Elep

# Protocol Buffers - Google's data interchange format
# Copyright 2008 Google Inc.  All rights reserved.
# http://code.google.com/p/protobuf/
#
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# modification, are permitted provided that the following conditions are
# met:
#
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# notice, this list of conditions and the following disclaimer.
#     * Redistributions in binary form must reproduce the above
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# in the documentation and/or other materials provided with the
# distribution.
#     * Neither the name of Google Inc. nor the names of its
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"""Contains routines for printing protocol messages in text format."""

__author__ = 'kenton@google.com (Kenton Varda)'

import cStringIO
import re

from collections import deque
from google.protobuf.internal import type_checkers
from google.protobuf import descriptor

__all__ = [ 'MessageToString', 'PrintMessage', 'PrintField',
            'PrintFieldValue', 'Merge' ]

_INTEGER_CHECKERS = (type_checkers.Uint32ValueChecker(),
                     type_checkers.Int32ValueChecker(),
                     type_checkers.Uint64ValueChecker(),
                     type_checkers.Int64ValueChecker())
_FLOAT_INFINITY = re.compile('-?inf(?:inity)?f?', re.IGNORECASE)
_FLOAT_NAN = re.compile('nanf?', re.IGNORECASE)

class ParseError(Exception):
  """Thrown in case of ASCII parsing error."""

def MessageToString(message, as_utf8=False, as_one_line=False):
  out = cStringIO.StringIO()
  PrintMessage(message, out, as_utf8=as_utf8, as_one_line=as_one_line)
  result = out.getvalue()
  out.close()
  if as_one_line:
    return result.rstrip()
  return result

def PrintMessage(message, out, indent=0, as_utf8=False, as_one_line=False):
  for field, value in message.ListFields():
    if field.label == descriptor.FieldDescriptor.LABEL_REPEATED:
      for element in value:
        PrintField(field, element, out, indent, as_utf8, as_one_line)
    else:
      PrintField(field, value, out, indent, as_utf8, as_one_line)

def PrintField(field, value, out, indent=0, as_utf8=False, as_one_line=False):
  """Print a single field name/value pair.  For repeated fields, the value
  should be a single element."""

out.write(' ' * indent);
  if field.is_extension:
    out.write('[')
    if (field.containing_type.GetOptions().message_set_wire_format and
        field.type == descriptor.FieldDescriptor.TYPE_MESSAGE and
        field.message_type == field.extension_scope and
        field.label == descriptor.FieldDescriptor.LABEL_OPTIONAL):
      out.write(field.message_type.full_name)
    else:
      out.write(field.full_name)
    out.write(']')
  elif field.type == descriptor.FieldDescriptor.TYPE_GROUP:
    # For groups, use the capitalized name.
    out.write(field.message_type.name)
  else:
    out.write(field.name)

if field.cpp_type != descriptor.FieldDescriptor.CPPTYPE_MESSAGE:
    # The colon is optional in this case, but our cross-language golden files
    # don't include it.
    out.write(': ')

PrintFieldValue(field, value, out, indent, as_utf8, as_one_line)
  if as_one_line:
    out.write(' ')
  else:
    out.write('\n')

def PrintFieldValue(field, value, out, indent=0,
                    as_utf8=False, as_one_line=False):
  """Print a single field value (not including name).  For repeated fields,
  the value should be a single element."""

if field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_MESSAGE:
    if as_one_line:
      out.write(' { ')
      PrintMessage(value, out, indent, as_utf8, as_one_line)
      out.write('}')
    else:
      out.write(' {\n')
      PrintMessage(value, out, indent + 2, as_utf8, as_one_line)
      out.write(' ' * indent + '}')
  elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_ENUM:
    enum_value = field.enum_type.values_by_number.get(value, None)
    if enum_value is not None:
      out.write(enum_value.name)
    else:
      out.write(str(value))
  elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_STRING:
    out.write('\"')
    if type(value) is unicode:
      out.write(_CEscape(value.encode('utf-8'), as_utf8))
    else:
      out.write(_CEscape(value, as_utf8))
    out.write('\"')
  elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_BOOL:
    if value:
      out.write("true")
    else:
      out.write("false")
  else:
    out.write(str(value))

def Merge(text, message):
  """Merges an ASCII representation of a protocol message into a message.

