Untested disconnect functionality.

ragconnect.base/src/main/jastadd/intermediate/Generation.jadd

@@ -26,6 +26,17 @@ aspect AttributesForMustache {
 
   syn String MEndpointDefinition.connectParameterName() = "uriString";
   syn String MEndpointDefinition.connectMethod() = "connect" + tokenName();
+
+  syn String MEndpointDefinition.disconnectMethod() {
+    // if both (send and receive) are defined for the token, ensure methods with different names
+    String extra = endpointDef().lookupTokenEndpointDefinitions(token()).size() > 1 ? uniqueSuffix() : "";
+    return "disconnect" + extra + tokenName();
+  }
+  //
+  syn String MEndpointDefinition.uniqueSuffix();
+  eq MSendDefinition.uniqueSuffix() = "Send";
+  eq MReceiveDefinition.uniqueSuffix() = "Receive";
+
   syn TokenComponent MEndpointDefinition.token() = endpointDef().getToken();
   syn boolean MEndpointDefinition.alwaysApply() = endpointDef().getAlwaysApply();
   syn String MEndpointDefinition.parentTypeName() = token().containingTypeDecl().getName();

ragconnect.base/src/main/resources/MqttHandler.jadd

@@ -4,6 +4,7 @@ import java.util.concurrent.TimeUnit;
 aspect MqttHandler {
 public class MqttServerHandler {
   private final java.util.Map<String, MqttHandler> handlers = new java.util.HashMap<>();
+  private final java.util.Map<ConnectToken, Object> tokensForRemoval = new java.util.HashMap<>();
   private long time;
   private java.util.concurrent.TimeUnit unit;
   private String name;
@@ -38,8 +39,16 @@ public class MqttServerHandler {
     return handler;
   }
 
-  public boolean newConnection(java.net.URI uri, java.util.function.Consumer<byte[]> callback) throws IOException {
-    return resolveHandler(uri).newConnection(extractTopic(uri), callback);
+  public ConnectToken newConnection(java.net.URI uri, java.util.function.Consumer<byte[]> callback) throws IOException {
+    ConnectToken connectToken = new ConnectToken(uri);
+    resolveHandler(uri).newConnection(extractTopic(uri), callback);
+    tokensForRemoval.put(connectToken, callback);
+    return connectToken;
+  }
+
+  public boolean disconnect(ConnectToken connectToken) throws IOException {
+    MqttHandler handler = resolveHandler(connectToken.uri);
+    return handler != null ? handler.disconnect(extractTopic(connectToken.uri), tokensForRemoval.get(connectToken)) : false;
   }
 
   public void publish(java.net.URI uri, byte[] bytes) throws IOException {
@@ -146,14 +155,16 @@ public class MqttHandler {
       }
 
       @Override
-      public void onPublish(org.fusesource.hawtbuf.UTF8Buffer topic, org.fusesource.hawtbuf.Buffer body, org.fusesource.mqtt.client.Callback<org.fusesource.mqtt.client.Callback<Void>> ack) {
+      public void onPublish(org.fusesource.hawtbuf.UTF8Buffer topic,
+                            org.fusesource.hawtbuf.Buffer body,
+                            org.fusesource.mqtt.client.Callback<org.fusesource.mqtt.client.Callback<Void>> ack) {
+        // this method is called, whenever a MQTT message is received
         String topicString = topic.toString();
         java.util.List<java.util.function.Consumer<byte[]>> callbackList = callbacks.get(topicString);
         if (callbackList == null || callbackList.isEmpty()) {
           logger.debug("Got a message, but no callback to call. Forgot to subscribe?");
         } else {
           byte[] message = body.toByteArray();
-//          System.out.println("message = " + Arrays.toString(message));
           for (java.util.function.Consumer<byte[]> callback : callbackList) {
             callback.accept(message);
           }
@@ -162,13 +173,15 @@ public class MqttHandler {
       }
 
       @Override
-      public void onPublish(org.fusesource.hawtbuf.UTF8Buffer topicBuffer, org.fusesource.hawtbuf.Buffer body, Runnable ack) {
+      public void onPublish(org.fusesource.hawtbuf.UTF8Buffer topicBuffer,
+                            org.fusesource.hawtbuf.Buffer body,
+                            Runnable ack) {
+        // not used by this type of connection
         logger.warn("onPublish should not be called");
       }
 
