Make pow script be a shared worker

boards/static/js/form.js

@@ -86,8 +86,8 b' function selectFileChoice() {'
 $(document).ready(function() {
     var powDifficulty = parseInt($('body').attr('data-pow-difficulty'));
     if (powDifficulty > 0) {
-        var worker = new Worker($('#powScript').attr('src'));
-        worker.onmessage = function(e) {
+        var worker = new SharedWorker($('#powScript').attr('src'));
+        worker.port.onmessage = function(e) {
             var form = $('#form');
             addHiddenInput(form, 'timestamp', e.data.timestamp);
             addHiddenInput(form, 'iteration', e.data.iteration);
@@ -96,6 +96,7 b' function selectFileChoice() {'
             form.submit();
             $('.post-form-w').unblock();
         };
+        worker.port.start();
 
         var form = $('#form');
         var submitButton = form.find('input[type=submit]');
@@ -110,7 +111,7 b' function selectFileChoice() {'
                 difficulty: parseInt($('body').attr('data-pow-difficulty')),
                 hasher: $('#sha256Script').attr('src')
             };
-            worker.postMessage(data);
+            worker.port.postMessage(data);
 
             return false;
         });

boards/static/js/proof_of_work.js

@@ -1,8 +1,10 b''
 var POW_COMPUTING_TIMEOUT = 2;
 var POW_HASH_LENGTH = 16;
 
+var hasher;
 
-function computeHash(iteration, guess, target, payload, timestamp, hasher) {
+
+function computeHash(iteration, guess, target, payload, timestamp, hasher, port) {
     iteration += 1;
     var hash = hasher(payload + iteration).toString();
     guess = hash.substring(0, POW_HASH_LENGTH);
@@ -17,19 +19,19 b' function computeHash(iteration, guess, t'
             timestamp: timestamp,
             guess: guess
         };
-        self.postMessage(data);
+        port.postMessage(data);
     } else {
         //console.log("Iteration: ", iteration);
         //console.log("Guess: ", guess);
         //console.log("Target: ", target);
 
         setTimeout(function() {
-            computeHash(iteration, guess, target, payload, timestamp, hasher);
+            computeHash(iteration, guess, target, payload, timestamp, hasher, port);
         }, POW_COMPUTING_TIMEOUT);
     }
 }
 
-function doWork(message, hasher, difficulty) {
+function doWork(message, hasher, difficulty, port) {
     var timestamp = Date.now();
     var iteration = 0;
     var payload = timestamp + message;
@@ -42,13 +44,20 b' function doWork(message, hasher, difficu'
     var guess = target + '0';
 
     setTimeout(function() {
-        computeHash(iteration, guess, target, payload, timestamp, hasher);
+        computeHash(iteration, guess, target, payload, timestamp, hasher, port);
     }, POW_COMPUTING_TIMEOUT);
 }
 
-self.onmessage = function(e) {
+onconnect = function(e) {
+    var port = e.ports[0];
+    port.start();
+
+    port.onmessage = function(e) {
     var difficulty = e.data.difficulty;
     importScripts(e.data.hasher);
     var hasher = CryptoJS.SHA256;
-    self.doWork(e.data.msg, hasher, difficulty);
+
+        self.doWork(e.data.msg, hasher, difficulty, port);
 };
+}
+