src/org/hsqldb/persist/LobStoreRAFile.java

/* Copyright (c) 2001-2010, 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,
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package org.hsqldb.persist;

import org.hsqldb.Database;
import org.hsqldb.error.Error;
import org.hsqldb.error.ErrorCode;
import org.hsqldb.lib.Storage;

/**
 * @author Fred Toussi (fredt@users dot sourceforge.net)
 * @version 1.9.0
 * @since 1.9.0
 */
public class LobStoreRAFile implements LobStore {

    final int lobBlockSize;
    Storage   file;
    Database  database;

    public LobStoreRAFile(Database database, int lobBlockSize) {

        this.lobBlockSize = lobBlockSize;
        this.database     = database;

        try {
            String name = database.getPath() + ".lobs";
            boolean exists =
                database.logger.getFileAccess().isStreamElement(name);

            if (exists) {
                openFile();
            }
        } catch (Throwable t) {
            throw Error.error(ErrorCode.DATA_FILE_ERROR, t);
        }
    }

    private void openFile() {

        try {
            String  name     = database.getPath() + ".lobs";
            boolean readonly = database.isReadOnly();

            if (database.logger.isStoredFileAccess()) {
                file = ScaledRAFile.newScaledRAFile(
                    database, name, readonly, ScaledRAFile.DATA_FILE_STORED);
            } else {
                file = new ScaledRAFileSimple(name, readonly ? "r"
                                                             : "rwd");
            }
        } catch (Throwable t) {
            throw Error.error(ErrorCode.DATA_FILE_ERROR, t);
        }
    }

    public byte[] getBlockBytes(int blockAddress, int blockCount) {

        if (file == null) {
            throw Error.error(ErrorCode.FILE_IO_ERROR);
        }

        try {
            long   address   = (long) blockAddress * lobBlockSize;
            int    count     = blockCount * lobBlockSize;
            byte[] dataBytes = new byte[count];

            file.seek(address);
            file.read(dataBytes, 0, count);

            return dataBytes;
        } catch (Throwable t) {
            throw Error.error(ErrorCode.DATA_FILE_ERROR, t);
        }
    }

    public void setBlockBytes(byte[] dataBytes, int blockAddress,
                              int blockCount) {

        if (file == null) {
            openFile();
        }

        try {
            long address = (long) blockAddress * lobBlockSize;
            int  count   = blockCount * lobBlockSize;

            file.seek(address);
            file.write(dataBytes, 0, count);
        } catch (Throwable t) {
            throw Error.error(ErrorCode.DATA_FILE_ERROR, t);
        }
    }

    public int getBlockSize() {
        return lobBlockSize;
    }

    public void close() {

        try {
            if (file != null) {
                file.close();
            }
        } catch (Throwable t) {
            throw Error.error(ErrorCode.DATA_FILE_ERROR, t);
        }
    }
}