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
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
|
/*
* ============LICENSE_START=======================================================
* ONAP
* ================================================================================
* Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
* ================================================================================
* 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.
* ============LICENSE_END=========================================================
*/
package org.onap.policy.drools.pooling;
import java.util.List;
import org.onap.policy.common.endpoints.event.comm.FilterableTopicSource;
import org.onap.policy.common.endpoints.event.comm.TopicEndpoint;
import org.onap.policy.common.endpoints.event.comm.TopicListener;
import org.onap.policy.common.endpoints.event.comm.TopicSink;
import org.onap.policy.common.endpoints.event.comm.TopicSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Manages the internal DMaaP topic. Assumes all topics are managed by
* {@link TopicEndpoint#manager}.
*/
public class DmaapManager {
private static final Logger logger = LoggerFactory.getLogger(DmaapManager.class);
/**
* Name of the DMaaP topic.
*/
private final String topic;
/**
* Topic source whose filter is to be manipulated.
*/
private final FilterableTopicSource topicSource;
/**
* Where to publish messages.
*/
private final TopicSink topicSink;
/**
* {@code True} if the consumer is running, {@code false} otherwise.
*/
private boolean consuming = false;
/**
* {@code True} if the publisher is running, {@code false} otherwise.
*/
private boolean publishing = false;
/**
* Constructs the manager, but does not start the source or sink.
*
* @param topic name of the internal DMaaP topic
* @throws PoolingFeatureException if an error occurs
*/
public DmaapManager(String topic) throws PoolingFeatureException {
logger.info("initializing bus for topic {}", topic);
try {
this.topic = topic;
this.topicSource = findTopicSource();
this.topicSink = findTopicSink();
// verify that we can set the filter
setFilter(null);
} catch (IllegalArgumentException e) {
logger.error("failed to attach to topic {}", topic);
throw new PoolingFeatureException(e);
}
}
public String getTopic() {
return topic;
}
/**
* Finds the topic source associated with the internal DMaaP topic.
*
* @return the topic source
* @throws PoolingFeatureException if the source doesn't exist or is not filterable
*/
private FilterableTopicSource findTopicSource() throws PoolingFeatureException {
for (TopicSource src : getTopicSources()) {
if (topic.equals(src.getTopic())) {
if (src instanceof FilterableTopicSource) {
return (FilterableTopicSource) src;
} else {
throw new PoolingFeatureException("topic source " + topic + " is not filterable");
}
}
}
throw new PoolingFeatureException("missing topic source " + topic);
}
/**
* Finds the topic sink associated with the internal DMaaP topic.
*
* @return the topic sink
* @throws PoolingFeatureException if the sink doesn't exist
*/
private TopicSink findTopicSink() throws PoolingFeatureException {
for (TopicSink sink : getTopicSinks()) {
if (topic.equals(sink.getTopic())) {
return sink;
}
}
throw new PoolingFeatureException("missing topic sink " + topic);
}
/**
* Starts the publisher, if it isn't already running.
*/
public void startPublisher() {
if (publishing) {
return;
}
logger.info("start publishing to topic {}", topic);
publishing = true;
}
/**
* Stops the publisher.
*
* @param waitMs time, in milliseconds, to wait for the sink to transmit any queued messages and
* close
*/
public void stopPublisher(long waitMs) {
if (!publishing) {
return;
}
/*
* Give the sink a chance to transmit messages in the queue. It would be better if "waitMs"
* could be passed to sink.stop(), but that isn't an option at this time.
*/
try {
Thread.sleep(waitMs);
} catch (InterruptedException e) {
logger.warn("message transmission stopped due to {}", e.getMessage());
Thread.currentThread().interrupt();
}
logger.info("stop publishing to topic {}", topic);
publishing = false;
}
/**
* Starts the consumer, if it isn't already running.
*
* @param listener listener to register with the source
*/
public void startConsumer(TopicListener listener) {
if (consuming) {
return;
}
logger.info("start consuming from topic {}", topic);
topicSource.register(listener);
consuming = true;
}
/**
* Stops the consumer.
*
* @param listener listener to unregister with the source
*/
public void stopConsumer(TopicListener listener) {
if (!consuming) {
return;
}
logger.info("stop consuming from topic {}", topic);
consuming = false;
topicSource.unregister(listener);
}
/**
* Sets the server-side filter to be used by the consumer.
*
* @param filter the filter string, or {@code null} if no filter is to be used
* @throws PoolingFeatureException if the topic is not filterable
*/
public void setFilter(String filter) throws PoolingFeatureException {
try {
logger.debug("change filter for topic {} to {}", topic, filter);
topicSource.setFilter(filter);
} catch (UnsupportedOperationException e) {
throw new PoolingFeatureException("cannot filter topic " + topic, e);
}
}
/**
* Publishes a message to the sink.
*
* @param msg message to be published
* @throws PoolingFeatureException if an error occurs or the publisher isn't running
*/
public void publish(String msg) throws PoolingFeatureException {
if (!publishing) {
throw new PoolingFeatureException(new IllegalStateException("no topic sink " + topic));
}
try {
if (!topicSink.send(msg)) {
throw new PoolingFeatureException("failed to send to topic sink " + topic);
}
} catch (IllegalStateException e) {
throw new PoolingFeatureException("cannot send to topic sink " + topic, e);
}
}
/*
* The remaining methods may be overridden by junit tests.
*/
/**
* Get topic source.
*
* @return the topic sources
*/
protected List<TopicSource> getTopicSources() {
return TopicEndpoint.manager.getTopicSources();
}
/**
* Get topic sinks.
*
* @return the topic sinks
*/
protected List<TopicSink> getTopicSinks() {
return TopicEndpoint.manager.getTopicSinks();
}
}
|