HadoopIgfsIo.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.ignite.internal.processors.hadoop.impl.igfs;

import org.apache.ignite.IgniteCheckedException;
import org.apache.ignite.internal.IgniteInternalFuture;
import org.apache.ignite.internal.igfs.common.IgfsMessage;
import org.jetbrains.annotations.Nullable;

/**
 * IO abstraction layer for IGFS client. Two kind of messages are expected to be sent: requests with response
 * and request without response.
 */
public interface HadoopIgfsIo {
    /**
     * Sends given IGFS client message and asynchronously awaits for response.
     *
     * @param msg Message to send.
     * @return Future that will be completed.
     * @throws IgniteCheckedException If a message cannot be sent (connection is broken or client was closed).
     */
    public IgniteInternalFuture<IgfsMessage> send(IgfsMessage msg) throws IgniteCheckedException;

    /**
     * Sends given IGFS client message and asynchronously awaits for response. When IO detects response
     * beginning for given message it stops reading data and passes input stream to closure which can read
     * response in a specific way.
     *
     * @param msg Message to send.
     * @param outBuf Output buffer. If {@code null}, the output buffer is not used.
     * @param outOff Output buffer offset.
     * @param outLen Output buffer length.
     * @return Future that will be completed when response is returned from closure.
     * @throws IgniteCheckedException If a message cannot be sent (connection is broken or client was closed).
     */
    public <T> IgniteInternalFuture<T> send(IgfsMessage msg, @Nullable byte[] outBuf, int outOff, int outLen)
        throws IgniteCheckedException;

    /**
     * Sends given message and does not wait for response.
     *
     * @param msg Message to send.
     * @throws IgniteCheckedException If send failed.
     */
    public void sendPlain(IgfsMessage msg) throws IgniteCheckedException;

    /**
     * Adds event listener that will be invoked when connection with server is lost or remote error has occurred.
     * If connection is closed already, callback will be invoked synchronously inside this method.
     *
     * @param lsnr Event listener.
     */
    public void addEventListener(HadoopIgfsIpcIoListener lsnr);

    /**
     * Removes event listener that will be invoked when connection with server is lost or remote error has occurred.
     *
     * @param lsnr Event listener.
     */
    public void removeEventListener(HadoopIgfsIpcIoListener lsnr);
}