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Diffstat (limited to 'python/google/protobuf/descriptor.py')
| -rwxr-xr-x | python/google/protobuf/descriptor.py | 419 |
1 files changed, 419 insertions, 0 deletions
diff --git a/python/google/protobuf/descriptor.py b/python/google/protobuf/descriptor.py new file mode 100755 index 00000000..04748053 --- /dev/null +++ b/python/google/protobuf/descriptor.py @@ -0,0 +1,419 @@ +# Protocol Buffers - Google's data interchange format +# Copyright 2008 Google Inc. +# http://code.google.com/p/protobuf/ +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +# TODO(robinson): We probably need to provide deep-copy methods for +# descriptor types. When a FieldDescriptor is passed into +# Descriptor.__init__(), we should make a deep copy and then set +# containing_type on it. Alternatively, we could just get +# rid of containing_type (iit's not needed for reflection.py, at least). +# +# TODO(robinson): Print method? +# +# TODO(robinson): Useful __repr__? + +"""Descriptors essentially contain exactly the information found in a .proto +file, in types that make this information accessible in Python. +""" + +__author__ = 'robinson@google.com (Will Robinson)' + +class DescriptorBase(object): + + """Descriptors base class. + + This class is the base of all descriptor classes. It provides common options + related functionaility. + """ + + def __init__(self, options, options_class_name): + """Initialize the descriptor given its options message and the name of the + class of the options message. The name of the class is required in case + the options message is None and has to be created. + """ + self._options = options + self._options_class_name = options_class_name + + def GetOptions(self): + """Retrieves descriptor options. + + This method returns the options set or creates the default options for the + descriptor. + """ + if self._options: + return self._options + from google.protobuf import descriptor_pb2 + try: + options_class = getattr(descriptor_pb2, self._options_class_name) + except AttributeError: + raise RuntimeError('Unknown options class name %s!' % + (self._options_class_name)) + self._options = options_class() + return self._options + + +class Descriptor(DescriptorBase): + + """Descriptor for a protocol message type. + + A Descriptor instance has the following attributes: + + name: (str) Name of this protocol message type. + full_name: (str) Fully-qualified name of this protocol message type, + which will include protocol "package" name and the name of any + enclosing types. + + filename: (str) Name of the .proto file containing this message. + + containing_type: (Descriptor) Reference to the descriptor of the + type containing us, or None if we have no containing type. + + fields: (list of FieldDescriptors) Field descriptors for all + fields in this type. + fields_by_number: (dict int -> FieldDescriptor) Same FieldDescriptor + objects as in |fields|, but indexed by "number" attribute in each + FieldDescriptor. + fields_by_name: (dict str -> FieldDescriptor) Same FieldDescriptor + objects as in |fields|, but indexed by "name" attribute in each + FieldDescriptor. + + nested_types: (list of Descriptors) Descriptor references + for all protocol message types nested within this one. + nested_types_by_name: (dict str -> Descriptor) Same Descriptor + objects as in |nested_types|, but indexed by "name" attribute + in each Descriptor. + + enum_types: (list of EnumDescriptors) EnumDescriptor references + for all enums contained within this type. + enum_types_by_name: (dict str ->EnumDescriptor) Same EnumDescriptor + objects as in |enum_types|, but indexed by "name" attribute + in each EnumDescriptor. + enum_values_by_name: (dict str -> EnumValueDescriptor) Dict mapping + from enum value name to EnumValueDescriptor for that value. + + extensions: (list of FieldDescriptor) All extensions defined directly + within this message type (NOT within a nested type). + extensions_by_name: (dict, string -> FieldDescriptor) Same FieldDescriptor + objects as |extensions|, but indexed by "name" attribute of each + FieldDescriptor. + + options: (descriptor_pb2.MessageOptions) Protocol message options or None + to use default message options. + """ + + def __init__(self, name, full_name, filename, containing_type, + fields, nested_types, enum_types, extensions, options=None): + """Arguments to __init__() are as described in the description + of Descriptor fields above. + """ + super(Descriptor, self).