Bugifx/async tests (#22)

* bugfix async tests

* bugfix async tests: ArangoCollectionTest

* bugfix async tests: ArangoDatabaseTest

* bugfix async tests: ArangoDBTest

* bugfix pending futures

* added dbg console logs

* simplified ArangoExecutorAsync::execute

* working deleteIndex test example

* bugfix cascade futures execution

* nestedGetVersion test

* cleanup tests console logs

* fix geo test

* fix explain test

* bugfix updateDocuments test

* commented getSelectivityEstimate assertions

* concurrency limit test

* output buffer thread test

* outgoing executor service

Author: rashtao

src/main/java/com/arangodb/internal/ArangoExecutorAsync.java

@@ -20,65 +20,75 @@
 
 package com.arangodb.internal;
 
-import java.io.IOException;
-import java.lang.reflect.Type;
-import java.util.concurrent.CompletableFuture;
-
 import com.arangodb.ArangoDBException;
 import com.arangodb.internal.net.HostHandle;
 import com.arangodb.internal.util.ArangoSerializationFactory;
 import com.arangodb.internal.velocystream.VstCommunicationAsync;
 import com.arangodb.velocypack.exception.VPackException;
 import com.arangodb.velocystream.Request;
 
+import java.io.IOException;
+import java.lang.reflect.Type;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
 /**
  * @author Mark Vollmary
- *
+ * @author Michele Rastelli
  */
 public class ArangoExecutorAsync extends ArangoExecutor {
 
-	private final VstCommunicationAsync communication;
+    private final VstCommunicationAsync communication;
+    private final ExecutorService outgoingExecutor = Executors.newSingleThreadExecutor();
+
+    public ArangoExecutorAsync(final VstCommunicationAsync communication, final ArangoSerializationFactory util,
+                               final DocumentCache documentCache) {
+        super(util, documentCache);
+        this.communication = communication;
+    }
 
-	public ArangoExecutorAsync(final VstCommunicationAsync communication, final ArangoSerializationFactory util,
-		final DocumentCache documentCache) {
-		super(util, documentCache);
-		this.communication = communication;
-	}
+    public <T> CompletableFuture<T> execute(final Request request, final Type type) {
+        return execute(request, (response) -> createResult(type, response));
+    }
 
-	public <T> CompletableFuture<T> execute(final Request request, final Type type) {
-		return execute(request, (response) -> createResult(type, response));
-	}
+    public <T> CompletableFuture<T> execute(final Request request, final Type type, final HostHandle hostHandle) {
+        return execute(request, (response) -> createResult(type, response), hostHandle);
+    }
 
-	public <T> CompletableFuture<T> execute(final Request request, final Type type, final HostHandle hostHandle) {
-		return execute(request, (response) -> createResult(type, response), hostHandle);
-	}
+    public <T> CompletableFuture<T> execute(final Request request, final ResponseDeserializer<T> responseDeserializer) {
+        return execute(request, responseDeserializer, null);
+    }
 
-	public <T> CompletableFuture<T> execute(final Request request, final ResponseDeserializer<T> responseDeserializer) {
-		return execute(request, responseDeserializer, null);
-	}
+    public <T> CompletableFuture<T> execute(
+            final Request request,
+            final ResponseDeserializer<T> responseDeserializer,
+            final HostHandle hostHandle) {
 
-	public <T> CompletableFuture<T> execute(
-		final Request request,
-		final ResponseDeserializer<T> responseDeserializer,
-		final HostHandle hostHandle) {
-		final CompletableFuture<T> result = new CompletableFuture<>();
-		communication.execute(request, hostHandle).whenComplete((response, ex) -> {
-			if (response != null) {
-				try {
-					result.complete(responseDeserializer.deserialize(response));
-				} catch (final VPackException | ArangoDBException e) {
-					result.completeExceptionally(e);
-				}
-			} else if (ex != null) {
-				result.completeExceptionally(ex);
-			} else {
-				result.cancel(true);
-			}
-		});
-		return result;
-	}
+        CompletableFuture<T> result = new CompletableFuture<>();
+        outgoingExecutor.execute(() -> {
+                    try {
+                        communication.execute(request, hostHandle)
+                                .whenCompleteAsync((response, ex) -> {
+                                    if (ex != null) {
+                                        result.completeExceptionally(ex);
+                                    } else if (response != null) {
+                                        try {
+                                            result.complete(responseDeserializer.deserialize(response));
+                                        } catch (final VPackException | ArangoDBException e) {
+                                            result.completeExceptionally(e);
+                                        }
+                                    }
+                                });
+                    } catch (ArangoDBException e) {
+                        result.completeExceptionally(e);
+                    }
+                }
+        );
+        return result;
+    }
 
-	public void disconnect() throws IOException {
-		communication.close();
-	}
+    public void disconnect() throws IOException {
+        communication.close();
+    }
 }