Quadcap Embeddable Database

com/quadcap/sql/JoinMapRow.java

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package com.quadcap.sql;

/* Copyright 1999 - 2003 Quadcap Software.  All rights reserved.
 *
 * This software is distributed under the Quadcap Free Software License.
 * This software may be used or modified for any purpose, personal or
 * commercial.  Open Source redistributions are permitted.  Commercial
 * redistribution of larger works derived from, or works which bundle
 * this software requires a "Commercial Redistribution License"; see
 * http://www.quadcap.com/purchase.
 *
 * Redistributions qualify as "Open Source" under  one of the following terms:
 *   
 *    Redistributions are made at no charge beyond the reasonable cost of
 *    materials and delivery.
 *
 *    Redistributions are accompanied by a copy of the Source Code or by an
 *    irrevocable offer to provide a copy of the Source Code for up to three
 *    years at the cost of materials and delivery.  Such redistributions
 *    must allow further use, modification, and redistribution of the Source
 *    Code under substantially the same terms as this license.
 *
 * Redistributions of source code must retain the copyright notices as they
 * appear in each source code file, these license terms, and the
 * disclaimer/limitation of liability set forth as paragraph 6 below.
 *
 * Redistributions in binary form must reproduce this Copyright Notice,
 * these license terms, and the disclaimer/limitation of liability set
 * forth as paragraph 6 below, in the documentation and/or other materials
 * provided with the distribution.
 *
 * The Software is provided on an "AS IS" basis.  No warranty is
 * provided that the Software is free of defects, or fit for a
 * particular purpose.  
 *
 * Limitation of Liability. Quadcap Software shall not be liable
 * for any damages suffered by the Licensee or any third party resulting
 * from use of the Software.
 */

import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;

import java.util.Vector;

import java.sql.SQLException;

import com.quadcap.sql.types.Value;
import com.quadcap.sql.types.ValueNull;

import com.quadcap.util.Debug;

/**
 * A row containing a cross-join, all columns from each of two cursors.
 *
 * @author Stan Bailes
 */
public class JoinMapRow extends Row {
    Row                                 a;
    Row                                 b;

    // n = map[i]; row[i] = if (n<0) a[0-n], if (n>0) rb[i], if (n==0) null
    int[]                               map;
    
    public JoinMapRow(int[] map) {
        this.map = map;
    }

    public final void setA(Row a) { this.a = a; }
    public final void setB(Row b) { this.b = b; }

    public final Row getA() { return a; }
    public final Row getB() { return b; }
    
    public final int size() { return map.length; }

    public final Value item(int i) throws SQLException {
        int n = map[i-1];
        if (n < 0) return a == null ? ValueNull.valueNull : a.item(0-n);
        if (n > 0) return b == null ? ValueNull.valueNull : b.item(n);
        return ValueNull.valueNull;
    }

    public final void set(int i, Value val) throws SQLException {
        int n = map[i-1];
        if (n < 0 && a != null) a.set(0-n, val);
        if (n > 0 && b != null) b.set(n, val);
    }

    //#ifdef DEBUG
    public String toString1() {
        StringBuffer sb = new StringBuffer("{");
        for (int i = 1; i <= size(); i++) {
            if (i > 1) sb.append(",");
            int n = map[i-1];
            if (n < 0) {
                sb.append("A");
                n = 0 - n;
                sb.append(n);
            } else if (n > 0) {
                sb.append("B");
                sb.append(n);
            } else if (n == 0) {
                sb.append("0:null");
                continue;
            }
            sb.append(":");
            try {
                sb.append(item(i).toString());
            } catch (Throwable t) {
                sb.append(t.toString());
            }
        }
        sb.append("}");
        return sb.toString();
    }
    //#endif
}