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// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CONTENT_BROWSER_BACKGROUND_SYNC_BACKGROUND_SYNC_OP_SCHEDULER_H_
#define CONTENT_BROWSER_BACKGROUND_SYNC_BACKGROUND_SYNC_OP_SCHEDULER_H_
#include <map>
#include <vector>
#include "base/containers/queue.h"
#include "base/feature_list.h"
#include "base/functional/bind.h"
#include "base/functional/callback.h"
#include "base/memory/weak_ptr.h"
#include "base/task/sequenced_task_runner.h"
#include "content/common/content_export.h"
namespace content {
// BackgroundSyncOpScheduler runs the scheduled callbacks sequentially. Add an
// operation by calling ScheduleOperation() with your callback. Once your
// operation is done be sure to call CompleteOperationAndRunNext() to schedule
// the next operation. This is a simplified version of CacheStorageScheduler.
class CONTENT_EXPORT BackgroundSyncOpScheduler {
public:
explicit BackgroundSyncOpScheduler(
scoped_refptr<base::SequencedTaskRunner> task_runner);
BackgroundSyncOpScheduler(const BackgroundSyncOpScheduler&) = delete;
BackgroundSyncOpScheduler& operator=(const BackgroundSyncOpScheduler&) =
delete;
virtual ~BackgroundSyncOpScheduler();
// Adds the operation to the tail of the queue and starts it if possible.
void ScheduleOperation(base::OnceClosure closure);
// Call this after each operation completes. It cleans up the operation
// associated with the given id. If may also start the next set of
// operations.
void CompleteOperationAndRunNext();
// Returns true if there are any running or pending operations.
bool ScheduledOperations() const;
// Wraps |callback| to also call CompleteOperationAndRunNext.
template <typename... Args>
base::OnceCallback<void(Args...)> WrapCallbackToRunNext(
base::OnceCallback<void(Args...)> callback) {
return base::BindOnce(
&BackgroundSyncOpScheduler::RunNextContinuation<Args...>,
weak_ptr_factory_.GetWeakPtr(), std::move(callback));
}
protected:
// virtual for testing
virtual void DoneStartingAvailableOperations() {}
private:
class Operation;
// Maybe start running the next operation depending on the current
// set of running operations and the mode of the next operation.
void MaybeRunOperation();
template <typename... Args>
void RunNextContinuation(base::OnceCallback<void(Args...)> callback,
Args... args) {
// Grab a weak ptr to guard against the scheduler being deleted during the
// callback.
base::WeakPtr<BackgroundSyncOpScheduler> scheduler =
weak_ptr_factory_.GetWeakPtr();
std::move(callback).Run(std::forward<Args>(args)...);
if (scheduler)
CompleteOperationAndRunNext();
}
scoped_refptr<base::SequencedTaskRunner> task_runner_;
base::queue<std::unique_ptr<Operation>> pending_operations_;
std::unique_ptr<Operation> running_operation_;
SEQUENCE_CHECKER(sequence_checker_);
base::WeakPtrFactory<BackgroundSyncOpScheduler> weak_ptr_factory_{this};
};
} // namespace content
#endif // CONTENT_BROWSER_BACKGROUND_SYNC_BACKGROUND_SYNC_OP_SCHEDULER_H_
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