File size: 6,996 Bytes
375a1cf
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
# Protocol Buffers - Google's data interchange format
# Copyright 2008 Google Inc.  All rights reserved.
# https://developers.google.com/protocol-buffers/
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
#     * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#     * Redistributions in binary form must reproduce the above
# copyright notice, this list of conditions and the following disclaimer
# in the documentation and/or other materials provided with the
# distribution.
#     * Neither the name of Google Inc. nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

"""Provides a container for DescriptorProtos."""

__author__ = '[email protected] (Matt Toia)'

import warnings


class Error(Exception):
  pass


class DescriptorDatabaseConflictingDefinitionError(Error):
  """Raised when a proto is added with the same name & different descriptor."""


class DescriptorDatabase(object):
  """A container accepting FileDescriptorProtos and maps DescriptorProtos."""

  def __init__(self):
    self._file_desc_protos_by_file = {}
    self._file_desc_protos_by_symbol = {}

  def Add(self, file_desc_proto):
    """Adds the FileDescriptorProto and its types to this database.



    Args:

      file_desc_proto: The FileDescriptorProto to add.

    Raises:

      DescriptorDatabaseConflictingDefinitionError: if an attempt is made to

        add a proto with the same name but different definition than an

        existing proto in the database.

    """
    proto_name = file_desc_proto.name
    if proto_name not in self._file_desc_protos_by_file:
      self._file_desc_protos_by_file[proto_name] = file_desc_proto
    elif self._file_desc_protos_by_file[proto_name] != file_desc_proto:
      raise DescriptorDatabaseConflictingDefinitionError(
          '%s already added, but with different descriptor.' % proto_name)
    else:
      return

    # Add all the top-level descriptors to the index.
    package = file_desc_proto.package
    for message in file_desc_proto.message_type:
      for name in _ExtractSymbols(message, package):
        self._AddSymbol(name, file_desc_proto)
    for enum in file_desc_proto.enum_type:
      self._AddSymbol(('.'.join((package, enum.name))), file_desc_proto)
      for enum_value in enum.value:
        self._file_desc_protos_by_symbol[
            '.'.join((package, enum_value.name))] = file_desc_proto
    for extension in file_desc_proto.extension:
      self._AddSymbol(('.'.join((package, extension.name))), file_desc_proto)
    for service in file_desc_proto.service:
      self._AddSymbol(('.'.join((package, service.name))), file_desc_proto)

  def FindFileByName(self, name):
    """Finds the file descriptor proto by file name.



    Typically the file name is a relative path ending to a .proto file. The

    proto with the given name will have to have been added to this database

    using the Add method or else an error will be raised.



    Args:

      name: The file name to find.



    Returns:

      The file descriptor proto matching the name.



    Raises:

      KeyError if no file by the given name was added.

    """

    return self._file_desc_protos_by_file[name]

  def FindFileContainingSymbol(self, symbol):
    """Finds the file descriptor proto containing the specified symbol.



    The symbol should be a fully qualified name including the file descriptor's

    package and any containing messages. Some examples:



    'some.package.name.Message'

    'some.package.name.Message.NestedEnum'

    'some.package.name.Message.some_field'



    The file descriptor proto containing the specified symbol must be added to

    this database using the Add method or else an error will be raised.



    Args:

      symbol: The fully qualified symbol name.



    Returns:

      The file descriptor proto containing the symbol.



    Raises:

      KeyError if no file contains the specified symbol.

    """
    try:
      return self._file_desc_protos_by_symbol[symbol]
    except KeyError:
      # Fields, enum values, and nested extensions are not in
      # _file_desc_protos_by_symbol. Try to find the top level
      # descriptor. Non-existent nested symbol under a valid top level
      # descriptor can also be found. The behavior is the same with
      # protobuf C++.
      top_level, _, _ = symbol.rpartition('.')
      try:
        return self._file_desc_protos_by_symbol[top_level]
      except KeyError:
        # Raise the original symbol as a KeyError for better diagnostics.
        raise KeyError(symbol)

  def FindFileContainingExtension(self, extendee_name, extension_number):
    # TODO(jieluo): implement this API.
    return None

  def FindAllExtensionNumbers(self, extendee_name):
    # TODO(jieluo): implement this API.
    return []

  def _AddSymbol(self, name, file_desc_proto):
    if name in self._file_desc_protos_by_symbol:
      warn_msg = ('Conflict register for file "' + file_desc_proto.name +
                  '": ' + name +
                  ' is already defined in file "' +
                  self._file_desc_protos_by_symbol[name].name + '"')
      warnings.warn(warn_msg, RuntimeWarning)
    self._file_desc_protos_by_symbol[name] = file_desc_proto


def _ExtractSymbols(desc_proto, package):
  """Pulls out all the symbols from a descriptor proto.



  Args:

    desc_proto: The proto to extract symbols from.

    package: The package containing the descriptor type.



  Yields:

    The fully qualified name found in the descriptor.

  """
  message_name = package + '.' + desc_proto.name if package else desc_proto.name
  yield message_name
  for nested_type in desc_proto.nested_type:
    for symbol in _ExtractSymbols(nested_type, message_name):
      yield symbol
  for enum_type in desc_proto.enum_type:
    yield '.'.join((message_name, enum_type.name))