__init__(options, 'MessageOptions') + self.name = name + self.full_name = full_name + self.filename = filename + self.containing_type = containing_type + + # We have fields in addition to fields_by_name and fields_by_number, + # so that: + # 1. Clients can index fields by "order in which they're listed." + # 2. Clients can easily iterate over all fields with the terse + # syntax: for f in descriptor.fields: ... + self.fields = fields + for field in self.fields: + field.containing_type = self + self.fields_by_number = dict((f.number, f) for f in fields) + self.fields_by_name = dict((f.name, f) for f in fields) + + self.nested_types = nested_types + self.nested_types_by_name = dict((t.name, t) for t in nested_types) + + self.enum_types = enum_types + for enum_type in self.enum_types: + enum_type.containing_type = self + self.enum_types_by_name = dict((t.name, t) for t in enum_types) + self.enum_values_by_name = dict( + (v.name, v) for t in enum_types for v in t.values) + + self.extensions = extensions + for extension in self.extensions: + extension.extension_scope = self + self.extensions_by_name = dict((f.name, f) for f in extensions) + + +# TODO(robinson): We should have aggressive checking here, +# for example: +# * If you specify a repeated field, you should not be allowed +# to specify a default value. +# * [Other examples here as needed]. +# +# TODO(robinson): for this and other *Descriptor classes, we +# might also want to lock things down aggressively (e.g., +# prevent clients from setting the attributes). Having +# stronger invariants here in general will reduce the number +# of runtime checks we must do in reflection.py... +class FieldDescriptor(DescriptorBase): + + """Descriptor for a single field in a .proto file. + + A FieldDescriptor instance has the following attriubtes: + + name: (str) Name of this field, exactly as it appears in .proto. + full_name: (str) Name of this field, including containing scope. This is + particularly relevant for extensions. + index: (int) Dense, 0-indexed index giving the order that this + field textually appears within its message in the .proto file. + number: (int) Tag number declared for this field in the .proto file. + + type: (One of the TYPE_* constants below) Declared type. + cpp_type: (One of the CPPTYPE_* constants below) C++ type used to + represent this field. + + label: (One of the LABEL_* constants below) Tells whether this + field is optional, required, or repeated. + default_value: (Varies) Default value of this field. Only + meaningful for non-repeated scalar fields. Repeated fields + should always set this to [], and non-repeated composite + fields should always set this to None. + + containing_type: (Descriptor) Descriptor of the protocol message + type that contains this field. Set by the Descriptor constructor + if we're passed into one. + Somewhat confusingly, for extension fields, this is the + descriptor of the EXTENDED message, not the descriptor + of the message containing this field. (See is_extension and + extension_scope below). + message_type: (Descriptor) If a composite field, a descriptor + of the message type contained in this field. Otherwise, this is None. + enum_type: (EnumDescriptor) If this field contains an enum, a + descriptor of that enum. Otherwise, this is None. + + is_extension: True iff this describes an extension field. + extension_scope: (Descriptor) Only meaningful if is_extension is True. + Gives the message that immediately contains this extension field. + Will be None iff we're a top-level (file-level) extension field. + + options: (descriptor_pb2.FieldOptions) Protocol message field options or + None to use default field options. + """ + + # Must be consistent with C++ FieldDescriptor::Type enum in + # descriptor.h. + # + # TODO(robinson): Find a way to eliminate this repetition. + TYPE_DOUBLE = 1 + TYPE_FLOAT = 2 + TYPE_INT64 = 3 + TYPE_UINT64 = 4 + TYPE_INT32 = 5 + TYPE_FIXED64 = 6 + TYPE_FIXED32 = 7 + TYPE_BOOL = 8 + TYPE_STRING = 9 + TYPE_GROUP = 10 + TYPE_MESSAGE = 11 + TYPE_BYTES = 12 + TYPE_UINT32 = 13 + TYPE_ENUM = 14 + TYPE_SFIXED32 = 15 + TYPE_SFIXED64 = 16 + TYPE_SINT32 = 17 + TYPE_SINT64 = 18 + MAX_TYPE = 18 + + # Must be consistent with C++ FieldDescriptor::CppType enum in + # descriptor.h. + # + # TODO(robinson): Find a way to eliminate this repetition. + CPPTYPE_INT32 = 1 + CPPTYPE_INT64 = 2 + CPPTYPE_UINT32 = 3 + CPPTYPE_UINT64 = 4 + CPPTYPE_DOUBLE = 5 + CPPTYPE_FLOAT = 6 + CPPTYPE_BOOL = 7 + CPPTYPE_ENUM = 8 + CPPTYPE_STRING = 9 + CPPTYPE_MESSAGE = 10 + MAX_CPPTYPE = 10 + + # Must be consistent with C++ FieldDescriptor::Label enum in + # descriptor.h. + # + # TODO(robinson): Find a way to eliminate this repetition. + LABEL_OPTIONAL = 1 + LABEL_REQUIRED = 2 + LABEL_REPEATED = 3 + MAX_LABEL = 3 + + def __init__(self, name, full_name, index, number, type, cpp_type, label, + default_value, message_type, enum_type, containing_type, + is_extension, extension_scope, options=None): + """The arguments are as described in the description of FieldDescriptor + attributes above. + + Note that containing_type may be None, and may be set later if necessary + (to deal with circular references between message types, for example). + Likewise for extension_scope. + """ + super(FieldDescriptor, self).