LobStoreInJar.java

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package org.hsqldb.persist;

import java.io.DataInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;

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

/**
 * @author Fred Toussi (fredt@users dot sourceforge.net)
 * @version 2.3.0
 * @since 1.9.0
 */
public class LobStoreInJar implements LobStore {

    final int       lobBlockSize;
    Database        database;
    DataInputStream dataInput;
    final String    fileName;

    //
    long realPosition;

    public LobStoreInJar(Database database, int lobBlockSize) {

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

        try {
            fileName = database.getPath() + ".lobs";
        } catch (Throwable t) {
            throw Error.error(ErrorCode.DATA_FILE_ERROR, t);
        }
    }

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

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

            fileSeek(address);
            dataInput.readFully(dataBytes, 0, count);

            realPosition = address + count;

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

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

    public void setBlockBytes(
            byte[] dataBytes,
            long position,
            int offset,
            int length) {}

    public int getBlockSize() {
        return lobBlockSize;
    }

    public long getLength() {
        return 0;
    }

    public void setLength(long length) {}

    public void close() {

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

    public void synch() {}

    private void resetStream() throws IOException {

        if (dataInput != null) {
            dataInput.close();
        }

        InputStream fis = null;

        try {
            fis = getClass().getResourceAsStream(fileName);

            if (fis == null) {
                ClassLoader cl = Thread.currentThread().getContextClassLoader();

                if (cl != null) {
                    fis = cl.getResourceAsStream(fileName);
                }
            }
        } catch (Throwable t) {

            //
        } finally {
            if (fis == null) {
                throw new FileNotFoundException(fileName);
            }
        }

        dataInput    = new DataInputStream(fis);
        realPosition = 0;
    }

    private void fileSeek(long position) throws IOException {

        if (dataInput == null) {
            resetStream();
        }

        long skipPosition = realPosition;

        if (position < skipPosition) {
            resetStream();

            skipPosition = 0;
        }

        while (position > skipPosition) {
            skipPosition += dataInput.skip(position - skipPosition);
        }

        realPosition = position;
    }
}