       @Override
       public void onFailure(Throwable cause) {
-//        logger.catching(cause);
         error.set(cause);
       }
     });
@@ -179,7 +192,11 @@ public class MqttHandler {
       @Override
       public void onSuccess(Void value) {
         if (MqttHandler.this.sendWelcomeMessage) {
-          connection.publish("components", (name + " is connected").getBytes(), org.fusesource.mqtt.client.QoS.AT_LEAST_ONCE, false, new org.fusesource.mqtt.client.Callback<Void>() {
+          connection.publish("components",
+                             (name + " is connected").getBytes(),
+                             org.fusesource.mqtt.client.QoS.AT_LEAST_ONCE,
+                             false,
+                             new org.fusesource.mqtt.client.Callback<Void>() {
             @Override
             public void onSuccess(Void value) {
               logger.debug("success sending welcome message");
@@ -198,7 +215,6 @@ public class MqttHandler {
 
       @Override
       public void onFailure(Throwable cause) {
-//        logger.error("Could not connect", cause);
         error.set(cause);
       }
     });
@@ -228,8 +244,6 @@ public class MqttHandler {
     if (readyLatch.getCount() > 0) {
       System.err.println("Handler not ready");
       return false;
-//      // should maybe be something more kind than throwing an exception here
-//      throw new IllegalStateException("Updater not ready");
     }
     // register callback
     logger.debug("new connection for {}", topic);
@@ -256,6 +270,35 @@ public class MqttHandler {
     return true;
   }
 
+  public boolean disconnect(String topic, Object callback) {
+    java.util.List<java.util.function.Consumer<byte[]>> callbackList = callbacks.get(topic);
+    if (callbackList == null) {
+      logger.warn("Disconnect for not connected topic '{}'", topic);
+      return false;
+    }
+    java.util.concurrent.atomic.AtomicReference<Boolean> success = new java.util.concurrent.atomic.AtomicReference<>();
+    success.set(callbackList.remove(callback));
+    if (callbackList.isEmpty()) {
+      // no callbacks anymore for this topic, unsubscribe from mqtt
+      connection.getDispatchQueue().execute(() -> {
+        org.fusesource.hawtbuf.UTF8Buffer topicBuffer = org.fusesource.hawtbuf.Buffer.utf8(topic);
+        org.fusesource.hawtbuf.UTF8Buffer[] topicArray = new org.fusesource.hawtbuf.UTF8Buffer[]{topicBuffer};
+        connection.unsubscribe(topicArray, new org.fusesource.mqtt.client.Callback<Void>() {
+          @Override
+          public void onSuccess(Void value) {
+            // empty, all good
+          }
+
+          @Override
+          public void onFailure(Throwable cause) {
+            success.set(false);
+          }
+        });
+      });
+    }
+    return success.get();
+  }
+
   /**
    * Waits until this updater is ready to receive MQTT messages.
    * If it already is ready, return immediately with the value <code>true</code>.

ragconnect.base/src/main/resources/RestHandler.jadd

@@ -2,6 +2,7 @@ import java.util.concurrent.TimeUnit;aspect RestHandler {
 public class RestServerHandler {
   private static final int DEFAULT_PORT = 4567;
   private final java.util.Map<Integer, RestHandler> handlers = new java.util.HashMap<>();
+  private final java.util.Map<ConnectToken, Object> tokensForRemoval = new java.util.HashMap<>();
   private String name;
 
   public RestServerHandler() {
@@ -24,14 +25,23 @@ public class RestServerHandler {
     return handler;
   }
 
-  public boolean newPUTConnection(java.net.URI uri, java.util.function.Consumer<String> callback) {
+  public ConnectToken newPUTConnection(java.net.URI uri, java.util.function.Consumer<String> callback) {
+    ConnectToken connectToken = new ConnectToken(uri);
     resolveHandler(uri).newPUTConnection(uri.getPath(), callback);
-    return true;
+    tokensForRemoval.put(connectToken, callback);
+    return connectToken;
   }
 
-  public boolean newGETConnection(java.net.URI uri, SupplierWithException<String> supplier) {
+  public ConnectToken newGETConnection(java.net.URI uri, SupplierWithException<String> supplier) {
+    ConnectToken connectToken = new ConnectToken(uri);
     resolveHandler(uri).newGETConnection(uri.getPath(), supplier);
-    return true;
+    tokensForRemoval.put(connectToken, supplier);
+    return connectToken;
+  }
+
+  public boolean disconnect(ConnectToken connectToken) {
+    RestHandler handler = resolveHandler(connectToken.uri);
+    return handler != null ? handler.disconnect(connectToken.uri.getPath(), tokensForRemoval.get(connectToken)) : false;
   }
 
   public void close() {
@@ -108,6 +118,7 @@ public class RestHandler {
     suppliers.put(path, supplier);
     spark.Spark.get(path, (request, response) -> {
       try {
+        // we could check for null here in case supplier has been disconnected
         return supplier.get();
       } catch (Exception e) {
         return makeError(response, 500, e.getMessage());
@@ -115,6 +126,12 @@ public class RestHandler {
     });
   }
 
