Stop the timer when all callbacks removed

src/main/scala/com/github/shadowsocks/utils/TrafficMonitor.scala

@@ -39,20 +39,23 @@ object TrafficMonitor {
     else numberFormat.format(n) + ' ' + units(i)
   }
 
-  def update(tx: Long, rx: Long) {
-    val now = getTraffic(tx, rx)
+  def updateRate() {
+    val now = getTraffic(txTotal, rxTotal)
     val delta = now.timestamp - last.timestamp
-    txLast = now.tx - last.tx
-    rxLast = now.rx - last.rx
+    val deltaTx = now.tx - last.tx
+    val deltaRx = now.rx - last.rx
     if (delta != 0) {
-      txRate = txLast * 1000 / delta
-      rxRate = rxLast * 1000 / delta
+      txRate = deltaTx * 1000 / delta
+      rxRate = deltaRx * 1000 / delta
     }
-    txTotal += txLast
-    rxTotal += rxLast
     last = now
   }
 
+  def update(tx: Long, rx: Long) {
+    txTotal = tx;
+    rxTotal = rx;
+  }
+
   def reset() {
     txRate = 0
     rxRate = 0
@@ -84,5 +87,17 @@ object TrafficMonitor {
   def getRate(): String = {
     formatTraffic(txRate + rxRate)
   }
+
+  def getDeltaTx(): Long = {
+    val last = txLast
+    txLast = txTotal
+    txTotal - last
+  }
+
+  def getDeltaRx(): Long = {
+    val last = rxLast
+    rxLast = rxTotal
+    rxTotal - last
+  }
 }
 

src/main/scala/com/github/shadowsocks/utils/TrafficMonitorThread.scala

@@ -46,7 +46,7 @@ import android.net.{LocalServerSocket, LocalSocket, LocalSocketAddress}
 import android.util.Log
 import com.github.shadowsocks.BaseService
 
-class TrafficMonitorThread(service: BaseService) extends Thread {
+class TrafficMonitorThread() extends Thread {
 
   val TAG = "TrafficMonitorThread"
   val PATH = "/data/data/com.github.shadowsocks/stat_path"
@@ -108,9 +108,6 @@ class TrafficMonitorThread(service: BaseService) extends Thread {
             val stat = new String(array, "UTF-8").split("\\|")
             if (stat.length == 2) {
               TrafficMonitor.update(stat(0).toLong, stat(1).toLong)
-              service.updateTrafficTotal(TrafficMonitor.txLast, TrafficMonitor.rxLast)
-              service.updateTrafficRate(TrafficMonitor.getTxRate, TrafficMonitor.getRxRate,
-                TrafficMonitor.getTxTotal, TrafficMonitor.getRxTotal)
             }
 
             output.write(0)