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JDBC Driver for the Firebird RDBMS
There is a newer version: 4.0.10.java7
/*
 * Firebird Open Source JavaEE Connector - JDBC Driver
 *
 * Distributable under LGPL license.
 * You may obtain a copy of the License at http://www.gnu.org/copyleft/lgpl.html
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * LGPL License for more details.
 *
 * This file was created by members of the firebird development team.
 * All individual contributions remain the Copyright (C) of those
 * individuals.  Contributors to this file are either listed here or
 * can be obtained from a source control history command.
 *
 * All rights reserved.
 */
package org.firebirdsql.gds.ng.wire;

import org.firebirdsql.gds.BlobParameterBuffer;
import org.firebirdsql.gds.ISCConstants;
import org.firebirdsql.gds.impl.wire.WireProtocolConstants;
import org.firebirdsql.gds.impl.wire.XdrOutputStream;
import org.firebirdsql.gds.ng.AbstractFbBlob;
import org.firebirdsql.gds.ng.FbExceptionBuilder;

import java.io.IOException;
import java.sql.SQLException;

/**
 * @author Mark Rotteveel
 * @since 3.0
 */
public abstract class AbstractFbWireBlob extends AbstractFbBlob implements FbWireBlob {

    private int blobHandle;

    protected AbstractFbWireBlob(FbWireDatabase database, FbWireTransaction transaction,
                                 BlobParameterBuffer blobParameterBuffer) {
        super(database, transaction, blobParameterBuffer);
    }

    @Override
    public FbWireDatabase getDatabase() {
        return (FbWireDatabase) super.getDatabase();
    }

    @Override
    public final int getHandle() {
        synchronized (getSynchronizationObject()) {
            return blobHandle;
        }
    }

    /**
     * @param blobHandle
     *         The Firebird blob handle identifier
     */
    protected final void setHandle(int blobHandle) {
        synchronized (getSynchronizationObject()) {
            this.blobHandle = blobHandle;
        }
    }

    /**
     * Release this blob with the specified operation.
     * 
     * Implementations should only do the operation and not perform any further clean up or checks
     * on attached database and active transaction, as those checks and clean up should be done by the caller.
     * 
     *
     * @param releaseOperation
     *         Either {@link WireProtocolConstants#op_close_blob} or {@link WireProtocolConstants#op_cancel_blob}
     * @throws SQLException
     *         For database communication errors.
     */
    protected void releaseBlob(int releaseOperation) throws SQLException {
        synchronized (getSynchronizationObject()) {
            getDatabase().releaseObject(releaseOperation, getHandle());
        }
    }

    @Override
    protected void closeImpl() throws SQLException {
        releaseBlob(WireProtocolConstants.op_close_blob);
    }

    @Override
    protected void cancelImpl() throws SQLException {
        releaseBlob(WireProtocolConstants.op_cancel_blob);
    }

    // NOTE If we need to override some of the blob operations below in the future, consider introducing a separate
    // object that is injected by the ProtocolDescriptor so that we don't need to override separately for input and output.

    @Override
    public byte[] getBlobInfo(final byte[] requestItems, final int bufferLength) throws SQLException {
        try {
            synchronized (getSynchronizationObject()) {
                try {
                    final XdrOutputStream xdrOut = getDatabase().getXdrStreamAccess().getXdrOut();
                    xdrOut.writeInt(WireProtocolConstants.op_info_blob);
                    xdrOut.writeInt(getHandle());
                    xdrOut.writeInt(0); // incarnation
                    xdrOut.writeBuffer(requestItems);
                    xdrOut.writeInt(bufferLength);
                    xdrOut.flush();
                } catch (IOException ex) {
                    throw new FbExceptionBuilder().exception(ISCConstants.isc_net_write_err).cause(ex).toSQLException();
                }
                try {
                    // TODO: Blob warning callback or just database default?
                    GenericResponse response = getDatabase().readGenericResponse(null);
                    return response.getData();
                } catch (IOException ex) {
                    throw new FbExceptionBuilder().exception(ISCConstants.isc_net_read_err).cause(ex).toSQLException();
                }
            }
        } catch (SQLException e) {
            exceptionListenerDispatcher.errorOccurred(e);
            throw e;
        }
    }
}