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HSQLDB - Lightweight 100% Java SQL Database Engine
/* Copyright (c) 2001-2019, The HSQL Development Group
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the HSQL Development Group nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.hsqldb.persist;
import java.io.FileDescriptor;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.FileChannel.MapMode;
import org.hsqldb.Database;
import org.hsqldb.error.Error;
import org.hsqldb.error.ErrorCode;
import org.hsqldb.lib.ArrayUtil;
import org.hsqldb.lib.java.JavaSystem;
/**
* NIO version of ScaledRAFile. This class is used only for storing a CACHED
* TABLE .data file and cannot be used for TEXT TABLE source files.
*
* Once the maximum data file size allowed for NIO is reached, an ordinary
* ScaledRAFile is used for data access.
*
* @author Fred Toussi (fredt@users dot sourceforge.net)
* @version 2.5.0
* @since 1.8.0.5
*/
final class RAFileNIO implements RandomAccessInterface {
private final EventLogInterface logger;
private final boolean readOnly;
private final long maxLength;
private long fileLength;
private RandomAccessFile file;
private FileDescriptor fileDescriptor;
private MappedByteBuffer buffer;
private long bufferPosition;
private int bufferLength;
private long currentPosition;
private FileChannel channel;
private boolean buffersModified;
//
private MappedByteBuffer[] buffers = new MappedByteBuffer[]{};
//
private static final String JVM_ERROR = "NIO access failed";
//
static final int largeBufferScale = 24;
static final int largeBufferSize = 1 << largeBufferScale;
static final long largeBufferMask = 0xffffffffffffffffL
<< largeBufferScale;
RAFileNIO(EventLogInterface logger, String name, boolean readOnly,
long requiredLength, long maxLength) throws IOException {
this.logger = logger;
this.maxLength = maxLength;
java.io.File tempFile = new java.io.File(name);
if (readOnly) {
requiredLength = tempFile.length();
} else {
if (tempFile.length() > requiredLength) {
requiredLength = tempFile.length();
}
requiredLength =
ArrayUtil.getBinaryNormalisedCeiling(requiredLength,
largeBufferScale);
}
file = new RandomAccessFile(name, readOnly ? "r"
: "rw");
this.readOnly = readOnly;
this.channel = file.getChannel();
this.fileDescriptor = file.getFD();
if (ensureLength(requiredLength)) {
buffer = buffers[0];
bufferLength = buffer.limit();
bufferPosition = 0;
currentPosition = 0;
} else {
close();
IOException io = new IOException("NIO buffer allocation failed");
throw io;
}
}
public long length() throws IOException {
try {
return file.length();
} catch (IOException e) {
logger.logWarningEvent(JVM_ERROR, e);
throw e;
} catch (Throwable t) {
logger.logWarningEvent(JVM_ERROR, t);
IOException io = JavaSystem.toIOException(t);
throw io;
}
}
public void seek(long newPos) throws IOException {
try {
positionBufferSeek(newPos);
buffer.position((int) (newPos - bufferPosition));
} catch (IllegalArgumentException e) {
logger.logWarningEvent(JVM_ERROR, e);
IOException io = JavaSystem.toIOException(e);
throw io;
} catch (Throwable t) {
logger.logWarningEvent(JVM_ERROR, t);
IOException io = JavaSystem.toIOException(t);
throw io;
}
}
public long getFilePointer() throws IOException {
try {
return currentPosition;
} catch (Throwable t) {
logger.logWarningEvent(JVM_ERROR, t);
IOException io = JavaSystem.toIOException(t);
throw io;
}
}
public int read() throws IOException {
try {
int value = buffer.get();
positionBufferMove(1);
return value;
} catch (Throwable t) {
logger.logWarningEvent(JVM_ERROR, t);
IOException io = JavaSystem.toIOException(t);
throw io;
}
}
public void read(byte[] b, int offset, int length) throws IOException {
try {
while (true) {
checkBuffer();
long transferLength = bufferPosition + bufferLength
- currentPosition;
if (transferLength > length) {
transferLength = length;
}
buffer.get(b, offset, (int) transferLength);
positionBufferMove((int) transferLength);
length -= transferLength;
offset += transferLength;
if (length == 0) {
break;
}
}
} catch (Throwable t) {
logger.logWarningEvent(JVM_ERROR, t);
IOException io = JavaSystem.toIOException(t);
throw io;
}
}
public int readInt() throws IOException {
try {
int value = buffer.getInt();
positionBufferMove(4);
return value;
} catch (Throwable t) {
logger.logWarningEvent(JVM_ERROR, t);
IOException io = JavaSystem.toIOException(t);
throw io;
}
}
public long readLong() throws IOException {
try {
long value = buffer.getLong();
positionBufferMove(8);
return value;
} catch (Throwable t) {
logger.logWarningEvent(JVM_ERROR, t);
IOException io = JavaSystem.toIOException(t);
throw io;
}
}
public void write(byte[] b, int offset, int length) throws IOException {
long transferLength;
try {
buffersModified = true;
while (true) {
checkBuffer();
transferLength = bufferPosition + bufferLength