+  public boolean disconnect(String path, Object callbackOrSupplier) {
+    // only one will succeed (or false will be returned)
+    return callbacks.getOrDefault(path, java.util.Collections.emptyList()).remove(callbackOrSupplier) ||
+           suppliers.remove(path, callbackOrSupplier);
+  }
+
   private String makeError(spark.Response response, int statusCode, String message) {
     response.status(statusCode);
     return message;

ragconnect.base/src/main/resources/handler.mustache

@@ -14,4 +14,15 @@ aspect RagConnectHandler {
     {{#InUse}}{{FieldName}}.close();{{/InUse}}
     {{/Handlers}}
   }
+  class ConnectToken {
+    static java.util.concurrent.atomic.AtomicLong counter = new java.util.concurrent.atomic.AtomicLong(0);
+    final long id;
+    final java.net.URI uri;
+    public ConnectToken(java.net.URI uri) {
+      this.id = counter.incrementAndGet();
+      this.uri = uri;
+    }
+
+  }
+  static java.util.Map<ASTNode, java.util.Map<java.net.URI, ConnectToken>> ASTNode.connectTokens = new java.util.HashMap<>();
 }

ragconnect.base/src/main/resources/receiveDefinition.mustache

@@ -9,12 +9,42 @@ public boolean {{parentTypeName}}.{{connectMethod}}(String {{connectParameterNam
   };
   switch (scheme) {
   {{#usesMqtt}}
-    case "mqtt": return {{mqttHandlerAttribute}}().newConnection(uri, consumer);
+    case "mqtt":
+      ConnectToken connectToken = {{mqttHandlerAttribute}}().newConnection(uri, consumer);
+      if (connectToken == null) {
+        return false;
+      }
+      connectTokens.computeIfAbsent(this, astNode -> new java.util.HashMap<java.net.URI, ConnectToken>())
+                   .put(uri, connectToken);
+      break;
   {{/usesMqtt}}
   {{#usesRest}}
-    case "rest": return {{restHandlerAttribute}}().newPUTConnection(uri, input -> {
+    case "rest":
+      ConnectToken connectToken = {{restHandlerAttribute}}().newPUTConnection(uri, input -> {
         consumer.accept(input.getBytes());
       });
+      if (connectToken == null) {
+        return false;
+      }
+      connectTokens.computeIfAbsent(this, astNode -> new java.util.HashMap<java.net.URI, ConnectToken>())
+                   .put(uri, connectToken);
+      break;
+  {{/usesRest}}
+    default:
+      System.err.println("Unknown protocol '" + scheme + "'.");
+      return false;
+  }
+  return true;
+}
+
+public boolean {{parentTypeName}}.{{disconnectMethod}}(String {{connectParameterName}}) throws java.io.IOException {
+  {{>handleUri}}
+  switch (scheme) {
+  {{#usesMqtt}}
+    case "mqtt": return {{mqttHandlerAttribute}}().disconnect(connectTokens.get(this).get(uri));
+  {{/usesMqtt}}
+  {{#usesRest}}
+    case "rest": return {{restHandlerAttribute}}().disconnect(connectTokens.get(this).get(uri));
   {{/usesRest}}
     default:
       System.err.println("Unknown protocol '" + scheme + "'.");

ragconnect.base/src/main/resources/sendDefinition.mustache

@@ -22,10 +22,36 @@ public boolean {{parentTypeName}}.{{connectMethod}}(String {{connectParameterNam
   {{/usesMqtt}}
   {{#usesRest}}
     case "rest":
-      {{restHandlerAttribute}}().newGETConnection(uri, () -> {
+      ConnectToken connectToken = {{restHandlerAttribute}}().newGETConnection(uri, () -> {
         {{updateMethod}}();
         return new String({{lastValue}});
       });
+      if (connectToken == null) {
+        return false;
+      }
+      connectTokens.computeIfAbsent(this, astNode -> new java.util.HashMap<java.net.URI, ConnectToken>())
+                   .put(uri, connectToken);
+      break;
+  {{/usesRest}}
+    default:
+      System.err.println("Unknown protocol '" + scheme + "'.");
+      return false;
+  }
+  return true;
+}
+
+public boolean {{parentTypeName}}.{{disconnectMethod}}(String {{connectParameterName}}) throws java.io.IOException {
+  {{>handleUri}}
+  switch (scheme) {
+  {{#usesMqtt}}
+    case "mqtt":
+      {{sender}} = null;
+      {{lastValue}} = null;
+      break;
+  {{/usesMqtt}}
+  {{#usesRest}}
+    case "rest":
+      {{restHandlerAttribute}}().disconnect(connectTokens.get(this).get(uri));
       break;
   {{/usesRest}}
     default: