io.streamnative.pulsar.handlers.kop.KafkaPayloadProcessor Maven / Gradle / Ivy
/**
* 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 io.streamnative.pulsar.handlers.kop;
import io.netty.buffer.ByteBuf;
import io.netty.util.concurrent.FastThreadLocal;
import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;
import java.util.function.Consumer;
import org.apache.kafka.common.header.Header;
import org.apache.kafka.common.record.MemoryRecords;
import org.apache.kafka.common.record.Record;
import org.apache.kafka.common.record.RecordBatch;
import org.apache.kafka.common.serialization.StringDeserializer;
import org.apache.pulsar.client.api.Message;
import org.apache.pulsar.client.api.MessagePayload;
import org.apache.pulsar.client.api.MessagePayloadContext;
import org.apache.pulsar.client.api.MessagePayloadProcessor;
import org.apache.pulsar.client.api.Schema;
import org.apache.pulsar.client.impl.MessagePayloadImpl;
import org.apache.pulsar.client.impl.MessagePayloadUtils;
import org.apache.pulsar.common.allocator.PulsarByteBufAllocator;
import org.apache.pulsar.common.api.proto.SingleMessageMetadata;
/**
* Process Kafka messages so that Pulsar consumer can recognize.
*/
public class KafkaPayloadProcessor implements MessagePayloadProcessor {
static final String ENTRY_ORIGINAL_BASEOFFSET_KEY = "entry.originaloriginal";
private static final StringDeserializer deserializer = new StringDeserializer();
private static final FastThreadLocal LOCAL_SINGLE_MESSAGE_METADATA =
new FastThreadLocal() {
@Override
protected SingleMessageMetadata initialValue() throws Exception {
return new SingleMessageMetadata();
}
};
@Override
public void process(MessagePayload payload,
MessagePayloadContext context,
Schema schema,
Consumer> messageConsumer) throws Exception {
if (!isKafkaFormat(context)) {
DEFAULT.process(payload, context, schema, messageConsumer);
return;
}
final ByteBuf buf = MessagePayloadUtils.convertToByteBuf(payload);
try {
final MemoryRecords records = MemoryRecords.readableRecords(buf.nioBuffer());
final RecordBatch firstBatch = records.firstBatch();
if (firstBatch == null) {
return;
}
final int numMessages = context.getNumMessages();
long baseOffset = baseOffset(firstBatch, context);
for (RecordBatch batch : records.batches()) {
if (batch.isControlBatch()) {
continue;
}
// TODO: Currently KoP doesn't support multi batches in an entry so it works well at this moment. After
// we supported multi batches in future, the following code should be changed. See
// https://github.com/streamnative/kop/issues/537 for details.
for (Record record : batch) {
final MessagePayload singlePayload = newByteBufFromRecord(record);
try {
int batchIndex = (int) (record.offset() - baseOffset);
messageConsumer.accept(
context.getMessageAt(batchIndex, numMessages, singlePayload, true, schema));
} finally {
singlePayload.release();
}
}
}
} finally {
buf.release();
}
}
private static boolean isKafkaFormat(final MessagePayloadContext context) {
final String value = context.getProperty("entry.format");
return value != null && value.equalsIgnoreCase("kafka");
}
private static byte[] bufferToBytes(final ByteBuffer buffer) {
final byte[] data = new byte[buffer.remaining()];
buffer.get(data);
return data;
}
private MessagePayload newByteBufFromRecord(final Record record) {
final SingleMessageMetadata singleMessageMetadata = LOCAL_SINGLE_MESSAGE_METADATA.get();
singleMessageMetadata.clear();
if (record.hasKey()) {
final byte[] data = bufferToBytes(record.key());
// It's okay to pass a null topic because it's not used in StringDeserializer
singleMessageMetadata.setPartitionKey(deserializer.deserialize(null, data));
singleMessageMetadata.setOrderingKey(data);
}
final ByteBuffer valueBuffer;
if (record.hasValue()) {
valueBuffer = record.value();
singleMessageMetadata.setPayloadSize(record.valueSize());
} else {
valueBuffer = null;
singleMessageMetadata.setNullValue(true);
singleMessageMetadata.setPayloadSize(0);
}
for (Header header : record.headers()) {
singleMessageMetadata.addProperty()
.setKey(header.key())
.setValue(new String(header.value(), StandardCharsets.UTF_8));
}
final ByteBuf buf = PulsarByteBufAllocator.DEFAULT.buffer(
4 + singleMessageMetadata.getSerializedSize() + record.valueSize());
buf.writeInt(singleMessageMetadata.getSerializedSize());
singleMessageMetadata.writeTo(buf);
if (valueBuffer != null) {
buf.writeBytes(valueBuffer);
}
return MessagePayloadImpl.create(buf);
}
private static long baseOffset(final RecordBatch recordBatch, final MessagePayloadContext context) {
if (recordBatch.magic() >= RecordBatch.MAGIC_VALUE_V2) {
return recordBatch.baseOffset();
}
String property = context.getProperty(ENTRY_ORIGINAL_BASEOFFSET_KEY);
return property != null ? Long.parseLong(property) : recordBatch.baseOffset();
}
}