// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

module metrics.mojom;

import "mojo/public/mojom/base/byte_string.mojom";
import "mojo/public/mojom/base/time.mojom";

// |contents| is a serialized protobuf from
// src/third_party/metrics_proto/sampled_profile.proto.
//
// We pass this state via serialized protobuf because that is the ultimate
// metrics upload format.
struct SampledProfile {
  mojo_base.mojom.ByteString contents;
};

// The type of data that's sampled in a profile.
enum ProfileType {
  kCPU,
  kHeap,
};

// Passes SampledProfile reports from a sampling profiler running in a child
// process to CallStackProfileMetricsProvider in the browser process, to be
// included in metrics uploads.
interface CallStackProfileCollector {

  // Passes the report in `profile` to CallStackProfileMetricsProvider.
  // `start_timestamp` is the timestamp of the oldest sample in the report, and
  // `profile_type` is the type of sampled data in the report.
  //
  // Note that the `trigger_event` field of the SampledProfile proto should be
  // PERIODIC_HEAP_COLLECTION iff `profile_type` is kHeap. But the profile
  // comes from an untrusted process so the implementation must not depend on
  // this.
  Collect(mojo_base.mojom.TimeTicks start_timestamp,
          ProfileType profile_type,
          SampledProfile profile);
};