add missing lock.js

update chrome launch flag

crawler.js

@@ -259,7 +259,7 @@ class Crawler {
       "--no-sandbox",
       "--disable-background-media-suspend",
       "--autoplay-policy=no-user-gesture-required",
-      "--disable-features=IsolateOrigins,site-per-process",
+      "--disable-features=Translate,LazyFrameLoading,IsolateOrigins,site-per-process",
       "--disable-popup-blocking",
       "--disable-backgrounding-occluded-windows",
     ];

util/lock.js

@@ -0,0 +1,37 @@
+const path = require("path");
+const fs = require("fs");
+const os = require("os");
+
+class Lock
+{
+  constructor(dir) {
+    this.lockDir = path.join(dir, ".lock");
+    this.lockFile = path.join(this.lockDir, "." + os.hostname());
+    fs.mkdirSync(this.lockDir, {recursive: true});
+    fs.closeSync(fs.openSync(this.lockFile, "a"));
+    console.log(`Created lock file ${this.lockFile}`);
+  }
+
+  release() {
+    try {
+      fs.unlinkSync(this.lockFile);
+      console.log(`Removed lock file ${this.lockFile}`);
+    } catch (e) {
+      // ignore remove failure, but see if other locks exist
+    }
+
+    try {
+      fs.rmdirSync(this.lockDir);
+    } catch (e) {
+      // true if no such dir, otherwise not released
+      return (e.code === "ENOENT");
+    }
+
+    console.log("No more locks");
+    return true;
+  }
+}
+    
+
+
+module.exports.Lock = Lock;