org.netbeans.lib.profiler.heap.HprofFileBuffer Maven / Gradle / Ivy
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 1997-2010 Oracle and/or its affiliates. All rights reserved.
*
* Oracle and Java are registered trademarks of Oracle and/or its affiliates.
* Other names may be trademarks of their respective owners.
*
* 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
* specific language governing permissions and limitations under the
* License. When distributing the software, include this License Header
* Notice in each file and include the License file at
* nbbuild/licenses/CDDL-GPL-2-CP. Oracle designates this
* 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
* your own identifying information:
* "Portions Copyrighted [year] [name of copyright owner]"
*
* Contributor(s):
* The Original Software is NetBeans. The Initial Developer of the Original
* Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun
* Microsystems, Inc. All Rights Reserved.
*
* 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
* under the [CDDL or GPL Version 2] license." If you do not indicate a
* single choice of license, a recipient has the option to distribute
* your version of this file under either the CDDL, the GPL Version 2 or
* to extend the choice of license to its licensees as provided above.
* However, if you add GPL Version 2 code and therefore, elected the GPL
* Version 2 license, then the option applies only if the new code is
* made subject to such option by the copyright holder.
*/
package org.netbeans.lib.profiler.heap;
import java.io.EOFException;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
/**
*
* @author Tomas Hurka
*/
class HprofFileBuffer extends HprofByteBuffer {
//~ Static fields/initializers -----------------------------------------------------------------------------------------------
private static final int MAX_bufferSizeBits = 17;
private static final int MIN_bufferSizeBits = 7;
private static final int MIN_bufferSize = 1 << MIN_bufferSizeBits;
private static final int MIN_bufferSizeMask = MIN_bufferSize - 1;
private static final int BUFFER_EXT = 8;
//~ Instance fields ----------------------------------------------------------------------------------------------------------
RandomAccessFile fis;
private byte[] dumpBuffer;
private long bufferStartOffset;
private int bufferSizeBits;
private int bufferSize;
//~ Constructors -------------------------------------------------------------------------------------------------------------
HprofFileBuffer(File dumpFile) throws IOException {
fis = new RandomAccessFile(dumpFile, "r");
length = fis.length();
bufferStartOffset = Long.MAX_VALUE;
readHeader();
}
//~ Methods ------------------------------------------------------------------------------------------------------------------
synchronized char getChar(long index) {
int i = loadBufferIfNeeded(index);
int ch1 = ((int) dumpBuffer[i++]) & 0xFF;
int ch2 = ((int) dumpBuffer[i]) & 0xFF;
return (char) ((ch1 << 8) + (ch2 << 0));
}
synchronized double getDouble(long index) {
int i = loadBufferIfNeeded(index);
return Double.longBitsToDouble(getLong(i));
}
synchronized float getFloat(long index) {
int i = loadBufferIfNeeded(index);
return Float.intBitsToFloat(getInt(i));
}
synchronized int getInt(long index) {
int i = loadBufferIfNeeded(index);
int ch1 = ((int) dumpBuffer[i++]) & 0xFF;
int ch2 = ((int) dumpBuffer[i++]) & 0xFF;
int ch3 = ((int) dumpBuffer[i++]) & 0xFF;
int ch4 = ((int) dumpBuffer[i]) & 0xFF;
return ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + (ch4 << 0));
}
synchronized long getLong(long index) {
return ((long) (getInt(index)) << 32) + (getInt(index + 4) & 0xFFFFFFFFL);
}
synchronized short getShort(long index) {
int i = loadBufferIfNeeded(index);
int ch1 = ((int) dumpBuffer[i++]) & 0xFF;
int ch2 = ((int) dumpBuffer[i]) & 0xFF;
return (short) ((ch1 << 8) + (ch2 << 0));
}
// delegate to MappedByteBuffer
synchronized byte get(long index) {
int i = loadBufferIfNeeded(index);
return dumpBuffer[i];
}
synchronized void get(long position, byte[] chars) {
int i = loadBufferIfNeeded(position);
if ((i + chars.length) < dumpBuffer.length) {
System.arraycopy(dumpBuffer, i, chars, 0, chars.length);
} else {
try {
fis.seek(position);
fis.readFully(chars);
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
private void setBufferSize(long newBufferStart) {
if ((newBufferStart > bufferStartOffset) && (newBufferStart < (bufferStartOffset + (2 * bufferSize)))) { // sequential read -> increase buffer size
if (bufferSizeBits < MAX_bufferSizeBits) {
setBufferSize(bufferSizeBits + 1);
}
} else { // reset buffer size
setBufferSize(MIN_bufferSizeBits);
}
}
private void setBufferSize(int newBufferSizeBits) {
bufferSizeBits = newBufferSizeBits;
bufferSize = 1 << bufferSizeBits;
dumpBuffer = new byte[bufferSize + BUFFER_EXT];
}
private int loadBufferIfNeeded(long index) {
if ((index >= bufferStartOffset) && (index < (bufferStartOffset + bufferSize))) {
return (int) (index - bufferStartOffset);
}
long newBufferStart = index & ~MIN_bufferSizeMask;
setBufferSize(newBufferStart);
try {
fis.seek(newBufferStart);
fis.readFully(dumpBuffer);
//System.out.println("Reading at "+newBufferStart+" size "+dumpBuffer.length+" thread "+Thread.currentThread().getName());
} catch (EOFException ex) {
// ignore
} catch (IOException ex) {
ex.printStackTrace();
}
bufferStartOffset = newBufferStart;
return (int) (index - bufferStartOffset);
}
public String toString() {
return "Single buffer, random access strategy";
}
}