1 /* 2 * Copyright (C) 2022 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.nearby.fastpair.provider.simulator.testing; 18 19 import static com.google.common.base.Preconditions.checkState; 20 21 import android.util.Log; 22 23 import com.google.common.util.concurrent.FutureCallback; 24 import com.google.common.util.concurrent.Futures; 25 import com.google.common.util.concurrent.ListenableFuture; 26 import com.google.common.util.concurrent.ListeningExecutorService; 27 import com.google.common.util.concurrent.MoreExecutors; 28 import com.google.protobuf.ByteString; 29 30 import java.io.IOException; 31 import java.util.HashMap; 32 import java.util.Map; 33 import java.util.concurrent.Callable; 34 import java.util.concurrent.Executors; 35 36 /** 37 * Manages the IO streams with remote devices. 38 * 39 * <p>The caller must invoke {@link #registerRemoteDevice} before starting to communicate with the 40 * remote device, and invoke {@link #unregisterRemoteDevice} after finishing tasks. If this instance 41 * is not used anymore, the caller need to invoke {@link #destroy} to release all resources. 42 * 43 * <p>All of the methods are thread-safe. 44 */ 45 public class RemoteDevicesManager { 46 private static final String TAG = "RemoteDevicesManager"; 47 48 private final Map<String, RemoteDevice> mRemoteDeviceMap = new HashMap<>(); 49 private final ListeningExecutorService mBackgroundExecutor = 50 MoreExecutors.listeningDecorator(Executors.newSingleThreadExecutor()); 51 private final ListeningExecutorService mListenInputStreamExecutors = 52 MoreExecutors.listeningDecorator(Executors.newCachedThreadPool()); 53 private final Map<String, ListenableFuture<Void>> mListeningTaskMap = new HashMap<>(); 54 55 /** 56 * Opens input and output data streams for {@code remoteDevice} in the background and notifies 57 * the 58 * open result via {@code callback}, and assigns a dedicated executor to listen the input data 59 * stream if data streams are opened successfully. The dedicated executor will invoke the 60 * {@code 61 * remoteDevice.inputStreamListener().onInputData()} directly if the new data exists in the 62 * input 63 * stream and invoke the {@code remoteDevice.inputStreamListener().onClose()} if the input 64 * stream 65 * is closed. 66 */ registerRemoteDevice(String id, RemoteDevice remoteDevice)67 public synchronized void registerRemoteDevice(String id, RemoteDevice remoteDevice) { 68 checkState(mRemoteDeviceMap.put(id, remoteDevice) == null, 69 "The %s is already registered", id); 70 startListeningInputStreamTask(remoteDevice); 71 } 72 73 /** 74 * Closes the data streams for specific remote device {@code id} in the background and notifies 75 * the result via {@code callback}. 76 */ unregisterRemoteDevice(String id)77 public synchronized void unregisterRemoteDevice(String id) { 78 RemoteDevice remoteDevice = mRemoteDeviceMap.remove(id); 79 checkState(remoteDevice != null, "The %s is not registered", id); 80 if (mListeningTaskMap.containsKey(id)) { 81 mListeningTaskMap.remove(id).cancel(/* mayInterruptIfRunning= */ true); 82 } 83 } 84 85 /** Closes all data streams of registered remote devices and stop all background tasks. */ destroy()86 public synchronized void destroy() { 87 mRemoteDeviceMap.clear(); 88 mListeningTaskMap.clear(); 89 mListenInputStreamExecutors.shutdownNow(); 90 } 91 92 /** 93 * Writes {@code data} into the output data stream of specific remote device {@code id} in the 94 * background and notifies the result via {@code callback}. 95 */ writeDataToRemoteDevice( String id, ByteString data, FutureCallback<Void> callback)96 public synchronized void writeDataToRemoteDevice( 97 String id, ByteString data, FutureCallback<Void> callback) { 98 RemoteDevice remoteDevice = mRemoteDeviceMap.get(id); 99 checkState(remoteDevice != null, "The %s is not registered", id); 100 101 runInBackground(() -> { 102 remoteDevice.getStreamIOHandler().write(data); 103 return null; 104 }, callback); 105 } 106 runInBackground(Callable<Void> callable, FutureCallback<Void> callback)107 private void runInBackground(Callable<Void> callable, FutureCallback<Void> callback) { 108 Futures.addCallback( 109 mBackgroundExecutor.submit(callable), callback, MoreExecutors.directExecutor()); 110 } 111 startListeningInputStreamTask(RemoteDevice remoteDevice)112 private void startListeningInputStreamTask(RemoteDevice remoteDevice) { 113 ListenableFuture<Void> listenFuture = mListenInputStreamExecutors.submit(() -> { 114 Log.i(TAG, "Start listening " + remoteDevice.getId()); 115 while (true) { 116 ByteString data; 117 try { 118 data = remoteDevice.getStreamIOHandler().read(); 119 } catch (IOException | IllegalStateException e) { 120 break; 121 } 122 remoteDevice.getInputStreamListener().onInputData(data); 123 } 124 }, /* result= */ null); 125 Futures.addCallback(listenFuture, new FutureCallback<Void>() { 126 @Override 127 public void onSuccess(Void result) { 128 Log.i(TAG, "Stop listening " + remoteDevice.getId()); 129 remoteDevice.getInputStreamListener().onClose(); 130 } 131 132 @Override 133 public void onFailure(Throwable t) { 134 Log.w(TAG, "Stop listening " + remoteDevice.getId() + ", cause: " + t); 135 remoteDevice.getInputStreamListener().onClose(); 136 } 137 }, MoreExecutors.directExecutor()); 138 mListeningTaskMap.put(remoteDevice.getId(), listenFuture); 139 } 140 } 141