Add configurable connection pooling for http

Author: mpv1989

src/main/java/com/arangodb/ArangoDB.java

@@ -350,7 +350,8 @@ public synchronized ArangoDB build() {
 							.user(user).password(password).useSsl(useSsl).sslContext(sslContext).chunksize(chunksize)
 							.maxConnections(maxConnections),
 					new HttpCommunication.Builder(new DefaultHostHandler(new ArrayList<Host>(hosts))).timeout(timeout)
-							.user(user).password(password).useSsl(useSsl).sslContext(sslContext),
+							.user(user).password(password).useSsl(useSsl).sslContext(sslContext)
+							.maxConnections(maxConnections),
 					new ArangoUtilImpl(serializerTemp, deserializerTemp), collectionCache, protocol);
 		}
 

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

@@ -37,7 +37,8 @@ public class ArangoDBConstants {
 	public static final int CHUNK_MIN_HEADER_SIZE = INTEGER_BYTES + INTEGER_BYTES + LONG_BYTES;
 	public static final int CHUNK_MAX_HEADER_SIZE = CHUNK_MIN_HEADER_SIZE + LONG_BYTES;
 	public static final int CHUNK_DEFAULT_CONTENT_SIZE = 30000;
-	public static final int MAX_CONNECTIONS_DEFAULT = 1;
+	public static final int MAX_CONNECTIONS_VST_DEFAULT = 1;
+	public static final int MAX_CONNECTIONS_HTTP_DEFAULT = 20;
 
 	public static final String PATH_API_DOCUMENT = "/_api/document";
 	public static final String PATH_API_COLLECTION = "/_api/collection";

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

@@ -120,7 +120,7 @@ protected static Integer loadChunkSize(final Properties properties, final Intege
 
 	protected static Integer loadMaxConnections(final Properties properties, final Integer currentValue) {
 		return Integer.parseInt(getProperty(properties, PROPERTY_KEY_MAX_CONNECTIONS, currentValue,
-			ArangoDBConstants.MAX_CONNECTIONS_DEFAULT));
+			ArangoDBConstants.MAX_CONNECTIONS_VST_DEFAULT));
 	}
 
 	private static <T> String getProperty(

src/main/java/com/arangodb/internal/http/HttpCommunication.java

@@ -71,6 +71,7 @@
 
 import com.arangodb.ArangoDBException;
 import com.arangodb.entity.ErrorEntity;
+import com.arangodb.internal.ArangoDBConstants;
 import com.arangodb.internal.util.CURLLogger;
 import com.arangodb.internal.util.IOUtils;
 import com.arangodb.internal.velocystream.Host;
@@ -101,7 +102,7 @@ public static class Builder {
 		private Boolean useSsl;
 		private SSLContext sslContext;
 		// private Integer chunksize;
-		// private Integer maxConnections;
+		private Integer maxConnections;
 
 		public Builder(final HostHandler hostHandler) {
 			super();
@@ -138,13 +139,13 @@ public Builder sslContext(final SSLContext sslContext) {
 		// return this;
 		// }
 		//
-		// public Builder maxConnections(final Integer maxConnections) {
-		// this.maxConnections = maxConnections;
-		// return this;
-		// }
+		public Builder maxConnections(final Integer maxConnections) {
+			this.maxConnections = maxConnections;
+			return this;
+		}
 
 		public HttpCommunication build(final ArangoSerialization util) {
-			return new HttpCommunication(timeout, user, password, useSsl, sslContext, util, hostHandler,
+			return new HttpCommunication(timeout, user, password, useSsl, sslContext, util, hostHandler, maxConnections,
 					HttpContentType.JSON);
 		}
 	}
@@ -165,7 +166,7 @@ public HttpCommunication build(final ArangoSerialization util) {
 
 	private HttpCommunication(final Integer timeout, final String user, final String password, final Boolean useSsl,
 		final SSLContext sslContext, final ArangoSerialization util, final HostHandler hostHandler,
-		final HttpContentType contentType) {
+		final Integer maxConnections, final HttpContentType contentType) {
 		super();
 		this.user = user;
 		this.password = password;
@@ -185,8 +186,10 @@ private HttpCommunication(final Integer timeout, final String user, final String
 			a.register("http", new PlainConnectionSocketFactory());
 		}
 		cm = new PoolingHttpClientConnectionManager(a.build());
-		cm.setDefaultMaxPerRoute(20);// TODO configurable
-		cm.setMaxTotal(20);// TODO configurable
+		final int connections = maxConnections != null ? Math.max(1, maxConnections)
+				: ArangoDBConstants.MAX_CONNECTIONS_HTTP_DEFAULT;
+		cm.setDefaultMaxPerRoute(connections);
+		cm.setMaxTotal(connections);
 
 		final RequestConfig.Builder custom = RequestConfig.custom();
 		// if (configure.getConnectionTimeout() >= 0) {

src/main/java/com/arangodb/internal/velocystream/ConnectionPool.java

@@ -36,7 +36,7 @@ public abstract class ConnectionPool<C extends Connection> {
 	public ConnectionPool(final Integer maxConnections) {
 		super();
 		this.maxConnections = maxConnections != null ? Math.max(1, maxConnections)
-				: ArangoDBConstants.MAX_CONNECTIONS_DEFAULT;
+				: ArangoDBConstants.MAX_CONNECTIONS_VST_DEFAULT;
 		connections = new LinkedList<C>();
 	}