src/google/protobuf/descriptor.proto

// 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.

// Author: kenton@google.com (Kenton Varda)
//  Based on original Protocol Buffers design by
//  Sanjay Ghemawat, Jeff Dean, and others.
//
// The messages in this file describe the definitions found in .proto files.
// A valid .proto file can be translated directly to a FileDescriptorProto
// without any other information (e.g. without reading its imports).



package google.protobuf;
option java_package = "com.google.protobuf";
option java_outer_classname = "DescriptorProtos";

// descriptor.proto must be optimized for speed because reflection-based
// algorithms don't work during bootstrapping.
option optimize_for = SPEED;

// Describes a complete .proto file.
message FileDescriptorProto {
  optional string name = 1;       // file name, relative to root of source tree
  optional string package = 2;    // e.g. "foo", "foo.bar", etc.

  // Names of files imported by this file.
  repeated string dependency = 3;

  // All top-level definitions in this file.
  repeated DescriptorProto message_type = 4;
  repeated EnumDescriptorProto enum_type = 5;
  repeated ServiceDescriptorProto service = 6;
  repeated FieldDescriptorProto extension = 7;

  optional FileOptions options = 8;
}

// Describes a message type.
message DescriptorProto {
  optional string name = 1;

  repeated FieldDescriptorProto field = 2;
  repeated FieldDescriptorProto extension = 6;

  repeated DescriptorProto nested_type = 3;
  repeated EnumDescriptorProto enum_type = 4;

  message ExtensionRange {
    optional int32 start = 1;
    optional int32 end = 2;
  }
  repeated ExtensionRange extension_range = 5;

  optional MessageOptions options = 7;
}

// Describes a field within a message.
message FieldDescriptorProto {
  enum Type {
    // 0 is reserved for errors.
    // Order is weird for historical reasons.
    TYPE_DOUBLE         = 1;
    TYPE_FLOAT          = 2;
    TYPE_INT64          = 3;   // Not ZigZag encoded.  Negative numbers
                               // take 10 bytes.  Use TYPE_SINT64 if negative
                               // values are likely.
    TYPE_UINT64         = 4;
    TYPE_INT32          = 5;   // Not ZigZag encoded.  Negative numbers
                               // take 10 bytes.  Use TYPE_SINT32 if negative
                               // values are likely.
    TYPE_FIXED64        = 6;
    TYPE_FIXED32        = 7;
    TYPE_BOOL           = 8;
    TYPE_STRING         = 9;
    TYPE_GROUP          = 10;  // Tag-delimited aggregate.
    TYPE_MESSAGE        = 11;  // Length-delimited aggregate.

    // New in version 2.
    TYPE_BYTES          = 12;
    TYPE_UINT32         = 13;
    TYPE_ENUM           = 14;
    TYPE_SFIXED32       = 15;
    TYPE_SFIXED64       = 16;
    TYPE_SINT32         = 17;  // Uses ZigZag encoding.
    TYPE_SINT64         = 18;  // Uses ZigZag encoding.
  };

  enum Label {
    // 0 is reserved for errors
    LABEL_OPTIONAL      = 1;
    LABEL_REQUIRED      = 2;
    LABEL_REPEATED      = 3;
    // TODO(sanjay): Should we add LABEL_MAP?
  };

  optional string name = 1;
  optional int32 number = 3;
  optional Label label = 4;

  // If type_name is set, this need not be set.  If both this and type_name
  // are set, this must be either TYPE_ENUM or TYPE_MESSAGE.
  optional Type type = 5;

  // For message and enum types, this is the name of the type.  If the name
  // starts with a '.', it is fully-qualified.  Otherwise, C++-like scoping
  // rules are used to find the type (i.e. first the nested types within this
  // message are searched, then within the parent, on up to the root
  // namespace).
  optional string type_name = 6;

  // For extensions, this is the name of the type being extended.  It is
  // resolved in the same manner as type_name.
  optional string extendee = 2;

