/*
* 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 com.facebook.presto.kafka;
import com.facebook.presto.decoder.DecoderColumnHandle;
import com.facebook.presto.decoder.FieldDecoder;
import com.facebook.presto.decoder.FieldValueProvider;
import com.facebook.presto.decoder.RowDecoder;
import com.facebook.presto.spi.PrestoException;
import com.facebook.presto.spi.RecordCursor;
import com.facebook.presto.spi.RecordSet;
import com.facebook.presto.spi.type.Type;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import io.airlift.log.Logger;
import io.airlift.slice.Slice;
import io.airlift.slice.Slices;
import kafka.api.FetchRequest;
import kafka.api.FetchRequestBuilder;
import kafka.javaapi.FetchResponse;
import kafka.javaapi.consumer.SimpleConsumer;
import kafka.message.MessageAndOffset;
import java.nio.ByteBuffer;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;
import static com.facebook.presto.kafka.KafkaErrorCode.KAFKA_SPLIT_ERROR;
import static com.google.common.base.Preconditions.checkArgument;
import static java.util.Objects.requireNonNull;
/**
* Kafka specific record set. Returns a cursor for a topic which iterates over a Kafka partition segment.
*/
public class KafkaRecordSet
implements RecordSet
{
private static final Logger log = Logger.get(KafkaRecordSet.class);
private static final int KAFKA_READ_BUFFER_SIZE = 100_000;
private static final byte [] EMPTY_BYTE_ARRAY = new byte [0];
private final KafkaSplit split;
private final KafkaSimpleConsumerManager consumerManager;
private final RowDecoder keyDecoder;
private final RowDecoder messageDecoder;
private final Map<DecoderColumnHandle, FieldDecoder<?>> keyFieldDecoders;
private final Map<DecoderColumnHandle, FieldDecoder<?>> messageFieldDecoders;
private final List<DecoderColumnHandle> columnHandles;
private final List<Type> columnTypes;
private final Set<FieldValueProvider> globalInternalFieldValueProviders;
KafkaRecordSet(KafkaSplit split,
KafkaSimpleConsumerManager consumerManager,
List<DecoderColumnHandle> columnHandles,
RowDecoder keyDecoder,
RowDecoder messageDecoder,
Map<DecoderColumnHandle, FieldDecoder<?>> keyFieldDecoders,
Map<DecoderColumnHandle, FieldDecoder<?>> messageFieldDecoders)
{
this.split = requireNonNull(split, "split is null");
this.globalInternalFieldValueProviders = ImmutableSet.of(
KafkaInternalFieldDescription.PARTITION_ID_FIELD.forLongValue(split.getPartitionId()),
KafkaInternalFieldDescription.SEGMENT_START_FIELD.forLongValue(split.getStart()),
KafkaInternalFieldDescription.SEGMENT_END_FIELD.forLongValue(split.getEnd()));
this.consumerManager = requireNonNull(consumerManager, "consumerManager is null");
this.keyDecoder = requireNonNull(keyDecoder, "rowDecoder is null");
this.messageDecoder = requireNonNull(messageDecoder, "rowDecoder is null");
this.keyFieldDecoders = requireNonNull(keyFieldDecoders, "keyFieldDecoders is null");
this.messageFieldDecoders = requireNonNull(messageFieldDecoders, "messageFieldDecoders is null");
this.columnHandles = requireNonNull(columnHandles, "columnHandles is null");
ImmutableList.Builder<Type> typeBuilder = ImmutableList.builder();
for (DecoderColumnHandle handle : columnHandles) {
typeBuilder.add(handle.getType());
}
this.columnTypes = typeBuilder.build();
}
@Override
public List<Type> getColumnTypes()
{
return columnTypes;
}
@Override
public RecordCursor cursor()
{
return new KafkaRecordCursor();
}
public class KafkaRecordCursor
implements RecordCursor
{
private long totalBytes;
private long totalMessages;
private long cursorOffset = split.getStart();
private Iterator<MessageAndOffset> messageAndOffsetIterator;
private final AtomicBoolean reported = new AtomicBoolean();
private FieldValueProvider[] fieldValueProviders;
KafkaRecordCursor()
{
}
@Override
public long getTotalBytes()
{
return totalBytes;
}
@Override
public long getCompletedBytes()
{
return totalBytes;
}
@Override
public long getReadTimeNanos()
{
return 0;
}
@Override
public Type getType(int field)
{
checkArgument(field < columnHandles.size(), "Invalid field index");
return columnHandles.get(field).getType();
}
@Override
public boolean advanceNextPosition()
{
while (true) {
if (cursorOffset >= split.getEnd()) {
return endOfData(); // Split end is exclusive.
}
// Create a fetch request
openFetchRequest();
while (messageAndOffsetIterator.hasNext()) {
MessageAndOffset currentMessageAndOffset = messageAndOffsetIterator.next();
long messageOffset = currentMessageAndOffset.offset();
if (messageOffset >= split.getEnd()) {
return endOfData(); // Past our split end. Bail.
