/*
 * Copyright 2018 The Kythe Authors. All rights reserved.
 *
 * 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.
 */

syntax = "proto3";

package kythe.proto.serving.graph;

option go_package = "graph_serving_go_proto";
option java_package = "com.google.devtools.kythe.proto";

import "kythe/proto/schema.proto";
import "kythe/proto/storage.proto";

// Columnar protocol buffer format for Edges.
//
// Design: https://github.com/kythe/kythe/blob/master/kythe/docs/rfc/2909.md
//
// Columnar key prefix: "eg"-source
message Edges {
  kythe.proto.VName source = 1;

  oneof entry {
    Index index = 2;
    Edge edge = 3;
    Target target = 4;
  }

  // Index for columnar edges data.
  //
  // Columnar key: <empty>
  message Index {
    kythe.proto.schema.Node node = 1;
  }

  // A single edge
  //
  // Columnar key: 10-kind-reverse-ordinal-target
  message Edge {
    oneof kind {
      kythe.proto.schema.EdgeKind kythe_kind = 1;
      string generic_kind = 2;
    }
    // Edge ordinal for this relation to the node.
    int32 ordinal = 3;
    // Whether the relation is a reverse edge.
    bool reverse = 4;

    // TODO(schroederc): add priority grouping
    kythe.proto.VName target = 5;
  }

  // Edge target node
  //
  // Columnar key: 20-target
  message Target {
    kythe.proto.schema.Node node = 1;
  }
}