| # 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 DescriptorPool to use as a container for proto2 descriptors. |
| |
| The DescriptorPool is used in conjection with a DescriptorDatabase to maintain |
| a collection of protocol buffer descriptors for use when dynamically creating |
| message types at runtime. |
| |
| For most applications protocol buffers should be used via modules generated by |
| the protocol buffer compiler tool. This should only be used when the type of |
| protocol buffers used in an application or library cannot be predetermined. |
| |
| Below is a straightforward example on how to use this class: |
| |
| pool = DescriptorPool() |
| file_descriptor_protos = [ ... ] |
| for file_descriptor_proto in file_descriptor_protos: |
| pool.Add(file_descriptor_proto) |
| my_message_descriptor = pool.FindMessageTypeByName('some.package.MessageType') |
| |
| The message descriptor can be used in conjunction with the message_factory |
| module in order to create a protocol buffer class that can be encoded and |
| decoded. |
| """ |
| |
| __author__ = 'matthewtoia@google.com (Matt Toia)' |
| |
| from google.protobuf import descriptor_pb2 |
| from google.protobuf import descriptor |
| from google.protobuf import descriptor_database |
| |
| |
| class DescriptorPool(object): |
| """A collection of protobufs dynamically constructed by descriptor protos.""" |
| |
| def __init__(self, descriptor_db=None): |
| """Initializes a Pool of proto buffs. |
| |
| The descriptor_db argument to the constructor is provided to allow |
| specialized file descriptor proto lookup code to be triggered on demand. An |
| example would be an implementation which will read and compile a file |
| specified in a call to FindFileByName() and not require the call to Add() |
| at all. Results from this database will be cached internally here as well. |
| |
| Args: |
| descriptor_db: A secondary source of file descriptors. |
| """ |
| |
| self._internal_db = descriptor_database.DescriptorDatabase() |
| self._descriptor_db = descriptor_db |
| self._descriptors = {} |
| self._enum_descriptors = {} |
| self._file_descriptors = {} |
| |
| def Add(self, file_desc_proto): |
| """Adds the FileDescriptorProto and its types to this pool. |
| |
| Args: |
| file_desc_proto: The FileDescriptorProto to add. |
| """ |
| |
| self._internal_db.Add(file_desc_proto) |
| |
| def FindFileByName(self, file_name): |
| """Gets a FileDescriptor by file name. |
| |
| Args: |
| file_name: The path to the file to get a descriptor for. |
| |
| Returns: |
| A FileDescriptor for the named file. |
| |
| Raises: |
| KeyError: if the file can not be found in the pool. |
| """ |
| |
| try: |
| file_proto = self._internal_db.FindFileByName(file_name) |
| except KeyError as error: |
| if self._descriptor_db: |
| file_proto = self._descriptor_db.FindFileByName(file_name) |
| else: |
| raise error |
| if not file_proto: |
| raise KeyError('Cannot find a file named %s' % file_name) |
| return self._ConvertFileProtoToFileDescriptor(file_proto) |
| |
| def FindFileContainingSymbol(self, symbol): |
| """Gets the FileDescriptor for the file containing the specified symbol. |
| |
| Args: |
| symbol: The name of the symbol to search for. |
| |
| Returns: |
| A FileDescriptor that contains the specified symbol. |
| |
| Raises: |
| KeyError: if the file can not be found in the pool. |
| """ |
| |
| try: |
| file_proto = self._internal_db.FindFileContainingSymbol(symbol) |
| except KeyError as error: |
| if self._descriptor_db: |
| file_proto = self._descriptor_db.FindFileContainingSymbol(symbol) |
| else: |
| raise error |
| if not file_proto: |
| raise KeyError('Cannot find a file containing %s' % symbol) |
| return self._ConvertFileProtoToFileDescriptor(file_proto) |
| |
| def FindMessageTypeByName(self, full_name): |
| """Loads the named descriptor from the pool. |
| |
| Args: |
| full_name: The full name of the descriptor to load. |
| |
| Returns: |
| The descriptor for the named type. |
| """ |
| |
| full_name = full_name.lstrip('.') # fix inconsistent qualified name formats |
