org.apache.hadoop.hbase.ipc.ExecRPCInvoker.java Source code

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Here is the source code for org.apache.hadoop.hbase.ipc.ExecRPCInvoker.java

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/*
 * Copyright 2010 The Apache Software Foundation
 *
 * 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.hadoop.hbase.ipc;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.client.coprocessor.Exec;
import org.apache.hadoop.hbase.client.coprocessor.ExecResult;
import org.apache.hadoop.hbase.util.Bytes;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;

/**
 * Backs a {@link CoprocessorProtocol} subclass proxy and forwards method
 * invocations for server execution.  Note that internally this will issue a
 * separate RPC call for each method invocation (using a
 * {@link org.apache.hadoop.hbase.client.ServerCallable} instance).
 */
public class ExecRPCInvoker implements InvocationHandler {
    // LOG is NOT in hbase subpackage intentionally so that the default HBase
    // DEBUG log level does NOT emit RPC-level logging. 
    private static final Log LOG = LogFactory.getLog("org.apache.hadoop.ipc.ExecRPCInvoker");

    private Configuration conf;
    private final HConnection connection;
    private Class<? extends CoprocessorProtocol> protocol;
    private final byte[] table;
    private final byte[] row;
    private byte[] regionName;

    public ExecRPCInvoker(Configuration conf, HConnection connection, Class<? extends CoprocessorProtocol> protocol,
            byte[] table, byte[] row) {
        this.conf = conf;
        this.connection = connection;
        this.protocol = protocol;
        this.table = table;
        this.row = row;
    }

    @Override
    public Object invoke(Object instance, final Method method, final Object[] args) throws Throwable {
        if (LOG.isDebugEnabled()) {
            LOG.debug("Call: " + method.getName() + ", " + (args != null ? args.length : 0));
        }

        if (row != null) {
            final Exec exec = new Exec(conf, row, protocol, method, args);
            ServerCallable<ExecResult> callable = new ServerCallable<ExecResult>(connection, table, row) {
                public ExecResult call() throws Exception {
                    return server.execCoprocessor(location.getRegionInfo().getRegionName(), exec);
                }
            };
            ExecResult result = callable.withRetries();
            this.regionName = result.getRegionName();
            LOG.debug("Result is region=" + Bytes.toStringBinary(regionName) + ", value=" + result.getValue());
            return result.getValue();
        }

        return null;
    }

    public byte[] getRegionName() {
        return regionName;
    }
}