1 files changed, 204 insertions, 0 deletions
diff --git a/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/IndexedKafkaTopicSourceFactory.java b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/IndexedKafkaTopicSourceFactory.java
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+++ b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/IndexedKafkaTopicSourceFactory.java
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+/*
+ * ============LICENSE_START=======================================================
+ * Copyright (C) 2022-2023 Nordix Foundation.
+ * ================================================================================
+ * 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.common.endpoints.event.comm.bus;
+
+import com.google.re2j.Pattern;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Properties;
+import org.apache.commons.lang3.StringUtils;
+import org.onap.policy.common.endpoints.event.comm.bus.internal.BusTopicParams;
+import org.onap.policy.common.endpoints.event.comm.bus.internal.SingleThreadedKafkaTopicSource;
+import org.onap.policy.common.endpoints.properties.PolicyEndPointProperties;
+import org.onap.policy.common.endpoints.utils.KafkaPropertyUtils;
+import org.onap.policy.common.endpoints.utils.PropertyUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Factory of KAFKA Source Topics indexed by topic name.
+ */
+class IndexedKafkaTopicSourceFactory implements KafkaTopicSourceFactory {
+    private static final Pattern COMMA_SPACE_PAT = Pattern.compile("\\s*,\\s*");
+    private static final String MISSING_TOPIC = "A topic must be provided";
+
+    /**
+     * Logger.
+     */
+    private static final Logger logger = LoggerFactory.getLogger(IndexedKafkaTopicSourceFactory.class);
+
+    /**
+     * KAFKA Topic Name Index.
+     */
+    protected HashMap<String, KafkaTopicSource> kafkaTopicSources = new HashMap<>();
+
+    @Override
+    public KafkaTopicSource build(BusTopicParams busTopicParams) {
+        if (busTopicParams.getServers() == null || busTopicParams.getServers().isEmpty()) {
+            throw new IllegalArgumentException("KAFKA Server(s) must be provided");
+        }
+
+        if (busTopicParams.getTopic() == null || busTopicParams.getTopic().isEmpty()) {
+            throw new IllegalArgumentException(MISSING_TOPIC);
+        }
+
+        synchronized (this) {
+            if (kafkaTopicSources.containsKey(busTopicParams.getTopic())) {
+                return kafkaTopicSources.get(busTopicParams.getTopic());
+            }
+
+            var kafkaTopicSource = makeSource(busTopicParams);
+
+            kafkaTopicSources.put(busTopicParams.getTopic(), kafkaTopicSource);
+
+            return kafkaTopicSource;
+        }
+    }
+
+    @Override
+    public List<KafkaTopicSource> build(Properties properties) {
+
+        String readTopics = properties.getProperty(PolicyEndPointProperties.PROPERTY_KAFKA_SOURCE_TOPICS);
+        if (StringUtils.isBlank(readTopics)) {
+            logger.info("{}: no topic for KAFKA Source", this);
+            return new ArrayList<>();
+        }
+
+        List<KafkaTopicSource> newKafkaTopicSources = new ArrayList<>();
+        synchronized (this) {
+            for (String topic : COMMA_SPACE_PAT.split(readTopics)) {
+                addTopic(newKafkaTopicSources, topic.toLowerCase(), properties);
+            }
+        }
+        return newKafkaTopicSources;
+    }
+
+    @Override
+    public KafkaTopicSource build(List<String> servers, String topic) {
+        return this.build(BusTopicParams.builder()
+                .servers(servers)
+                .topic(topic)
+                .managed(true)
+                .fetchTimeout(PolicyEndPointProperties.DEFAULT_TIMEOUT_MS_FETCH)
