/* Copyright (c) 2001-2009, 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;
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.hsqldb.persist;
import java.io.IOException;
import org.hsqldb.Database;
/**
* Mixe NIO / non-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.
*
* Due to various issues with java.nio classes, this class will use a mapped
* channel of fixed size. After reaching this size, the file and channel are
* closed and a new one opened, up to the maximum size.
*
* @author Fred Toussi (fredt@users dot sourceforge.net)
* @version 1.8.0.5
* @since 1.7.2
*/
public final class ScaledRAFileHybrid implements ScaledRAInterface {
final Database database;
final String fileName;
final boolean isReadOnly;
final boolean wasNio;
long maxLength;
ScaledRAInterface store;
public ScaledRAFileHybrid(Database database, String name,
boolean readOnly) throws IOException {
this.database = database;
this.fileName = name;
this.isReadOnly = readOnly;
newStore(0);
this.wasNio = store.wasNio();
}
public long length() throws IOException {
return store.length();
}
public void seek(long position) throws IOException {
checkSeek(position);
store.seek(position);
}
public long getFilePointer() throws IOException {
return store.getFilePointer();
}
public int read() throws IOException {
checkLength(1);
return store.read();
}
public void read(byte[] b, int offset, int length) throws IOException {
checkLength(length);
store.read(b, offset, length);
}
public void write(byte[] b, int offset, int length) throws IOException {
checkLength(length);
store.write(b, offset, length);
}
public int readInt() throws IOException {
checkLength(4);
return store.readInt();
}
public void writeInt(int i) throws IOException {
checkLength(4);
store.writeInt(i);
}
public long readLong() throws IOException {
checkLength(8);
return store.readLong();
}
public void writeLong(long i) throws IOException {
checkLength(8);
store.writeLong(i);
}
public void close() throws IOException {
store.close();
}
public boolean isReadOnly() {
return store.isReadOnly();
}
public boolean wasNio() {
return wasNio;
}
public boolean canAccess(int length) {
return true;
}
public boolean canSeek(long position) {
return true;
}
public Database getDatabase() {
return null;
}
private void checkLength(int length) throws IOException {
if (store.canAccess(length)) {
return;
}
newStore(store.getFilePointer() + length);
}
private void checkSeek(long position) throws IOException {
if (store.canSeek(position)) {
return;
}
newStore(position);
}
void newStore(long requiredPosition) throws IOException {
long currentPosition = 0;
if (store != null) {
currentPosition = store.getFilePointer();
store.close();
}
if (requiredPosition <= ScaledRAFile.MAX_NIO_LENGTH) {
try {
store = new ScaledRAFileNIO(database, fileName, isReadOnly,
(int) requiredPosition);
store.seek(currentPosition);
return;
} catch (Throwable e) {}
}
store = new ScaledRAFile(database, fileName, isReadOnly);
store.seek(currentPosition);
}
}