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google.protobuf.symbol_database¶
A database of Python protocol buffer generated symbols.
SymbolDatabase is the MessageFactory for messages generated at compile time, and makes it easy to create new instances of a registered type, given only the type’s protocol buffer symbol name.
Example usage:
db = symbol_database.SymbolDatabase()
# Register symbols of interest, from one or multiple files.
db.RegisterFileDescriptor(my_proto_pb2.DESCRIPTOR)
db.RegisterMessage(my_proto_pb2.MyMessage)
db.RegisterEnumDescriptor(my_proto_pb2.MyEnum.DESCRIPTOR)
# The database can be used as a MessageFactory, to generate types based on
# their name:
types = db.GetMessages(['my_proto.proto'])
my_message_instance = types['MyMessage']()
# The database's underlying descriptor pool can be queried, so it's not
# necessary to know a type's filename to be able to generate it:
filename = db.pool.FindFileContainingSymbol('MyMessage')
my_message_instance = db.GetMessages([filename])['MyMessage']()
# This functionality is also provided directly via a convenience method:
my_message_instance = db.GetSymbol('MyMessage')()
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google.protobuf.symbol_database.
Default
()¶ Returns the default SymbolDatabase.
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class
google.protobuf.symbol_database.
SymbolDatabase
(pool=None)¶ A database of Python generated symbols.
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GetMessages
(files)¶ Gets all registered messages from a specified file.
Only messages already created and registered will be returned; (this is the case for imported _pb2 modules) But unlike MessageFactory, this version also returns already defined nested messages, but does not register any message extensions.
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GetPrototype
(descriptor)¶ Builds a proto2 message class based on the passed in descriptor.
Passing a descriptor with a fully qualified name matching a previous invocation will cause the same class to be returned.
- Parameters
descriptor – The descriptor to build from.
- Returns
A class describing the passed in descriptor.
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GetSymbol
(symbol)¶ Tries to find a symbol in the local database.
Currently, this method only returns message.Message instances, however, if may be extended in future to support other symbol types.
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RegisterEnumDescriptor
(enum_descriptor)¶ Registers the given enum descriptor in the local database.
- Parameters
enum_descriptor (EnumDescriptor) – The enum descriptor to register.
- Returns
The provided descriptor.
- Return type
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RegisterFileDescriptor
(file_descriptor)¶ Registers the given file descriptor in the local database.
- Parameters
file_descriptor (FileDescriptor) – The file descriptor to register.
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RegisterMessage
(message)¶ Registers the given message type in the local database.
Calls to GetSymbol() and GetMessages() will return messages registered here.
- Parameters
message – A
google.protobuf.message.Message
subclass (or instance); its descriptor will be registered.- Returns
The provided message.
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RegisterMessageDescriptor
(message_descriptor)¶ Registers the given message descriptor in the local database.
- Parameters
message_descriptor (Descriptor) – the message descriptor to add.
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RegisterServiceDescriptor
(service_descriptor)¶ Registers the given service descriptor in the local database.
- Parameters
service_descriptor (ServiceDescriptor) – the service descriptor to register.
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