+                .fetchLimit(PolicyEndPointProperties.DEFAULT_LIMIT_FETCH)
+                .useHttps(false).build());
+    }
+
+    private void addTopic(List<KafkaTopicSource> newKafkaTopicSources, String topic, Properties properties) {
+        if (this.kafkaTopicSources.containsKey(topic)) {
+            newKafkaTopicSources.add(this.kafkaTopicSources.get(topic));
+            return;
+        }
+
+        String topicPrefix = PolicyEndPointProperties.PROPERTY_KAFKA_SOURCE_TOPICS + "." + topic;
+
+        var props = new PropertyUtils(properties, topicPrefix,
+            (name, value, ex) -> logger.warn("{}: {} {} is in invalid format for topic source {} ",
+                this, name, value, topic));
+
+        String servers = properties.getProperty(topicPrefix + PolicyEndPointProperties.PROPERTY_TOPIC_SERVERS_SUFFIX);
+        if (StringUtils.isBlank(servers)) {
+            logger.error("{}: no KAFKA servers configured for source {}", this, topic);
+            return;
+        }
+
+        var kafkaTopicSource = this.build(KafkaPropertyUtils.makeBuilder(props, topic, servers)
+                .consumerGroup(props.getString(
+                        PolicyEndPointProperties.PROPERTY_TOPIC_SOURCE_CONSUMER_GROUP_SUFFIX, null))
+                .consumerInstance(props.getString(
+                        PolicyEndPointProperties.PROPERTY_TOPIC_SOURCE_CONSUMER_INSTANCE_SUFFIX, null))
+                .fetchTimeout(props.getInteger(
+                        PolicyEndPointProperties.PROPERTY_TOPIC_SOURCE_FETCH_TIMEOUT_SUFFIX,
+                        PolicyEndPointProperties.DEFAULT_TIMEOUT_MS_FETCH))
+                .fetchLimit(props.getInteger(PolicyEndPointProperties.PROPERTY_TOPIC_SOURCE_FETCH_LIMIT_SUFFIX,
+                        PolicyEndPointProperties.DEFAULT_LIMIT_FETCH))
+                .build());
+
+        newKafkaTopicSources.add(kafkaTopicSource);
+    }
+
+    /**
+     * Makes a new source.
+     *
+     * @param busTopicParams parameters to use to configure the source
+     * @return a new source
+     */
+    protected KafkaTopicSource makeSource(BusTopicParams busTopicParams) {
+        return new SingleThreadedKafkaTopicSource(busTopicParams);
+    }
+
+    @Override
+    public void destroy(String topic) {
+
+        if (topic == null || topic.isEmpty()) {
+            throw new IllegalArgumentException(MISSING_TOPIC);
+        }
+
+        KafkaTopicSource kafkaTopicSource;
+
+        synchronized (this) {
+            if (!kafkaTopicSources.containsKey(topic)) {
+                return;
+            }
+
+            kafkaTopicSource = kafkaTopicSources.remove(topic);
+        }
+
+        kafkaTopicSource.shutdown();
+    }
+
+    @Override
+    public void destroy() {
+        List<KafkaTopicSource> readers = this.inventory();
+        for (KafkaTopicSource reader : readers) {
+            reader.shutdown();
+        }
+
+        synchronized (this) {
+            this.kafkaTopicSources.clear();
+        }
+    }
+
+    @Override
+    public KafkaTopicSource get(String topic) {
+
+        if (topic == null || topic.isEmpty()) {
+            throw new IllegalArgumentException(MISSING_TOPIC);
+        }
+
+        synchronized (this) {
+            if (kafkaTopicSources.containsKey(topic)) {
+                return kafkaTopicSources.get(topic);
+            } else {
+                throw new IllegalStateException("KafkaTopiceSource for " + topic + " not found");
+            }
+        }
+    }
+
+    @Override
+    public synchronized List<KafkaTopicSource> inventory() {
+        return new ArrayList<>(this.kafkaTopicSources.values());
+    }
+
+    @Override
+    public String toString() {
+        return "IndexedKafkaTopicSourceFactory " + kafkaTopicSources.keySet();
+    }
+}