Refrain from unregistering stateChanged callbacks too aggressively

This commit adds `startListeningForBandwidth` and `stopListeningForBandwidth` to save battery as well as keeping the listener for state changing alive.
2016-12-28 00:49:18 +08:00
parent fdd8a1127c
commit 418ae2151c
5 changed files with 46 additions and 45 deletions
@@ -7,6 +7,8 @@ interface IShadowsocksService {
  String getProfileName();

  oneway void registerCallback(IShadowsocksServiceCallback cb);
+  oneway void startListeningForBandwidth(IShadowsocksServiceCallback cb);
+  oneway void stopListeningForBandwidth(IShadowsocksServiceCallback cb);
  oneway void unregisterCallback(IShadowsocksServiceCallback cb);

  oneway void use(in int profileId);
@@ -29,7 +29,7 @@ import java.util.{Timer, TimerTask}
 import android.app.Service
 import android.content.{BroadcastReceiver, Context, Intent, IntentFilter}
 import android.net.ConnectivityManager
-import android.os.{Handler, RemoteCallbackList}
+import android.os.{Handler, IBinder, RemoteCallbackList}
 import android.text.TextUtils
 import android.util.Log
 import android.widget.Toast
@@ -39,6 +39,7 @@ import com.github.shadowsocks.database.Profile
 import com.github.shadowsocks.utils._
 import okhttp3.{Dns, FormBody, OkHttpClient, Request}

+import scala.collection.mutable
 import scala.util.Random

 trait BaseService extends Service {
@@ -54,7 +55,7 @@ trait BaseService extends Service {
  var trafficMonitorThread: TrafficMonitorThread = _

  final val callbacks = new RemoteCallbackList[IShadowsocksServiceCallback]
-  var callbacksCount: Int = _
+  private final val bandwidthListeners = new mutable.HashSet[IBinder]() // the binder is the real identifier
  lazy val handler = new Handler(getMainLooper)
  lazy val restartHanlder = new Handler(getMainLooper)
  lazy val protectPath: String = getApplicationInfo.dataDir + "/protect_path"
@@ -85,31 +86,29 @@ trait BaseService extends Service {

    override def getProfileName: String = if (profile == null) null else profile.getName

-    override def unregisterCallback(cb: IShadowsocksServiceCallback) {
-      if (cb != null && callbacks.unregister(cb)) {
-        callbacksCount -= 1
-        if (callbacksCount == 0 && timer != null) {
-          timer.cancel()
-          timer = null
-        }
-      }
-    }
+    override def registerCallback(cb: IShadowsocksServiceCallback): Unit = callbacks.register(cb)

-    override def registerCallback(cb: IShadowsocksServiceCallback) {
-      if (cb != null && callbacks.register(cb)) {
-        callbacksCount += 1
-        if (callbacksCount != 0 && timer == null) {
-          val task = new TimerTask {
-            def run() {
-              if (TrafficMonitor.updateRate()) updateTrafficRate()
-            }
-          }
+    override def startListeningForBandwidth(cb: IShadowsocksServiceCallback): Unit =
+      if (bandwidthListeners.add(cb.asBinder)){
+        if (timer == null) {
          timer = new Timer(true)
-          timer.schedule(task, 1000, 1000)
+          timer.schedule(new TimerTask {
+            def run(): Unit = if (TrafficMonitor.updateRate()) updateTrafficRate()
+          }, 1000, 1000)
        }
        TrafficMonitor.updateRate()
        cb.trafficUpdated(TrafficMonitor.txRate, TrafficMonitor.rxRate, TrafficMonitor.txTotal, TrafficMonitor.rxTotal)
      }
+
+    override def stopListeningForBandwidth(cb: IShadowsocksServiceCallback): Unit =
+      if (bandwidthListeners.remove(cb.asBinder) && bandwidthListeners.isEmpty) {
+        timer.cancel()
+        timer = null
+      }
+
+    override def unregisterCallback(cb: IShadowsocksServiceCallback) {
+      stopListeningForBandwidth(cb) // saves an RPC, and safer
+      callbacks.unregister(cb)
    }

    override def use(profileId: Int): Unit = synchronized(if (profileId < 0) stopRunner(stopService = true) else {
@@ -258,7 +257,7 @@ trait BaseService extends Service {

