michael@0: /*
michael@0:  * Copyright (C) 2013 Square, Inc.
michael@0:  *
michael@0:  * Licensed under the Apache License, Version 2.0 (the "License");
michael@0:  * you may not use this file except in compliance with the License.
michael@0:  * You may obtain a copy of the License at
michael@0:  *
michael@0:  *      http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing, software
michael@0:  * distributed under the License is distributed on an "AS IS" BASIS,
michael@0:  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
michael@0:  * See the License for the specific language governing permissions and
michael@0:  * limitations under the License.
michael@0:  */
michael@0: package com.squareup.picasso;
michael@0: 
michael@0: import android.Manifest;
michael@0: import android.content.BroadcastReceiver;
michael@0: import android.content.Context;
michael@0: import android.content.Intent;
michael@0: import android.content.IntentFilter;
michael@0: import android.net.ConnectivityManager;
michael@0: import android.net.NetworkInfo;
michael@0: import android.os.Bundle;
michael@0: import android.os.Handler;
michael@0: import android.os.HandlerThread;
michael@0: import android.os.Looper;
michael@0: import android.os.Message;
michael@0: import java.util.ArrayList;
michael@0: import java.util.LinkedHashMap;
michael@0: import java.util.List;
michael@0: import java.util.Map;
michael@0: import java.util.concurrent.ExecutorService;
michael@0: 
michael@0: import static android.content.Context.CONNECTIVITY_SERVICE;
michael@0: import static android.content.Intent.ACTION_AIRPLANE_MODE_CHANGED;
michael@0: import static android.net.ConnectivityManager.CONNECTIVITY_ACTION;
michael@0: import static android.os.Process.THREAD_PRIORITY_BACKGROUND;
michael@0: import static com.squareup.picasso.BitmapHunter.forRequest;
michael@0: 
michael@0: class Dispatcher {
michael@0:   private static final int RETRY_DELAY = 500;
michael@0:   private static final int AIRPLANE_MODE_ON = 1;
michael@0:   private static final int AIRPLANE_MODE_OFF = 0;
michael@0: 
michael@0:   static final int REQUEST_SUBMIT = 1;
michael@0:   static final int REQUEST_CANCEL = 2;
michael@0:   static final int REQUEST_GCED = 3;
michael@0:   static final int HUNTER_COMPLETE = 4;
michael@0:   static final int HUNTER_RETRY = 5;
michael@0:   static final int HUNTER_DECODE_FAILED = 6;
michael@0:   static final int HUNTER_DELAY_NEXT_BATCH = 7;
michael@0:   static final int HUNTER_BATCH_COMPLETE = 8;
michael@0:   static final int NETWORK_STATE_CHANGE = 9;
michael@0:   static final int AIRPLANE_MODE_CHANGE = 10;
michael@0: 
michael@0:   private static final String DISPATCHER_THREAD_NAME = "Dispatcher";
michael@0:   private static final int BATCH_DELAY = 200; // ms
michael@0: 
michael@0:   final DispatcherThread dispatcherThread;
michael@0:   final Context context;
michael@0:   final ExecutorService service;
michael@0:   final Downloader downloader;
michael@0:   final Map<String, BitmapHunter> hunterMap;
michael@0:   final Handler handler;
michael@0:   final Handler mainThreadHandler;
michael@0:   final Cache cache;
michael@0:   final Stats stats;
michael@0:   final List<BitmapHunter> batch;
michael@0:   final NetworkBroadcastReceiver receiver;
michael@0: 
michael@0:   NetworkInfo networkInfo;
michael@0:   boolean airplaneMode;
michael@0: 
michael@0:   Dispatcher(Context context, ExecutorService service, Handler mainThreadHandler,
michael@0:       Downloader downloader, Cache cache, Stats stats) {
michael@0:     this.dispatcherThread = new DispatcherThread();
michael@0:     this.dispatcherThread.start();
michael@0:     this.context = context;
michael@0:     this.service = service;
michael@0:     this.hunterMap = new LinkedHashMap<String, BitmapHunter>();
michael@0:     this.handler = new DispatcherHandler(dispatcherThread.getLooper(), this);
michael@0:     this.downloader = downloader;
michael@0:     this.mainThreadHandler = mainThreadHandler;
michael@0:     this.cache = cache;
michael@0:     this.stats = stats;
michael@0:     this.batch = new ArrayList<BitmapHunter>(4);
michael@0:     this.airplaneMode = Utils.isAirplaneModeOn(this.context);
michael@0:     this.receiver = new NetworkBroadcastReceiver(this.context);
michael@0:     receiver.register();
michael@0:   }
michael@0: 
michael@0:   void shutdown() {
michael@0:     service.shutdown();
michael@0:     dispatcherThread.quit();
