1 /* 2 * ModeShape (http://www.modeshape.org) 3 * See the COPYRIGHT.txt file distributed with this work for information 4 * regarding copyright ownership. Some portions may be licensed 5 * to Red Hat, Inc. under one or more contributor license agreements. 6 * See the AUTHORS.txt file in the distribution for a full listing of 7 * individual contributors. 8 * 9 * ModeShape is free software. Unless otherwise indicated, all code in ModeShape 10 * is licensed to you under the terms of the GNU Lesser General Public License as 11 * published by the Free Software Foundation; either version 2.1 of 12 * the License, or (at your option) any later version. 13 * 14 * ModeShape is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 17 * Lesser General Public License for more details. 18 * 19 * You should have received a copy of the GNU Lesser General Public 20 * License along with this software; if not, write to the Free 21 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 22 * 02110-1301 USA, or see the FSF site: http://www.fsf.org. 23 */ 24 package org.modeshape.graph.query; 25 26 import java.util.Collections; 27 import java.util.HashMap; 28 import java.util.Map; 29 import net.jcip.annotations.Immutable; 30 import org.modeshape.common.collection.Problems; 31 import org.modeshape.common.collection.SimpleProblems; 32 import org.modeshape.common.util.CheckArg; 33 import org.modeshape.graph.query.model.BindVariableName; 34 import org.modeshape.graph.query.model.TypeSystem; 35 import org.modeshape.graph.query.plan.PlanHints; 36 import org.modeshape.graph.query.validate.Schemata; 37 38 /** 39 * An immutable context in which queries are to be executed. Each query context defines the information that is available during 40 * query execution. 41 */ 42 @Immutable 43 public class QueryContext { 44 private final TypeSystem typeSystem; 45 private final PlanHints hints; 46 private final Schemata schemata; 47 private final Problems problems; 48 private final Map<String, Object> variables; 49 50 /** 51 * Create a new context for query execution. 52 * 53 * @param schemata the schemata 54 * @param typeSystem the types system 55 * @param hints the hints, or null if there are no hints 56 * @param problems the problems container, or null if a new problems container should be created 57 * @param variables the mapping of variables and values, or null if there are no such variables 58 * @throws IllegalArgumentException if the values or schmata are null 59 */ 60 public QueryContext( Schemata schemata, 61 TypeSystem typeSystem, 62 PlanHints hints, 63 Problems problems, 64 Map<String, Object> variables ) { 65 CheckArg.isNotNull(typeSystem, "typeSystem"); 66 CheckArg.isNotNull(schemata, "schemata"); 67 this.typeSystem = typeSystem; 68 this.hints = hints != null ? hints : new PlanHints(); 69 this.schemata = schemata; 70 this.problems = problems != null ? problems : new SimpleProblems(); 71 this.variables = variables != null ? Collections.<String, Object>unmodifiableMap(new HashMap<String, Object>(variables)) : Collections.<String, Object>emptyMap(); 72 assert this.typeSystem != null; 73 assert this.hints != null; 74 assert this.schemata != null; 75 assert this.problems != null; 76 assert this.variables != null; 77 } 78 79 /** 80 * Create a new context for query execution. 81 * 82 * @param schemata the schemata 83 * @param typeSystem the types system 84 * @param hints the hints, or null if there are no hints 85 * @param problems the problems container, or null if a new problems container should be created 86 * @throws IllegalArgumentException if the values or schmata are null 87 */ 88 public QueryContext( Schemata schemata, 89 TypeSystem typeSystem, 90 PlanHints hints, 91 Problems problems ) { 92 this(schemata, typeSystem, hints, problems, null); 93 } 94 95 /** 96 * Create a new context for query execution. 97 * 98 * @param schemata the schemata 99 * @param typeSystem the types system 100 * @param hints the hints, or null if there are no hints 101 * @throws IllegalArgumentException if the context or schmata are null 102 */ 103 public QueryContext( Schemata schemata, 104 TypeSystem typeSystem, 105 PlanHints hints ) { 106 this(schemata, typeSystem, hints, null, null); 107 } 108 109 /** 110 * Create a new context for query execution. 