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f72d9dd08b
Summary: If tracking is enabled and the sampling check passes on a scroll or layout event, we compare the scroll offset to the layout of the rendered items. If the items don't cover the visible area of the list, we fire an `onFillRateExceeded` call with relevant stats for logging the event through an analytics pipeline. The measurement methodology is a little jank because everything is async, but it seems directionally useful for getting ballpark numbers, catching regressions, and tracking improvements. Benchmark testing shows a ~2014 MotoX starts hitting the fill rate limit at about 2500 px / sec, which is pretty fast scrolling. This also reworks our frame rate stuff so we can use a shared `SceneTracking` thing and track blankness globally. Reviewed By: bvaughn Differential Revision: D4806867 fbshipit-source-id: 119bf177463c8c3aa51fa13d1a9d03b1a96042aa
31 lines
958 B
JavaScript
31 lines
958 B
JavaScript
/**
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* Copyright (c) 2015-present, Facebook, Inc.
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* All rights reserved.
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*
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* This source code is licensed under the BSD-style license found in the
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* LICENSE file in the root directory of this source tree. An additional grant
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* of patent rights can be found in the PATENTS file in the same directory.
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*
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*/
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'use strict';
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jest.unmock('SceneTracker');
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const SceneTracker = require('SceneTracker');
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describe('setActiveScene', function() {
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it('can handle multiple listeners and unsubscribe', function() {
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const listeners = [jest.fn(), jest.fn(), jest.fn()];
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const subscriptions = listeners.map(
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(listener) => SceneTracker.addActiveSceneChangedListener(listener)
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);
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subscriptions[1].remove();
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const newScene = {name: 'scene1'};
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SceneTracker.setActiveScene(newScene);
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expect(listeners[0]).toBeCalledWith(newScene);
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expect(listeners[1]).not.toBeCalled();
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expect(listeners[2]).toBeCalledWith(newScene);
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});
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});
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