gremlin-driver/src/main/java/org/apache/tinkerpop/gremlin/driver/HandshakeInterceptor.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.tinkerpop.gremlin.driver;

import io.netty.handler.codec.http.FullHttpRequest;

import java.util.function.UnaryOperator;

/**
 * This function is called when the websocket handshake is attempted and the first {@code FullHttpRequest} is sent to
 * the server. The interceptor allows this message to be modified as needed before it is sent to the server.
 * Implementations are supplied to {@link Cluster.Builder#handshakeInterceptor(HandshakeInterceptor)}.
 */
public interface HandshakeInterceptor extends UnaryOperator<FullHttpRequest> {

    /**
     * The default implementation of a {@link HandshakeInterceptor} and behaves as a no-op.
     */
    public static final HandshakeInterceptor NO_OP = o -> o;
}