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// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef COMPONENTS_CRYPTAUTH_SYNC_SCHEDULER_IMPL_H_
#define COMPONENTS_CRYPTAUTH_SYNC_SCHEDULER_IMPL_H_
#include <stddef.h>
#include "base/macros.h"
#include "base/timer/timer.h"
#include "components/cryptauth/sync_scheduler.h"
namespace cryptauth {
// Implementation of SyncScheduler.
class SyncSchedulerImpl : public SyncScheduler {
public:
// Creates the scheduler:
// |delegate|: Handles sync requests and must outlive the scheduler.
// |refresh_period|: The time to wait for the PERIODIC_REFRESH strategy.
// |base_recovery_period|: The initial time to wait for the
// AGGRESSIVE_RECOVERY strategy. The time delta is increased for each
// subsequent failure.
// |max_jitter_ratio|: The maximum ratio that the time to next sync can be
// jittered (both positively and negatively).
// |scheduler_name|: The name of the scheduler for debugging purposes.
SyncSchedulerImpl(Delegate* delegate,
base::TimeDelta refresh_period,
base::TimeDelta base_recovery_period,
double max_jitter_ratio,
const std::string& scheduler_name);
~SyncSchedulerImpl() override;
// SyncScheduler:
void Start(const base::TimeDelta& elapsed_time_since_last_sync,
Strategy strategy) override;
void ForceSync() override;
base::TimeDelta GetTimeToNextSync() const override;
Strategy GetStrategy() const override;
SyncState GetSyncState() const override;
protected:
// Creates and returns a base::Timer object. Exposed for testing.
virtual std::unique_ptr<base::Timer> CreateTimer();
private:
// SyncScheduler:
void OnSyncCompleted(bool success) override;
// Called when |timer_| is fired.
void OnTimerFired();
// Schedules |timer_| for the next sync request.
void ScheduleNextSync(const base::TimeDelta& sync_delta);
// Adds a random jitter to the value of GetPeriod(). The returned
// TimeDelta will be clamped to be non-negative.
base::TimeDelta GetJitteredPeriod();
// Returns the time to wait for the current strategy.
base::TimeDelta GetPeriod();
// The delegate handling sync requests when they are fired.
Delegate* const delegate_;
// The time to wait until the next refresh when the last sync attempt was
// successful.
const base::TimeDelta refresh_period_;
// The base recovery period for the AGGRESSIVE_RECOVERY strategy before
// backoffs are applied.
const base::TimeDelta base_recovery_period_;
// The maximum percentage (both positively and negatively) that the time to
// wait between each sync request is jittered. The jitter is randomly applied
// to each period so we can avoid synchronous calls to the server.
const double max_jitter_ratio_;
// The name of the scheduler, used for debugging purposes.
const std::string scheduler_name_;
// The current strategy of the scheduler.
Strategy strategy_;
// The current state of the scheduler.
SyncState sync_state_;
// The number of failed syncs made in a row. Once a sync request succeeds,
// this counter is reset.
size_t failure_count_;
// Timer firing for the next sync request.
std::unique_ptr<base::Timer> timer_;
base::WeakPtrFactory<SyncSchedulerImpl> weak_ptr_factory_;
DISALLOW_COPY_AND_ASSIGN(SyncSchedulerImpl);
};
} // namespace cryptauth
#endif // COMPONENTS_CRYPTAUTH_SYNC_SCHEDULER_IMPL_H_
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