- currentPosition;
if (transferLength > length) {
transferLength = length;
}
buffer.put(b, offset, (int) transferLength);
positionBufferMove((int) transferLength);
length -= transferLength;
offset += transferLength;
if (length == 0) {
break;
}
}
} catch (Throwable t) {
logger.logWarningEvent(JVM_ERROR, t);
IOException io = JavaSystem.toIOException(t);
throw io;
}
}
public void writeInt(int i) throws IOException {
try {
buffersModified = true;
buffer.putInt(i);
positionBufferMove(4);
} catch (Throwable t) {
logger.logWarningEvent(JVM_ERROR, t);
IOException io = JavaSystem.toIOException(t);
throw io;
}
}
public void writeLong(long i) throws IOException {
try {
buffersModified = true;
buffer.putLong(i);
positionBufferMove(8);
} catch (Throwable t) {
logger.logWarningEvent(JVM_ERROR, t);
IOException io = JavaSystem.toIOException(t);
throw io;
}
}
public void close() throws IOException {
Throwable thrown = null;
try {
logger.logDetailEvent("NIO file close, size: " + fileLength);
buffer = null;
channel = null;
for (int i = 0; i < buffers.length; i++) {
thrown = JavaSystem.unmap(buffers[i]);
buffers[i] = null;
}
file.close();
} catch (Throwable t) {
logger.logWarningEvent("NIO buffer close error", t);
IOException io = JavaSystem.toIOException(t);
throw io;
} finally {
if (thrown != null) {
logger.logWarningEvent("NIO buffer unmap exception", thrown);
}
}
}
public boolean isReadOnly() {
return readOnly;
}
public boolean ensureLength(long newLength) {
if (newLength > maxLength) {
return false;
}
while (newLength > fileLength) {
if (!enlargeFile(newLength)) {
return false;
}
}
return true;
}
private boolean enlargeFile(long newFileLength) {
try {
long newBufferLength = newFileLength;
if (!readOnly) {
newBufferLength = largeBufferSize;
}
MapMode mapMode = readOnly ? FileChannel.MapMode.READ_ONLY
: FileChannel.MapMode.READ_WRITE;
if (!readOnly && file.length() < fileLength + newBufferLength) {
file.seek(fileLength + newBufferLength - 1);
file.writeByte(0);
}
MappedByteBuffer[] newBuffers =
new MappedByteBuffer[buffers.length + 1];
MappedByteBuffer newBuffer = channel.map(mapMode, fileLength,
newBufferLength);
System.arraycopy(buffers, 0, newBuffers, 0, buffers.length);
newBuffers[buffers.length] = newBuffer;
buffers = newBuffers;
fileLength += newBufferLength;
logger.logDetailEvent("NIO buffer instance, file size "
+ fileLength);
} catch (Throwable e) {
logger.logDetailEvent("NOI buffer allocate failed, file size "
+ newFileLength);
return false;
}
return true;
}
public boolean setLength(long newLength) {
if (newLength > fileLength) {
return enlargeFile(newLength);
} else {
try {
seek(0);
} catch (Throwable t) {
//
}
return true;
}
}
public Database getDatabase() {
return null;
}
public void synch() {
boolean error = false;
int errIndex = 0;
for (int i = 0; i < buffers.length; i++) {
try {
buffers[i].force();
} catch (Throwable t) {
logger.logWarningEvent("NIO buffer force error: pos "
+ i * largeBufferSize + " ", t);
if (!error) {
errIndex = i;
}
error = true;
}
}
if (error) {
for (int i = errIndex; i < buffers.length; i++) {
try {
buffers[i].force();
} catch (Throwable t) {
logger.logWarningEvent("NIO buffer force error "
+ i * largeBufferSize + " ", t);
}
}
}
try {
fileDescriptor.sync();
buffersModified = false;
} catch (Throwable t) {
logger.logSevereEvent("NIO RA file sync error ", t);
throw Error.error(t, ErrorCode.FILE_IO_ERROR, null);
}
}
private void positionBufferSeek(long offset) {
if (offset < bufferPosition
|| offset >= bufferPosition + bufferLength) {
setCurrentBuffer(offset);
}
buffer.position((int) (offset - bufferPosition));
currentPosition = offset;
}
private void positionBufferMove(int relOffset) {
long offset = currentPosition + relOffset;
if (offset >= bufferPosition + bufferLength) {
setCurrentBuffer(offset);
}
buffer.position((int) (offset - bufferPosition));
currentPosition = offset;
}
private void setCurrentBuffer(long offset) {
if (readOnly) {
return;
}
int bufferIndex = (int) (offset >> largeBufferScale);
// when moving to last position in file
if (bufferIndex == buffers.length) {
bufferIndex = buffers.length - 1;
bufferPosition = (long) bufferIndex * largeBufferSize;
buffer = buffers[bufferIndex];
return;
}
buffer = buffers[bufferIndex];
bufferPosition = offset & largeBufferMask;
}
/**
* checks for two types of potential errors before reads and writes and
* fixes them.
*
*/
private void checkBuffer() {
if (readOnly) {
return;
}
int bufferIndex = (int) (currentPosition >> largeBufferScale);
if (currentPosition != bufferPosition + buffer.position()) {
buffer = buffers[bufferIndex];
bufferPosition = currentPosition & largeBufferMask;
buffer.position((int) (currentPosition - bufferPosition));
} else if (buffer != buffers[bufferIndex]) {
buffer = buffers[bufferIndex];
}
}
}