michael@0:     receiver.unregister();
michael@0:   }
michael@0: 
michael@0:   void dispatchSubmit(Action action) {
michael@0:     handler.sendMessage(handler.obtainMessage(REQUEST_SUBMIT, action));
michael@0:   }
michael@0: 
michael@0:   void dispatchCancel(Action action) {
michael@0:     handler.sendMessage(handler.obtainMessage(REQUEST_CANCEL, action));
michael@0:   }
michael@0: 
michael@0:   void dispatchComplete(BitmapHunter hunter) {
michael@0:     handler.sendMessage(handler.obtainMessage(HUNTER_COMPLETE, hunter));
michael@0:   }
michael@0: 
michael@0:   void dispatchRetry(BitmapHunter hunter) {
michael@0:     handler.sendMessageDelayed(handler.obtainMessage(HUNTER_RETRY, hunter), RETRY_DELAY);
michael@0:   }
michael@0: 
michael@0:   void dispatchFailed(BitmapHunter hunter) {
michael@0:     handler.sendMessage(handler.obtainMessage(HUNTER_DECODE_FAILED, hunter));
michael@0:   }
michael@0: 
michael@0:   void dispatchNetworkStateChange(NetworkInfo info) {
michael@0:     handler.sendMessage(handler.obtainMessage(NETWORK_STATE_CHANGE, info));
michael@0:   }
michael@0: 
michael@0:   void dispatchAirplaneModeChange(boolean airplaneMode) {
michael@0:     handler.sendMessage(handler.obtainMessage(AIRPLANE_MODE_CHANGE,
michael@0:         airplaneMode ? AIRPLANE_MODE_ON : AIRPLANE_MODE_OFF, 0));
michael@0:   }
michael@0: 
michael@0:   void performSubmit(Action action) {
michael@0:     BitmapHunter hunter = hunterMap.get(action.getKey());
michael@0:     if (hunter != null) {
michael@0:       hunter.attach(action);
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     if (service.isShutdown()) {
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     hunter = forRequest(context, action.getPicasso(), this, cache, stats, action, downloader);
michael@0:     hunter.future = service.submit(hunter);
michael@0:     hunterMap.put(action.getKey(), hunter);
michael@0:   }
michael@0: 
michael@0:   void performCancel(Action action) {
michael@0:     String key = action.getKey();
michael@0:     BitmapHunter hunter = hunterMap.get(key);
michael@0:     if (hunter != null) {
michael@0:       hunter.detach(action);
michael@0:       if (hunter.cancel()) {
michael@0:         hunterMap.remove(key);
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   void performRetry(BitmapHunter hunter) {
michael@0:     if (hunter.isCancelled()) return;
michael@0: 
michael@0:     if (service.isShutdown()) {
michael@0:       performError(hunter);
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     if (hunter.shouldRetry(airplaneMode, networkInfo)) {
michael@0:       hunter.future = service.submit(hunter);
michael@0:     } else {
michael@0:       performError(hunter);
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   void performComplete(BitmapHunter hunter) {
michael@0:     if (!hunter.shouldSkipMemoryCache()) {
michael@0:       cache.set(hunter.getKey(), hunter.getResult());
michael@0:     }
michael@0:     hunterMap.remove(hunter.getKey());
michael@0:     batch(hunter);
michael@0:   }
michael@0: 
michael@0:   void performBatchComplete() {
michael@0:     List<BitmapHunter> copy = new ArrayList<BitmapHunter>(batch);
michael@0:     batch.clear();
michael@0:     mainThreadHandler.sendMessage(mainThreadHandler.obtainMessage(HUNTER_BATCH_COMPLETE, copy));
michael@0:   }
michael@0: 
michael@0:   void performError(BitmapHunter hunter) {
michael@0:     hunterMap.remove(hunter.getKey());
michael@0:     batch(hunter);
michael@0:   }
michael@0: 
michael@0:   void performAirplaneModeChange(boolean airplaneMode) {
michael@0:     this.airplaneMode = airplaneMode;
michael@0:   }
michael@0: 
michael@0:   void performNetworkStateChange(NetworkInfo info) {
michael@0:     networkInfo = info;
michael@0:     if (service instanceof PicassoExecutorService) {
michael@0:       ((PicassoExecutorService) service).adjustThreadCount(info);
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   private void batch(BitmapHunter hunter) {
michael@0:     if (hunter.isCancelled()) {
michael@0:       return;
michael@0:     }
michael@0:     batch.add(hunter);
michael@0:     if (!handler.hasMessages(HUNTER_DELAY_NEXT_BATCH)) {
michael@0:       handler.sendEmptyMessageDelayed(HUNTER_DELAY_NEXT_BATCH, BATCH_DELAY);
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   private static class DispatcherHandler extends Handler {
michael@0:     private final Dispatcher dispatcher;