| if full_name not in self._descriptors: |
| self.FindFileContainingSymbol(full_name) |
| return self._descriptors[full_name] |
| |
| def FindEnumTypeByName(self, full_name): |
| """Loads the named enum descriptor from the pool. |
| |
| Args: |
| full_name: The full name of the enum descriptor to load. |
| |
| Returns: |
| The enum descriptor for the named type. |
| """ |
| |
| full_name = full_name.lstrip('.') # fix inconsistent qualified name formats |
| if full_name not in self._enum_descriptors: |
| self.FindFileContainingSymbol(full_name) |
| return self._enum_descriptors[full_name] |
| |
| def _ConvertFileProtoToFileDescriptor(self, file_proto): |
| """Creates a FileDescriptor from a proto or returns a cached copy. |
| |
| This method also has the side effect of loading all the symbols found in |
| the file into the appropriate dictionaries in the pool. |
| |
| Args: |
| file_proto: The proto to convert. |
| |
| Returns: |
| A FileDescriptor matching the passed in proto. |
| """ |
| |
| if file_proto.name not in self._file_descriptors: |
| file_descriptor = descriptor.FileDescriptor( |
| name=file_proto.name, |
| package=file_proto.package, |
| options=file_proto.options, |
| serialized_pb=file_proto.SerializeToString()) |
| scope = {} |
| dependencies = list(self._GetDeps(file_proto)) |
| |
| for dependency in dependencies: |
| dep_desc = self.FindFileByName(dependency.name) |
| dep_proto = descriptor_pb2.FileDescriptorProto.FromString( |
| dep_desc.serialized_pb) |
| package = '.' + dep_proto.package |
| package_prefix = package + '.' |
| |
| def _strip_package(symbol): |
| if symbol.startswith(package_prefix): |
| return symbol[len(package_prefix):] |
| return symbol |
| |
| symbols = list(self._ExtractSymbols(dep_proto.message_type, package)) |
| scope.update(symbols) |
| scope.update((_strip_package(k), v) for k, v in symbols) |
| |
| symbols = list(self._ExtractEnums(dep_proto.enum_type, package)) |
| scope.update(symbols) |
| scope.update((_strip_package(k), v) for k, v in symbols) |
| |
| for message_type in file_proto.message_type: |
| message_desc = self._ConvertMessageDescriptor( |
| message_type, file_proto.package, file_descriptor, scope) |
| file_descriptor.message_types_by_name[message_desc.name] = message_desc |
| for enum_type in file_proto.enum_type: |
| self._ConvertEnumDescriptor(enum_type, file_proto.package, |
| file_descriptor, None, scope) |
| for desc_proto in self._ExtractMessages(file_proto.message_type): |
| self._SetFieldTypes(desc_proto, scope) |
| |
| for desc_proto in file_proto.message_type: |
| desc = scope[desc_proto.name] |
| file_descriptor.message_types_by_name[desc_proto.name] = desc |
| self.Add(file_proto) |
| self._file_descriptors[file_proto.name] = file_descriptor |
| |
| return self._file_descriptors[file_proto.name] |
| |
| def _ConvertMessageDescriptor(self, desc_proto, package=None, file_desc=None, |
| scope=None): |
| """Adds the proto to the pool in the specified package. |
| |
| Args: |
| desc_proto: The descriptor_pb2.DescriptorProto protobuf message. |
| package: The package the proto should be located in. |
| file_desc: The file containing this message. |
| scope: Dict mapping short and full symbols to message and enum types. |
| |
| Returns: |
| The added descriptor. |
| """ |
| |
| if package: |
| desc_name = '.'.join((package, desc_proto.name)) |
| else: |
| desc_name = desc_proto.name |
| |
| if file_desc is None: |
| file_name = None |
| else: |
| file_name = file_desc.name |
| |
| if scope is None: |
| scope = {} |
| |
| nested = [ |
| self._ConvertMessageDescriptor(nested, desc_name, file_desc, scope) |
| for nested in desc_proto.nested_type] |
| enums = [ |
| self._ConvertEnumDescriptor(enum, desc_name, file_desc, None, scope) |
| for enum in desc_proto.enum_type] |
| fields = [self._MakeFieldDescriptor(field, desc_name, index) |
| for index, field in enumerate(desc_proto.field)] |
| extensions = [self._MakeFieldDescriptor(extension, desc_name, True) |
| for index, extension in enumerate(desc_proto.extension)] |
| extension_ranges = [(r.start, r.end) for r in desc_proto.extension_range] |
