chrome/browser/chromeos/drive/job_queue.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_BROWSER_CHROMEOS_DRIVE_JOB_QUEUE_H_
   6 #define CHROME_BROWSER_CHROMEOS_DRIVE_JOB_QUEUE_H_
   7
   8 #include <deque>
   9 #include <set>
  10 #include <vector>
  11
  12 #include "chrome/browser/chromeos/drive/job_list.h"
  13
  14 namespace drive {
  15
  16 // Priority queue for managing jobs in JobScheduler.
  17 class JobQueue {
  18  public:
  19   // Creates a queue that allows |num_max_concurrent_jobs| concurrent job
  20   // execution and has |num_priority_levels| levels of priority.
  21   JobQueue(size_t num_max_concurrent_jobs, size_t num_priority_levels);
  22   ~JobQueue();
  23
  24   // Pushes a job |id| of |priority|. The job with the smallest priority value
  25   // is popped first (lower values are higher priority). In the same priority,
  26   // the queue is "first-in first-out".
  27   void Push(JobID id, int priority);
  28
  29   // Pops the first job which meets |accepted_priority| (i.e. the first job in
  30   // the queue with equal or higher priority (lower value)), and the limit of
  31   // concurrent job count is satisfied.
  32   //
  33   // For instance, if |accepted_priority| is 1, the first job with priority 0
  34   // (higher priority) in the queue is picked even if a job with priority 1 was
  35   // pushed earlier. If there is no job with priority 0, the first job with
  36   // priority 1 in the queue is picked.
  37   bool PopForRun(int accepted_priority, JobID* id);
  38
  39   // Gets queued jobs with the given priority.
  40   void GetQueuedJobs(int priority, std::vector<JobID>* jobs) const;
  41
  42   // Marks a running job |id| as finished running. This decreases the count
  43   // of running parallel jobs and makes room for other jobs to be popped.
  44   void MarkFinished(JobID id);
  45
  46   // Generates a string representing the internal state for logging.
  47   std::string ToString() const;
  48
  49   // Gets the total number of jobs in the queue.
  50   size_t GetNumberOfJobs() const;
  51
  52   // Removes the job from the queue.
  53   void Remove(JobID id);
  54
  55  private:
  56   size_t num_max_concurrent_jobs_;
  57   std::vector<std::deque<JobID> > queue_;
  58   std::set<JobID> running_;
  59
  60   DISALLOW_COPY_AND_ASSIGN(JobQueue);
  61 };
  62
  63 }  // namespace drive
  64
  65 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_JOB_QUEUE_H_