// Copyright 2019, OpenTelemetry Authors
//
// 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 opentelemetry.proto.collector.trace.v1;

import "opentelemetry/proto/trace/v1/trace.proto";

option csharp_namespace = "OpenTelemetry.Proto.Collector.Trace.V1";
option java_multiple_files = true;
option java_package = "io.opentelemetry.proto.collector.trace.v1";
option java_outer_classname = "TraceServiceProto";
option go_package = "go.opentelemetry.io/proto/otlp/collector/trace/v1";

// Service that can be used to push spans between one Application instrumented with
// OpenTelemetry and a collector, or between a collector and a central collector (in this
// case spans are sent/received to/from multiple Applications).
service TraceService {
  // For performance reasons, it is recommended to keep this RPC
  // alive for the entire life of the application.
  rpc Export(ExportTraceServiceRequest) returns (ExportTraceServiceResponse) {}
}

message ExportTraceServiceRequest {
  // An array of ResourceSpans.
  // For data coming from a single resource this array will typically contain one
  // element. Intermediary nodes (such as OpenTelemetry Collector) that receive
  // data from multiple origins typically batch the data before forwarding further and
  // in that case this array will contain multiple elements.
  repeated opentelemetry.proto.trace.v1.ResourceSpans resource_spans = 1;
}

message ExportTraceServiceResponse {
  // The details of a partially successful export request.
  //
  // If the request is only partially accepted
  // (i.e. when the server accepts only parts of the data and rejects the rest)
  // the server MUST initialize the `partial_success` field and MUST
  // set the `rejected_<signal>` with the number of items it rejected.
  //
  // Servers MAY also make use of the `partial_success` field to convey
  // warnings/suggestions to senders even when the request was fully accepted.
  // In such cases, the `rejected_<signal>` MUST have a value of `0` and
  // the `error_message` MUST be non-empty.
  //
  // A `partial_success` message with an empty value (rejected_<signal> = 0 and
  // `error_message` = "") is equivalent to it not being set/present. Senders
  // SHOULD interpret it the same way as in the full success case.
  ExportTracePartialSuccess partial_success = 1;
}

message ExportTracePartialSuccess {
  // The number of rejected spans.
  //
  // A `rejected_<signal>` field holding a `0` value indicates that the
  // request was fully accepted.
  int64 rejected_spans = 1;

  // A developer-facing human-readable message in English. It should be used
  // either to explain why the server rejected parts of the data during a partial
  // success or to convey warnings/suggestions during a full success. The message
  // should offer guidance on how users can address such issues.
  //
  // error_message is an optional field. An error_message with an empty value
  // is equivalent to it not being set.
  string error_message = 2;
}