| if extension_ranges: |
| is_extendable = True |
| else: |
| is_extendable = False |
| desc = descriptor.Descriptor( |
| name=desc_proto.name, |
| full_name=desc_name, |
| filename=file_name, |
| containing_type=None, |
| fields=fields, |
| nested_types=nested, |
| enum_types=enums, |
| extensions=extensions, |
| options=desc_proto.options, |
| is_extendable=is_extendable, |
| extension_ranges=extension_ranges, |
| file=file_desc, |
| serialized_start=None, |
| serialized_end=None) |
| for nested in desc.nested_types: |
| nested.containing_type = desc |
| for enum in desc.enum_types: |
| enum.containing_type = desc |
| scope[desc_proto.name] = desc |
| scope['.' + desc_name] = desc |
| self._descriptors[desc_name] = desc |
| return desc |
| |
| def _ConvertEnumDescriptor(self, enum_proto, package=None, file_desc=None, |
| containing_type=None, scope=None): |
| """Make a protobuf EnumDescriptor given an EnumDescriptorProto protobuf. |
| |
| Args: |
| enum_proto: The descriptor_pb2.EnumDescriptorProto protobuf message. |
| package: Optional package name for the new message EnumDescriptor. |
| file_desc: The file containing the enum descriptor. |
| containing_type: The type containing this enum. |
| scope: Scope containing available types. |
| |
| Returns: |
| The added descriptor |
| """ |
| |
| if package: |
| enum_name = '.'.join((package, enum_proto.name)) |
| else: |
| enum_name = enum_proto.name |
| |
| if file_desc is None: |
| file_name = None |
| else: |
| file_name = file_desc.name |
| |
| values = [self._MakeEnumValueDescriptor(value, index) |
| for index, value in enumerate(enum_proto.value)] |
| desc = descriptor.EnumDescriptor(name=enum_proto.name, |
| full_name=enum_name, |
| filename=file_name, |
| file=file_desc, |
| values=values, |
| containing_type=containing_type, |
| options=enum_proto.options) |
| scope[enum_proto.name] = desc |
| scope['.%s' % enum_name] = desc |
| self._enum_descriptors[enum_name] = desc |
| return desc |
| |
| def _MakeFieldDescriptor(self, field_proto, message_name, index, |
| is_extension=False): |
| """Creates a field descriptor from a FieldDescriptorProto. |
| |
| For message and enum type fields, this method will do a look up |
| in the pool for the appropriate descriptor for that type. If it |
| is unavailable, it will fall back to the _source function to |
| create it. If this type is still unavailable, construction will |
| fail. |
| |
| Args: |
| field_proto: The proto describing the field. |
| message_name: The name of the containing message. |
| index: Index of the field |
| is_extension: Indication that this field is for an extension. |
| |
| Returns: |
| An initialized FieldDescriptor object |
| """ |
| |
| if message_name: |
| full_name = '.'.join((message_name, field_proto.name)) |
| else: |
| full_name = field_proto.name |
| |
| return descriptor.FieldDescriptor( |
| name=field_proto.name, |
| full_name=full_name, |
| index=index, |
| number=field_proto.number, |
| type=field_proto.type, |
| cpp_type=None, |
| message_type=None, |
| enum_type=None, |
| containing_type=None, |
| label=field_proto.label, |
| has_default_value=False, |
| default_value=None, |
| is_extension=is_extension, |
| extension_scope=None, |
| options=field_proto.options) |
| |
| def _SetFieldTypes(self, desc_proto, scope): |
| """Sets the field's type, cpp_type, message_type and enum_type. |
| |
| Args: |
| desc_proto: The message descriptor to update. |
| scope: Enclosing scope of available types. |
| """ |
| |
| desc = scope[desc_proto.name] |
| for field_proto, field_desc in zip(desc_proto.field, desc.fields): |
| if field_proto.type_name: |
| type_name = field_proto.type_name |
| if type_name not in scope: |
| type_name = '.' + type_name |
| desc = scope[type_name] |
| else: |
| desc = None |
| |
| if not field_proto.HasField('type'): |
| if isinstance(desc, descriptor.Descriptor): |
| field_proto.type = descriptor.FieldDescriptor.TYPE_MESSAGE |
| else: |
| field_proto.type = descriptor.FieldDescriptor.TYPE_ENUM |
| |
| field_desc.cpp_type = descriptor.FieldDescriptor.ProtoTypeToCppProtoType( |
