| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.iapi.sql.dictionary.IndexLister |
| 4 | |
| 5 | Copyright 1997, 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.iapi.sql.dictionary; |
| 22 | |
| 23 | import org.apache.derby.iapi.services.context.ContextManager; |
| 24 | |
| 25 | import org.apache.derby.iapi.error.StandardException; |
| 26 | |
| 27 | import org.apache.derby.iapi.sql.depend.Dependent; |
| 28 | |
| 29 | import org.apache.derby.iapi.services.context.ContextManager; |
| 30 | |
| 31 | import org.apache.derby.iapi.sql.dictionary.DataDictionary; |
| 32 | import org.apache.derby.iapi.sql.dictionary.TableDescriptor; |
| 33 | import org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor; |
| 34 | import org.apache.derby.iapi.sql.dictionary.IndexRowGenerator; |
| 35 | |
| 36 | import org.apache.derby.iapi.sql.depend.Dependent; |
| 37 | import org.apache.derby.iapi.sql.depend.DependencyManager; |
| 38 | import org.apache.derby.iapi.sql.dictionary.DataDictionaryContext; |
| 39 | import org.apache.derby.iapi.services.sanity.SanityManager; |
| 40 | |
| 41 | import org.apache.derby.iapi.error.StandardException; |
| 42 | |
| 43 | import java.util.Enumeration; |
| 44 | import java.util.Vector; |
| 45 | |
| 46 | /** |
| 47 | * This interface gathers up some tasty information about the indices on a |
| 48 | * table from the DataDictionary. |
| 49 | * |
| 50 | */ |
| 51 | public class IndexLister |
| 52 | { |
| 53 | //////////////////////////////////////////////////////////////////////// |
| 54 | // |
| 55 | // STATE |
| 56 | // |
| 57 | //////////////////////////////////////////////////////////////////////// |
| 58 | |
| 59 | private TableDescriptor tableDescriptor; |
| 60 | private IndexRowGenerator[] indexRowGenerators; |
| 61 | private long[] indexConglomerateNumbers; |
| 62 | private String[] indexNames; |
| 63 | // the following 3 are the compact arrays, without duplicate indexes |
| 64 | private IndexRowGenerator[] distinctIndexRowGenerators; |
| 65 | private long[] distinctIndexConglomerateNumbers; |
| 66 | private String[] distinctIndexNames; |
| 67 | |
| 68 | //////////////////////////////////////////////////////////////////////// |
| 69 | // |
| 70 | // CONSTRUCTORS |
| 71 | // |
| 72 | //////////////////////////////////////////////////////////////////////// |
| 73 | |
| 74 | /** |
| 75 | * Make an IndexLister |
| 76 | * |
| 77 | * @param tableDescriptor Describes the table in question. |
| 78 | * |
| 79 | */ |
| 80 | public IndexLister( TableDescriptor tableDescriptor ) |
| 81 | { |
| 82 | this.tableDescriptor = tableDescriptor; |
| 83 | } |
| 84 | |
| 85 | |
| 86 | //////////////////////////////////////////////////////////////////////// |
| 87 | // |
| 88 | // INDEXLISTER METHODS |
| 89 | // |
| 90 | //////////////////////////////////////////////////////////////////////// |
| 91 | |
| 92 | /** |
| 93 | * Returns an array of all the index row generators on a table. |
| 94 | * |
| 95 | * @return an array of index row generators |
| 96 | * |
| 97 | * @exception StandardException Thrown on error |
| 98 | */ |
| 99 | public IndexRowGenerator[] getIndexRowGenerators() |
| 100 | throws StandardException |
| 101 | { |
| 102 | if ( indexRowGenerators == null ) { getAllIndexes(); } |
| 103 | return indexRowGenerators; |
| 104 | } |
| 105 | |
| 106 | /** |
| 107 | * Returns an array of all the index conglomerate ids on a table. |
| 108 | * |
| 109 | * @return an array of index conglomerate ids |
| 110 | * |
| 111 | * @exception StandardException Thrown on error |
| 112 | */ |
| 113 | public long[] getIndexConglomerateNumbers() |
| 114 | throws StandardException |
| 115 | { |
| 116 | if ( indexConglomerateNumbers == null ) { getAllIndexes(); } |
| 117 | return indexConglomerateNumbers; |
| 118 | } |
| 119 | |
| 120 | /** |
| 121 | * Returns an array of all the index names on a table. |
| 122 | * |
| 123 | * @return an array of index names |
| 124 | * |
| 125 | * @exception StandardException Thrown on error |
| 126 | */ |
| 127 | public String[] getIndexNames() throws StandardException |
| 128 | { |
| 129 | if ( indexNames == null ) { getAllIndexes(); } |
| 130 | return indexNames; |
| 131 | } |
| 132 | |
| 133 | /** |
| 134 | * Returns an array of distinct index row generators on a table, |
| 135 | * erasing entries for duplicate indexes (which share same conglomerate). |
| 136 | * |
| 137 | * @return an array of index row generators |
| 138 | * |
| 139 | * @exception StandardException Thrown on error |
| 140 | */ |
