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Java > Open Source Codes > smallsql > database > Expressions


1 /* =============================================================
2  * SmallSQL : a free Java DBMS library for the Java(tm) platform
3  * =============================================================
4  *
5  * (C) Copyright 2004-2006, by Volker Berlin.
6  *
7  * Project Info: http://www.smallsql.de/
8  *
9  * This library is free software; you can redistribute it and/or modify it
10  * under the terms of the GNU Lesser General Public License as published by
11  * the Free Software Foundation; either version 2.1 of the License, or
12  * (at your option) any later version.
13  *
14  * This library is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
16  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
17  * License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with this library; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
22  * USA.
23  *
24  * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
25  * in the United States and other countries.]
26  *
27  * ---------------
28  * Expressions.java
29  * ---------------
30  * Author: Volker Berlin
31  *
32  */
33 package smallsql.database;
34
35 /**
36  * @author Volker Berlin
37  *
38  */
39 final class Expressions {
40     private int size;
41     private Expression[] data;
42     
43     Expressions(){
44         data = new Expression[16];
45     }
46     
47     Expressions(int initSize){
48         data = new Expression[initSize];
49     }
50     
51     
52     final int size(){
53         return size;
54     }
55     
56
57     final void setSize(int newSize){
58         for(int i=newSize; i<size; i++) data[i] = null;
59         size = newSize;
60         if(size>data.length) resize(newSize);
61     }
62     
63
64     final Expression get(int idx){
65         if (idx >= size)
66             throw new IndexOutOfBoundsException JavaDoc("Index: "+idx+", Size: "+size);
67         return data[idx];
68     }
69     
70     
71     final void add(Expression expr){
72         if(size >= data.length ){
73             resize(size << 1);
74         }
75         data[size++] = expr;
76     }
77
78     final void add(int idx, Expression expr){
79         if(size >= data.length ){
80             resize(size << 1);
81         }
82         System.arraycopy( data, idx, data, idx+1, (size++)-idx);
83         data[idx] = expr;
84     }
85     
86     final void addAll(Expressions cols){
87         int count = cols.size();
88         if(size + count >= data.length ){
89             resize(size + count);
90         }
91         System.arraycopy( cols.data, 0, data, size, count);
92         size += count;
93     }
94     
95     final void clear(){
96         size = 0;
97     }
98     
99     final void remove(int idx){
100         System.arraycopy( data, idx+1, data, idx, (--size)-idx);
101     }
102
103     final void set(int idx, Expression expr){
104         data[idx] = expr;
105     }
106
107     final int indexOf(Expression expr) {
108         if (expr == null) {
109             for (int i = 0; i < size; i++)
110                 if (data[i]==null)
111                     return i;
112         } else {
113             for (int i = 0; i < size; i++)
114                 if (expr.equals(data[i]))
115                     return i;
116         }
117         return -1;
118     }
119     
120     final void toArray(Expression[] array){
121         System.arraycopy( data, 0, array, 0, size);
122     }
123     
124     final Expression[] toArray(){
125         Expression[] array = new Expression[size];
126         System.arraycopy( data, 0, array, 0, size);
127         return array;
128     }
129     
130     private final void resize(int newSize){
131         Expression[] dataNew = new Expression[newSize];
132         System.arraycopy(data, 0, dataNew, 0, size);
133         data = dataNew;
134     }
135 }
136
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