content/browser/cache_storage/cache_storage_scheduler.h

   1 // Copyright 2015 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 CONTENT_BROWSER_CACHE_STORAGE_CACHE_STORAGE_SCHEDULER_H_
   6 #define CONTENT_BROWSER_CACHE_STORAGE_CACHE_STORAGE_SCHEDULER_H_
   7
   8 #include <list>
   9
  10 #include "base/callback.h"
  11 #include "content/common/content_export.h"
  12
  13 namespace content {
  14
  15 // TODO(jkarlin): Support readers and writers so operations can run in parallel.
  16 // TODO(jkarlin): Support operation identification so that ops can be checked in
  17 // DCHECKs.
  18
  19 // CacheStorageScheduler runs the scheduled callbacks sequentially. Add an
  20 // operation by calling ScheduleOperation() with your callback. Once your
  21 // operation is done be sure to call CompleteOperationAndRunNext() to schedule
  22 // the next operation.
  23 class CONTENT_EXPORT CacheStorageScheduler {
  24  public:
  25   CacheStorageScheduler();
  26   virtual ~CacheStorageScheduler();
  27
  28   // Adds the operation to the tail of the queue and starts it if the scheduler
  29   // is idle.
  30   void ScheduleOperation(const base::Closure& closure);
  31
  32   // Call this after each operation completes. It cleans up the current
  33   // operation and starts the next.
  34   void CompleteOperationAndRunNext();
  35
  36   // Returns true if there are any running or pending operations.
  37   bool ScheduledOperations() const;
  38
  39  private:
  40   void RunOperationIfIdle();
  41
  42   // The list of operations waiting on initialization.
  43   std::list<base::Closure> pending_operations_;
  44   bool operation_running_;
  45
  46   DISALLOW_COPY_AND_ASSIGN(CacheStorageScheduler);
  47 };
  48
  49 }  // namespace content
  50
  51 #endif  // CONTENT_BROWSER_CACHE_STORAGE_CACHE_STORAGE_SCHEDULER_H_