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Diffstat (limited to 'netconfsimulator/src/main/java/org/onap/netconfsimulator/kafka/StoreService.java')
-rw-r--r-- | netconfsimulator/src/main/java/org/onap/netconfsimulator/kafka/StoreService.java | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/netconfsimulator/src/main/java/org/onap/netconfsimulator/kafka/StoreService.java b/netconfsimulator/src/main/java/org/onap/netconfsimulator/kafka/StoreService.java new file mode 100644 index 0000000..5fddff5 --- /dev/null +++ b/netconfsimulator/src/main/java/org/onap/netconfsimulator/kafka/StoreService.java @@ -0,0 +1,91 @@ +/*- + * ============LICENSE_START======================================================= + * Simulator + * ================================================================================ + * Copyright (C) 2019 Nokia. 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.netconfsimulator.kafka; + +import lombok.extern.slf4j.Slf4j; +import org.apache.kafka.clients.consumer.Consumer; +import org.apache.kafka.clients.consumer.ConsumerRecords; +import org.apache.kafka.common.TopicPartition; +import org.springframework.beans.factory.annotation.Autowired; +import org.springframework.kafka.core.ConsumerFactory; +import org.springframework.stereotype.Service; + +import java.time.Instant; +import java.util.ArrayList; +import java.util.Collections; +import java.util.List; + +@Slf4j +@Service +public class StoreService { + + private static final String CONFIG_TOPIC = "config"; + private static final long CONSUMING_DURATION_IN_MS = 1000; + + private ConsumerFactory<String, String> consumerFactory; + static final List<String> TOPICS_TO_SUBSCRIBE = Collections.singletonList(CONFIG_TOPIC); + + @Autowired + StoreService(ConsumerFactory<String, String> consumerFactory) { + this.consumerFactory = consumerFactory; + } + + List<MessageDTO> getAllMessages() { + List<MessageDTO> messages = new ArrayList<>(); + String clientID = Long.toString(Instant.now().getEpochSecond()); + try (Consumer<String, String> consumer = consumerFactory.createConsumer(clientID, clientID)) { + consumer.subscribe(TOPICS_TO_SUBSCRIBE); + ConsumerRecords<String, String> consumerRecords = consumer.poll(CONSUMING_DURATION_IN_MS); + consumerRecords.forEach( + consumerRecord -> + messages.add(new MessageDTO(consumerRecord.timestamp(), consumerRecord.value()))); + log.debug(String.format("consumed %d messages", consumerRecords.count())); + } + return messages; + } + + List<MessageDTO> getLastMessages(long offset) { + List<MessageDTO> messages = new ArrayList<>(); + try (Consumer<String, String> consumer = createConsumer(offset)) { + ConsumerRecords<String, String> consumerRecords = consumer.poll(CONSUMING_DURATION_IN_MS); + consumerRecords.forEach(consumerRecord -> + messages.add(new MessageDTO(consumerRecord.timestamp(), consumerRecord.value()))); + } + return messages; + } + + private Consumer<String, String> createConsumer(long offsetFromLastIndex) { + String clientID = Long.toString(Instant.now().getEpochSecond()); + Consumer<String, String> consumer = consumerFactory.createConsumer(clientID, clientID); + consumer.subscribe(TOPICS_TO_SUBSCRIBE); + seekConsumerTo(consumer, offsetFromLastIndex); + return consumer; + } + + private void seekConsumerTo(Consumer<String, String> consumer, long offsetFromLastIndex) { + consumer.seekToEnd(consumer.assignment()); + consumer.poll(CONSUMING_DURATION_IN_MS); + TopicPartition topicPartition = consumer.assignment().iterator().next(); + long topicCurrentSize = consumer.position(topicPartition); + long indexToSeek = offsetFromLastIndex > topicCurrentSize ? 0 : topicCurrentSize - offsetFromLastIndex; + consumer.seek(topicPartition, indexToSeek); + } +} |