make miner multi threaded

contrib/js/cuckoo_miner.js

@@ -1,17 +1,61 @@
+var easiness = 55.0;
+var miner_threads = 4;
+var randoffs = 64;
+
 onready(function(){
 	document.getElementById("start_miner").onclick = function() {
 		var btn = document.getElementById("start_miner");
 		var label = btn.value;
 		btn.value = "..."
 		btn.disabled = true;
-		var worker = new Worker("./static/mineworker.js");
-		worker.onmessage = function(e) {
-		  miner_cb(e.data);
-		  btn.value=label;
-		  btn.disabled = false;
-		  worker.terminate();
+		
+		
+		var b = new Uint8Array(randoffs);
+		window.crypto.getRandomValues(b);
+		var b_cur = 0;
+		var b_i = 0;
+		var tmp = new Uint8Array(randoffs+b_i+1);
+		tmp.set(b)
+		tmp[b.length]=0
+		b = tmp;
+		
+		var workers = new Array(miner_threads);
+		
+		var worker_cb =  function(e) {
+			if (e.data[0] == "ok") {
+			  miner_cb(e.data[1]);
+			  btn.value=label;
+			  btn.disabled = false;
+			  for (i=0; i<miner_threads; i++) {
+			  	workers[i].terminate();
+			  }
+			} else {
+				if (b_cur >= 256) {
+					var tmp = new Uint8Array(randoffs+b_i+1);
+					tmp.set(b)
+					tmp[b.length]=0
+					b = tmp;
+					b_i++;
+					b_cur=0;
+				}
+				b[randoffs+b_i]=b_cur;
+				b_cur++;
+				var params = [b, easiness, e.data[2]];
+				workers[e.data[2]].postMessage(params);
+			}	
+		
 		}
-		worker.postMessage(55.0); // Start the worker.
+		
+		
+		for (i=0; i<miner_threads; i++) {
+			b[randoffs+b_i]=b_cur;
+			b_cur++;
+			var params = [b, easiness, i];
+			workers[i] = new Worker("./static/mineworker.js");
+			workers[i].onmessage = worker_cb;
+			workers[i].postMessage(params); // Start the worker.
+		}
+		b_cur=4;
 	};
 });
 function miner_cb(s) {