111 * 112 * @param schemata the schemata 113 * @param typeSystem the types system 114 * @throws IllegalArgumentException if the values or schmata are null 115 */ 116 public QueryContext( Schemata schemata, 117 TypeSystem typeSystem ) { 118 this(schemata, typeSystem, null, null, null); 119 } 120 121 /** 122 * Create a new context that is a copy of the supplied context. This constructor is useful for subclasses that wish to add 123 * store additional fields in a QueryContext. 124 * 125 * @param original the original context 126 * @throws IllegalArgumentException if the original is null 127 */ 128 protected QueryContext( QueryContext original ) { 129 this(original.schemata, original.typeSystem, original.hints, original.problems, original.variables); 130 } 131 132 /** 133 * Get the interface for working with literal values and types. 134 * 135 * @return the type system; never null 136 */ 137 public TypeSystem getTypeSystem() { 138 return typeSystem; 139 } 140 141 /** 142 * Get the plan hints. 143 * 144 * @return the plan hints; never null 145 */ 146 public final PlanHints getHints() { 147 return hints; 148 } 149 150 /** 151 * Get the problem container used by this query context. Any problems that have been encountered will be accumlated in this 152 * container. 153 * 154 * @return the problem container; never null 155 */ 156 public final Problems getProblems() { 157 return problems; 158 } 159 160 /** 161 * Get the definition of the tables available within this query context. 162 * 163 * @return the schemata; never null 164 */ 165 public Schemata getSchemata() { 166 return schemata; 167 } 168 169 /** 170 * Get the variables that are to be substituted into the {@link BindVariableName} used in the query. 171 * 172 * @return immutable map of variable values keyed by their name; never null but possibly empty 173 */ 174 public Map<String, Object> getVariables() { 175 return variables; 176 } 177 178 /** 179 * {@inheritDoc} 180 * 181 * @see java.lang.Object#equals(java.lang.Object) 182 */ 183 @Override 184 public boolean equals( Object obj ) { 185 if (obj == this) return true; 186 if (obj instanceof QueryContext) { 187 QueryContext that = (QueryContext)obj; 188 if (!this.typeSystem.equals(that.getTypeSystem())) return false; 189 if (!this.schemata.equals(that.getSchemata())) return false; 190 if (!this.variables.equals(that.getVariables())) return false; 191 return true; 192 } 193 return false; 194 } 195 196 /** 197 * Obtain a copy of this context, except that the copy uses the supplied type system. 198 * 199 * @param typeSystem the type system that should be used in the new query context 200 * @return the new context; never null 201 * @throws IllegalArgumentException if the execution context reference is null 202 */ 203 public QueryContext with( TypeSystem typeSystem ) { 204 CheckArg.isNotNull(typeSystem, "typeSystem"); 205 return new QueryContext(schemata, typeSystem, hints, problems, variables); 206 } 207 208 /** 209 * Obtain a copy of this context, except that the copy uses the supplied schemata. 210 * 211 * @param schemata the schemata that should be used in the new context 212 * @return the new context; never null 213 * @throws IllegalArgumentException if the schemata reference is null 214 */ 215 public QueryContext with( Schemata schemata ) { 216 CheckArg.isNotNull(schemata, "schemata"); 217 return new QueryContext(schemata, typeSystem, hints, problems, variables); 218 } 219 220 /** 221 * Obtain a copy of this context, except that the copy uses the supplied hints. 222 * 223 * @param hints the hints that should be used in the new context 224 * @return the new context; never null 225 * @throws IllegalArgumentException if the hints reference is null 226 */ 227 public QueryContext with( PlanHints hints ) { 228 CheckArg.isNotNull(hints, "hints"); 229 return new QueryContext(schemata, typeSystem, hints, problems, variables); 230 } 231 232 /** 233 * Obtain a copy of this context, except that the copy uses the supplied problem container. 234 * 235 * @param problems the problems that should be used in the new context; may be null if a new problem container should be used 236 * @return the new context; never null 237 */ 238 public QueryContext with( Problems problems ) { 239 return new QueryContext(schemata, typeSystem, hints, problems, variables); 240 } 241 242 /** 243 * Obtain a copy of this context, except that the copy uses the supplied variables. 244 * 245 * @param variables the variables that should be used in the new context; may be null if there are no such variables 246 * @return the new context; never null 247 */ 248 public QueryContext with( Map<String, Object> variables ) { 249 return new QueryContext(schemata, typeSystem, hints, problems, variables); 250 } 251 252 }