrintField(field, element, out, indent, as_utf8, as_one_line) |
| 73 else: |
| 74 PrintField(field, value, out, indent, as_utf8, as_one_line) |
| 75 |
| 76 |
| 77 def PrintField(field, value, out, indent=0, as_utf8=False, as_one_line=False): |
| 78 """Print a single field name/value pair. For repeated fields, the value |
| 79 should be a single element.""" |
| 80 |
| 81 out.write(' ' * indent); |
| 82 if field.is_extension: |
| 83 out.write('[') |
| 84 if (field.containing_type.GetOptions().message_set_wire_format and |
| 85 field.type == descriptor.FieldDescriptor.TYPE_MESSAGE and |
| 86 field.message_type == field.extension_scope and |
| 87 field.label == descriptor.FieldDescriptor.LABEL_OPTIONAL): |
| 88 out.write(field.message_type.full_name) |
| 89 else: |
| 90 out.write(field.full_name) |
| 91 out.write(']') |
| 92 elif field.type == descriptor.FieldDescriptor.TYPE_GROUP: |
| 93 # For groups, use the capitalized name. |
| 94 out.write(field.message_type.name) |
| 95 else: |
| 96 out.write(field.name) |
| 97 |
| 98 if field.cpp_type != descriptor.FieldDescriptor.CPPTYPE_MESSAGE: |
| 99 # The colon is optional in this case, but our cross-language golden files |
| 100 # don't include it. |
| 101 out.write(': ') |
| 102 |
| 103 PrintFieldValue(field, value, out, indent, as_utf8, as_one_line) |
| 104 if as_one_line: |
| 105 out.write(' ') |
| 106 else: |
| 107 out.write('\n') |
| 108 |
| 109 |
| 110 def PrintFieldValue(field, value, out, indent=0, |
| 111 as_utf8=False, as_one_line=False): |
| 112 """Print a single field value (not including name). For repeated fields, |
| 113 the value should be a single element.""" |
| 114 |
| 115 if field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_MESSAGE: |
| 116 if as_one_line: |
| 117 out.write(' { ') |
| 118 PrintMessage(value, out, indent, as_utf8, as_one_line) |
| 119 out.write('}') |
| 120 else: |
| 121 out.write(' {\n') |
| 122 PrintMessage(value, out, indent + 2, as_utf8, as_one_line) |
| 123 out.write(' ' * indent + '}') |
| 124 elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_ENUM: |
| 125 enum_value = field.enum_type.values_by_number.get(value, None) |
| 126 if enum_value is not None: |
| 127 out.write(enum_value.name) |
| 128 else: |
| 129 out.write(str(value)) |
| 130 elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_STRING: |
| 131 out.write('\"') |
| 132 if type(value) is unicode: |
| 133 out.write(_CEscape(value.encode('utf-8'), as_utf8)) |
| 134 else: |
| 135 out.write(_CEscape(value, as_utf8)) |
| 136 out.write('\"') |
| 137 elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_BOOL: |
| 138 if value: |
| 139 out.write("true") |
| 140 else: |
| 141 out.write("false") |
| 142 else: |
| 143 out.write(str(value)) |
| 144 |
| 145 |
| 146 def Merge(text, message): |
| 147 """Merges an ASCII representation of a protocol message into a message. |
| 148 |
| 149 Args: |
| 150 text: Message ASCII representation. |
| 151 message: A protocol buffer message to merge into. |
| 152 |
| 153 Raises: |
| 154 ParseError: On ASCII parsing problems. |
| 155 """ |
| 156 tokenizer = _Tokenizer(text) |
| 157 while not tokenizer.AtEnd(): |
| 158 _MergeField(tokenizer, message) |
| 159 |
| 160 |
| 161 def _MergeField(tokenizer, message): |
| 162 """Merges a single protocol message field into a message. |
| 163 |
| 164 Args: |
| 165 tokenizer: A tokenizer to parse the field name and values. |
| 166 message: A protocol message to record the data. |
| 167 |
| 168 Raises: |
| 169 ParseError: In case of ASCII parsing problems. |
| 170 """ |
| 171 message_descriptor = message.DESCRIPTOR |
| 172 if tokenizer.TryConsume('['): |
| 173 name = [tokenizer.ConsumeIdentifier()] |
