001 /**
002 * Copyright 2005-2014 The Kuali Foundation
003 *
004 * Licensed under the Educational Community License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.opensource.org/licenses/ecl2.php
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016 package org.kuali.rice.krms.framework.engine;
017
018 import java.util.Map;
019
020 import org.joda.time.DateTime;
021 import org.kuali.rice.krms.api.engine.Engine;
022 import org.kuali.rice.krms.api.engine.EngineResults;
023 import org.kuali.rice.krms.api.engine.ExecutionEnvironment;
024 import org.kuali.rice.krms.api.engine.ExecutionOptions;
025 import org.kuali.rice.krms.api.engine.Facts;
026 import org.kuali.rice.krms.api.engine.ResultEvent;
027 import org.kuali.rice.krms.api.engine.SelectionCriteria;
028 import org.kuali.rice.krms.api.engine.Term;
029 import org.kuali.rice.krms.framework.engine.result.TimingResult;
030
031 /**
032 * An implementation of {@link Engine}
033 * @author Kuali Rice Team (rice.collab@kuali.org)
034 */
035 public class ProviderBasedEngine implements Engine {
036
037 private static final Term effectiveExecutionTimeTerm = new Term("effectiveExecutionTime", null);
038
039 private static final org.apache.log4j.Logger LOG = org.apache.log4j.Logger.getLogger(ProviderBasedEngine.class);
040 private static final ResultLogger KLog = ResultLogger.getInstance();
041
042 private ContextProvider contextProvider;
043
044 @Override
045 public EngineResults execute(SelectionCriteria selectionCriteria, Map<String, Object> facts,
046 ExecutionOptions executionOptions) {
047 return execute(selectionCriteria,
048 Facts.Builder.create().addFactsByName(facts).build(),
049 executionOptions);
050 }
051
052 @Override
053 public EngineResults execute(SelectionCriteria selectionCriteria, Facts facts, ExecutionOptions executionOptions) {
054 DateTime start, end;
055 start = new DateTime();
056 ExecutionEnvironment environment = establishExecutionEnvironment(selectionCriteria, facts.getFactMap(), executionOptions);
057
058 // set execution time
059 Long effectiveExecutionTime = environment.getSelectionCriteria().getEffectiveExecutionTime();
060 if (effectiveExecutionTime == null) { effectiveExecutionTime = System.currentTimeMillis(); }
061 environment.publishFact(effectiveExecutionTimeTerm, effectiveExecutionTime);
062
063 Context context = selectContext(selectionCriteria, facts.getFactMap(), executionOptions);
064 if (context == null) {
065 LOG.info("Failed to locate a Context for the given qualifiers, skipping rule engine execution: " + selectionCriteria.getContextQualifiers());
066 return null;
067 }
068 context.execute(environment);
069 end = new DateTime();
070 if (KLog.isEnabled(environment)){
071 KLog.logResult(new TimingResult(ResultEvent.TIMING_EVENT, this, environment, start, end));
072 }
073 return environment.getEngineResults();
074 }
075
076 /**
077 * Return a {@link BasicExecutionEnvironment} using the given parameters
078 * @param selectionCriteria {@link SelectionCriteria}
079 * @param facts
080 * @param executionOptions {@link ExecutionOptions}
081 * @return {@link ExecutionEnvironment} created with the given parameters
082 */
083 protected ExecutionEnvironment establishExecutionEnvironment(SelectionCriteria selectionCriteria, Map<Term, Object> facts, ExecutionOptions executionOptions) {
084 return new BasicExecutionEnvironment(selectionCriteria, facts, executionOptions, new TermResolutionEngineImpl());
085 }
086
087 /**
088 * Load a Context from the contextProvider using the given parameters
089 * @see ContextProvider loadContext
090 * @param selectionCriteria
091 * @param facts
092 * @param executionOptions
093 * @return {@link Context}
094 * @throws IllegalStateException if the contextProvider is null;
095 */
096 protected Context selectContext(SelectionCriteria selectionCriteria, Map<Term, Object> facts, ExecutionOptions executionOptions) {
097 if (contextProvider == null) {
098 throw new IllegalStateException("No ContextProvider was configured.");
099 }
100 return contextProvider.loadContext(selectionCriteria, facts, executionOptions);
101 }
102
103 /**
104 * Set the {@link ContextProvider}
105 * @param contextProvider to loadContext from.
106 */
107 public void setContextProvider(ContextProvider contextProvider) {
108 this.contextProvider = contextProvider;
109 }
110
111 }