  def updateTrafficRate() {
    handler.post(() => {
-      if (callbacksCount > 0) {
+      if (bandwidthListeners.nonEmpty) {
        val txRate = TrafficMonitor.txRate
        val rxRate = TrafficMonitor.rxRate
        val txTotal = TrafficMonitor.txTotal
@@ -266,7 +265,8 @@ trait BaseService extends Service {
        val n = callbacks.beginBroadcast()
        for (i <- 0 until n) {
          try {
-            callbacks.getBroadcastItem(i).trafficUpdated(txRate, rxRate, txTotal, rxTotal)
+            val item = callbacks.getBroadcastItem(i)
+            if (bandwidthListeners.contains(item.asBinder)) item.trafficUpdated(txRate, rxRate, txTotal, rxTotal)
          } catch {
            case _: Exception => // Ignore
          }
@@ -289,7 +289,7 @@ trait BaseService extends Service {
  protected def changeState(s: Int, msg: String = null) {
    val handler = new Handler(getMainLooper)
    handler.post(() => if (state != s || msg != null) {
-      if (callbacksCount > 0) {
+      if (callbacks.getRegisteredCallbackCount > 0) {
        val n = callbacks.beginBroadcast()
        for (i <- 0 until n) {
          try {
@@ -142,7 +142,9 @@ class MainActivity extends Activity with ServiceBoundContext with Drawer.OnDrawe
  override def onServiceConnected() {
    // Update the UI
    if (fab != null) fab.setEnabled(true)
-    updateState()
+    Log.d(TAG, "bgService " + bgService.getState)
+    callback.stateChanged(bgService.getState, null, null)
+    state = bgService.getState
    if (Build.VERSION.SDK_INT >= 21 && app.isNatEnabled) {
      val snackbar = Snackbar.make(findViewById(R.id.snackbar), R.string.nat_deprecated, Snackbar.LENGTH_LONG)
      addDisableNatToSnackbar(snackbar)
@@ -393,25 +395,14 @@ class MainActivity extends Activity with ServiceBoundContext with Drawer.OnDrawe
    }
  }

-  private def updateState() {
-    if (bgService != null) {
-      Log.d(TAG, "bgService " + bgService.getState)
-      callback.stateChanged(bgService.getState, null, null)
-      state = bgService.getState
-    }
-  }
-
  protected override def onResume() {
    super.onResume()
-
    app.refreshContainerHolder()
-
-    updateState()
  }

  override def onStart() {
    super.onStart()
-    registerCallback()
+    setListeningForBandwidth(true)
  }

  override def onBackPressed(): Unit =
@@ -421,8 +412,8 @@ class MainActivity extends Activity with ServiceBoundContext with Drawer.OnDrawe
    } else super.onBackPressed()

  override def onStop() {
+    setListeningForBandwidth(false)
    super.onStop()
-    unregisterCallback()
  }

  override def onDestroy() {
@@ -35,7 +35,13 @@ trait ServiceBoundContext extends Context with IBinder.DeathRecipient {
      binder = service
      service.linkToDeath(ServiceBoundContext.this, 0)
      bgService = IShadowsocksService.Stub.asInterface(service)
-      registerCallback()
+      if (callback != null && !callbackRegistered) try {
+        bgService.registerCallback(callback)
+        callbackRegistered = true
+        if (listeningForBandwidth) bgService.startListeningForBandwidth(callback)
+      } catch {
+        case _: RemoteException => // Nothing
+      }
      ServiceBoundContext.this.onServiceConnected()
    }
    override def onServiceDisconnected(name: ComponentName) {
@@ -46,17 +52,17 @@ trait ServiceBoundContext extends Context with IBinder.DeathRecipient {
    }
  }

-  def registerCallback(): Unit = if (bgService != null && callback != null && !callbackRegistered) try {
-    bgService.registerCallback(callback)
-    callbackRegistered = true
-  } catch {
-    case _: RemoteException => // Nothing
+  def setListeningForBandwidth(value: Boolean) {
+    if (listeningForBandwidth != value && bgService != null && callback != null)
+      if (value) bgService.startListeningForBandwidth(callback) else bgService.stopListeningForBandwidth(callback)
+    listeningForBandwidth = value
  }

-  def unregisterCallback() {
+  private def unregisterCallback() {
    if (bgService != null && callback != null && callbackRegistered) try bgService.unregisterCallback(callback) catch {
      case _: RemoteException =>
    }
+    listeningForBandwidth = false
    callbackRegistered = false
  }

@@ -67,6 +73,7 @@ trait ServiceBoundContext extends Context with IBinder.DeathRecipient {
  private var callback: IShadowsocksServiceCallback.Stub = _
  private var connection: ShadowsocksServiceConnection = _
  private var callbackRegistered: Boolean = _
+  private var listeningForBandwidth: Boolean = _

  // Variables
  var binder: IBinder = _
@@ -80,6 +80,7 @@ class ShadowsocksNotification(private val service: BaseService, profileName: Str
      case Intent.ACTION_SCREEN_ON =>
        setVisible(visible && Utils.isLollipopOrAbove && !keyGuard.inKeyguardRestrictedInputMode, forceShow)
        service.binder.registerCallback(callback)
+        service.binder.startListeningForBandwidth(callback)
        callbackRegistered = true
      case Intent.ACTION_USER_PRESENT => setVisible(visible = true, forceShow = forceShow)
    }