storage/browser/quota/quota_task.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 STORAGE_BROWSER_QUOTA_QUOTA_TASK_H_
   6 #define STORAGE_BROWSER_QUOTA_QUOTA_TASK_H_
   7
   8 #include <set>
   9
  10 #include "base/basictypes.h"
  11 #include "base/compiler_specific.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "base/sequenced_task_runner_helpers.h"
  14 #include "storage/browser/storage_browser_export.h"
  15
  16 namespace base {
  17 class SingleThreadTaskRunner;
  18 class TaskRunner;
  19 }
  20
  21 namespace storage {
  22
  23 class QuotaTaskObserver;
  24
  25 // A base class for quota tasks.
  26 // TODO(kinuko): Revise this using base::Callback.
  27 class QuotaTask {
  28  public:
  29   void Start();
  30
  31  protected:
  32   explicit QuotaTask(QuotaTaskObserver* observer);
  33   virtual ~QuotaTask();
  34
  35   // The task body.
  36   virtual void Run() = 0;
  37
  38   // Called upon completion, on the original message loop.
  39   virtual void Completed() = 0;
  40
  41   // Called when the task is aborted.
  42   virtual void Aborted() {}
  43
  44   void CallCompleted();
  45
  46   // Call this to delete itself.
  47   void DeleteSoon();
  48
  49   QuotaTaskObserver* observer() const { return observer_; }
  50   base::SingleThreadTaskRunner* original_task_runner() const {
  51     return original_task_runner_.get();
  52   }
  53
  54  private:
  55   friend class base::DeleteHelper<QuotaTask>;
  56   friend class QuotaTaskObserver;
  57
  58   void Abort();
  59   QuotaTaskObserver* observer_;
  60   scoped_refptr<base::SingleThreadTaskRunner> original_task_runner_;
  61   bool delete_scheduled_;
  62 };
  63
  64 class STORAGE_EXPORT QuotaTaskObserver {
  65  protected:
  66   friend class QuotaTask;
  67
  68   QuotaTaskObserver();
  69   virtual ~QuotaTaskObserver();
  70
  71   void RegisterTask(QuotaTask* task);
  72   void UnregisterTask(QuotaTask* task);
  73
  74   typedef std::set<QuotaTask*> TaskSet;
  75   TaskSet running_quota_tasks_;
  76 };
  77 }
  78
  79 #endif  // STORAGE_BROWSER_QUOTA_QUOTA_TASK_H_