Args:
    text: Message ASCII representation.
    message: A protocol buffer message to merge into.

Raises:
    ParseError: On ASCII parsing problems.
  """
  tokenizer = _Tokenizer(text)
  while not tokenizer.AtEnd():
    _MergeField(tokenizer, message)

def _MergeField(tokenizer, message):
  """Merges a single protocol message field into a message.

Args:
    tokenizer: A tokenizer to parse the field name and values.
    message: A protocol message to record the data.

Raises:
    ParseError: In case of ASCII parsing problems.
  """
  message_descriptor = message.DESCRIPTOR
  if tokenizer.TryConsume('['):
    name = [tokenizer.ConsumeIdentifier()]
    while tokenizer.TryConsume('.'):
      name.append(tokenizer.ConsumeIdentifier())
    name = '.'.join(name)

if not message_descriptor.is_extendable:
      raise tokenizer.ParseErrorPreviousToken(
          'Message type "%s" does not have extensions.' %
          message_descriptor.full_name)
    field = message.Extensions._FindExtensionByName(name)
    if not field:
      raise tokenizer.ParseErrorPreviousToken(
          'Extension "%s" not registered.' % name)
    elif message_descriptor != field.containing_type:
      raise tokenizer.ParseErrorPreviousToken(
          'Extension "%s" does not extend message type "%s".' % (
              name, message_descriptor.full_name))
    tokenizer.Consume(']')
  else:
    name = tokenizer.ConsumeIdentifier()
    field = message_descriptor.fields_by_name.get(name, None)

# Group names are expected to be capitalized as they appear in the
    # .proto file, which actually matches their type names, not their field
    # names.
    if not field:
      field = message_descriptor.fields_by_name.get(name.lower(), None)
      if field and field.type != descriptor.FieldDescriptor.TYPE_GROUP:
        field = None

if (field and field.type == descriptor.FieldDescriptor.TYPE_GROUP and
        field.message_type.name != name):
      field = None

if not field:
      raise tokenizer.ParseErrorPreviousToken(
          'Message type "%s" has no field named "%s".' % (
              message_descriptor.full_name, name))

if field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_MESSAGE:
    tokenizer.TryConsume(':')

if tokenizer.TryConsume('<'):
      end_token = '>'
    else:
      tokenizer.Consume('{')
      end_token = '}'

if field.label == descriptor.FieldDescriptor.LABEL_REPEATED:
      if field.is_extension:
        sub_message = message.Extensions[field].add()
      else:
        sub_message = getattr(message, field.name).add()
    else:
      if field.is_extension:
        sub_message = message.Extensions[field]
      else:
        sub_message = getattr(message, field.name)
      sub_message.SetInParent()

while not tokenizer.TryConsume(end_token):
      if tokenizer.AtEnd():
        raise tokenizer.ParseErrorPreviousToken('Expected "%s".' % (end_token))
      _MergeField(tokenizer, sub_message)
  else:
    _MergeScalarField(tokenizer, message, field)

def _MergeScalarField(tokenizer, message, field):
  """Merges a single protocol message scalar field into a message.

Args:
    tokenizer: A tokenizer to parse the field value.
    message: A protocol message to record the data.
    field: The descriptor of the field to be merged.

Raises:
    ParseError: In case of ASCII parsing problems.
    RuntimeError: On runtime errors.
  """
  tokenizer.Consume(':')
  value = None

