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   1 /**
   2  * Copyright (c) 2010-2023 Contributors to the openHAB project
   3  *
   4  * See the NOTICE file(s) distributed with this work for additional
   5  * information.
   6  *
   7  * This program and the accompanying materials are made available under the
   8  * terms of the Eclipse Public License 2.0 which is available at
   9  * http://www.eclipse.org/legal/epl-2.0
  10  *
  11  * SPDX-License-Identifier: EPL-2.0
  12  */
  13 package org.openhab.binding.bluetooth.bluez.internal;
  14
  15 import java.util.concurrent.CompletableFuture;
  16 import java.util.concurrent.ScheduledExecutorService;
  17 import java.util.concurrent.TimeUnit;
  18 import java.util.concurrent.atomic.AtomicInteger;
  19
  20 import org.eclipse.jdt.annotation.NonNullByDefault;
  21 import org.eclipse.jdt.annotation.Nullable;
  22 import org.freedesktop.dbus.exceptions.DBusException;
  23 import org.openhab.binding.bluetooth.util.RetryException;
  24 import org.openhab.binding.bluetooth.util.RetryFuture;
  25 import org.openhab.core.common.ThreadPoolManager;
  26 import org.osgi.service.component.annotations.Activate;
  27 import org.osgi.service.component.annotations.Component;
  28 import org.osgi.service.component.annotations.Deactivate;
  29 import org.slf4j.Logger;
  30 import org.slf4j.LoggerFactory;
  31
  32 import com.github.hypfvieh.bluetooth.DeviceManager;
  33
  34 /**
  35  * This service handles the lifecycle of the {@link DeviceManager} singleton instance.
  36  * In addition, this class is responsible for managing the BlueZPropertiesChangedHandler instance
  37  * used by the binding for listening and dispatching dbus events from the DeviceManager.
  38  *
  39  * Creation of the DeviceManagerWrapper is asynchronous and thus attempts to retrieve the
  40  * DeviceManagerWrapper through 'getDeviceManager' may initially fail.
  41  *
  42  * @author Connor Petty - Initial Contribution
  43  *
  44  */
  45 @NonNullByDefault
  46 @Component(service = DeviceManagerFactory.class)
  47 public class DeviceManagerFactory {
  48
  49     private final Logger logger = LoggerFactory.getLogger(DeviceManagerFactory.class);
  50     private final ScheduledExecutorService scheduler = ThreadPoolManager.getScheduledPool("bluetooth");
  51
  52     private final BlueZPropertiesChangedHandler changeHandler = new BlueZPropertiesChangedHandler();
  53
  54     private @Nullable CompletableFuture<@Nullable DeviceManager> deviceManagerFuture;
  55     private @Nullable CompletableFuture<DeviceManagerWrapper> deviceManagerWrapperFuture;
  56
  57     public BlueZPropertiesChangedHandler getPropertiesChangedHandler() {
  58         return changeHandler;
  59     }
  60
  61     public @Nullable DeviceManagerWrapper getDeviceManager() {
  62         // we can cheat the null checker with casting here
  63         var future = (CompletableFuture<@Nullable DeviceManagerWrapper>) deviceManagerWrapperFuture;
  64         if (future != null) {
  65             return future.getNow(null);
  66         }
  67         return null;
  68     }
  69
  70     @Activate
  71     public void initialize() {
  72         logger.debug("initializing DeviceManagerFactory");
  73
  74         var stage1 = this.deviceManagerFuture = RetryFuture.callWithRetry(() -> {
  75             try {
  76                 // if this is the first call to the library, this call
  77                 // should throw an exception (that we are catching)
  78                 return DeviceManager.getInstance();
  79                 // Experimental - seems reuse does not work
  80             } catch (IllegalStateException e) {
  81                 // Exception caused by first call to the library
  82                 try {
  83                     return DeviceManager.createInstance(false);
  84                 } catch (DBusException ex) {
  85                     // we might be on a system without DBus, such as macOS or Windows
  86                     logger.debug("Failed to initialize DeviceManager: {}", ex.getMessage());
  87                     return null;
  88                 }
  89             }
  90         }, scheduler);
  91
  92         this.deviceManagerWrapperFuture = stage1.thenCompose(devManager -> {
  93             // lambdas can't modify outside variables due to scoping, so instead we use an AtomicInteger.
  94             AtomicInteger tryCount = new AtomicInteger();
  95             return RetryFuture.callWithRetry(() -> {
  96                 int count = tryCount.incrementAndGet();
  97                 try {
  98                     logger.debug("Registering property handler attempt: {}", count);
  99                     if (devManager != null) {
 100                         devManager.registerPropertyHandler(changeHandler);
 101                         logger.debug("Successfully registered property handler");
 102                     }
 103                     return new DeviceManagerWrapper(devManager);
 104                 } catch (DBusException e) {
 105                     if (count < 3) {
 106                         throw new RetryException(5, TimeUnit.SECONDS);
 107                     } else {
 108                         throw e;
 109                     }
 110                 }
 111             }, scheduler);
 112         }).whenComplete((devManagerWrapper, th) -> {
 113             if (th != null) {
 114                 if (th.getCause() instanceof DBusException) {
 115                     // we might be on a system without DBus, such as macOS or Windows
 116                     logger.debug("Failed to initialize DeviceManager: {}", th.getMessage());
 117                 } else {
 118                     logger.warn("Failed to initialize DeviceManager: {}", th.getMessage());
 119                 }
 120             }
 121         });
 122     }
 123
 124     @Deactivate
 125     public void dispose() {
 126         var stage1 = this.deviceManagerFuture;
 127         if (stage1 != null) {
 128             if (!stage1.cancel(true)) {
 129                 // a failure to cancel means that the stage completed normally
 130                 stage1.thenAccept(devManager -> {
 131                     if (devManager != null) {
 132                         devManager.closeConnection();
 133                     }
 134                 });
 135             }
 136         }
 137         this.deviceManagerFuture = null;
 138
 139         var stage2 = this.deviceManagerWrapperFuture;
 140         if (stage2 != null) {
 141             stage2.cancel(true);
 142         }
 143         this.deviceManagerWrapperFuture = null;
 144     }
 145 }