// Copyright 2013 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 CHROME_BROWSER_CHROMEOS_DRIVE_JOB_QUEUE_H_
#define CHROME_BROWSER_CHROMEOS_DRIVE_JOB_QUEUE_H_
#include <deque>
#include <set>
#include <vector>
#include "chrome/browser/chromeos/drive/job_list.h"
namespace drive {
// Priority queue for managing jobs in JobScheduler.
class JobQueue {
public:
// Creates a queue that allows |num_max_concurrent_jobs| concurrent job
// execution and has |num_priority_levels| levels of priority.
JobQueue(size_t num_max_concurrent_jobs, size_t num_priority_levels);
~JobQueue();
// Pushes a job |id| of |priority|. The job with the smallest priority value
// is popped first (lower values are higher priority). In the same priority,
// the queue is "first-in first-out".
void Push(JobID id, int priority);
// Pops the first job which meets |accepted_priority| (i.e. the first job in
// the queue with equal or higher priority (lower value)), and the limit of
// concurrent job count is satisfied.
//
// For instance, if |accepted_priority| is 1, the first job with priority 0
// (higher priority) in the queue is picked even if a job with priority 1 was
// pushed earlier. If there is no job with priority 0, the first job with
// priority 1 in the queue is picked.
bool PopForRun(int accepted_priority, JobID* id);
// Gets queued jobs with the given priority.
void GetQueuedJobs(int priority, std::vector<JobID>* jobs) const;
// Marks a running job |id| as finished running. This decreases the count
// of running parallel jobs and makes room for other jobs to be popped.
void MarkFinished(JobID id);
// Generates a string representing the internal state for logging.
std::string ToString() const;
// Gets the total number of jobs in the queue.
size_t GetNumberOfJobs() const;
// Removes the job from the queue.
void Remove(JobID id);
private:
size_t num_max_concurrent_jobs_;
std::vector<std::deque<JobID> > queue_;
std::set<JobID> running_;
DISALLOW_COPY_AND_ASSIGN(JobQueue);
};
} // namespace drive
#endif // CHROME_BROWSER_CHROMEOS_DRIVE_JOB_QUEUE_H_