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207/**
* Copyright (c) Microsoft Corporation.
*
* Licensed under the Apache License, Version 2.0 (the 'License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import path from 'path';
import { assert, createGuid, eventsHelper, RegisteredListener } from '../utils';
import { debugLogger } from '../utils';
import { VideoRecorder } from './videoRecorder';
import { Page } from './page';
import { registry } from './registry';
import type * as types from './types';
export class Screencast {
private _page: Page;
private _videoRecorder: VideoRecorder | null = null;
private _videoId: string | null = null;
private _screencastClients = new Set<unknown>();
// Aiming at 25 fps by default - each frame is 40ms, but we give some slack with 35ms.
// When throttling for tracing, 200ms between frames, except for 10 frames around the action.
private _frameThrottler = new FrameThrottler(10, 35, 200);
private _frameListener: RegisteredListener | null = null;
constructor(page: Page) {
this._page = page;
}
stopFrameThrottler() {
this._frameThrottler.dispose();
}
setOptions(options: { width: number, height: number, quality: number } | null) {
this._setOptions(options).catch(e => debugLogger.log('error', e));
this._frameThrottler.setThrottlingEnabled(!!options);
}
throttleFrameAck(ack: () => void) {
// Don't ack immediately, tracing has smart throttling logic that is implemented here.
this._frameThrottler.ack(ack);
}
temporarilyDisableThrottling() {
this._frameThrottler.recharge();
}
launchVideoRecorder(): types.VideoOptions | undefined {
const recordVideo = this._page.browserContext._options.recordVideo;
if (!recordVideo)
return undefined;
assert(!this._videoId);
this._videoId = createGuid();
const outputFile = path.join(recordVideo.dir, this._videoId + '.webm');
const videoOptions = {
// validateBrowserContextOptions ensures correct video size.
...recordVideo.size!,
outputFile,
};
// Note: it is important to start video recorder before sending Screencast.startScreencast,
// and it is equally important to send Screencast.startScreencast before sending Target.resume.
const ffmpegPath = registry.findExecutable('ffmpeg')!.executablePathOrDie(this._page.browserContext._browser.sdkLanguage());
this._videoRecorder = new VideoRecorder(ffmpegPath, videoOptions);
this._frameListener = eventsHelper.addEventListener(this._page, Page.Events.ScreencastFrame, frame => this._videoRecorder!.writeFrame(frame.buffer, frame.frameSwapWallTime / 1000));
this._page.waitForInitializedOrError().then(p => {
if (p instanceof Error)
this.stopVideoRecording().catch(() => {});
});
return videoOptions;
}
async startVideoRecording(options: types.VideoOptions) {
const videoId = this._videoId;
assert(videoId);
this._page.once(Page.Events.Close, () => this.stopVideoRecording().catch(() => {}));
const gotFirstFrame = new Promise(f => this._page.once(Page.Events.ScreencastFrame, f));
await this._startScreencast(this._videoRecorder, {
quality: 90,
width: options.width,
height: options.height,
});
// Wait for the first frame before reporting video to the client.
gotFirstFrame.then(() => {
this._page.browserContext._browser._videoStarted(this._page.browserContext, videoId, options.outputFile, this._page.waitForInitializedOrError());
});
}
async stopVideoRecording(): Promise<void> {
if (!this._videoId)
return;
if (this._frameListener)
eventsHelper.removeEventListeners([this._frameListener]);
this._frameListener = null;
const videoId = this._videoId;
this._videoId = null;
const videoRecorder = this._videoRecorder!;
this._videoRecorder = null;
await this._stopScreencast(videoRecorder);
await videoRecorder.stop();
// Keep the video artifact in the map until encoding is fully finished, if the context
// starts closing before the video is fully written to disk it will wait for it.
const video = this._page.browserContext._browser._takeVideo(videoId);
video?.reportFinished();
}
private async _setOptions(options: { width: number, height: number, quality: number } | null): Promise<void> {
if (options)
await this._startScreencast(this, options);
else
await this._stopScreencast(this);
}
private async _startScreencast(client: unknown, options: { width: number, height: number, quality: number }) {
this._screencastClients.add(client);
if (this._screencastClients.size === 1) {
await this._page.delegate.startScreencast({
width: options.width,
height: options.height,
quality: options.quality,
});
}
}
private async _stopScreencast(client: unknown) {
this._screencastClients.delete(client);
if (!this._screencastClients.size)
await this._page.delegate.stopScreencast();
}
}
class FrameThrottler {
private _acks: (() => void)[] = [];
private _defaultInterval: number;
private _throttlingInterval: number;
private _nonThrottledFrames: number;
private _budget: number;
private _throttlingEnabled = false;
private _timeoutId: NodeJS.Timeout | undefined;
constructor(nonThrottledFrames: number, defaultInterval: number, throttlingInterval: number) {
this._nonThrottledFrames = nonThrottledFrames;
this._budget = nonThrottledFrames;
this._defaultInterval = defaultInterval;
this._throttlingInterval = throttlingInterval;
this._tick();
}
dispose() {
if (this._timeoutId) {
clearTimeout(this._timeoutId);
this._timeoutId = undefined;
}
}
setThrottlingEnabled(enabled: boolean) {
this._throttlingEnabled = enabled;
}
recharge() {
// Send all acks, reset budget.
for (const ack of this._acks)
ack();
this._acks = [];
this._budget = this._nonThrottledFrames;
if (this._timeoutId) {
clearTimeout(this._timeoutId);
this._tick();
}
}
ack(ack: () => void) {
if (!this._timeoutId) {
// Already disposed.
ack();
return;
}
this._acks.push(ack);
}
private _tick() {
const ack = this._acks.shift();
if (ack) {
--this._budget;
ack();
}
if (this._throttlingEnabled && this._budget <= 0) {
// Non-throttled frame budget is exceeded. Next ack will be throttled.
this._timeoutId = setTimeout(() => this._tick(), this._throttlingInterval);
} else {
// Either not throttling, or still under budget. Next ack will be after the default timeout.
this._timeoutId = setTimeout(() => this._tick(), this._defaultInterval);
}
}
}