text: // Copyright 2013 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #ifndef UI_LATENCY_LATENCY_INFO_H_
  #define UI_LATENCY_LATENCY_INFO_H_
  
  #include <stdint.h>
  
  #include <map>
  #include <memory>
  #include <utility>
  #include <vector>
  
  #include "base/containers/flat_map.h"
  #include "base/time/time.h"
  #include "build/build_config.h"
  #include "services/metrics/public/cpp/ukm_source_id.h"
  #include "third_party/perfetto/protos/perfetto/trace/track_event/chrome_latency_info.pbzero.h"
  #include "ui/gfx/geometry/point_f.h"
  
  #if !defined(OS_IOS)
  #include "ipc/ipc_param_traits.h"  // nogncheck
  #include "mojo/public/cpp/bindings/struct_traits.h"  // nogncheck
  #endif
  
  namespace ui {
  
  #if !defined(OS_IOS)
  namespace mojom {
  class LatencyInfoDataView;
  }
  #endif
  
  // When adding new components, or new metrics based on LatencyInfo,
  // please update latency_info.dot.
  //
  // When adding new components, please update
  // //third_party/perfetto/protos/perfetto/trace/track_event/chrome_latency_info.proto
  // so both this and the internal versions can be kept up to date. Or reach out
  // to tracing@chromium.org so we can assist.
  enum LatencyComponentType {
    // ---------------------------BEGIN COMPONENT-------------------------------
    // BEGIN COMPONENT is when we show the latency begin in chrome://tracing.
    // Timestamp when the input event is sent from RenderWidgetHost to renderer.
    INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT,
    // ---------------------------NORMAL COMPONENT-------------------------------
    // The original timestamp of the touch event which converts to scroll update.
    INPUT_EVENT_LATENCY_SCROLL_UPDATE_ORIGINAL_COMPONENT,
    // The original timestamp of the touch event which converts to the *first*
    // scroll update in a scroll gesture sequence.
    INPUT_EVENT_LATENCY_FIRST_SCROLL_UPDATE_ORIGINAL_COMPONENT,
    // Original timestamp for input event (e.g. timestamp from kernel).
    INPUT_EVENT_LATENCY_ORIGINAL_COMPONENT,
    // Timestamp when the UI event is created.
    INPUT_EVENT_LATENCY_UI_COMPONENT,
    // Timestamp when the event is dispatched on the main thread of the renderer.
    INPUT_EVENT_LATENCY_RENDERER_MAIN_COMPONENT,
    // This is special component indicating there is rendering scheduled for
    // the event associated with this LatencyInfo on main thread.
    INPUT_EVENT_LATENCY_RENDERING_SCHEDULED_MAIN_COMPONENT,
    // This is special component indicating there is rendering scheduled for
    // the event associated with this LatencyInfo on impl thread.
    INPUT_EVENT_LATENCY_RENDERING_SCHEDULED_IMPL_COMPONENT,
    // Original timestamp of the last event that has been coalesced into this one.
    INPUT_EVENT_LATENCY_SCROLL_UPDATE_LAST_EVENT_COMPONENT,
    // Timestamp when the frame is swapped in renderer.
    INPUT_EVENT_LATENCY_RENDERER_SWAP_COMPONENT,
    // Timestamp of when the display compositor receives a compositor frame from
    // the renderer.
    // Display compositor can be either in the browser process or in Mus.
    DISPLAY_COMPOSITOR_RECEIVED_FRAME_COMPONENT,
    // Timestamp of when the gpu service began swap buffers, unlike
    // INPUT_EVENT_LATENCY_FRAME_SWAP_COMPONENT which measures after.
    INPUT_EVENT_GPU_SWAP_BUFFER_COMPONENT,
    // Timestamp when the frame is swapped (i.e. when the rendering caused by
    // input event actually takes effect).
    INPUT_EVENT_LATENCY_FRAME_SWAP_COMPONENT,
  
    LATENCY_COMPONENT_TYPE_LAST = INPUT_EVENT_LATENCY_FRAME_SWAP_COMPONENT,
  };
  
  enum class SourceEventType {
    UNKNOWN,
    WHEEL,
    MOUSE,
    TOUCH,
    INERTIAL,
    KEY_PRESS,
    // TODO(crbug.com/868056) Touchpad scrolling latency report as WHEEL.
    TOUCHPAD,
    SCROLLBAR,
    OTHER,
    LAST = OTHER,
  };
  
  class LatencyInfo {
   public:
    enum : size_t { kMaxInputCoordinates = 2 };
  
    // Map a Latency Component (with a component-specific int64_t id) to a
    // timestamp.
    using LatencyMap = base::flat_map<LatencyComponentType, base::TimeTicks>;
  
    LatencyInfo();
    LatencyInfo(const LatencyInfo& other);
    LatencyInfo(LatencyInfo&& other);
    LatencyInfo(SourceEventType type);
    ~LatencyInfo();
  
    // For test only.
    LatencyInfo(int64_t trace_id, bool terminated);
  
    LatencyInfo& operator=(const LatencyInfo& other);
  
    // Returns true if the vector |latency_info| is valid. Returns false
    // if it is not valid and log the |referring_msg|.
    // This function is mainly used to check the latency_info vector that
    // is passed between processes using IPC message has reasonable size
    // so that we are confident the IPC message is not corrupted/compromised.
    // This check will go away once the IPC system has better built-in scheme
    // for corruption/compromise detection.
    static bool Verify(const std::vector<LatencyInfo>& latency_info,
                       const char* referring_msg);
  
