/*
* Copyright (C) 2008-2015 by Holger Arndt
*
* This file is part of the Universal Java Matrix Package (UJMP).
* See the NOTICE file distributed with this work for additional
* information regarding copyright ownership and licensing.
*
* UJMP is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* UJMP is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with UJMP; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301 USA
*/
package org.ujmp.core.util.io;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.lang.ref.WeakReference;
import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.DoubleBuffer;
import java.nio.FloatBuffer;
import java.nio.IntBuffer;
import java.nio.LongBuffer;
import java.nio.ShortBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.FileChannel.MapMode;
import org.ujmp.core.util.MathUtil;
public class WeakMappedByteBuffer {
public static final int DEFAULTBUFFERSIZE = AbstractByteBufferConcatenation.DEFAULTBUFFERSIZE;
private WeakReference<ByteBuffer> byteBufferReference = null;
private final FileChannel fileChannel;
private final MapMode mapMode;
private final long pos;
private final long size;
public WeakMappedByteBuffer(FileChannel fileChannel, MapMode mapMode, long pos, int size) {
this.fileChannel = fileChannel;
this.mapMode = mapMode;
this.pos = pos;
this.size = size;
}
public static final WeakMappedByteBuffer[] create(RandomAccessFile randomAccessFile)
throws IOException {
long fileLength = randomAccessFile.length();
FileChannel fc = randomAccessFile.getChannel();
MapMode mapMode = MapMode.READ_ONLY;
final int bufferCount = (int) Math.ceil((double) fileLength / (double) DEFAULTBUFFERSIZE);
final WeakMappedByteBuffer[] buffers = new WeakMappedByteBuffer[bufferCount];
int i = 0;
for (long filePos = 0; filePos < fileLength; filePos += DEFAULTBUFFERSIZE) {
WeakMappedByteBuffer buf = new WeakMappedByteBuffer(fc, mapMode, filePos,
MathUtil.longToInt(Math.min(DEFAULTBUFFERSIZE, fileLength - filePos)));
buffers[i++] = buf;
}
return buffers;
}
public ByteBuffer getOrCreateByteBuffer() {
try {
ByteBuffer byteBuffer = byteBufferReference == null ? null : byteBufferReference.get();
if (byteBuffer == null || byteBufferReference == null
|| byteBufferReference.get() == null) {
synchronized (this) {
if (byteBuffer == null || byteBufferReference == null
|| byteBufferReference.get() == null) {
byteBuffer = fileChannel.map(mapMode, pos, size);
byteBufferReference = new WeakReference<ByteBuffer>(byteBuffer);
}
}
}
return byteBuffer;
} catch (IOException e) {
throw new RuntimeException(e);
}
}
public ByteBuffer slice() {
return getOrCreateByteBuffer().slice();
}
public ByteBuffer duplicate() {
return getOrCreateByteBuffer().duplicate();
}
public ByteBuffer asReadOnlyBuffer() {
return getOrCreateByteBuffer().asReadOnlyBuffer();
}
public byte get() {
return getOrCreateByteBuffer().get();
}
public ByteBuffer put(byte b) {
return getOrCreateByteBuffer().put(b);
}
public byte get(int index) {
return getOrCreateByteBuffer().get(index);
}
public ByteBuffer put(int index, byte b) {
return getOrCreateByteBuffer().put(index, b);
}
public ByteBuffer compact() {
return getOrCreateByteBuffer().compact();
}
public boolean isDirect() {
return getOrCreateByteBuffer().isDirect();
}
public char getChar() {
return getOrCreateByteBuffer().getChar();
}
public ByteBuffer putChar(char value) {
return getOrCreateByteBuffer().putChar(value);
}
public char getChar(int index) {
return getOrCreateByteBuffer().getChar(index);
}
public ByteBuffer putChar(int index, char value) {
return getOrCreateByteBuffer().putChar(index, value);
}
public CharBuffer asCharBuffer() {
return getOrCreateByteBuffer().asCharBuffer();
}
public short getShort() {
return getOrCreateByteBuffer().getShort();
}
public ByteBuffer putShort(short value) {
return getOrCreateByteBuffer().putShort(value);
}
public short getShort(int index) {
return getOrCreateByteBuffer().getShort(index);
}
public ByteBuffer putShort(int index, short value) {
return getOrCreateByteBuffer().putShort(index, value);
}
public ShortBuffer asShortBuffer() {
return getOrCreateByteBuffer().asShortBuffer();
}
public int getInt() {
return getOrCreateByteBuffer().getInt();
}
public ByteBuffer putInt(int value) {
return getOrCreateByteBuffer().putInt(value);
}
public int getInt(int index) {
return getOrCreateByteBuffer().getInt(index);
}
public ByteBuffer putInt(int index, int value) {
return getOrCreateByteBuffer().putInt(index, value);
}
public IntBuffer asIntBuffer() {
return getOrCreateByteBuffer().asIntBuffer();
}
public long getLong() {
return getOrCreateByteBuffer().getLong();
}
public ByteBuffer putLong(long value) {
return getOrCreateByteBuffer().putLong(value);
}
public long getLong(int index) {
return getOrCreateByteBuffer().getLong(index);
}
public ByteBuffer putLong(int index, long value) {
return getOrCreateByteBuffer().putLong(index, value);
}
public LongBuffer asLongBuffer() {
return getOrCreateByteBuffer().asLongBuffer();
}
public float getFloat() {
return getOrCreateByteBuffer().getFloat();
}
public ByteBuffer putFloat(float value) {
return getOrCreateByteBuffer().putFloat(value);
}
public float getFloat(int index) {
return getOrCreateByteBuffer().getFloat(index);
}
public ByteBuffer putFloat(int index, float value) {
return getOrCreateByteBuffer().putFloat(index, value);
}
public FloatBuffer asFloatBuffer() {
return getOrCreateByteBuffer().asFloatBuffer();
}
public double getDouble() {
return getOrCreateByteBuffer().getDouble();
}
public ByteBuffer putDouble(double value) {
return getOrCreateByteBuffer().putDouble(value);
}
public double getDouble(int index) {
return getOrCreateByteBuffer().getDouble(index);
}
public ByteBuffer putDouble(int index, double value) {
return getOrCreateByteBuffer().putDouble(index, value);
}
public DoubleBuffer asDoubleBuffer() {
return getOrCreateByteBuffer().asDoubleBuffer();
}
public boolean isReadOnly() {
return getOrCreateByteBuffer().isReadOnly();
}
public long capacity() {
return getOrCreateByteBuffer().capacity();
}
public void position(int offset) {
getOrCreateByteBuffer().position(offset);
}
public void put(byte[] bytes, int offset, int length) {
getOrCreateByteBuffer().put(bytes, offset, length);
}
public void get(byte[] dst, int offset, int length) {
getOrCreateByteBuffer().get(dst, offset, length);
}
public Buffer rewind() {
return getOrCreateByteBuffer().rewind();
}
public Buffer reset() {
return getOrCreateByteBuffer().rewind();
}
}