if field.type in (descriptor.FieldDescriptor.TYPE_INT32,
                    descriptor.FieldDescriptor.TYPE_SINT32,
                    descriptor.FieldDescriptor.TYPE_SFIXED32):
    value = tokenizer.ConsumeInt32()
  elif field.type in (descriptor.FieldDescriptor.TYPE_INT64,
                      descriptor.FieldDescriptor.TYPE_SINT64,
                      descriptor.FieldDescriptor.TYPE_SFIXED64):
    value = tokenizer.ConsumeInt64()
  elif field.type in (descriptor.FieldDescriptor.TYPE_UINT32,
                      descriptor.FieldDescriptor.TYPE_FIXED32):
    value = tokenizer.ConsumeUint32()
  elif field.type in (descriptor.FieldDescriptor.TYPE_UINT64,
                      descriptor.FieldDescriptor.TYPE_FIXED64):
    value = tokenizer.ConsumeUint64()
  elif field.type in (descriptor.FieldDescriptor.TYPE_FLOAT,
                      descriptor.FieldDescriptor.TYPE_DOUBLE):
    value = tokenizer.ConsumeFloat()
  elif field.type == descriptor.FieldDescriptor.TYPE_BOOL:
    value = tokenizer.ConsumeBool()
  elif field.type == descriptor.FieldDescriptor.TYPE_STRING:
    value = tokenizer.ConsumeString()
  elif field.type == descriptor.FieldDescriptor.TYPE_BYTES:
    value = tokenizer.ConsumeByteString()
  elif field.type == descriptor.FieldDescriptor.TYPE_ENUM:
    value = tokenizer.ConsumeEnum(field)
  else:
    raise RuntimeError('Unknown field type %d' % field.type)

if field.label == descriptor.FieldDescriptor.LABEL_REPEATED:
    if field.is_extension:
      message.Extensions[field].append(value)
    else:
      getattr(message, field.name).append(value)
  else:
    if field.is_extension:
      message.Extensions[field] = value
    else:
      setattr(message, field.name, value)

class _Tokenizer(object):
  """Protocol buffer ASCII representation tokenizer.

This class handles the lower level string parsing by splitting it into
  meaningful tokens.

It was directly ported from the Java protocol buffer API.
  """

def __init__(self, text_message):
    self._text_message = text_message

self._position = 0
    self._line = -1
    self._column = 0
    self._token_start = None
    self.token = ''
    self._lines = deque(text_message.split('\n'))
    self._current_line = ''
    self._previous_line = 0
    self._previous_column = 0
    self._SkipWhitespace()
    self.NextToken()

def AtEnd(self):
    """Checks the end of the text was reached.

Returns:
      True iff the end was reached.
    """
    return self.token == ''

def _PopLine(self):
    while len(self._current_line) <= self._column:
      if not self._lines:
        self._current_line = ''
        return
      self._line += 1
      self._column = 0
      self._current_line = self._lines.popleft()

def _SkipWhitespace(self):
    while True:
      self._PopLine()
      match = self._WHITESPACE.match(self._current_line, self._column)
      if not match:
        break
      length = len(match.group(0))
      self._column += length

def TryConsume(self, token):
    """Tries to consume a given piece of text.

Args:
      token: Text to consume.

Returns:
      True iff the text was consumed.
    """
    if self.token == token:
      self.NextToken()
      return True
    return False

def Consume(self, token):
    """Consumes a piece of text.

Args:
      token: Text to consume.

Raises:
      ParseError: If the text couldn't be consumed.
    """
    if not self.TryConsume(token):
      raise self._ParseError('Expected "%s".' % token)

def ConsumeIdentifier(self):
    """Consumes protocol message field identifier.

Returns:
      Identifier string.

Raises:
      ParseError: If an identifier couldn't be consumed.
    """
    result = self.token
    if not self._IDENTIFIER.match(result):
      raise self._ParseError('Expected identifier.')
    self.NextToken()
    return result

def ConsumeInt32(self):
    """Consumes a signed 32bit integer number.

Returns:
      The integer parsed.

Raises:
      ParseError: If a signed 32bit integer couldn't be consumed.
    """
    try:
      result = ParseInteger(self.token, is_signed=True, is_long=False)
    except ValueError, e:
      raise self._ParseError(str(e))
    self.NextToken()
    return result

def ConsumeUint32(self):
    """Consumes an unsigned 32bit integer number.

Returns:
      The integer parsed.