| 174 while tokenizer.TryConsume('.'): |
| 175 name.append(tokenizer.ConsumeIdentifier()) |
| 176 name = '.'.join(name) |
| 177 |
| 178 if not message_descriptor.is_extendable: |
| 179 raise tokenizer.ParseErrorPreviousToken( |
| 180 'Message type "%s" does not have extensions.' % |
| 181 message_descriptor.full_name) |
| 182 field = message.Extensions._FindExtensionByName(name) |
| 183 if not field: |
| 184 raise tokenizer.ParseErrorPreviousToken( |
| 185 'Extension "%s" not registered.' % name) |
| 186 elif message_descriptor != field.containing_type: |
| 187 raise tokenizer.ParseErrorPreviousToken( |
| 188 'Extension "%s" does not extend message type "%s".' % ( |
| 189 name, message_descriptor.full_name)) |
| 190 tokenizer.Consume(']') |
| 191 else: |
| 192 name = tokenizer.ConsumeIdentifier() |
| 193 field = message_descriptor.fields_by_name.get(name, None) |
| 194 |
| 195 # Group names are expected to be capitalized as they appear in the |
| 196 # .proto file, which actually matches their type names, not their field |
| 197 # names. |
| 198 if not field: |
| 199 field = message_descriptor.fields_by_name.get(name.lower(), None) |
| 200 if field and field.type != descriptor.FieldDescriptor.TYPE_GROUP: |
| 201 field = None |
| 202 |
| 203 if (field and field.type == descriptor.FieldDescriptor.TYPE_GROUP and |
| 204 field.message_type.name != name): |
| 205 field = None |
| 206 |
| 207 if not field: |
| 208 raise tokenizer.ParseErrorPreviousToken( |
| 209 'Message type "%s" has no field named "%s".' % ( |
| 210 message_descriptor.full_name, name)) |
| 211 |
| 212 if field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_MESSAGE: |
| 213 tokenizer.TryConsume(':') |
| 214 |
| 215 if tokenizer.TryConsume('<'): |
| 216 end_token = '>' |
| 217 else: |
| 218 tokenizer.Consume('{') |
| 219 end_token = '}' |
| 220 |
| 221 if field.label == descriptor.FieldDescriptor.LABEL_REPEATED: |
| 222 if field.is_extension: |
| 223 sub_message = message.Extensions[field].add() |
| 224 else: |
| 225 sub_message = getattr(message, field.name).add() |
| 226 else: |
| 227 if field.is_extension: |
| 228 sub_message = message.Extensions[field] |
| 229 else: |
| 230 sub_message = getattr(message, field.name) |
| 231 sub_message.SetInParent() |
| 232 |
| 233 while not tokenizer.TryConsume(end_token): |
| 234 if tokenizer.AtEnd(): |
| 235 raise tokenizer.ParseErrorPreviousToken('Expected "%s".' % (end_token)) |
| 236 _MergeField(tokenizer, sub_message) |
| 237 else: |
| 238 _MergeScalarField(tokenizer, message, field) |
| 239 |
| 240 |
| 241 def _MergeScalarField(tokenizer, message, field): |
| 242 """Merges a single protocol message scalar field into a message. |
| 243 |
| 244 Args: |
| 245 tokenizer: A tokenizer to parse the field value. |
| 246 message: A protocol message to record the data. |
| 247 field: The descriptor of the field to be merged. |
| 248 |
| 249 Raises: |
| 250 ParseError: In case of ASCII parsing problems. |
| 251 RuntimeError: On runtime errors. |
| 252 """ |
| 253 tokenizer.Consume(':') |
| 254 value = None |
| 255 |
| 256 if field.type in (descriptor.FieldDescriptor.TYPE_INT32, |
| 257 descriptor.FieldDescriptor.TYPE_SINT32, |
| 258 descriptor.FieldDescriptor.TYPE_SFIXED32): |
| 259 value = tokenizer.ConsumeInt32() |
| 260 elif field.type in (descriptor.FieldDescriptor.TYPE_INT64, |
| 261 descriptor.FieldDescriptor.TYPE_SINT64, |
| 262 descriptor.FieldDescriptor.TYPE_SFIXED64): |
| 263 value = tokenizer.ConsumeInt64() |
| 264 elif field.type in (descriptor.FieldDescriptor.TYPE_UINT32, |
| 265 descriptor.FieldDescriptor.TYPE_FIXED32): |
| 266 value = tokenizer.ConsumeUint32() |
