Receivers: Added playlist support

receivers/common/web/UtilityBackend.ts

@@ -0,0 +1,74 @@
+import * as fs from 'fs';
+import { http, https } from 'modules/follow-redirects';
+import * as memfs from 'modules/memfs';
+import { Logger, LoggerType } from 'common/Logger';
+const logger = new Logger('UtilityBackend', LoggerType.BACKEND);
+
+export function deepEqual(x, y) {
+    const ok = Object.keys, tx = typeof x, ty = typeof y;
+    return x && y && tx === 'object' && tx === ty ? (
+        ok(x).length === ok(y).length &&
+        ok(x).every(key => deepEqual(x[key], y[key]))
+    ) : (x === y);
+}
+
+export async function fetchJSON(url: string): Promise<any> {
+    const protocol = url.startsWith('https') ? https : http;
+
+    return new Promise((resolve, reject) => {
+        protocol.get(url, (res) => {
+            let data = '';
+            res.on('data', (chunk) => {
+                data += chunk;
+            });
+
+            res.on('end', () => {
+                try {
+                    resolve(JSON.parse(data));
+                } catch (err) {
+                    reject(err);
+                }
+            });
+        }).on('error', (err) => {
+            reject(err);
+        });
+    });
+}
+
+export async function downloadFile(url: string, destination: string, startCb: (downloadSize: number) => boolean = null, progressCb: (downloadedBytes: number, downloadSize: number) => void = null, finishCb: (downloadedBytes: number) => void = null, inMemory: boolean = false): Promise<void> {
+    return new Promise((resolve, reject) => {
+        const file = inMemory ? memfs.fs.createWriteStream(destination) : fs.createWriteStream(destination);
+        const protocol = url.startsWith('https') ? https : http;
+
+        protocol.get(url, (response) => {
+            const downloadSize = Number(response.headers['content-length']);
+            logger.info(`Downloading file ${url} to ${destination} with size: ${downloadSize} bytes`);
+            if (startCb) {
+                if (!startCb(downloadSize)) {
+                    file.close();
+                    reject('Error: Aborted download');
+                }
+            }
+
+            response.pipe(file);
+            let downloadedBytes = 0;
+
+            response.on('data', (chunk) => {
+                downloadedBytes += chunk.length;
+                if (progressCb) {
+                    progressCb(downloadedBytes, downloadSize);
+                }
+            });
+            file.on('finish', () => {
+                file.close();
+                if (finishCb) {
+                    finishCb(downloadedBytes);
+                }
+                resolve();
+            });
+        }).on('error', (err) => {
+            file.close();
+            reject(err);
+        });
+    });
+}