Raises:
      ParseError: If an unsigned 32bit integer couldn't be consumed.
    """
    try:
      result = ParseInteger(self.token, is_signed=False, is_long=False)
    except ValueError, e:
      raise self._ParseError(str(e))
    self.NextToken()
    return result

def ConsumeInt64(self):
    """Consumes a signed 64bit integer number.

Returns:
      The integer parsed.

Raises:
      ParseError: If a signed 64bit integer couldn't be consumed.
    """
    try:
      result = ParseInteger(self.token, is_signed=True, is_long=True)
    except ValueError, e:
      raise self._ParseError(str(e))
    self.NextToken()
    return result

def ConsumeUint64(self):
    """Consumes an unsigned 64bit integer number.

Returns:
      The integer parsed.

Raises:
      ParseError: If an unsigned 64bit integer couldn't be consumed.
    """
    try:
      result = ParseInteger(self.token, is_signed=False, is_long=True)
    except ValueError, e:
      raise self._ParseError(str(e))
    self.NextToken()
    return result

def ConsumeFloat(self):
    """Consumes an floating point number.

Returns:
      The number parsed.

Raises:
      ParseError: If a floating point number couldn't be consumed.
    """
    try:
      result = ParseFloat(self.token)
    except ValueError, e:
      raise self._ParseError(str(e))
    self.NextToken()
    return result

def ConsumeBool(self):
    """Consumes a boolean value.

Returns:
      The bool parsed.

Raises:
      ParseError: If a boolean value couldn't be consumed.
    """
    try:
      result = ParseBool(self.token)
    except ValueError, e:
      raise self._ParseError(str(e))
    self.NextToken()
    return result

def ConsumeString(self):
    """Consumes a string value.

Returns:
      The string parsed.

Raises:
      ParseError: If a string value couldn't be consumed.
    """
    bytes = self.ConsumeByteString()
    try:
      return unicode(bytes, 'utf-8')
    except UnicodeDecodeError, e:
      raise self._StringParseError(e)

def ConsumeByteString(self):
    """Consumes a byte array value.

Returns:
      The array parsed (as a string).

Raises:
      ParseError: If a byte array value couldn't be consumed.
    """
    list = [self._ConsumeSingleByteString()]
    while len(self.token) > 0 and self.token[0] in ('\'', '"'):
      list.append(self._ConsumeSingleByteString())
    return "".join(list)

def _ConsumeSingleByteString(self):
    """Consume one token of a string literal.

String literals (whether bytes or text) can come in multiple adjacent
    tokens which are automatically concatenated, like in C or Python.  This
    method only consumes one token.
    """
    text = self.token
    if len(text) < 1 or text[0] not in ('\'', '"'):
      raise self._ParseError('Expected string.')

if len(text) < 2 or text[-1] != text[0]:
      raise self._ParseError('String missing ending quote.')

try:
      result = _CUnescape(text[1:-1])
    except ValueError, e:
      raise self._ParseError(str(e))
    self.NextToken()
    return result

def ConsumeEnum(self, field):
    try:
      result = ParseEnum(field, self.token)
    except ValueError, e:
      raise self._ParseError(str(e))
    self.NextToken()
    return result

def ParseErrorPreviousToken(self, message):
    """Creates and *returns* a ParseError for the previously read token.

Args:
      message: A message to set for the exception.

Returns:
      A ParseError instance.
    """
    return ParseError('%d:%d : %s' % (
        self._previous_line + 1, self._previous_column + 1, message))

def _ParseError(self, message):
    """Creates and *returns* a ParseError for the current token."""
    return ParseError('%d:%d : %s' % (
        self._line + 1, self._column + 1, message))

def _StringParseError(self, e):
    return self._ParseError('Couldn\'t parse string: ' + str(e))

def NextToken(self):
    """Reads the next meaningful token."""
    self._previous_line = self._line
    self._previous_column = self._column

self._column += len(self.token)
    self._SkipWhitespace()

if not self._lines and len(self._current_line) <= self._column:
      self.token = ''
      return

match = self._TOKEN.match(self._current_line, self._column)
    if match:
      token = match.group(0)
      self.token = token
    else:
      self.token = self._current_line[self._column]

