components/sync/engine/events/protocol_event.h

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_SYNC_ENGINE_EVENTS_PROTOCOL_EVENT_H_
#define COMPONENTS_SYNC_ENGINE_EVENTS_PROTOCOL_EVENT_H_

#include <memory>
#include <string>

#include "base/time/time.h"
#include "base/values.h"

namespace syncer {

// SyncNetworkEvents represent a single client <-> server sync protocol event
// that recently took place. Sync protocol events occur when the client decides
// to send a sync protocol request (such as GetUpdates or Commit) to the server,
// and when the server responds. Note that the requests and responses themselves
// are modelled by {GetUpdates, Commit}x{Request,Response} objects.
//
// These objects are intended to be used for displaying information on
// chrome://sync-internals.  They should be considered to be immutable and
// opaque.  No program behavior should depend on their contents.
//
// Each type of request can maintain its own set of additional metadata and have
// its own custom serialization routines.  For example, the "configure"
// GetUpdates request will include information about its "origin" in its debug
// info.
class ProtocolEvent {
 public:
  ProtocolEvent();
  virtual ~ProtocolEvent();

  // Need a virtual copy constructor to copy this object across threads.
  virtual std::unique_ptr<ProtocolEvent> Clone() const = 0;

  // Assembles the data exposed through the ProtocolEvent's interface into a
  // single base::Value::Dict.
  base::Value::Dict ToValue(bool include_specifics) const;

  // Returns the time when the request was sent or received.
  base::Time GetTimestampForTesting() const;

 private:
  // Returns the time when the request was sent or received.
  virtual base::Time GetTimestamp() const = 0;

  // Returns a string representing they type of the request.  Should be short.
  virtual std::string GetType() const = 0;

  // Returns a string representing details of the request.  May be verbose.  The
  // implementer is allowed to return lots of data separated by newlines.
  virtual std::string GetDetails() const = 0;

  // Returns a base::Value::Dict representing the protobuf message associated
  // with this event.
  virtual base::Value::Dict GetProtoMessage(bool include_specifics) const = 0;
};

}  // namespace syncer

#endif  // COMPONENTS_SYNC_ENGINE_EVENTS_PROTOCOL_EVENT_H_