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+# Protocol Buffers - Google's data interchange format
+# Copyright 2008 Google Inc. All rights reserved.
+# http://code.google.com/p/protobuf/
+#
+# 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__ = 'matthewtoia@google.com (Matt Toia)'
+
+
+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:
+ DescriptorDatabaseException: if an attempt is made to add a proto
+ with the same name but different definition than an exisiting
+ 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)
+
+ package = file_desc_proto.package
+ for message in file_desc_proto.message_type:
+ self._file_desc_protos_by_symbol.update(
+ (name, file_desc_proto) for name in _ExtractSymbols(message, package))
+ for enum in file_desc_proto.enum_type:
+ self._file_desc_protos_by_symbol[
+ '.'.join((package, enum.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'
+
+ 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.
+ """
+
+ return self._file_desc_protos_by_symbol[symbol]
+
+
+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 = '.'.join((package, 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))