result.java

一个用java写的开源的数据库系统

/* Copyrights and Licenses
 *
 * This product includes Hypersonic SQL.
 * Originally developed by Thomas Mueller and the Hypersonic SQL Group. 
 *
 * Copyright (c) 1995-2000 by the Hypersonic SQL 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. 
 *     -  All advertising materials mentioning features or use of this software must display the
 *        following acknowledgment: "This product includes Hypersonic SQL." 
 *     -  Products derived from this software may not be called "Hypersonic SQL" nor may
 *        "Hypersonic SQL" appear in their names without prior written permission of the
 *         Hypersonic SQL Group. 
 *     -  Redistributions of any form whatsoever must retain the following acknowledgment: "This
 *          product includes Hypersonic SQL." 
 * This software is provided "as is" and any expressed or implied warranties, including, but
 * not limited to, the implied warranties of merchantability and fitness for a particular purpose are
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 * 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 any 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. 
 * This software consists of voluntary contributions made by many individuals on behalf of the
 * Hypersonic SQL Group.
 *
 *
 * For work added by the HSQL Development Group:
 *
 * Copyright (c) 2001-2002, 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, including earlier
 * license statements (above) and comply with all above license conditions.
 *
 * 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, including earlier
 * license statements (above) and comply with all above license conditions.
 *
 * 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, 
 * 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.hsqldb;

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

// fredt@users 20020130 - patch 1.7.0 by fredt
// to ensure consistency of r.rTail r.iSize in all operations
// methods for set operations moved here from Select.java
// fredt@users 20020130 - patch 1.7.0 by fredt
// rewrite of LIMIT n m to apply to each select statement separately
// tony_lai@users 20020820 - patch 595073 by tlai@users - duplicated exception msg

/**
 *  Class declaration
 *
 * @version    1.7.0
 */
class Result {

    private Record   rTail;
    private int      iSize;
    private int      iColumnCount;
    static final int UPDATECOUNT = 0;
    static final int ERROR       = 1;
    static final int DATA        = 2;
    int              iMode;
    String           sError;
    int              errorCode;
    int              iUpdateCount;
    Record           rRoot;
    String           sLabel[];
    String           sTable[];
    String           sName[];
    boolean          isLabelQuoted[];
    int              colType[];
    int              colSize[];
    int              colScale[];

    /**
     *  Constructor declaration
     */
    Result() {
        iMode        = UPDATECOUNT;
        iUpdateCount = 0;
    }

// fredt@users 20020221 - patch 513005 by sqlbob@users (RMP)

    /**
     *  Constructor declaration
     *
     * @param  error
     * @param  code   Description of the Parameter
     */
    Result(String error, int code) {

        iMode     = ERROR;
        sError    = error;
        errorCode = code;
    }

    /**
     *  Constructor declaration
     *
     * @param  columns
     */
    Result(int columns) {

        prepareData(columns);

        iColumnCount = columns;
    }

    /**
     *  Constructor declaration
     *
     * @param  b
     * @exception  SQLException  Description of the Exception
     */
    Result(byte b[]) throws SQLException {

        try {
            DatabaseRowInputInterface in = new BinaryServerRowInput(b);

            iMode = in.readIntData();

            if (iMode == ERROR) {

// tony_lai@users 20020820 - patch 595073
                int code = in.readIntData();

                throw Trace.getError(in.readString(), code);

//                throw Trace.getError(in.readIntData(), in.readString());
            } else if (iMode == UPDATECOUNT) {
                iUpdateCount = in.readIntData();
            } else if (iMode == DATA) {
                int l = in.readIntData();

                prepareData(l);

                iColumnCount = l;

                for (int i = 0; i < l; i++) {
                    colType[i] = in.readType();
                    sLabel[i]  = in.readString();
                    sTable[i]  = in.readString();
                    sName[i]   = in.readString();
                }

                while (in.available() != 0) {
                    add(in.readData(colType));
                }
            }
        } catch (IOException e) {
            throw Trace.error(Trace.TRANSFER_CORRUPTED);
        }
    }

    /**
     *  Method declaration
     *
     * @return
     */
    int getSize() {
        return iSize;
    }

    /**
     *  Method declaration
     *
     * @param  columns
     */
    void setColumnCount(int columns) {
        iColumnCount = columns;
    }

    /**
     *  Method declaration
     *
     * @return
     */
    int getColumnCount() {
        return iColumnCount;
    }

    /**
     *  Method declaration
     *
     * @param  a
     */
    void append(Result a) {

        if (rRoot == null) {
            rRoot = a.rRoot;
        } else {
            rTail.next = a.rRoot;
        }

        rTail = a.rTail;
        iSize += a.iSize;
    }

    /**
     *  Method declaration
     *
     * @param  a
     */
    void setRows(Result a) {

        rRoot = a.rRoot;
        rTail = a.rTail;
        iSize = a.iSize;
    }

    /**
     *  Method declaration
     *
     * @param  d
     */
    void add(Object d[]) {

        Record r = new Record();

        r.data = d;

        if (rRoot == null) {
            rRoot = r;
        } else {
            rTail.next = r;
        }

        rTail = r;

        iSize++;
    }

    /**
     *  Method declaration
     *
     * @param  limitstart  number of records to discard at the head
     * @param  limitcount  number of records to keep, all the rest if 0
     */

// fredt@users 20020130 - patch 1.7.0 by fredt
// rewritten and moved from Select.java
    void trimResult(int limitstart, int limitcount) {

        Record n = rRoot;

        if (n == null) {
            return;
        }

        if (limitstart >= iSize) {
            iSize = 0;
            rRoot = rTail = null;

            return;
        }

        iSize -= limitstart;

        for (int i = 0; i < limitstart; i++) {
            n = n.next;

            if (n == null) {

                // if iSize is consistent this block will never be reached
                iSize = 0;
                rRoot = rTail = n;

                return;
            }
        }

        rRoot = n;

        if (limitcount == 0 || limitcount >= iSize) {
            return;
        }

        for (int i = 1; i < limitcount; i++) {
            n = n.next;

            if (n == null) {

                // if iSize is consistent this block will never be reached
                return;
            }
        }

        n.next = null;
        rTail  = n;
    }

    /**
     *  Method declaration
     *
     * @throws  SQLException
     */

// fredt@users 20020130 - patch 1.7.0 by fredt
// to ensure consistency of r.rTail r.iSize in all set operations
    void removeDuplicates() throws SQLException {

        if (rRoot == null) {
            return;
        }

        int len     = getColumnCount();
        int order[] = new int[len];
        int way[]   = new int[len];

        for (int i = 0; i < len; i++) {