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JDBC driver for MariaDB and MySQL for java 7
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/*
 *
 * MariaDB Client for Java
 *
 * Copyright (c) 2012-2014 Monty Program Ab.
 * Copyright (c) 2015-2017 MariaDB Ab.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library 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 GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along
 * with this library; if not, write to Monty Program Ab [email protected].
 *
 * This particular MariaDB Client for Java file is work
 * derived from a Drizzle-JDBC. Drizzle-JDBC file which is covered by subject to
 * the following copyright and notice provisions:
 *
 * Copyright (c) 2009-2011, Marcus Eriksson
 *
 * 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 driver nor the names of its contributors may not 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 THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 */

package org.mariadb.jdbc.internal.util.dao;

import org.mariadb.jdbc.internal.ColumnType;
import org.mariadb.jdbc.internal.com.read.dao.Results;
import org.mariadb.jdbc.internal.com.read.resultset.ColumnInformation;
import org.mariadb.jdbc.internal.protocol.Protocol;

import java.sql.SQLException;
import java.util.concurrent.atomic.AtomicBoolean;

public class ServerPrepareResult implements PrepareResult {
    private int statementId;
    private ColumnInformation[] columns;
    private ColumnInformation[] parameters;
    private ColumnType[] parameterTypeHeader;
    private Protocol unProxiedProtocol;
    private String sql;
    private Results activeCursorResult;


    //share indicator
    private volatile int shareCounter = 1;
    private volatile boolean isBeingDeallocate;
    private AtomicBoolean inCache = new AtomicBoolean();

    /**
     * PrepareStatement Result object.
     *
     * @param sql               query
     * @param statementId       server statement Id.
     * @param columns           columns information
     * @param parameters        parameters information
     * @param unProxiedProtocol indicate the protocol on which the prepare has been done
     */
    public ServerPrepareResult(String sql, int statementId, ColumnInformation[] columns, ColumnInformation[] parameters,
                               Protocol unProxiedProtocol) {
        this.sql = sql;
        this.statementId = statementId;
        this.columns = columns;
        this.parameters = parameters;
        this.unProxiedProtocol = unProxiedProtocol;
        this.parameterTypeHeader = new ColumnType[parameters.length];
    }

    public void resetParameterTypeHeader() {
        this.parameterTypeHeader = new ColumnType[parameters.length];
    }

    /**
     * Update information after a failover.
     *
     * @param statementId       new statement Id
     * @param unProxiedProtocol the protocol on which the prepare has been done
     */
    public void failover(int statementId, Protocol unProxiedProtocol) {
        this.statementId = statementId;
        this.unProxiedProtocol = unProxiedProtocol;
        this.parameterTypeHeader = new ColumnType[parameters.length];
        this.shareCounter = 1;
        this.isBeingDeallocate = false;

    }

    public void setAddToCache() {
        inCache.set(true);
    }

    public void setRemoveFromCache() {
        inCache.set(false);
    }

    /**
     * Increment share counter.
     *
     * @return true if can be used (is not been deallocate).
     */
    public synchronized boolean incrementShareCounter() {
        fetchAllOpenCursor();

        if (isBeingDeallocate) {
            return false;
        }

        shareCounter++;
        return true;
    }

    public synchronized void decrementShareCounter() {
        shareCounter--;
    }

    /**
     * Asked if can be deallocate (is not shared in other statement and not in cache)
     * Set deallocate flag to true if so.
     *
     * @return true if can be deallocate
     */
    public synchronized boolean canBeDeallocate() {
        if (shareCounter > 0 || isBeingDeallocate) {
            return false;
        }
        if (!inCache.get()) {
            isBeingDeallocate = true;
            return true;
        }
        return false;
    }

    public int getParamCount() {
        return parameters.length;
    }

    //for unit test
    public synchronized int getShareCounter() {
        return shareCounter;
    }

    public int getStatementId() {
        return statementId;
    }

    public ColumnInformation[] getColumns() {
        return columns;
    }

    public ColumnInformation[] getParameters() {
        return parameters;
    }

    public Protocol getUnProxiedProtocol() {
        return unProxiedProtocol;
    }

    public String getSql() {
        return sql;
    }

    public ColumnType[] getParameterTypeHeader() {
        return parameterTypeHeader;
    }

    public void openCursor(Results result) {
        activeCursorResult = result;
    }

    /**
     * if a new query will be done using this statementId and there is an open cursor,
     * then fetch all results in resultSet (Cursor will be closed after executing a query).
     */
    public void fetchAllOpenCursor() {
        if (activeCursorResult != null && activeCursorResult.getResultSet() != null) {
            //will then fetch all remaining results
            try {
                activeCursorResult.getResultSet().setFetchSize(0);
            } catch (SQLException sqle) {
                //error will be thrown by query that cause this closing.
            }
        }
        activeCursorResult = null;
    }


}