| field_proto.type) |
| |
| if (field_proto.type == descriptor.FieldDescriptor.TYPE_MESSAGE |
| or field_proto.type == descriptor.FieldDescriptor.TYPE_GROUP): |
| field_desc.message_type = desc |
| |
| if field_proto.type == descriptor.FieldDescriptor.TYPE_ENUM: |
| field_desc.enum_type = desc |
| |
| if field_proto.label == descriptor.FieldDescriptor.LABEL_REPEATED: |
| field_desc.has_default = False |
| field_desc.default_value = [] |
| elif field_proto.HasField('default_value'): |
| field_desc.has_default = True |
| if (field_proto.type == descriptor.FieldDescriptor.TYPE_DOUBLE or |
| field_proto.type == descriptor.FieldDescriptor.TYPE_FLOAT): |
| field_desc.default_value = float(field_proto.default_value) |
| elif field_proto.type == descriptor.FieldDescriptor.TYPE_STRING: |
| field_desc.default_value = field_proto.default_value |
| elif field_proto.type == descriptor.FieldDescriptor.TYPE_BOOL: |
| field_desc.default_value = field_proto.default_value.lower() == 'true' |
| elif field_proto.type == descriptor.FieldDescriptor.TYPE_ENUM: |
| field_desc.default_value = field_desc.enum_type.values_by_name[ |
| field_proto.default_value].index |
| else: |
| field_desc.default_value = int(field_proto.default_value) |
| else: |
| field_desc.has_default = False |
| field_desc.default_value = None |
| |
| field_desc.type = field_proto.type |
| |
| for nested_type in desc_proto.nested_type: |
| self._SetFieldTypes(nested_type, scope) |
| |
| def _MakeEnumValueDescriptor(self, value_proto, index): |
| """Creates a enum value descriptor object from a enum value proto. |
| |
| Args: |
| value_proto: The proto describing the enum value. |
| index: The index of the enum value. |
| |
| Returns: |
| An initialized EnumValueDescriptor object. |
| """ |
| |
| return descriptor.EnumValueDescriptor( |
| name=value_proto.name, |
| index=index, |
| number=value_proto.number, |
| options=value_proto.options, |
| type=None) |
| |
| def _ExtractSymbols(self, desc_protos, package): |
| """Pulls out all the symbols from descriptor protos. |
| |
| Args: |
| desc_protos: The protos to extract symbols from. |
| package: The package containing the descriptor type. |
| Yields: |
| A two element tuple of the type name and descriptor object. |
| """ |
| |
| for desc_proto in desc_protos: |
| if package: |
| message_name = '.'.join((package, desc_proto.name)) |
| else: |
| message_name = desc_proto.name |
| message_desc = self.FindMessageTypeByName(message_name) |
| yield (message_name, message_desc) |
| for symbol in self._ExtractSymbols(desc_proto.nested_type, message_name): |
| yield symbol |
| for symbol in self._ExtractEnums(desc_proto.enum_type, message_name): |
| yield symbol |
| |
| def _ExtractEnums(self, enum_protos, package): |
| """Pulls out all the symbols from enum protos. |
| |
| Args: |
| enum_protos: The protos to extract symbols from. |
| package: The package containing the enum type. |
| |
| Yields: |
| A two element tuple of the type name and enum descriptor object. |
| """ |
| |
| for enum_proto in enum_protos: |
| if package: |
| enum_name = '.'.join((package, enum_proto.name)) |
| else: |
| enum_name = enum_proto.name |
| enum_desc = self.FindEnumTypeByName(enum_name) |
| yield (enum_name, enum_desc) |
| |
| def _ExtractMessages(self, desc_protos): |
| """Pulls out all the message protos from descriptos. |
| |
| Args: |
| desc_protos: The protos to extract symbols from. |
| |
| Yields: |
| Descriptor protos. |
| """ |
| |
| for desc_proto in desc_protos: |
| yield desc_proto |
| for message in self._ExtractMessages(desc_proto.nested_type): |
| yield message |
| |
| def _GetDeps(self, file_proto): |
| """Recursively finds dependencies for file protos. |
| |
| Args: |
| file_proto: The proto to get dependencies from. |
| |
| Yields: |
| Each direct and indirect dependency. |
| """ |
| |
| for dependency in file_proto.dependency: |
| dep_desc = self.FindFileByName(dependency) |
| dep_proto = descriptor_pb2.FileDescriptorProto.FromString( |
| dep_desc.serialized_pb) |
| yield dep_proto |
| for parent_dep in self._GetDeps(dep_proto): |
| yield parent_dep |