__init__(options, 'FieldOptions') + self.name = name + self.full_name = full_name + self.index = index + self.number = number + self.type = type + self.cpp_type = cpp_type + self.label = label + self.default_value = default_value + self.containing_type = containing_type + self.message_type = message_type + self.enum_type = enum_type + self.is_extension = is_extension + self.extension_scope = extension_scope + + +class EnumDescriptor(DescriptorBase): + + """Descriptor for an enum defined in a .proto file. + + An EnumDescriptor instance has the following attributes: + + name: (str) Name of the enum type. + full_name: (str) Full name of the type, including package name + and any enclosing type(s). + filename: (str) Name of the .proto file in which this appears. + + values: (list of EnumValueDescriptors) List of the values + in this enum. + values_by_name: (dict str -> EnumValueDescriptor) Same as |values|, + but indexed by the "name" field of each EnumValueDescriptor. + values_by_number: (dict int -> EnumValueDescriptor) Same as |values|, + but indexed by the "number" field of each EnumValueDescriptor. + containing_type: (Descriptor) Descriptor of the immediate containing + type of this enum, or None if this is an enum defined at the + top level in a .proto file. Set by Descriptor's constructor + if we're passed into one. + options: (descriptor_pb2.EnumOptions) Enum options message or + None to use default enum options. + """ + + def __init__(self, name, full_name, filename, values, + containing_type=None, options=None): + """Arguments are as described in the attribute description above.""" + super(EnumDescriptor, self).__init__(options, 'EnumOptions') + self.name = name + self.full_name = full_name + self.filename = filename + self.values = values + for value in self.values: + value.type = self + self.values_by_name = dict((v.name, v) for v in values) + self.values_by_number = dict((v.number, v) for v in values) + self.containing_type = containing_type + + +class EnumValueDescriptor(DescriptorBase): + + """Descriptor for a single value within an enum. + + name: (str) Name of this value. + index: (int) Dense, 0-indexed index giving the order that this + value appears textually within its enum in the .proto file. + number: (int) Actual number assigned to this enum value. + type: (EnumDescriptor) EnumDescriptor to which this value + belongs. Set by EnumDescriptor's constructor if we're + passed into one. + options: (descriptor_pb2.EnumValueOptions) Enum value options message or + None to use default enum value options options. + """ + + def __init__(self, name, index, number, type=None, options=None): + """Arguments are as described in the attribute description above.""" + super(EnumValueDescriptor, self).__init__(options, 'EnumValueOptions') + self.name = name + self.index = index + self.number = number + self.type = type + + +class ServiceDescriptor(DescriptorBase): + + """Descriptor for a service. + + name: (str) Name of the service. + full_name: (str) Full name of the service, including package name. + index: (int) 0-indexed index giving the order that this services + definition appears withing the .proto file. + methods: (list of MethodDescriptor) List of methods provided by this + service. + options: (descriptor_pb2.ServiceOptions) Service options message or + None to use default service options. + """ + + def __init__(self, name, full_name, index, methods, options=None): + super(ServiceDescriptor, self).__init__(options, 'ServiceOptions') + self.name = name + self.full_name = full_name + self.index = index + self.methods = methods + # Set the containing service for each method in this service. + for method in self.methods: + method.containing_service = self + + def FindMethodByName(self, name): + """Searches for the specified method, and returns its descriptor.""" + for method in self.methods: + if name == method.name: + return method + return None + + +class MethodDescriptor(DescriptorBase): + + """Descriptor for a method in a service. + + name: (str) Name of the method within the service. + full_name: (str) Full name of method. + index: (int) 0-indexed index of the method inside the service. + containing_service: (ServiceDescriptor) The service that contains this + method. + input_type: The descriptor of the message that this method accepts. + output_type: The descriptor of the message that this method returns. + options: (descriptor_pb2.MethodOptions) Method options message or + None to use default method options. + """ + + def __init__(self, name, full_name, index, containing_service, + input_type, output_type, options=None): + """The arguments are as described in the description of MethodDescriptor + attributes above. + + Note that containing_service may be None, and may be set later if necessary. + """ + super(MethodDescriptor, self).__init__(options, 'MethodOptions') + self.name = name + self.full_name = full_name + self.index = index + self.containing_service = containing_service + self.input_type = input_type + self.output_type = output_type + + +def _ParseOptions(message, string): + """Parses serialized options. + + This helper function is used to parse serialized options in generated + proto2 files. It must not be used outside proto2. + """ + message.ParseFromString(string) + return message; |