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# Protocol Buffers - Google's data interchange format
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# Copyright 2008 Google Inc. All rights reserved.
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# http://code.google.com/p/protobuf/
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# Redistribution and use in source and binary forms, with or without
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# modification, are permitted provided that the following conditions are
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# * Redistributions of source code must retain the above copyright
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# notice, this list of conditions and the following disclaimer.
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# * Redistributions in binary form must reproduce the above
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# copyright notice, this list of conditions and the following disclaimer
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# in the documentation and/or other materials provided with the
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# * Neither the name of Google Inc. nor the names of its
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# contributors may be used to endorse or promote products derived from
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# this software without specific prior written permission.
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# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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"""A database of Python protocol buffer generated symbols.
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SymbolDatabase makes it easy to create new instances of a registered type, given
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only the type's protocol buffer symbol name. Once all symbols are registered,
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they can be accessed using either the MessageFactory interface which
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SymbolDatabase exposes, or the DescriptorPool interface of the underlying
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db = symbol_database.SymbolDatabase()
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# Register symbols of interest, from one or multiple files.
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db.RegisterFileDescriptor(my_proto_pb2.DESCRIPTOR)
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db.RegisterMessage(my_proto_pb2.MyMessage)
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db.RegisterEnumDescriptor(my_proto_pb2.MyEnum.DESCRIPTOR)
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# The database can be used as a MessageFactory, to generate types based on
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types = db.GetMessages(['my_proto.proto'])
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my_message_instance = types['MyMessage']()
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# The database's underlying descriptor pool can be queried, so it's not
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# necessary to know a type's filename to be able to generate it:
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filename = db.pool.FindFileContainingSymbol('MyMessage')
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my_message_instance = db.GetMessages([filename])['MyMessage']()
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# This functionality is also provided directly via a convenience method:
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my_message_instance = db.GetSymbol('MyMessage')()
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from google.protobuf import descriptor_pool
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class SymbolDatabase(object):
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"""A database of Python generated symbols.
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SymbolDatabase also models message_factory.MessageFactory.
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The symbol database can be used to keep a global registry of all protocol
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buffer types used within a program.
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self._symbols_by_file = {}
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self.pool = descriptor_pool.DescriptorPool()
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def RegisterMessage(self, message):
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"""Registers the given message type in the local database.
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message: a message.Message, to be registered.
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desc = message.DESCRIPTOR
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self._symbols[desc.full_name] = message
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if desc.file.name not in self._symbols_by_file:
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self._symbols_by_file[desc.file.name] = {}
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self._symbols_by_file[desc.file.name][desc.full_name] = message
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self.pool.AddDescriptor(desc)
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def RegisterEnumDescriptor(self, enum_descriptor):
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"""Registers the given enum descriptor in the local database.
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enum_descriptor: a descriptor.EnumDescriptor.
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The provided descriptor.
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self.pool.AddEnumDescriptor(enum_descriptor)
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return enum_descriptor
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def RegisterFileDescriptor(self, file_descriptor):
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"""Registers the given file descriptor in the local database.
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file_descriptor: a descriptor.FileDescriptor.
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The provided descriptor.
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self.pool.AddFileDescriptor(file_descriptor)
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def GetSymbol(self, symbol):
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"""Tries to find a symbol in the local database.
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Currently, this method only returns message.Message instances, however, if
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may be extended in future to support other symbol types.
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symbol: A str, a protocol buffer symbol.
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A Python class corresponding to the symbol.
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KeyError: if the symbol could not be found.
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return self._symbols[symbol]
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def GetPrototype(self, descriptor):
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"""Builds a proto2 message class based on the passed in descriptor.
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Passing a descriptor with a fully qualified name matching a previous
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invocation will cause the same class to be returned.
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descriptor: The descriptor to build from.
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A class describing the passed in descriptor.
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return self.GetSymbol(descriptor.full_name)
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def GetMessages(self, files):
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"""Gets all the messages from a specified file.
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This will find and resolve dependencies, failing if they are not registered
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in the symbol database.
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files: The file names to extract messages from.
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A dictionary mapping proto names to the message classes. This will include
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any dependent messages as well as any messages defined in the same file as
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KeyError: if a file could not be found.
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result.update(self._symbols_by_file[f])
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_DEFAULT = SymbolDatabase()
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"""Returns the default SymbolDatabase."""
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removed
python/google/protobuf/symbol_database.py
