/
DroolsRulesEngineImpl.java
217 lines (183 loc) · 6.44 KB
/
DroolsRulesEngineImpl.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
/*
* Copyright 2015 Red Hat, Inc. and/or its affiliates
* and other contributors as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.hawkular.alerts.engine.impl;
import java.util.Collection;
import java.util.TreeSet;
import java.util.function.Predicate;
import javax.ejb.Singleton;
import org.drools.core.event.DebugAgendaEventListener;
import org.drools.core.event.DebugRuleRuntimeEventListener;
import org.hawkular.alerts.api.model.data.Data;
import org.hawkular.alerts.engine.rules.RulesEngine;
import org.jboss.logging.Logger;
import org.kie.api.KieServices;
import org.kie.api.runtime.KieContainer;
import org.kie.api.runtime.KieSession;
import org.kie.api.runtime.ObjectFilter;
import org.kie.api.runtime.rule.FactHandle;
/**
* An implementation of RulesEngine based on drools framework.
*
* This implementations has an approach of fixed rules based on filesystem.
*
* @author Jay Shaughnessy
* @author Lucas Ponce
*/
@Singleton
public class DroolsRulesEngineImpl implements RulesEngine {
// private final MsgLogger msgLog = MsgLogger.LOGGER;
private final Logger log = Logger.getLogger(DroolsRulesEngineImpl.class);
private static final String SESSION_NAME = "hawkular-alerts-engine-session";
private KieServices ks;
private KieContainer kc;
private KieSession kSession;
TreeSet<Data> pendingData = new TreeSet<>();
public DroolsRulesEngineImpl() {
log.debugf("Creating instance.");
ks = KieServices.Factory.get();
kc = ks.getKieClasspathContainer();
kSession = kc.newKieSession(SESSION_NAME);
if (log.isEnabled(Logger.Level.TRACE)) {
kSession.addEventListener(new DebugAgendaEventListener());
kSession.addEventListener(new DebugRuleRuntimeEventListener());
}
}
@Override
public void addFact(Object fact) {
if (fact instanceof Data) {
throw new IllegalArgumentException(fact.toString());
}
log.debugf("Insert %s ", fact);
kSession.insert(fact);
}
@Override
public void addFacts(Collection facts) {
for (Object fact : facts) {
if (fact instanceof Data) {
throw new IllegalArgumentException(fact.toString());
}
}
for (Object fact : facts) {
log.debugf("Insert %s ", fact);
kSession.insert(fact);
}
}
@Override
public void addData(Data data) {
pendingData.add(data);
}
@Override
public void addData(Collection<Data> data) {
pendingData.addAll(data);
}
@Override
public void addGlobal(String name, Object global) {
log.debugf("Add Global %s = %s", name, global);
kSession.setGlobal(name, global);
}
@Override
public void clear() {
for (FactHandle factHandle : kSession.getFactHandles()) {
log.debugf("Delete %s ", factHandle);
kSession.delete(factHandle);
}
}
@Override
public void fire() {
// The rules engine requires that for any DataId only the oldest Data instance is processed in one
// execution of the rules. So, if we find multiple Data instances for the same Id, defer all but
// the oldest to a subsequent run. Note that pendingData is already sorted by (id ASC, timestamp ASC) so
// the iterator will present Data with the same id together, and time-ordered.
while (!pendingData.isEmpty()) {
log.debugf("Data found. Firing rules on [%1$d] datums.", pendingData.size());
TreeSet<Data> batchData = new TreeSet<Data>(pendingData);
Data previousData = null;
pendingData.clear();
for (Data data : batchData) {
if (null == previousData || !data.getId().equals(previousData.getId())) {
kSession.insert(data);
previousData = data;
} else {
pendingData.add(data);
log.debugf("Deferring more recent %1$s until older %2$s is processed", data, previousData);
}
}
if (!pendingData.isEmpty()) {
log.debugf("Deferring [%1$d] Datum(s) to next firing !!", pendingData.size());
}
batchData.clear();
kSession.fireAllRules();
}
}
@Override
public void fireNoData() {
kSession.fireAllRules();
}
@Override
public Object getFact(Object o) {
return kSession.getFactHandle(o);
}
@Override
public void removeFact(Object fact) {
FactHandle factHandle = kSession.getFactHandle(fact);
if (factHandle != null) {
log.debugf("Delete %s ", factHandle);
kSession.delete(factHandle);
}
}
@Override
public void updateFact(Object fact) {
FactHandle factHandle = kSession.getFactHandle(fact);
if (factHandle != null) {
log.debugf("Update %s ", factHandle);
kSession.update(factHandle, fact);
}
}
@Override
public void removeFacts(Collection facts) {
for (Object fact : facts) {
removeFact(fact);
}
}
@Override
public void removeFacts(Predicate<Object> factFilter) {
Collection<FactHandle> handles = kSession.getFactHandles(new ObjectFilter() {
@Override
public boolean accept(Object object) {
return factFilter.test(object);
}
});
if (null == handles) {
return;
}
for (FactHandle h : handles) {
log.debugf("Delete %s ", h);
removeFact(h);
}
}
@Override
public void removeGlobal(String name) {
log.debugf("Remove Global %s ", name);
kSession.setGlobal(name, null);
}
@Override
public void reset() {
log.debugf("Reset session");
kSession.dispose();
kSession = kc.newKieSession(SESSION_NAME);
}
}