| 141 | public IndexRowGenerator[] getDistinctIndexRowGenerators() |
| 142 | throws StandardException |
| 143 | { |
| 144 | if ( distinctIndexRowGenerators == null ) { getAllIndexes(); } |
| 145 | return distinctIndexRowGenerators; |
| 146 | } |
| 147 | |
| 148 | /** |
| 149 | * Returns an array of distinct index conglomerate ids on a table. |
| 150 | * erasing entries for duplicate indexes (which share same conglomerate). |
| 151 | * |
| 152 | * @return an array of index conglomerate ids |
| 153 | * |
| 154 | * @exception StandardException Thrown on error |
| 155 | */ |
| 156 | public long[] getDistinctIndexConglomerateNumbers() |
| 157 | throws StandardException |
| 158 | { |
| 159 | if ( distinctIndexConglomerateNumbers == null ) { getAllIndexes(); } |
| 160 | return distinctIndexConglomerateNumbers; |
| 161 | } |
| 162 | |
| 163 | /** |
| 164 | * Returns an array of index names for all distinct indexes on a table. |
| 165 | * erasing entries for duplicate indexes (which share same conglomerate). |
| 166 | * |
| 167 | * @return an array of index names |
| 168 | * |
| 169 | * @exception StandardException Thrown on error |
| 170 | */ |
| 171 | public String[] getDistinctIndexNames() throws StandardException |
| 172 | { |
| 173 | if ( indexNames == null ) { getAllIndexes(); } |
| 174 | return indexNames; |
| 175 | } |
| 176 | |
| 177 | //////////////////////////////////////////////////////////////////////// |
| 178 | // |
| 179 | // MINIONS |
| 180 | // |
| 181 | //////////////////////////////////////////////////////////////////////// |
| 182 | |
| 183 | /** |
| 184 | * Reads all the indices on the table and populates arrays with the |
| 185 | * corresponding index row generators and index conglomerate ids. |
| 186 | * |
| 187 | * |
| 188 | * @exception StandardException Thrown on error |
| 189 | */ |
| 190 | private void getAllIndexes() |
| 191 | throws StandardException |
| 192 | { |
| 193 | int indexCount = 0; |
| 194 | |
| 195 | ConglomerateDescriptor[] cds = |
| 196 | tableDescriptor.getConglomerateDescriptors(); |
| 197 | |
| 198 | /* from one end of work space, we record distinct conglomerate |
| 199 | * numbers for comparison while we iterate; from the other end of |
| 200 | * work space, we record duplicate indexes' indexes in "cds" array, |
| 201 | * so that we can skip them in later round. |
| 202 | */ |
| 203 | long[] workSpace = new long[cds.length - 1]; // 1 heap |
| 204 | int distinctIndexCount = 0, duplicateIndex = workSpace.length - 1; |
| 205 | |
| 206 | for (int i = 0; i < cds.length; i++) |
| 207 | { |
| 208 | // first count the number of indices. |
| 209 | ConglomerateDescriptor cd = cds[i]; |
| 210 | |
| 211 | if ( ! cd.isIndex()) |
| 212 | continue; |
| 213 | |
| 214 | int k; |
| 215 | long thisCongNum = cd.getConglomerateNumber(); |
| 216 | |
| 217 | for (k = 0; k < distinctIndexCount; k++) |
| 218 | { |
| 219 | if (workSpace[k] == thisCongNum) |
| 220 | { |
| 221 | workSpace[duplicateIndex--] = i; |
| 222 | break; |
| 223 | } |
| 224 | } |
| 225 | if (k == distinctIndexCount) // first appearence |
| 226 | workSpace[distinctIndexCount++] = thisCongNum; |
| 227 | |
| 228 | indexCount++; |
| 229 | } |
| 230 | |
| 231 | indexRowGenerators = new IndexRowGenerator[ indexCount ]; |
| 232 | indexConglomerateNumbers = new long[ indexCount ]; |
| 233 | indexNames = new String[ indexCount ]; |
| 234 | distinctIndexRowGenerators = new IndexRowGenerator[ distinctIndexCount ]; |
| 235 | distinctIndexConglomerateNumbers = new long[ distinctIndexCount ]; |
| 236 | distinctIndexNames = new String[ distinctIndexCount ]; |
| 237 | |
| 238 | int duplicatePtr = workSpace.length - 1; |
| 239 | for ( int i = 0, j = -1, k = -1; i < cds.length; i++ ) |
| 240 | { |
| 241 | ConglomerateDescriptor cd = cds[i]; |
| 242 | |
| 243 | if ( ! cd.isIndex()) |
| 244 | continue; |
| 245 | |
| 246 | indexRowGenerators[++j] = |
| 247 | (IndexRowGenerator)cd.getIndexDescriptor(); |
| 248 | indexConglomerateNumbers[j] = cd.getConglomerateNumber(); |
| 249 | if (!(cd.isConstraint())) |
| 250 | { |
| 251 | // only fill index name if it is not a constraint. |
| 252 | indexNames[j] = cd.getConglomerateName(); |
| 253 | } |
| 254 | |
| 255 | if (duplicatePtr > duplicateIndex && i == (int) workSpace[duplicatePtr]) |
| 256 | duplicatePtr--; |
| 257 | else |
| 258 | { |
| 259 | distinctIndexRowGenerators[++k] = indexRowGenerators[j]; |
| 260 | distinctIndexConglomerateNumbers[k] = indexConglomerateNumbers[j]; |
| 261 | distinctIndexNames[k] = indexNames[j]; |
| 262 | } |
| 263 | } |
| 264 | } |
| 265 | } |