webshot-factory/dist/lib/shot-pool.js

screenshots at scale based on headless chrome

"use strict";
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
    return new (P || (P = Promise))(function (resolve, reject) {
        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
        step((generator = generator.apply(thisArg, _arguments || [])).next());
    });
};
Object.defineProperty(exports, "__esModule", { value: true });
const job_queue_1 = require("./job-queue");
const shot_worker_1 = require("./shot-worker");
const _ = require("lodash");
const Logger = require("log4js");
const ON_DEATH = require("death");
let _logger = Logger.getLogger("shot-pool");
let idleWorkers = [];
let allWorkers = [];
let jobQueue = new job_queue_1.JobQueue();
let opts;
let concurrency = 0;
function create(options) {
    return __awaiter(this, void 0, void 0, function* () {
        opts = options;
        return addWorkers(options.concurrency);
    });
}
exports.create = create;
function addWorkers(numWorkers) {
    return __awaiter(this, void 0, void 0, function* () {
        try {
            let newWorkers = yield Promise.all(_.range(numWorkers).map((idx) => {
                return shot_worker_1.ShotWorker.create(concurrency + idx, opts);
            }));
            idleWorkers.push(...newWorkers);
            allWorkers.push(...newWorkers);
            concurrency += numWorkers;
        }
        catch (e) {
            _logger.error("error while adding worker to the queue", e);
            throw e;
        }
    });
}
function getShot(url) {
    return new Promise((resolve, reject) => {
        jobQueue.enqueue({
            url: url,
            done: (err, buffer) => {
                if (err) {
                    return reject(err);
                }
                return resolve(buffer);
            }
        });
    });
}
exports.getShot = getShot;
function getStatus() {
    return {
        jobQueue,
        allWorkers,
        idleWorkers
    };
}
exports.getStatus = getStatus;
let processJob = () => __awaiter(this, void 0, void 0, function* () {
    if (idleWorkers.length && jobQueue.hasJobs()) {
        let worker = idleWorkers.pop();
        let job = jobQueue.dequeue();
        try {
            let buffer = yield worker.takeShot(job.url);
            job.done(null, buffer);
        }
        catch (err) {
            _logger.error("error while taking screenshot", err);
            job.done(err, null);
        }
        finally {
            idleWorkers.unshift(worker);
            processJob();
        }
    }
});
jobQueue.on('process', processJob);
ON_DEATH(() => __awaiter(this, void 0, void 0, function* () {
    _logger.info('Exiting ...', allWorkers.length);
    yield Promise.all(allWorkers.map((worker) => {
        console.log(`Exiting Worker ${worker.id}`);
        return worker.exit();
    }));
    process.exit();
}));
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