/*
 * Copyright (C) 2018 The Android Open Source Project
 *
 * 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.
 */

// This is a subset of descriptor.proto from the Protobuf library.
syntax = "proto2";

package perfetto.protos;

// The protocol compiler can output a FileDescriptorSet containing the .proto
// files it parses.
message FileDescriptorSet {
  repeated FileDescriptorProto file = 1;
}

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

  // Names of files imported by this file.
  repeated string dependency = 3;
  // Indexes of the public imported files in the dependency list above.
  repeated int32 public_dependency = 10;
  // Indexes of the weak imported files in the dependency list.
  // For Google-internal migration only. Do not use.
  repeated int32 weak_dependency = 11;

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

  reserved 6;
  reserved 8;
  reserved 9;
  reserved 12;
}

// 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;

  reserved 5;

  repeated OneofDescriptorProto oneof_decl = 8;

  reserved 7;

  // Range of reserved tag numbers. Reserved tag numbers may not be used by
  // fields or extension ranges in the same message. Reserved ranges may
  // not overlap.
  message ReservedRange {
    // Inclusive.
    optional int32 start = 1;
    // Exclusive.
    optional int32 end = 2;
  }
  repeated ReservedRange reserved_range = 9;
  // Reserved field names, which may not be used by fields in the same message.
  // A given name may only be reserved once.
  repeated string reserved_name = 10;
}

message FieldOptions {
  // The packed option can be enabled for repeated primitive fields to enable
  // a more efficient representation on the wire. Rather than repeatedly
  // writing the tag and type for each element, the entire array is encoded as
  // a single length-delimited blob. In proto3, only explicit setting it to
  // false will avoid using packed encoding.
  optional bool packed = 2;
}

// 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;
    // Not ZigZag encoded.  Negative numbers take 10 bytes.  Use TYPE_SINT64 if
    // negative values are likely.
    TYPE_INT64 = 3;
    TYPE_UINT64 = 4;
    // Not ZigZag encoded.  Negative numbers take 10 bytes.  Use TYPE_SINT32 if
    // negative values are likely.
    TYPE_INT32 = 5;
    TYPE_FIXED64 = 6;
    TYPE_FIXED32 = 7;
    TYPE_BOOL = 8;
    TYPE_STRING = 9;
    // Tag-delimited aggregate.
    // Group type is deprecated and not supported in proto3. However, Proto3
    // implementations should still be able to parse the group wire format and
    // treat group fields as unknown fields.
    TYPE_GROUP = 10;
    // Length-delimited aggregate.
    TYPE_MESSAGE = 11;

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

  enum Label {
    // 0 is reserved for errors
    LABEL_OPTIONAL = 1;
    LABEL_REQUIRED = 2;
    LABEL_REPEATED = 3;
  };

  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 one of TYPE_ENUM, TYPE_MESSAGE or TYPE_GROUP.
  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;

  // If set, gives the index of a oneof in the containing type's oneof_decl
  // list.  This field is a member of that oneof.
  optional int32 oneof_index = 9;

  reserved 10;
}

// Describes a oneof.
message OneofDescriptorProto {
  optional string name = 1;
  optional OneofOptions options = 2;
}

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

  repeated EnumValueDescriptorProto value = 2;

  reserved 3;
  reserved 4;

  // Reserved enum value names, which may not be reused. A given name may only
  // be reserved once.
  repeated string reserved_name = 5;
}

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

  reserved 3;
}

message OneofOptions {
  reserved 999;

  // Clients can define custom options in extensions of this message. See above.
  extensions 1000 to max;
}