Quadcap Embeddable Database

com/quadcap/sql/file/NullStore.java

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package com.quadcap.sql.file;

/* Copyright 1997 - 2003 Quadcap Software.  All rights reserved.
 *
 * This software is distributed under the Quadcap Free Software License.
 * This software may be used or modified for any purpose, personal or
 * commercial.  Open Source redistributions are permitted.  Commercial
 * redistribution of larger works derived from, or works which bundle
 * this software requires a "Commercial Redistribution License"; see
 * http://www.quadcap.com/purchase.
 *
 * Redistributions qualify as "Open Source" under  one of the following terms:
 *   
 *    Redistributions are made at no charge beyond the reasonable cost of
 *    materials and delivery.
 *
 *    Redistributions are accompanied by a copy of the Source Code or by an
 *    irrevocable offer to provide a copy of the Source Code for up to three
 *    years at the cost of materials and delivery.  Such redistributions
 *    must allow further use, modification, and redistribution of the Source
 *    Code under substantially the same terms as this license.
 *
 * Redistributions of source code must retain the copyright notices as they
 * appear in each source code file, these license terms, and the
 * disclaimer/limitation of liability set forth as paragraph 6 below.
 *
 * Redistributions in binary form must reproduce this Copyright Notice,
 * these license terms, and the disclaimer/limitation of liability set
 * forth as paragraph 6 below, in the documentation and/or other materials
 * provided with the distribution.
 *
 * The Software is provided on an "AS IS" basis.  No warranty is
 * provided that the Software is free of defects, or fit for a
 * particular purpose.  
 *
 * Limitation of Liability. Quadcap Software shall not be liable
 * for any damages suffered by the Licensee or any third party resulting
 * from use of the Software.
 */

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

import java.util.BitSet;

import com.quadcap.util.collections.LongIterator;
import com.quadcap.util.collections.LongMap;

import com.quadcap.util.Debug;
import com.quadcap.util.Util;

import com.quadcap.sql.Version;

/**
 * The null store, which is part of the memory-only implementation.
 * @author Stan Bailes
 */
public class NullStore extends  BlockStore {

    public NullStore() {}

    /**
     * Initialize a new BlockStore object using the specified file and
     * blocksize.
     *
     * @param file the underlying file.
     * @param mode "r" for readonly access, otherwise "rw"
     * @param blocksize the block size to use when creating the file.
     * @param the synchronization object
     */
    public void init(File file, String mode, int blockSize, Object lock)
        throws IOException
    {
    }

    /**
     * Read a block into a buffer.  If the specified block is beyond the
     * current end of file, then grow the file
     *
     * @param blockNum the number of the block to read.
     * @param buf the buffer into which the data is read.
     */
    public void read(long blockNum, byte[] buf, int off)
        throws IOException
    {
        throw new IOException("NullStore.read()");
    }
    
    /**
     * Write a block from a buffer into the file.
     *
     * @param blockNum the number of the block to write.
     * @param buf the buffer from which the data is written.
     * @exception IOException if an I/O error occurs.
     */
    public void write(long blockNum, byte[] buf)
        throws IOException
    {
        throw new IOException("NullStore.write()");
    }

    /**
     * Restore a block image
     */
    public void restore(long blockNum, byte[] buf, int off)
        throws IOException
    {
        throw new IOException("NullStore.restore()");
    }

    public void setLength(long length) throws IOException {
    }

    public boolean isEncrypted() {
        return false;
    }
    
    public void close() throws IOException {
    }

    public void flush() throws IOException {
    }
}