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content / browser / renderer_host / visible_time_request_trigger.h [blame]
// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CONTENT_BROWSER_RENDERER_HOST_VISIBLE_TIME_REQUEST_TRIGGER_H_
#define CONTENT_BROWSER_RENDERER_HOST_VISIBLE_TIME_REQUEST_TRIGGER_H_
#include "content/common/content_export.h"
#include "third_party/blink/public/mojom/widget/record_content_to_visible_time_request.mojom.h"
namespace base {
class TimeTicks;
} // namespace base
namespace content {
// Records the time of an event that will make a WebContents become visible,
// and the reason it will become visible. This time will be passed to the
// compositor and used to calculate the latency before the visible WebContents
// appears.
//
// This class holds a single RecordContentToVisibleTimeRequestPtr that is
// modified whenever UpdateRequest is called, and cleared whenever TakeRequest
// is called. This means that calling UpdateRequest for multiple overlapping
// events without calling TakeRequest in between will record metrics for all
// events using the same timestamps instead of tracking each event separately.
//
// TODO(crbug.com/40203057): Stop doing that. There should be a separate start
// time for each event.
class CONTENT_EXPORT VisibleTimeRequestTrigger {
public:
VisibleTimeRequestTrigger();
~VisibleTimeRequestTrigger();
VisibleTimeRequestTrigger(const VisibleTimeRequestTrigger&) = delete;
VisibleTimeRequestTrigger& operator=(const VisibleTimeRequestTrigger&) =
delete;
// Returns a RecordContentToVisibleTimeRequestPtr that combines all passed
// requests, OR'ing all flags and using the minimum start time. Any null
// requests are ignored. The return value will only be nullptr if all
// arguments are nullptr. This function consumes its arguments.
static blink::mojom::RecordContentToVisibleTimeRequestPtr
ConsumeAndMergeRequests(
blink::mojom::RecordContentToVisibleTimeRequestPtr request1,
blink::mojom::RecordContentToVisibleTimeRequestPtr request2);
// Set the last time a content to visible event starts to be processed for
// this WebContents. Will merge with the previous value if it exists (which
// means that several events may happen at the same time and must be
// individually reported). |start_time| marks event start time to calculate
// the duration later.
//
// |destination_is_loaded| is true when
// ResourceCoordinatorTabHelper::IsLoaded() is true for the new tab
// contents. It is only used when |show_reason_tab_switching| is true.
// |show_reason_tab_switching| is true when tab switch event should be
// reported.
// |show_reason_bfcache_restore| is true when page restored from bfcache event
// should be reported.
void UpdateRequest(base::TimeTicks start_time,
bool destination_is_loaded,
bool show_reason_tab_switching,
bool show_reason_bfcache_restore);
// Returns the time set by UpdateRequest. If this was not preceded by a call
// to UpdateRequest it will return nullptr. Calling this will reset
// |last_request_| to null.
blink::mojom::RecordContentToVisibleTimeRequestPtr TakeRequest();
private:
// The last visible event start request. This should only be set and
// retrieved using UpdateRequest and TakeRequest.
blink::mojom::RecordContentToVisibleTimeRequestPtr last_request_;
};
} // namespace content
#endif // CONTENT_BROWSER_RENDERER_HOST_VISIBLE_TIME_REQUEST_TRIGGER_H_