/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.camel.component.aws.ddbstream;
import java.math.BigInteger;
import java.util.ArrayDeque;
import java.util.List;
import java.util.Queue;
import com.amazonaws.services.dynamodbv2.AmazonDynamoDBStreams;
import com.amazonaws.services.dynamodbv2.model.ExpiredIteratorException;
import com.amazonaws.services.dynamodbv2.model.GetRecordsRequest;
import com.amazonaws.services.dynamodbv2.model.GetRecordsResult;
import com.amazonaws.services.dynamodbv2.model.Record;
import org.apache.camel.AsyncCallback;
import org.apache.camel.Exchange;
import org.apache.camel.Processor;
import org.apache.camel.impl.ScheduledBatchPollingConsumer;
import org.apache.camel.util.CastUtils;
import org.apache.camel.util.ObjectHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class DdbStreamConsumer extends ScheduledBatchPollingConsumer {
private static final Logger LOG = LoggerFactory.getLogger(DdbStreamConsumer.class);
private final ShardIteratorHandler shardIteratorHandler;
private String lastSeenSequenceNumber;
public DdbStreamConsumer(DdbStreamEndpoint endpoint, Processor processor) {
this(endpoint, processor, new ShardIteratorHandler(endpoint));
}
DdbStreamConsumer(DdbStreamEndpoint endpoint, Processor processor, ShardIteratorHandler shardIteratorHandler) {
super(endpoint, processor);
this.shardIteratorHandler = shardIteratorHandler;
}
@Override
protected int poll() throws Exception {
GetRecordsResult result;
try {
GetRecordsRequest req = new GetRecordsRequest()
.withShardIterator(shardIteratorHandler.getShardIterator(null))
.withLimit(getEndpoint().getMaxResultsPerRequest());
result = getClient().getRecords(req);
} catch (ExpiredIteratorException e) {
LOG.warn("Expired Shard Iterator, attempting to resume from " + lastSeenSequenceNumber, e);
GetRecordsRequest req = new GetRecordsRequest()
.withShardIterator(shardIteratorHandler.getShardIterator(lastSeenSequenceNumber))
.withLimit(getEndpoint().getMaxResultsPerRequest());
result = getClient().getRecords(req);
}
List<Record> records = result.getRecords();
Queue<Exchange> exchanges = createExchanges(records, lastSeenSequenceNumber);
int processedExchangeCount = processBatch(CastUtils.cast(exchanges));
shardIteratorHandler.updateShardIterator(result.getNextShardIterator());
if (!records.isEmpty()) {
lastSeenSequenceNumber = records.get(records.size() - 1).getDynamodb().getSequenceNumber();
}
return processedExchangeCount;
}
@Override
public int processBatch(Queue<Object> exchanges) throws Exception {
int processedExchanges = 0;
while (!exchanges.isEmpty()) {
final Exchange exchange = ObjectHelper.cast(Exchange.class, exchanges.poll());
LOG.trace("Processing exchange [{}] started.", exchange);
getAsyncProcessor().process(exchange, new AsyncCallback() {
@Override
public void done(boolean doneSync) {
LOG.trace("Processing exchange [{}] done.", exchange);
}
});
processedExchanges++;
}
return processedExchanges;
}
private AmazonDynamoDBStreams getClient() {
return getEndpoint().getClient();
}
@Override
public DdbStreamEndpoint getEndpoint() {
return (DdbStreamEndpoint) super.getEndpoint();
}
private Queue<Exchange> createExchanges(List<Record> records, String lastSeenSequenceNumber) {
Queue<Exchange> exchanges = new ArrayDeque<>();
BigIntComparisons condition = null;
BigInteger providedSeqNum = null;
if (lastSeenSequenceNumber != null) {
providedSeqNum = new BigInteger(lastSeenSequenceNumber);
condition = BigIntComparisons.Conditions.LT;
}
switch(getEndpoint().getIteratorType()) {
case AFTER_SEQUENCE_NUMBER:
condition = BigIntComparisons.Conditions.LT;
providedSeqNum = new BigInteger(getEndpoint().getSequenceNumberProvider().getSequenceNumber());
break;
case AT_SEQUENCE_NUMBER:
condition = BigIntComparisons.Conditions.LTEQ;
providedSeqNum = new BigInteger(getEndpoint().getSequenceNumberProvider().getSequenceNumber());
break;
default:
}
for (Record record : records) {
BigInteger recordSeqNum = new BigInteger(record.getDynamodb().getSequenceNumber());
if (condition == null || condition.matches(providedSeqNum, recordSeqNum)) {
exchanges.add(getEndpoint().createExchange(record));
}
}
return exchanges;
}
}