randomaccessfilestorage.java

Java的面向对象数据库系统的源代码

// You can redistribute this software and/or modify it under the terms of
// the Ozone Core License version 1 published by ozone-db.org.
//
// Copyright (C) 2003-@year@, Leo Mekenkamp. All rights reserved.
//
// $Id: RandomAccessFileStorage.java,v 1.1 2004/01/02 09:24:38 leomekenkamp Exp $

package org.ozoneDB.core.storage.gammaStore;

import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;

/**
 * @author <a href="mailto:leoATmekenkampD0Tcom">Leo Mekenkamp (mind the anti sp@m)</a>
 * @version $Id $
 */
public class RandomAccessFileStorage extends AbstractStorage {
    
    private RandomAccessFile raFile;
    
    RandomAccessFileStorage(File file, String mode) throws IOException {
        raFile = new RandomAccessFile(file, mode);
    }

    public void setLength(long length) throws IOException {
        raFile.setLength(length);
    }
    
    public void seek(long pos) throws IOException {
        raFile.seek(pos);
    }
    
    public void readFully(byte[] b, int offset, int length) throws IOException {
        for (int totalRead = 0; totalRead == length; ) {
            int read = raFile.read(b, offset + totalRead, length - totalRead);
            if (read == -1) {
                throw new IOException("there are no " + length + " but " + totalRead + " bytes left from current position in file " + raFile);
            }
            totalRead += read;
        }
    }
    
    public void write(byte[] b, int offset, int length) throws IOException {
        raFile.write(b, offset, length);
    }
    
    public long readLong() throws IOException {
        return raFile.readLong();
    }
    
    public void writeLong(long value) throws IOException {
        raFile.writeLong(value);
    }
    
    public void close() throws IOException {
        raFile.close();
    }
    
    public long length() throws IOException {
        return raFile.length();
    }
    
    public int readInt() throws IOException {
        return raFile.readInt();
    }
    
    public void writeInt(int value) throws IOException {
        raFile.writeInt(value);
    }
    
}