1 // Copyright 2016 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 BASE_TASK_SCHEDULER_SEQUENCE_SORT_KEY_H_
6 #define BASE_TASK_SCHEDULER_SEQUENCE_SORT_KEY_H_
7 
8 #include "base/base_export.h"
9 #include "base/task_scheduler/task_traits.h"
10 #include "base/time/time.h"
11 
12 namespace base {
13 namespace internal {
14 
15 // An immutable but assignable representation of the priority of a Sequence.
16 class BASE_EXPORT SequenceSortKey final {
17  public:
18   SequenceSortKey(TaskPriority priority, TimeTicks next_task_sequenced_time);
19 
priority()20   TaskPriority priority() const { return priority_; }
21 
22   bool operator<(const SequenceSortKey& other) const;
23   bool operator>(const SequenceSortKey& other) const { return other < *this; }
24 
25   bool operator==(const SequenceSortKey& other) const {
26     return priority_ == other.priority_ &&
27            next_task_sequenced_time_ == other.next_task_sequenced_time_;
28   }
29   bool operator!=(const SequenceSortKey& other) const {
30     return !(other == *this);
31   };
32 
33  private:
34   // The private section allows this class to keep its immutable property while
35   // being copy-assignable (i.e. instead of making its members const).
36 
37   // Highest task priority in the sequence at the time this sort key was
38   // created.
39   TaskPriority priority_;
40 
41   // Sequenced time of the next task to run in the sequence at the time this
42   // sort key was created.
43   TimeTicks next_task_sequenced_time_;
44 };
45 
46 }  // namespace internal
47 }  // namespace base
48 
49 #endif  // BASE_TASK_SCHEDULER_SEQUENCE_SORT_KEY_H_
50