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 UI_BASE_LATENCY_INFO_H_
6#define UI_BASE_LATENCY_INFO_H_
7
8#include <map>
9#include <utility>
10
11#include "base/basictypes.h"
12#include "base/time/time.h"
13#include "ui/base/ui_export.h"
14
15namespace ui {
16
17enum LatencyComponentType {
18  // Timestamp when the input event is sent from RenderWidgetHost to renderer.
19  INPUT_EVENT_LATENCY_RWH_COMPONENT,
20  // Timestamp when the scroll update gesture event is sent from RWH to
21  // renderer. In Aura, touch event's LatencyInfo is carried over to the gesture
22  // event. So gesture event's INPUT_EVENT_LATENCY_RWH_COMPONENT is the
23  // timestamp when its original touch events is sent from RWH to renderer.
24  // In non-aura platform, INPUT_EVENT_LATENCY_SCROLL_UPDATE_RWH_COMPONENT
25  // is the same as INPUT_EVENT_LATENCY_RWH_COMPONENT.
26  INPUT_EVENT_LATENCY_SCROLL_UPDATE_RWH_COMPONENT,
27  // The original timestamp of the touch event which converts to scroll update.
28  INPUT_EVENT_LATENCY_SCROLL_UPDATE_ORIGINAL_COMPONENT,
29  // Original timestamp for input event (e.g. timestamp from kernel).
30  INPUT_EVENT_LATENCY_ORIGINAL_COMPONENT,
31  // Timestamp when the UI event is created.
32  INPUT_EVENT_LATENCY_UI_COMPONENT,
33  // Timestamp when the event is acked from renderer. This is currently set
34  // only for touch events.
35  INPUT_EVENT_LATENCY_ACKED_COMPONENT
36};
37
38struct UI_EXPORT LatencyInfo {
39  struct LatencyComponent {
40    // Nondecreasing number that can be used to determine what events happened
41    // in the component at the time this struct was sent on to the next
42    // component.
43    int64 sequence_number;
44    // Average time of events that happened in this component.
45    base::TimeTicks event_time;
46    // Count of events that happened in this component
47    uint32 event_count;
48  };
49
50  // Map a Latency Component (with a component-specific int64 id) to a
51  // component info.
52  typedef std::map<std::pair<LatencyComponentType, int64>, LatencyComponent>
53      LatencyMap;
54
55  LatencyInfo();
56
57  ~LatencyInfo();
58
59  // Merges the contents of another LatencyInfo into this one.
60  void MergeWith(const LatencyInfo& other);
61
62  // Add LatencyComponents that are in |other| but not in |this|.
63  void AddNewLatencyFrom(const LatencyInfo& other);
64
65  // Modifies the current sequence number for a component, and adds a new
66  // sequence number with the current timestamp.
67  void AddLatencyNumber(LatencyComponentType component,
68                        int64 id,
69                        int64 component_sequence_number);
70
71  // Modifies the current sequence number and adds a certain number of events
72  // for a specific component.
73  void AddLatencyNumberWithTimestamp(LatencyComponentType component,
74                                     int64 id,
75                                     int64 component_sequence_number,
76                                     base::TimeTicks time,
77                                     uint32 event_count);
78
79  // Returns true if the a component with |type| and |id| is found in
80  // the latency_components and the component is stored to |output| if
81  // |output| is not NULL. Returns false if no such component is found.
82  bool FindLatency(LatencyComponentType type,
83                   int64 id,
84                   LatencyComponent* output) const;
85
86  void Clear();
87
88  LatencyMap latency_components;
89
90  // This represents the final time that a frame is displayed it.
91  base::TimeTicks swap_timestamp;
92};
93
94}  // namespace ui
95
96#endif  // UI_BASE_LATENCY_INFO_H_
97