| 267 elif field.type in (descriptor.FieldDescriptor.TYPE_UINT64, |
| 268 descriptor.FieldDescriptor.TYPE_FIXED64): |
| 269 value = tokenizer.ConsumeUint64() |
| 270 elif field.type in (descriptor.FieldDescriptor.TYPE_FLOAT, |
| 271 descriptor.FieldDescriptor.TYPE_DOUBLE): |
| 272 value = tokenizer.ConsumeFloat() |
| 273 elif field.type == descriptor.FieldDescriptor.TYPE_BOOL: |
| 274 value = tokenizer.ConsumeBool() |
| 275 elif field.type == descriptor.FieldDescriptor.TYPE_STRING: |
| 276 value = tokenizer.ConsumeString() |
| 277 elif field.type == descriptor.FieldDescriptor.TYPE_BYTES: |
| 278 value = tokenizer.ConsumeByteString() |
| 279 elif field.type == descriptor.FieldDescriptor.TYPE_ENUM: |
| 280 value = tokenizer.ConsumeEnum(field) |
| 281 else: |
| 282 raise RuntimeError('Unknown field type %d' % field.type) |
| 283 |
| 284 if field.label == descriptor.FieldDescriptor.LABEL_REPEATED: |
| 285 if field.is_extension: |
| 286 message.Extensions[field].append(value) |
| 287 else: |
| 288 getattr(message, field.name).append(value) |
| 289 else: |
| 290 if field.is_extension: |
| 291 message.Extensions[field] = value |
| 292 else: |
| 293 setattr(message, field.name, value) |
| 294 |
| 295 |
| 296 class _Tokenizer(object): |
| 297 """Protocol buffer ASCII representation tokenizer. |
| 298 |
| 299 This class handles the lower level string parsing by splitting it into |
| 300 meaningful tokens. |
| 301 |
| 302 It was directly ported from the Java protocol buffer API. |
| 303 """ |
| 304 |
| 305 _WHITESPACE = re.compile('(\\s|(#.*$))+', re.MULTILINE) |
| 306 _TOKEN = re.compile( |
| 307 '[a-zA-Z_][0-9a-zA-Z_+-]*|' # an identifier |
| 308 '[0-9+-][0-9a-zA-Z_.+-]*|' # a number |
| 309 '\"([^\"\n\\\\]|\\\\.)*(\"|\\\\?$)|' # a double-quoted string |
| 310 '\'([^\'\n\\\\]|\\\\.)*(\'|\\\\?$)') # a single-quoted string |
| 311 _IDENTIFIER = re.compile('\w+') |
| 312 |
| 313 def __init__(self, text_message): |
| 314 self._text_message = text_message |
| 315 |
| 316 self._position = 0 |
| 317 self._line = -1 |
| 318 self._column = 0 |
| 319 self._token_start = None |
| 320 self.token = '' |
| 321 self._lines = deque(text_message.split('\n')) |
| 322 self._current_line = '' |
| 323 self._previous_line = 0 |
| 324 self._previous_column = 0 |
| 325 self._SkipWhitespace() |
| 326 self.NextToken() |
| 327 |
| 328 def AtEnd(self): |
| 329 """Checks the end of the text was reached. |
| 330 |
| 331 Returns: |
| 332 True iff the end was reached. |
| 333 """ |
| 334 return self.token == '' |
| 335 |
| 336 def _PopLine(self): |
| 337 while len(self._current_line) <= self._column: |
| 338 if not self._lines: |
| 339 self._current_line = '' |
| 340 return |
| 341 self._line += 1 |
| 342 self._column = 0 |
| 343 self._current_line = self._lines.popleft() |
| 344 |
| 345 def _SkipWhitespace(self): |
| 346 while True: |
| 347 self._PopLine() |
| 348 match = self._WHITESPACE.match(self._current_line, self._column) |
| 349 if not match: |
| 350 break |
| 351 length = len(match.group(0)) |
| 352 self._column += length |
| 353 |
| 354 def TryConsume(self, token): |
| 355 """Tries to consume a given piece of text. |
| 356 |
| 357 Args: |
| 358 token: Text to consume. |
| 359 |
| 360 Returns: |
| 361 True iff the text was consumed. |
| 362 """ |
| 363 if self.token == token: |
| 364 self.NextToken() |
| 365 return True |
| 366 return False |
| 367 |
| 368 def Consume(self, token): |
| 369 """Consumes a piece of text. |
| 370 |
| 371 Args: |
| 372 token: Text to consume. |
| 373 |
| 374 Raises: |
| 375 ParseError: If the text couldn't be consumed. |
| 376 """ |
| 377 if not self.TryConsume(token): |
| 378 raise self._ParseError('Expected "%s".' % token) |
| 379 |