}
if (messageOffset >= cursorOffset) {
return nextRow(currentMessageAndOffset);
}
}
messageAndOffsetIterator = null;
}
}
private boolean endOfData()
{
if (!reported.getAndSet(true)) {
log.debug("Found a total of %d messages with %d bytes (%d messages expected). Last Offset: %d (%d, %d)",
totalMessages, totalBytes, split.getEnd() - split.getStart(),
cursorOffset, split.getStart(), split.getEnd());
}
return false;
}
private boolean nextRow(MessageAndOffset messageAndOffset)
{
cursorOffset = messageAndOffset.offset() + 1; // Cursor now points to the next message.
totalBytes += messageAndOffset.message().payloadSize();
totalMessages++;
byte[] keyData = EMPTY_BYTE_ARRAY;
byte[] messageData = EMPTY_BYTE_ARRAY;
ByteBuffer key = messageAndOffset.message().key();
if (key != null) {
keyData = new byte[key.remaining()];
key.get(keyData);
}
ByteBuffer message = messageAndOffset.message().payload();
if (message != null) {
messageData = new byte[message.remaining()];
message.get(messageData);
}
Set<FieldValueProvider> fieldValueProviders = new HashSet<>();
fieldValueProviders.addAll(globalInternalFieldValueProviders);
fieldValueProviders.add(KafkaInternalFieldDescription.SEGMENT_COUNT_FIELD.forLongValue(totalMessages));
fieldValueProviders.add(KafkaInternalFieldDescription.PARTITION_OFFSET_FIELD.forLongValue(messageAndOffset.offset()));
fieldValueProviders.add(KafkaInternalFieldDescription.MESSAGE_FIELD.forByteValue(messageData));
fieldValueProviders.add(KafkaInternalFieldDescription.MESSAGE_LENGTH_FIELD.forLongValue(messageData.length));
fieldValueProviders.add(KafkaInternalFieldDescription.KEY_FIELD.forByteValue(keyData));
fieldValueProviders.add(KafkaInternalFieldDescription.KEY_LENGTH_FIELD.forLongValue(keyData.length));
fieldValueProviders.add(KafkaInternalFieldDescription.KEY_CORRUPT_FIELD.forBooleanValue(keyDecoder.decodeRow(keyData, null, fieldValueProviders, columnHandles, keyFieldDecoders)));
fieldValueProviders.add(KafkaInternalFieldDescription.MESSAGE_CORRUPT_FIELD.forBooleanValue(messageDecoder.decodeRow(messageData, null, fieldValueProviders, columnHandles, messageFieldDecoders)));
this.fieldValueProviders = new FieldValueProvider[columnHandles.size()];
// If a value provider for a requested internal column is present, assign the
// value to the internal cache. It is possible that an internal column is present
// where no value provider exists (e.g. the '_corrupt' column with the DummyRowDecoder).
// In that case, the cache is null (and the column is reported as null).
for (int i = 0; i < columnHandles.size(); i++) {
for (FieldValueProvider fieldValueProvider : fieldValueProviders) {
if (fieldValueProvider.accept(columnHandles.get(i))) {
this.fieldValueProviders[i] = fieldValueProvider;
break; // for(InternalColumnProvider...
}
}
}
return true; // Advanced successfully.
}
@SuppressWarnings("SimplifiableConditionalExpression")
@Override
public boolean getBoolean(int field)
{
checkArgument(field < columnHandles.size(), "Invalid field index");
checkFieldType(field, boolean.class);
return isNull(field) ? false : fieldValueProviders[field].getBoolean();
}
@Override
public long getLong(int field)
{
checkArgument(field < columnHandles.size(), "Invalid field index");
checkFieldType(field, long.class);
return isNull(field) ? 0L : fieldValueProviders[field].getLong();
}
@Override
public double getDouble(int field)
{
checkArgument(field < columnHandles.size(), "Invalid field index");
checkFieldType(field, double.class);
return isNull(field) ? 0.0d : fieldValueProviders[field].getDouble();
}
@Override
public Slice getSlice(int field)
{
checkArgument(field < columnHandles.size(), "Invalid field index");
checkFieldType(field, Slice.class);
return isNull(field) ? Slices.EMPTY_SLICE : fieldValueProviders[field].getSlice();
}
@Override
public Object getObject(int field)
{
throw new UnsupportedOperationException();
}
@Override
public boolean isNull(int field)
{
checkArgument(field < columnHandles.size(), "Invalid field index");
return fieldValueProviders[field] == null || fieldValueProviders[field].isNull();
}
private void checkFieldType(int field, Class<?> expected)
{
Class<?> actual = getType(field).getJavaType();
checkArgument(actual == expected, "Expected field %s to be type %s but is %s", field, expected, actual);
}
@Override
public void close()
{
}
private void openFetchRequest()
{
if (messageAndOffsetIterator == null) {
log.debug("Fetching %d bytes from offset %d (%d - %d). %d messages read so far", KAFKA_READ_BUFFER_SIZE, cursorOffset, split.getStart(), split.getEnd(), totalMessages);
FetchRequest req = new FetchRequestBuilder()
.clientId("presto-worker-" + Thread.currentThread().getName())
.addFetch(split.getTopicName(), split.getPartitionId(), cursorOffset, KAFKA_READ_BUFFER_SIZE)
.build();
// TODO - this should look at the actual node this is running on and prefer
// that copy if running locally. - look into NodeInfo
SimpleConsumer consumer = consumerManager.getConsumer(split.getLeader());
FetchResponse fetchResponse = consumer.fetch(req);
if (fetchResponse.hasError()) {
short errorCode = fetchResponse.errorCode(split.getTopicName(), split.getPartitionId());
log.warn("Fetch response has error: %d", errorCode);
throw new PrestoException(KAFKA_SPLIT_ERROR, "could not fetch data from Kafka, error code is '" + errorCode + "'");
}
messageAndOffsetIterator = fetchResponse.messageSet(split.getTopicName(), split.getPartitionId()).iterator();
}
}
}
}