| 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 | * IndexDescriptions.java |
| 29 | * --------------- |
| 30 | * Author: Volker Berlin |
| 31 | * |
| 32 | * Created on 23.04.2005 |
| 33 | */ |
| 34 | package smallsql.database; |
| 35 | /** |
| 36 | * A typed implementation of Arraylist for IndexDescription. |
| 37 | * |
| 38 | * @author Volker Berlin |
| 39 | * |
| 40 | */ |
| 41 | class IndexDescriptions { |
| 42 | private int size; |
| 43 | private IndexDescription[] data; |
| 44 | |
| 45 | |
| 46 | IndexDescriptions(){ |
| 47 | data = new IndexDescription[4]; |
| 48 | } |
| 49 | |
| 50 | |
| 51 | final int size(){ |
| 52 | return size; |
| 53 | } |
| 54 | |
| 55 | |
| 56 | final IndexDescription get(int idx){ |
| 57 | if (idx >= size) |
| 58 | throw new IndexOutOfBoundsException("Column index: "+idx+", Size: "+size); |
| 59 | return data[idx]; |
| 60 | } |
| 61 | |
| 62 | |
| 63 | final void add(IndexDescription descr){ |
| 64 | if(size >= data.length ){ |
| 65 | resize(size << 1); |
| 66 | } |
| 67 | data[size++] = descr; |
| 68 | } |
| 69 | |
| 70 | |
| 71 | private final void resize(int newSize){ |
| 72 | IndexDescription[] dataNew = new IndexDescription[newSize]; |
| 73 | System.arraycopy(data, 0, dataNew, 0, size); |
| 74 | data = dataNew; |
| 75 | } |
| 76 | |
| 77 | |
| 78 | final IndexDescription findBestMatch(Strings columns){ |
| 79 | int bestFactor = Integer.MAX_VALUE; |
| 80 | int bestIdx = 0; |
| 81 | for(int i=0; i<size; i++){ |
| 82 | int factor = data[i].matchFactor(columns); |
| 83 | if(factor == 0) |
| 84 | return data[i]; |
| 85 | |
| 86 | if(factor < bestFactor){ |
| 87 | bestFactor = factor; |
| 88 | bestIdx = i; |
| 89 | } |
| 90 | } |
| 91 | if(bestFactor == Integer.MAX_VALUE) |
| 92 | return null; |
| 93 | else |
| 94 | return data[bestIdx]; |
| 95 | } |
| 96 | |
| 97 | |
| 98 | /** |
| 99 | * Create all the indexes. This means a file for every index is save. |
| 100 | * @param database |
| 101 | * @param tableView |
| 102 | * @see IndexDescription#setTableView |
| 103 | */ |
| 104 | void create(Database database, TableView tableView) throws Exception{ |
| 105 | for(int i=0; i<size; i++){ |
| 106 | data[i].create(database, tableView); |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | |
| 111 | public void drop(Database database) throws Exception { |
| 112 | for(int i=0; i<size; i++){ |
| 113 | data[i].drop(database); |
| 114 | } |
| 115 | } |
| 116 | } |