| 380 def ConsumeIdentifier(self): |
| 381 """Consumes protocol message field identifier. |
| 382 |
| 383 Returns: |
| 384 Identifier string. |
| 385 |
| 386 Raises: |
| 387 ParseError: If an identifier couldn't be consumed. |
| 388 """ |
| 389 result = self.token |
| 390 if not self._IDENTIFIER.match(result): |
| 391 raise self._ParseError('Expected identifier.') |
| 392 self.NextToken() |
| 393 return result |
| 394 |
| 395 def ConsumeInt32(self): |
| 396 """Consumes a signed 32bit integer number. |
| 397 |
| 398 Returns: |
| 399 The integer parsed. |
| 400 |
| 401 Raises: |
| 402 ParseError: If a signed 32bit integer couldn't be consumed. |
| 403 """ |
| 404 try: |
| 405 result = ParseInteger(self.token, is_signed=True, is_long=False) |
| 406 except ValueError, e: |
| 407 raise self._ParseError(str(e)) |
| 408 self.NextToken() |
| 409 return result |
| 410 |
| 411 def ConsumeUint32(self): |
| 412 """Consumes an unsigned 32bit integer number. |
| 413 |
| 414 Returns: |
| 415 The integer parsed. |
| 416 |
| 417 Raises: |
| 418 ParseError: If an unsigned 32bit integer couldn't be consumed. |
| 419 """ |
| 420 try: |
| 421 result = ParseInteger(self.token, is_signed=False, is_long=False) |
| 422 except ValueError, e: |
| 423 raise self._ParseError(str(e)) |
| 424 self.NextToken() |
| 425 return result |
| 426 |
| 427 def ConsumeInt64(self): |
| 428 """Consumes a signed 64bit integer number. |
| 429 |
| 430 Returns: |
| 431 The integer parsed. |
| 432 |
| 433 Raises: |
| 434 ParseError: If a signed 64bit integer couldn't be consumed. |
| 435 """ |
| 436 try: |
| 437 result = ParseInteger(self.token, is_signed=True, is_long=True) |
| 438 except ValueError, e: |
| 439 raise self._ParseError(str(e)) |
| 440 self.NextToken() |
| 441 return result |
| 442 |
| 443 def ConsumeUint64(self): |
| 444 """Consumes an unsigned 64bit integer number. |
| 445 |
| 446 Returns: |
| 447 The integer parsed. |
| 448 |
| 449 Raises: |
| 450 ParseError: If an unsigned 64bit integer couldn't be consumed. |
| 451 """ |
| 452 try: |
| 453 result = ParseInteger(self.token, is_signed=False, is_long=True) |
| 454 except ValueError, e: |
| 455 raise self._ParseError(str(e)) |
| 456 self.NextToken() |
| 457 return result |
| 458 |
| 459 def ConsumeFloat(self): |
| 460 """Consumes an floating point number. |
| 461 |
| 462 Returns: |
| 463 The number parsed. |
| 464 |
| 465 Raises: |
| 466 ParseError: If a floating point number couldn't be consumed. |
| 467 """ |
| 468 try: |
| 469 result = ParseFloat(self.token) |
| 470 except ValueError, e: |
| 471 raise self._ParseError(str(e)) |
| 472 self.NextToken() |
| 473 return result |
| 474 |
| 475 def ConsumeBool(self): |
| 476 """Consumes a boolean value. |
| 477 |
| 478 Returns: |
| 479 The bool parsed. |
| 480 |
| 481 Raises: |
| 482 ParseError: If a boolean value couldn't be consumed. |
| 483 """ |
| 484 try: |
| 485 result = ParseBool(self.token) |
| 486 except ValueError, e: |
| 487 raise self._ParseError(str(e)) |
| 488 self.NextToken() |
| 489 return result |
| 490 |
| 491 def ConsumeString(self): |
| 492 """Consumes a string value. |
| 493 |
| 494 Returns: |
| 495 The string parsed. |
| 496 |
| 497 Raises: |
| 498 ParseError: If a string value couldn't be consumed. |
| 499 """ |
| 500 bytes = self.ConsumeByteString() |
| 501 try: |
| 502 return unicode(bytes, 'utf-8') |
| 503 except UnicodeDecodeError, e: |
| 504 raise self._StringParseError(e) |
| 505 |
| 506 def ConsumeByteString(self): |
| 507 """Consumes a byte array value. |
| 508 |
| 509 Returns: |
| 510 The array parsed (as a string). |
| 511 |
| 512 Raises: |
| 513 ParseError: If a byte array value couldn't be consumed. |
| 514 """ |
| 515 list = [self._ConsumeSingleByteString()] |
| 516 while len(self.token) > 0 and self.token[0] in ('\'', '"'): |
| 517 list.append(self._ConsumeSingleByteString()) |
| 518 return "".join(list) |
| 519 |
| 520 def _ConsumeSingleByteString(self): |
| 521 """Consume one token of a string literal. |
| 522 |
| 523 String literals (whether bytes or text) can come in multiple adjacent |
| 524 tokens which are automatically concatenated, like in C or Python. This |
| 525 method only consumes one token. |
| 526 """ |
| 527 text = self.token |
| 528 if len(text) < 1 or text[0] not in ('\'', '"'): |
| 529 raise self._ParseError('Expected string.') |
| 530 |
| 531 if len(text) < 2 or text[-1] != text[0]: |
| 532 raise self._ParseError('String missing ending quote.') |
| 533 |
| 534 try: |
| 535 result = _CUnescape(text[1:-1]) |
| 536 except ValueError, e: |
| 537 raise self._ParseError(str(e)) |
| 538 self.NextToken() |
| 539 return result |
| 540 |
| 541 def ConsumeEnum(self, field): |
| 542 try: |
| 543 result = ParseEnum(field, self.token) |
| 544 except ValueError, e: |
| 545 raise self._ParseError(str(e)) |
| 546 self.NextToken() |
| 547 return result |
| 548 |
| 549 def ParseErrorPreviousToken(self, message): |
| 550 """Creates and *returns* a ParseError for the previously read token. |
| 551 |
| 552 Args: |
| 553 message: A message to set for the exception. |
| 554 |
| 555 Returns: |
| 556 A ParseError instance. |
| 557 """ |
| 558 return ParseError('%d:%d : %s' % ( |
| 559 self._previous_line + 1, self._previous_column + 1, message)) |
| 560 |
| 561 def _ParseError(self, message): |
| 562 """Creates and *returns* a ParseError for the current token.""" |
| 563 return ParseError('%d:%d : %s' % ( |
| 564 self._line + 1, self._column + 1, message)) |
| 565 |
| 566 def _StringParseError(self, e): |
| 567 return self._ParseError('Couldn\'t parse string: ' + str(e)) |
| 568 |
| 569 def NextToken(self): |
| 570 """Reads the next meaningful token.""" |
| 571 self._previous_line = self._line |
| 572 self._previous_column = self._column |
| 573 |
| 574 self._column += len(self.token) |
| 575 self._SkipWhitespace() |
| 576 |
| 577 if not self._lines and len(self._current_line) <= self._column: |
| 578 self.token = '' |
| 579 return |
| 580 |
| 581 match = self._TOKEN.match(self._current_line, self._column) |
| 582 if match: |
| 583 token = match.group(0) |
| 584 self.token = token |
| 585 else: |
| 586 self.token = self._current_line[self._column] |
| 587 |
| 588 |
| 589 # text.encode('string_escape') does not seem to satisfy our needs as it |
| 590 # encodes unprintable characters using two-digit hex escapes whereas our |
| 591 # C++ unescaping function allows hex escapes to be any length. So, |
| 592 # "\0011".encode('string_escape') ends up being "\\x011", which will be |
| 593 # decoded in C++ as a single-character string with char code 0x11. |
| 594 def _CEscape(text, as_utf8): |
| 595 def escape(c): |
| 596 o = ord(c) |
| 597 if o == 10: return r"\n" # optional escape |
| 598 if o == 13: return r"\r" # optional escape |
| 599 if o == 9: return r"\t" # optional escape |
| 600 if o == 39: return r"\'" # optional escape |
| 601 |
| 602 if o == 34: return r'\"' # necessary escape |
| 603 if o == 92: return r"\\" # necessary escape |
| 604 |
| 605 # necessary escapes |
| 606 if not as_utf8 and (o >= 127 or o < 32): return "\\%03o" % o |
| 607 return c |
| 608 return "".join([escape(c) for c in text]) |
| 609 |
| 610 |
| 611 _CUNESCAPE_HEX = re.compile(r'(\\+)x([0-9a-fA-F])(?![0-9a-fA-F])') |
| 612 |
| 613 |
| 614 def _CUnescape(text): |
| 615 def ReplaceHex(m): |
| 616 # Only replace the match if the number of leading back slashes is odd. i.e. |
| 617 # the slash itself is not escaped. |
| 618 if len(m.group(1)) & 1: |
| 619 return m.group(1) + 'x0' + m.group(2) |
| 620 return m.group(0) |
| 621 |
| 622 # This is required because the 'string_escape' encoding doesn't |
| 623 # allow single-digit hex escapes (like '\xf'). |
| 624 result = _CUNESCAPE_HEX.sub(ReplaceHex, text) |
| 625 return result.decode('string_escape') |
| 626 |
| 627 |
| 628 def ParseInteger(text, is_signed=False, is_long=False): |
| 629 """Parses an integer. |
| 630 |
| 631 Args: |
| 632 text: The text to parse. |
| 633 is_signed: True if a signed integer must be parsed. |
| 634 is_long: True if a long integer must be parsed. |
| 635 |
| 636 Returns: |
| 637 The integer value. |
| 638 |
| 639 Raises: |
| 640 ValueError: Thrown Iff the text is not a valid integer. |
| 641 """ |
| 642 # Do the actual parsing. Exception handling is propagated to caller. |
| 643 try: |
| 644 result = int(text, 0) |
| 645 except ValueError: |
| 646 raise ValueError('Couldn\'t parse integer: %s' % text) |
| 647 |
| 648 # Check if the integer is sane. Exceptions handled by callers. |
| 649 checker = _INTEGER_CHECKERS[2 * int(is_long) + int(is_signed)] |
| 650 checker.CheckValue(result) |
| 651 return result |
| 652 |
| 653 |
| 654 def ParseFloat(text): |
| 655 """Parse a floating point number. |
| 656 |
| 657 Args: |
| 658 text: Text to parse. |
| 659 |
| 660 Returns: |
| 661 The number parsed. |
| 662 |
| 663 Raises: |
| 664 ValueError: If a floating point number couldn't be parsed. |
| 665 """ |
| 666 try: |
| 667 # Assume Python compatible syntax. |
| 668 return float(text) |
| 669 except ValueError: |
| 670 # Check alternative spellings. |
| 671 if _FLOAT_INFINITY.match(text): |
| 672 if text[0] == '-': |
| 673 return float('-inf') |
| 674 else: |
| 675 return float('inf') |
| 676 elif _FLOAT_NAN.match(text): |
| 677 return float('nan') |
| 678 else: |
| 679 # assume '1.0f' format |
| 680 try: |
| 681 return float(text.rstrip('f')) |
| 682 except ValueError: |
| 683 raise ValueError('Couldn\'t parse float: %s' % text) |
| 684 |
| 685 |
| 686 def ParseBool(text): |
| 687 """Parse a boolean value. |
| 688 |
| 689 Args: |
| 690 text: Text to parse. |
| 691 |
| 692 Returns: |
| 693 Boolean values parsed |
| 694 |
| 695 Raises: |
| 696 ValueError: If text is not a valid boolean. |
| 697 """ |
| 698 if text in ('true', 't', '1'): |
| 699 return True |
| 700 elif text in ('false', 'f', '0'): |
| 701 return False |
| 702 else: |
| 703 raise ValueError('Expected "true" or "false".') |
| 704 |
| 705 |
| 706 def ParseEnum(field, value): |
| 707 """Parse an enum value. |
| 708 |
| 709 The value can be specified by a number (the enum value), or by |
| 710 a string literal (the enum name). |
| 711 |
| 712 Args: |
| 713 field: Enum field descriptor. |
| 714 value: String value. |
| 715 |
| 716 Returns: |
| 717 Enum value number. |
| 718 |
| 719 Raises: |
| 720 ValueError: If the enum value could not be parsed. |
| 721 """ |
| 722 enum_descriptor = field.enum_type |
| 723 try: |
| 724 number = int(value, 0) |
| 725 except ValueError: |
| 726 # Identifier. |
| 727 enum_value = enum_descriptor.values_by_name.get(value, None) |
| 728 if enum_value is None: |
| 729 raise ValueError( |
| 730 'Enum type "%s" has no value named %s.' % ( |
| 731 enum_descriptor.full_name, value)) |
| 732 else: |
| 733 # Numeric value. |
| 734 enum_value = enum_descriptor.values_by_number.get(number, None) |
| 735 if enum_value is None: |
| 736 raise ValueError( |
| 737 'Enum type "%s" has no value with number %d.' % ( |
| 738 enum_descriptor.full_name, number)) |
| 739 return enum_value.number |
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