    // Adds trace flow events only to LatencyInfos that are being traced.
    static void TraceIntermediateFlowEvents(
        const std::vector<LatencyInfo>& latency_info,
        perfetto::protos::pbzero::ChromeLatencyInfo::Step step);
  
    // Copy timestamp with type |type| from |other| into |this|.
    void CopyLatencyFrom(const LatencyInfo& other, LatencyComponentType type);
  
    // Add timestamps for components that are in |other| but not in |this|.
    void AddNewLatencyFrom(const LatencyInfo& other);
  
    // Modifies the current sequence number for a component, and adds a new
    // sequence number with the current timestamp.
    void AddLatencyNumber(LatencyComponentType component);
  
    // Similar to |AddLatencyNumber|, and also appends |trace_name_str| to
    // the trace event's name.
    // This function should only be called when adding a BEGIN component.
    void AddLatencyNumberWithTraceName(LatencyComponentType component,
                                       const char* trace_name_str);
  
    // Modifies the current sequence number and adds a certain number of events
    // for a specific component.
    void AddLatencyNumberWithTimestamp(LatencyComponentType component,
                                       base::TimeTicks time);
  
    // Returns true if a component with |type| is found in the latency component.
    // The first such component (when iterating over latency_components_) is
    // stored to |output| if |output| is not NULL. Returns false if no such
    // component is found.
    bool FindLatency(LatencyComponentType type, base::TimeTicks* output) const;
  
    void Terminate();
  
    // When GestureScrollUpdate events are coalesced, update the aggregated
    // event's scroll_update_delta and the SCROLL_UPDATE_LAST_EVENT_COMPONENT.
    void CoalesceScrollUpdateWith(const LatencyInfo& other);
  
    // Scale scroll_update_delta and predicted_scroll_update_delta.
    LatencyInfo ScaledBy(float scale) const;
  
    const LatencyMap& latency_components() const { return latency_components_; }
  
    const SourceEventType& source_event_type() const {
      return source_event_type_;
    }
    void set_source_event_type(SourceEventType type) {
      source_event_type_ = type;
    }
  
    bool began() const { return began_; }
    bool terminated() const { return terminated_; }
    void set_coalesced() { coalesced_ = true; }
    bool coalesced() const { return coalesced_; }
    int64_t trace_id() const { return trace_id_; }
    void set_trace_id(int64_t trace_id) { trace_id_ = trace_id; }
    ukm::SourceId ukm_source_id() const { return ukm_source_id_; }
    void set_ukm_source_id(ukm::SourceId id) { ukm_source_id_ = id; }
    void set_scroll_update_delta(float delta) { scroll_update_delta_ = delta; }
    float scroll_update_delta() const { return scroll_update_delta_; }
    void set_predicted_scroll_update_delta(float delta) {
      predicted_scroll_update_delta_ = delta;
    }
    float predicted_scroll_update_delta() const {
      return predicted_scroll_update_delta_;
    }
    int64_t gesture_scroll_id() const { return gesture_scroll_id_; }
    void set_gesture_scroll_id(int64_t id) { gesture_scroll_id_ = id; }
    int64_t touch_trace_id() const { return touch_trace_id_; }
    void set_touch_trace_id(int64_t id) { touch_trace_id_ = id; }
  
   private:
    void AddLatencyNumberWithTimestampImpl(LatencyComponentType component,
                                           base::TimeTicks time,
                                           const char* trace_name_str);
  
    LatencyMap latency_components_;
  
    // The unique id for matching the ASYNC_BEGIN/END trace event.
    int64_t trace_id_;
    // UKM Source id to be used for recording UKM metrics associated with this
    // event.
    ukm::SourceId ukm_source_id_;
    // Whether this event has been coalesced into another event.
    bool coalesced_;
    // Whether a begin component has been added.
    bool began_;
    // Whether a terminal component has been added.
    bool terminated_;
    // Stores the type of the first source event.
    SourceEventType source_event_type_;
  
    float scroll_update_delta_;
    float predicted_scroll_update_delta_;
  
    // The unique id for denoting a scroll gesture. This is only set for
    // GestureScrollBegin, GestureScrollUpdate, and GestureScrollEnd events, and
    // allows easy grouping of these global async events into a single logical
    // scroll in the sql interface of TBMv3 (Trace Based Metrics v3). As a current
    // implementation detail this unique id comes from the |trace_id| of the
    // associated GestureScrollBegin (-1 if there was none or it wasn't valid).
    int64_t gesture_scroll_id_;
    // The unique id for denoting a touch, tracking from TouchStart through
    // TouchMoves to TouchEnd. Used for TBMv3 metrics as in the same way as
    // gesture_scroll_id_.
    int64_t touch_trace_id_;
  
  #if !defined(OS_IOS)
    friend struct IPC::ParamTraits<ui::LatencyInfo>;
    friend struct mojo::StructTraits<ui::mojom::LatencyInfoDataView,
                                     ui::LatencyInfo>;
  #endif
  };
  
  // This is declared here for use in gtest-based unit tests, but is defined in
  // //ui/latency:test_support target.
  // Without this the default PrintTo template in gtest tries to pass LatencyInfo
  // by value, which leads to an alignment compile error on Windows.
  void PrintTo(const LatencyInfo& latency, ::std::ostream* os);
  
  }  // namespace ui
  
  #endif  // UI_LATENCY_LATENCY_INFO_H_
  