# text.encode('string_escape') does not seem to satisfy our needs as it
# encodes unprintable characters using two-digit hex escapes whereas our
# C++ unescaping function allows hex escapes to be any length.  So,
# "\0011".encode('string_escape') ends up being "\\x011", which will be
# decoded in C++ as a single-character string with char code 0x11.
def _CEscape(text, as_utf8):
  def escape(c):
    o = ord(c)
    if o == 10: return r"\n"   # optional escape
    if o == 13: return r"\r"   # optional escape
    if o ==  9: return r"\t"   # optional escape
    if o == 39: return r"\'"   # optional escape

if o == 34: return r'\"'   # necessary escape
    if o == 92: return r"\\"   # necessary escape

# necessary escapes
    if not as_utf8 and (o >= 127 or o < 32): return "\\%03o" % o
    return c
  return "".join([escape(c) for c in text])

_CUNESCAPE_HEX = re.compile(r'(\\+)x([0-9a-fA-F])(?![0-9a-fA-F])')

def _CUnescape(text):
  def ReplaceHex(m):
    # Only replace the match if the number of leading back slashes is odd. i.e.
    # the slash itself is not escaped.
    if len(m.group(1)) & 1:
      return m.group(1) + 'x0' + m.group(2)
    return m.group(0)

# This is required because the 'string_escape' encoding doesn't
  # allow single-digit hex escapes (like '\xf').
  result = _CUNESCAPE_HEX.sub(ReplaceHex, text)
  return result.decode('string_escape')

def ParseInteger(text, is_signed=False, is_long=False):
  """Parses an integer.

Args:
    text: The text to parse.
    is_signed: True if a signed integer must be parsed.
    is_long: True if a long integer must be parsed.

Returns:
    The integer value.

Raises:
    ValueError: Thrown Iff the text is not a valid integer.
  """
  # Do the actual parsing. Exception handling is propagated to caller.
  try:
    result = int(text, 0)
  except ValueError:
    raise ValueError('Couldn\'t parse integer: %s' % text)

# Check if the integer is sane. Exceptions handled by callers.
  checker = _INTEGER_CHECKERS[2 * int(is_long) + int(is_signed)]
  checker.CheckValue(result)
  return result

def ParseFloat(text):
  """Parse a floating point number.

Args:
    text: Text to parse.

Returns:
    The number parsed.

Raises:
    ValueError: If a floating point number couldn't be parsed.
  """
  try:
    # Assume Python compatible syntax.
    return float(text)
  except ValueError:
    # Check alternative spellings.
    if _FLOAT_INFINITY.match(text):
      if text[0] == '-':
        return float('-inf')
      else:
        return float('inf')
    elif _FLOAT_NAN.match(text):
      return float('nan')
    else:
      # assume '1.0f' format
      try:
        return float(text.rstrip('f'))
      except ValueError:
        raise ValueError('Couldn\'t parse float: %s' % text)

def ParseBool(text):
  """Parse a boolean value.

Args:
    text: Text to parse.

Returns:
    Boolean values parsed

Raises:
    ValueError: If text is not a valid boolean.
  """
  if text in ('true', 't', '1'):
    return True
  elif text in ('false', 'f', '0'):
    return False
  else:
    raise ValueError('Expected "true" or "false".')

def ParseEnum(field, value):
  """Parse an enum value.

The value can be specified by a number (the enum value), or by
  a string literal (the enum name).

Args:
    field: Enum field descriptor.
    value: String value.

Returns:
    Enum value number.

Raises:
    ValueError: If the enum value could not be parsed.
  """
  enum_descriptor = field.enum_type
  try:
    number = int(value, 0)
  except ValueError:
    # Identifier.
    enum_value = enum_descriptor.values_by_name.get(value, None)
    if enum_value is None:
      raise ValueError(
          'Enum type "%s" has no value named %s.' % (
              enum_descriptor.full_name, value))
  else:
    # Numeric value.
    enum_value = enum_descriptor.values_by_number.get(number, None)
    if enum_value is None:
      raise ValueError(
          'Enum type "%s" has no value with number %d.' % (
              enum_descriptor.full_name, number))
  return enum_value.number