Streaming query

axon-server-connector/pom.xml

@@ -97,6 +97,18 @@
             <artifactId>reactor-test</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>testcontainers</artifactId>
+            <version>${testcontainers.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>${testcontainers.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>

axon-server-connector/src/main/java/org/axonframework/axonserver/connector/PrioritizedRunnable.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2010-2022. Axon Framework
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.axonframework.axonserver.connector;
+
+/**
+ * A {@link Runable} with a priority.
+ *
+ * @author Stefan Dragisic
+ * @author Milan Savic
+ * @since 4.6.0
+ */
+public interface PrioritizedRunnable extends Runnable {
+
+    /**
+     * The priority of this runnable.
+      *
+     * @return the priority of this runnable.
+     */
+    long priority();
+}

axon-server-connector/src/main/java/org/axonframework/axonserver/connector/query/BlockingQueryResponseProcessingTask.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2010-2022. Axon Framework
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.axonframework.axonserver.connector.query;
+
+import io.axoniq.axonserver.grpc.query.QueryResponse;
+import org.axonframework.axonserver.connector.ErrorCode;
+import org.axonframework.axonserver.connector.PrioritizedRunnable;
+import org.axonframework.common.AxonException;
+import org.axonframework.messaging.responsetypes.ResponseType;
+import org.axonframework.queryhandling.QueryResponseMessage;
+import org.reactivestreams.Publisher;
+import org.reactivestreams.Subscriber;
+import org.reactivestreams.Subscription;
+
+import java.util.concurrent.CompletableFuture;
+
+/**
+ * Task that processes query responses. It will block until all responses are received.
+ *
+ * @param <R> the type of expected final response
+ * @author Allard Buijze
+ * @author Steven van Beelen
+ * @author Milan Savic
+ * @author Stefan Dragisic
+ * @since 4.6.0
+ */
+class BlockingQueryResponseProcessingTask<R> implements PrioritizedRunnable {
+
+    private final Publisher<QueryResponse> result;
+    private final QuerySerializer serializer;
+    private final CompletableFuture<QueryResponseMessage<R>> queryTransaction;
+    private final long priority;
+    private final ResponseType<R> expectedResponseType;
+
+    public BlockingQueryResponseProcessingTask(Publisher<QueryResponse> result,
+                                               QuerySerializer serializer,
+                                               CompletableFuture<QueryResponseMessage<R>> queryTransaction,
+                                               long priority,
+                                               ResponseType<R> expectedResponseType) {
+        this.result = result;
+        this.serializer = serializer;
+        this.queryTransaction = queryTransaction;
+        this.priority = priority;
+        this.expectedResponseType = expectedResponseType;
+    }
+
+    @Override
+    public long priority() {
+        return priority;
+    }
+
+    @Override
+    public void run() {
+        result.subscribe(new Subscriber<QueryResponse>() {
+            @Override
+            public void onSubscribe(Subscription s) {
+                s.request(Long.MAX_VALUE);
+            }
+
+            @Override
+            public void onNext(QueryResponse queryResponse) {
+                queryTransaction.complete(serializer.deserializeResponse(queryResponse, expectedResponseType));
+            }
+
+            @Override
+            public void onError(Throwable t) {
+                AxonException exception = ErrorCode.QUERY_DISPATCH_ERROR.convert(t);
+                queryTransaction.completeExceptionally(exception);
+            }
+
+            @Override
+            public void onComplete() {
+                // noop
+            }
+        });
+    }
+}