  // For numeric types, contains the original text representation of the value.
  // For booleans, "true" or "false".
  // For strings, contains the default text contents (not escaped in any way).
  // For bytes, contains the C escaped value.  All bytes >= 128 are escaped.
  // TODO(kenton):  Base-64 encode?
  optional string default_value = 7;

  optional FieldOptions options = 8;
}

// Describes an enum type.
message EnumDescriptorProto {
  optional string name = 1;

  repeated EnumValueDescriptorProto value = 2;

  optional EnumOptions options = 3;
}

// Describes a value within an enum.
message EnumValueDescriptorProto {
  optional string name = 1;
  optional int32 number = 2;

  optional EnumValueOptions options = 3;
}

// Describes a service.
message ServiceDescriptorProto {
  optional string name = 1;
  repeated MethodDescriptorProto method = 2;

  optional ServiceOptions options = 3;
}

// Describes a method of a service.
message MethodDescriptorProto {
  optional string name = 1;

  // Input and output type names.  These are resolved in the same way as
  // FieldDescriptorProto.type_name, but must refer to a message type.
  optional string input_type = 2;
  optional string output_type = 3;

  optional MethodOptions options = 4;
}

// ===================================================================
// Options

// Each of the definitions above may have "options" attached.  These are
// just annotations which may cause code to be generated slightly differently
// or may contain hints for code that manipulates protocol messages.

// TODO(kenton):  Allow extensions to options.

message FileOptions {

  // Sets the Java package where classes generated from this .proto will be
  // placed.  By default, the proto package is used, but this is often
  // inappropriate because proto packages do not normally start with backwards
  // domain names.
  optional string java_package = 1;


  // If set, all the classes from the .proto file are wrapped in a single
  // outer class with the given name.  This applies to both Proto1
  // (equivalent to the old "--one_java_file" option) and Proto2 (where
  // a .proto always translates to a single class, but you may want to
  // explicitly choose the class name).
  optional string java_outer_classname = 8;

  // If set true, then the Java code generator will generate a separate .java
  // file for each top-level message, enum, and service defined in the .proto
  // file.  Thus, these types will *not* be nested inside the outer class
  // named by java_outer_classname.  However, the outer class will still be
  // generated to contain the file's getDescriptor() method as well as any
  // top-level extensions defined in the file.
  optional bool java_multiple_files = 10 [default=false];

  // Generated classes can be optimized for speed or code size.
  enum OptimizeMode {
    SPEED = 1;      // Generate complete code for parsing, serialization, etc.
    CODE_SIZE = 2;  // Use ReflectionOps to implement these methods.
  }
  optional OptimizeMode optimize_for = 9 [default=CODE_SIZE];
}

message MessageOptions {
  // Set true to use the old proto1 MessageSet wire format for extensions.
  // This is provided for backwards-compatibility with the MessageSet wire
  // format.  You should not use this for any other reason:  It's less
  // efficient, has fewer features, and is more complicated.
  //
  // The message must be defined exactly as follows:
  //   message Foo {
  //     option message_set_wire_format = true;
  //     extensions 4 to max;
  //   }
  // Note that the message cannot have any defined fields; MessageSets only
  // have extensions.
  //
  // All extensions of your type must be singular messages; e.g. they cannot
  // be int32s, enums, or repeated messages.
  //
  // Because this is an option, the above two restrictions are not enforced by
  // the protocol compiler.
  optional bool message_set_wire_format = 1 [default=false];
}

message FieldOptions {
  // The ctype option instructs the C++ code generator to use a different
  // representation of the field than it normally would.  See the specific
  // options below.  This option is not yet implemented in the open source
  // release -- sorry, we'll try to include it in a future version!
  optional CType ctype = 1;
  enum CType {
    CORD = 1;

    STRING_PIECE = 2;
  }

  // EXPERIMENTAL.  DO NOT USE.
  // For "map" fields, the name of the field in the enclosed type that
  // is the key for this map.  For example, suppose we have:
  //   message Item {
  //     required string name = 1;
  //     required string value = 2;
  //   }
  //   message Config {
  //     repeated Item items = 1 [experimental_map_key="name"];
  //   }
  // In this situation, the map key for Item will be set to "name".
  // TODO: Fully-implement this, then remove the "experimental_" prefix.
  optional string experimental_map_key = 9;
}

message EnumOptions {
}

message EnumValueOptions {
}

message ServiceOptions {

  // Note:  Field numbers 1 through 32 are reserved for Google's internal RPC
  //   framework.  We apologize for hoarding these numbers to ourselves, but
  //   we were already using them long before we decided to release Protocol
  //   Buffers.
}

message MethodOptions {

  // Note:  Field numbers 1 through 32 are reserved for Google's internal RPC
  //   framework.  We apologize for hoarding these numbers to ourselves, but
  //   we were already using them long before we decided to release Protocol
  //   Buffers.
}