/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 2014 Alexey Ragozin
*
* Oracle and Java are registered trademarks of Oracle and/or its affiliates.
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*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common
* Development and Distribution License("CDDL") (collectively, the
* "License"). You may not use this file except in compliance with the
* License. You can obtain a copy of the License at
* http://www.netbeans.org/cddl-gplv2.html
* or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the
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* particular file as subject to the "Classpath" exception as provided
* by Oracle in the GPL Version 2 section of the License file that
* accompanied this code. If applicable, add the following below the
* License Header, with the fields enclosed by brackets [] replaced by
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* Contributor(s):
* The Original Software is NetBeans. The Initial Developer of the Original
* Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun
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* If you wish your version of this file to be governed by only the CDDL
* or only the GPL Version 2, indicate your decision by adding
* "[Contributor] elects to include this software in this distribution
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package org.netbeans.lib.profiler.heap;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.nio.BufferUnderflowException;
import java.nio.ByteBuffer;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
/**
* This version of byte buffer is using multiple
* mapped byte buffers to workaround 2GiB limitation of {@link ByteBuffer}.
*
* <br/>
*
* Suitable only for 64bit architecture
*
* @author Alexey Ragozin (alexey.ragozin@gmail.com)
*/
class HprofStrippedMappedByteBuffer extends HprofByteBuffer {
private static int STRIPE_SHIFT = 30;
private static int STRIPE_SIZE = 1 << STRIPE_SHIFT;
private static long STRIPE_MASK = STRIPE_SIZE - 1;
private MappedByteBuffer[] bufferStripe;
HprofStrippedMappedByteBuffer(File dumpFile) throws IOException {
FileInputStream fis = new FileInputStream(dumpFile);
FileChannel channel = fis.getChannel();
length = channel.size();
int stripes = (int)((length + STRIPE_SIZE - 1) >> STRIPE_SHIFT);
bufferStripe = new MappedByteBuffer[stripes];
for(int i = 0; i != bufferStripe.length; ++i) {
long offs = ((long)i) << STRIPE_SHIFT;
long len = offs + STRIPE_SIZE <= length ? STRIPE_SIZE : length & STRIPE_MASK;
bufferStripe[i] = channel.map(FileChannel.MapMode.READ_ONLY, offs, len);
}
channel.close();
readHeader();
}
char getChar(long index) {
try {
return bufferStripe[stripeId(index)].getChar(stripeOffs(index));
}
catch(BufferUnderflowException e) {
return slowGet(index, 2).getChar();
}
}
double getDouble(long index) {
try {
return bufferStripe[stripeId(index)].getDouble(stripeOffs(index));
}
catch(BufferUnderflowException e) {
return slowGet(index, 8).getDouble();
}
}
float getFloat(long index) {
try {
return bufferStripe[stripeId(index)].getFloat(stripeOffs(index));
}
catch(BufferUnderflowException e) {
return slowGet(index, 4).getFloat();
}
}
int getInt(long index) {
try {
return bufferStripe[stripeId(index)].getInt(stripeOffs(index));
}
catch(BufferUnderflowException e) {
return slowGet(index, 4).getInt();
}
}
long getLong(long index) {
try {
return bufferStripe[stripeId(index)].getLong(stripeOffs(index));
}
catch(BufferUnderflowException e) {
return slowGet(index, 8).getLong();
}
}
short getShort(long index) {
try {
return bufferStripe[stripeId(index)].getShort(stripeOffs(index));
}
catch(BufferUnderflowException e) {
return slowGet(index, 2).getShort();
}
}
byte get(long index) {
return bufferStripe[stripeId(index)].get(stripeOffs(index));
}
private int stripeId(long pos) {
return (int)(pos >> STRIPE_SHIFT);
}
private int stripeOffs(long pos) {
return (int)(pos & STRIPE_MASK);
}
private ByteBuffer slowGet(long position, int len) {
byte[] buf = new byte[len];
ByteBuffer bb = ByteBuffer.wrap(buf);
get(position, buf);
return bb;
}
void get(long position, byte[] chars) {
try {
MappedByteBuffer buffer = bufferStripe[stripeId(position)];
buffer.position(stripeOffs(position));
buffer.get(chars);
}
catch(BufferUnderflowException e) {
// catch cross stripe access
int s = stripeId(position);
if (s == bufferStripe.length - 1) {
// last stripe
throw e;
}
int pos = stripeOffs(position);
int brk = STRIPE_SIZE - (int)(position & STRIPE_MASK);
bufferStripe[s].position(pos);
bufferStripe[s].get(chars, 0, brk);
bufferStripe[s + 1].position(0);
bufferStripe[s + 1].get(chars, brk, chars.length - brk);
}
}
}