bigbluebutton-Github/bbb-export-annotations/workers/collector.js
2022-08-10 15:03:26 +02:00

103 lines
3.1 KiB
JavaScript

const Logger = require('../lib/utils/logger');
const config = require('../config');
const fs = require('fs');
const redis = require('redis');
const {Worker, workerData} = require('worker_threads');
const path = require('path');
const cp = require('child_process');
const jobId = workerData;
const logger = new Logger('presAnn Collector');
logger.info('Collecting job ' + jobId);
const kickOffProcessWorker = (jobId) => {
return new Promise((resolve, reject) => {
const worker = new Worker('./workers/process.js', {workerData: jobId});
worker.on('message', resolve);
worker.on('error', reject);
worker.on('exit', (code) => {
if (code !== 0) {
reject(new Error(`Process Worker stopped with exit code ${code}`));
}
});
});
};
const dropbox = path.join(config.shared.presAnnDropboxDir, jobId);
// Takes the Job from the dropbox
const job = fs.readFileSync(path.join(dropbox, 'job'));
const exportJob = JSON.parse(job);
// Collect the annotations from Redis
(async () => {
const client = redis.createClient({
host: config.redis.host,
port: config.redis.port,
password: config.redis.password,
});
client.on('error', (err) => logger.info('Redis Client Error', err));
await client.connect();
const presAnn = await client.hGetAll(exportJob.jobId);
// Remove annotations from Redis
await client.del(jobId);
client.disconnect();
const annotations = JSON.stringify(presAnn);
const whiteboard = JSON.parse(annotations);
const pages = JSON.parse(whiteboard.pages);
fs.writeFile(path.join(dropbox, 'whiteboard'), annotations, function(err) {
if (err) {
return logger.error(err);
}
});
// Collect the presentation page files (PDF / PNG / JPEG)
// from the presentation directory
const presFile = path.join(exportJob.presLocation, exportJob.presId);
const pdfFile = `${presFile}.pdf`;
if (fs.existsSync(pdfFile)) {
for (const p of pages) {
const pageNumber = p.page;
const outputFile = path.join(dropbox, `slide${pageNumber}`);
// CairoSVG doesn't handle transparent SVG and PNG embeds properly,
// e.g., in rasterized text. So textboxes may get a black background
// when downloading/exporting repeatedly. To avoid that, we take slides
// from the uploaded file, but later probe the dimensions from the SVG
// so it matches what was shown in the browser.
const extract_png_from_pdf = [
'-png',
'-f', pageNumber,
'-l', pageNumber,
'-scale-to', config.collector.pngWidthRasterizedSlides,
'-singlefile',
'-cropbox',
pdfFile, outputFile,
];
cp.spawnSync(config.shared.pdftocairo, extract_png_from_pdf, {shell: false});
}
// If PNG file already available
} else if (fs.existsSync(`${presFile}.png`)) {
fs.copyFileSync(`${presFile}.png`, path.join(dropbox, 'slide1.png'));
// If JPEG file available
} else if (fs.existsSync(`${presFile}.jpeg`)) {
fs.copyFileSync(`${presFile}.jpeg`, path.join(dropbox, 'slide1.jpeg'));
} else {
return logger.error(`Could not find presentation file ${exportJob.jobId}`);
}
kickOffProcessWorker(exportJob.jobId);
})();