org.apache.flume.tools.DirectMemoryUtils.java Source code

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Here is the source code for org.apache.flume.tools.DirectMemoryUtils.java

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/*
 * 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.flume.tools;

import java.lang.management.ManagementFactory;
import java.lang.management.RuntimeMXBean;
import java.lang.reflect.Method;
import java.nio.ByteBuffer;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;

public class DirectMemoryUtils {

    private static final Logger LOG = LoggerFactory.getLogger(DirectMemoryUtils.class);
    private static final String MAX_DIRECT_MEMORY_PARAM = "-XX:MaxDirectMemorySize=";
    private static final long DEFAULT_SIZE = getDefaultDirectMemorySize();
    private static final AtomicInteger allocated = new AtomicInteger(0);

    public static ByteBuffer allocate(int size) {
        Preconditions.checkArgument(size > 0, "Size must be greater than zero");
        long maxDirectMemory = getDirectMemorySize();
        long allocatedCurrently = allocated.get();
        LOG.info("Direct Memory Allocation: " + " Allocation = " + size + ", Allocated = " + allocatedCurrently
                + ", MaxDirectMemorySize = " + maxDirectMemory + ", Remaining = "
                + Math.max(0, (maxDirectMemory - allocatedCurrently)));
        try {
            ByteBuffer result = ByteBuffer.allocateDirect(size);
            allocated.addAndGet(size);
            return result;
        } catch (OutOfMemoryError error) {
            LOG.error("Error allocating " + size + ", you likely want" + " to increase " + MAX_DIRECT_MEMORY_PARAM,
                    error);
            throw error;
        }
    }

    public static void clean(ByteBuffer buffer) throws Exception {
        Preconditions.checkArgument(buffer.isDirect(), "buffer isn't direct!");
        Method cleanerMethod = buffer.getClass().getMethod("cleaner");
        cleanerMethod.setAccessible(true);
        Object cleaner = cleanerMethod.invoke(buffer);
        Method cleanMethod = cleaner.getClass().getMethod("clean");
        cleanMethod.setAccessible(true);
        cleanMethod.invoke(cleaner);
        allocated.getAndAdd(-buffer.capacity());
        long maxDirectMemory = getDirectMemorySize();
        LOG.info("Direct Memory Deallocation: " + ", Allocated = " + allocated.get() + ", MaxDirectMemorySize = "
                + maxDirectMemory + ", Remaining = " + Math.max(0, (maxDirectMemory - allocated.get())));

    }

    public static long getDirectMemorySize() {
        RuntimeMXBean RuntimemxBean = ManagementFactory.getRuntimeMXBean();
        List<String> arguments = Lists.reverse(RuntimemxBean.getInputArguments());
        long multiplier = 1; //for the byte case.
        for (String s : arguments) {
            if (s.contains(MAX_DIRECT_MEMORY_PARAM)) {
                String memSize = s.toLowerCase().replace(MAX_DIRECT_MEMORY_PARAM.toLowerCase(), "").trim();

                if (memSize.contains("k")) {
                    multiplier = 1024;
                } else if (memSize.contains("m")) {
                    multiplier = 1048576;
                } else if (memSize.contains("g")) {
                    multiplier = 1073741824;
                }
                memSize = memSize.replaceAll("[^\\d]", "");
                long retValue = Long.parseLong(memSize);
                return retValue * multiplier;
            }
        }
        return DEFAULT_SIZE;
    }

    private static long getDefaultDirectMemorySize() {
        try {
            Class<?> VM = Class.forName("sun.misc.VM");
            Method maxDirectMemory = VM.getDeclaredMethod("maxDirectMemory", (Class<?>) null);
            Object result = maxDirectMemory.invoke(null, (Object[]) null);
            if (result != null && result instanceof Long) {
                return (Long) result;
            }
        } catch (Exception e) {
            LOG.info("Unable to get maxDirectMemory from VM: " + e.getClass().getSimpleName() + ": "
                    + e.getMessage());
        }
        // default according to VM.maxDirectMemory()
        return Runtime.getRuntime().maxMemory();
    }
}