michael@0: 
michael@0:     public DispatcherHandler(Looper looper, Dispatcher dispatcher) {
michael@0:       super(looper);
michael@0:       this.dispatcher = dispatcher;
michael@0:     }
michael@0: 
michael@0:     @Override public void handleMessage(final Message msg) {
michael@0:       switch (msg.what) {
michael@0:         case REQUEST_SUBMIT: {
michael@0:           Action action = (Action) msg.obj;
michael@0:           dispatcher.performSubmit(action);
michael@0:           break;
michael@0:         }
michael@0:         case REQUEST_CANCEL: {
michael@0:           Action action = (Action) msg.obj;
michael@0:           dispatcher.performCancel(action);
michael@0:           break;
michael@0:         }
michael@0:         case HUNTER_COMPLETE: {
michael@0:           BitmapHunter hunter = (BitmapHunter) msg.obj;
michael@0:           dispatcher.performComplete(hunter);
michael@0:           break;
michael@0:         }
michael@0:         case HUNTER_RETRY: {
michael@0:           BitmapHunter hunter = (BitmapHunter) msg.obj;
michael@0:           dispatcher.performRetry(hunter);
michael@0:           break;
michael@0:         }
michael@0:         case HUNTER_DECODE_FAILED: {
michael@0:           BitmapHunter hunter = (BitmapHunter) msg.obj;
michael@0:           dispatcher.performError(hunter);
michael@0:           break;
michael@0:         }
michael@0:         case HUNTER_DELAY_NEXT_BATCH: {
michael@0:           dispatcher.performBatchComplete();
michael@0:           break;
michael@0:         }
michael@0:         case NETWORK_STATE_CHANGE: {
michael@0:           NetworkInfo info = (NetworkInfo) msg.obj;
michael@0:           dispatcher.performNetworkStateChange(info);
michael@0:           break;
michael@0:         }
michael@0:         case AIRPLANE_MODE_CHANGE: {
michael@0:           dispatcher.performAirplaneModeChange(msg.arg1 == AIRPLANE_MODE_ON);
michael@0:           break;
michael@0:         }
michael@0:         default:
michael@0:           Picasso.HANDLER.post(new Runnable() {
michael@0:             @Override public void run() {
michael@0:               throw new AssertionError("Unknown handler message received: " + msg.what);
michael@0:             }
michael@0:           });
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   static class DispatcherThread extends HandlerThread {
michael@0:     DispatcherThread() {
michael@0:       super(Utils.THREAD_PREFIX + DISPATCHER_THREAD_NAME, THREAD_PRIORITY_BACKGROUND);
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   private class NetworkBroadcastReceiver extends BroadcastReceiver {
michael@0:     private static final String EXTRA_AIRPLANE_STATE = "state";
michael@0: 
michael@0:     private final ConnectivityManager connectivityManager;
michael@0: 
michael@0:     NetworkBroadcastReceiver(Context context) {
michael@0:       connectivityManager = (ConnectivityManager) context.getSystemService(CONNECTIVITY_SERVICE);
michael@0:     }
michael@0: 
michael@0:     void register() {
michael@0:       boolean shouldScanState = service instanceof PicassoExecutorService && //
michael@0:           Utils.hasPermission(context, Manifest.permission.ACCESS_NETWORK_STATE);
michael@0:       IntentFilter filter = new IntentFilter();
michael@0:       filter.addAction(ACTION_AIRPLANE_MODE_CHANGED);
michael@0:       if (shouldScanState) {
michael@0:         filter.addAction(CONNECTIVITY_ACTION);
michael@0:       }
michael@0:       context.registerReceiver(this, filter);
michael@0:     }
michael@0: 
michael@0:     void unregister() {
michael@0:       context.unregisterReceiver(this);
michael@0:     }
michael@0: 
michael@0:     @Override public void onReceive(Context context, Intent intent) {
michael@0:       // On some versions of Android this may be called with a null Intent
michael@0:       if (null == intent) {
michael@0:         return;
michael@0:       }
michael@0: 
michael@0:       String action = intent.getAction();
michael@0:       Bundle extras = intent.getExtras();
michael@0: 
michael@0:       if (ACTION_AIRPLANE_MODE_CHANGED.equals(action)) {
michael@0:         dispatchAirplaneModeChange(extras.getBoolean(EXTRA_AIRPLANE_STATE, false));
michael@0:       } else if (CONNECTIVITY_ACTION.equals(action)) {
michael@0:         dispatchNetworkStateChange(connectivityManager.getActiveNetworkInfo());
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: }