| /** |
| * 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 kafka.api |
| |
| import java.nio.ByteBuffer |
| import java.nio.channels.GatheringByteChannel |
| |
| import kafka.common.TopicAndPartition |
| import kafka.message.{MessageSet, ByteBufferMessageSet} |
| import kafka.api.ApiUtils._ |
| import org.apache.kafka.common.KafkaException |
| import org.apache.kafka.common.network.{Send, MultiSend} |
| import org.apache.kafka.common.protocol.Errors |
| |
| import scala.collection._ |
| |
| object FetchResponsePartitionData { |
| def readFrom(buffer: ByteBuffer): FetchResponsePartitionData = { |
| val error = buffer.getShort |
| val hw = buffer.getLong |
| val messageSetSize = buffer.getInt |
| val messageSetBuffer = buffer.slice() |
| messageSetBuffer.limit(messageSetSize) |
| buffer.position(buffer.position + messageSetSize) |
| new FetchResponsePartitionData(error, hw, new ByteBufferMessageSet(messageSetBuffer)) |
| } |
| |
| val headerSize = |
| 2 + /* error code */ |
| 8 + /* high watermark */ |
| 4 /* messageSetSize */ |
| } |
| |
| case class FetchResponsePartitionData(error: Short = Errors.NONE.code, hw: Long = -1L, messages: MessageSet) { |
| val sizeInBytes = FetchResponsePartitionData.headerSize + messages.sizeInBytes |
| } |
| |
| // SENDS |
| |
| class PartitionDataSend(val partitionId: Int, |
| val partitionData: FetchResponsePartitionData) extends Send { |
| private val emptyBuffer = ByteBuffer.allocate(0) |
| private val messageSize = partitionData.messages.sizeInBytes |
| private var messagesSentSize = 0 |
| private var pending = false |
| private val buffer = ByteBuffer.allocate( 4 /** partitionId **/ + FetchResponsePartitionData.headerSize) |
| buffer.putInt(partitionId) |
| buffer.putShort(partitionData.error) |
| buffer.putLong(partitionData.hw) |
| buffer.putInt(partitionData.messages.sizeInBytes) |
| buffer.rewind() |
| |
| override def completed = !buffer.hasRemaining && messagesSentSize >= messageSize && !pending |
| |
| override def destination: String = "" |
| |
| override def writeTo(channel: GatheringByteChannel): Long = { |
| var written = 0L |
| if (buffer.hasRemaining) |
| written += channel.write(buffer) |
| if (!buffer.hasRemaining) { |
| if (messagesSentSize < messageSize) { |
| val bytesSent = partitionData.messages.writeTo(channel, messagesSentSize, messageSize - messagesSentSize) |
| messagesSentSize += bytesSent |
| written += bytesSent |
| } |
| if (messagesSentSize >= messageSize && hasPendingWrites(channel)) |
| channel.write(emptyBuffer) |
| } |
| |
| pending = hasPendingWrites(channel) |
| |
| written |
| } |
| |
| override def size = buffer.capacity() + messageSize |
| } |
| |
| object TopicData { |
| def readFrom(buffer: ByteBuffer): TopicData = { |
| val topic = readShortString(buffer) |
| val partitionCount = buffer.getInt |
| val topicPartitionDataPairs = (1 to partitionCount).map(_ => { |
| val partitionId = buffer.getInt |
| val partitionData = FetchResponsePartitionData.readFrom(buffer) |
| (partitionId, partitionData) |
| }) |
| TopicData(topic, Map(topicPartitionDataPairs:_*)) |
| } |
| |
| def headerSize(topic: String) = |
| shortStringLength(topic) + |
| 4 /* partition count */ |
| } |
| |
| case class TopicData(topic: String, partitionData: Map[Int, FetchResponsePartitionData]) { |
| val sizeInBytes = |
| TopicData.headerSize(topic) + partitionData.values.foldLeft(0)(_ + _.sizeInBytes + 4) |
| |
| val headerSize = TopicData.headerSize(topic) |
| } |
| |
| class TopicDataSend(val dest: String, val topicData: TopicData) extends Send { |
| |
| private val emptyBuffer = ByteBuffer.allocate(0) |
| |
| private var sent = 0L |
| |
| private var pending = false |
| |
| override def completed: Boolean = sent >= size && !pending |
| |
| override def destination: String = dest |
| |
| override def size = topicData.headerSize + sends.size() |
| |
| private val buffer = ByteBuffer.allocate(topicData.headerSize) |
| writeShortString(buffer, topicData.topic) |
| buffer.putInt(topicData.partitionData.size) |
| buffer.rewind() |
| |
| private val sends = new MultiSend(dest, |
| JavaConversions.seqAsJavaList(topicData.partitionData.toList.map(d => new PartitionDataSend(d._1, d._2)))) |
| |
| override def writeTo(channel: GatheringByteChannel): Long = { |
| if (completed) |
| throw new KafkaException("This operation cannot be completed on a complete request.") |
| |
| var written = 0L |
| if (buffer.hasRemaining) |
| written += channel.write(buffer) |
| if (!buffer.hasRemaining) { |
| if (!sends.completed) |
| written += sends.writeTo(channel) |
| if (sends.completed && hasPendingWrites(channel)) |
| written += channel.write(emptyBuffer) |
| } |
| |
| pending = hasPendingWrites(channel) |
| |
| sent += written |
| written |
| } |
| } |
| |
| |
| object FetchResponse { |
| |
| // The request version is used to determine which fields we can expect in the response |
| def readFrom(buffer: ByteBuffer, requestVersion: Int): FetchResponse = { |
| val correlationId = buffer.getInt |
| val throttleTime = if (requestVersion > 0) buffer.getInt else 0 |
| val topicCount = buffer.getInt |
| val pairs = (1 to topicCount).flatMap(_ => { |
| val topicData = TopicData.readFrom(buffer) |
| topicData.partitionData.map { |
| case (partitionId, partitionData) => |
| (TopicAndPartition(topicData.topic, partitionId), partitionData) |
| } |
| }) |
| FetchResponse(correlationId, Map(pairs:_*), requestVersion, throttleTime) |
| } |
| |
| // Returns the size of the response header |
| def headerSize(requestVersion: Int): Int = { |
| val throttleTimeSize = if (requestVersion > 0) 4 else 0 |
| 4 + /* correlationId */ |
| 4 + /* topic count */ |
| throttleTimeSize |
| } |
| |
| // Returns the size of entire fetch response in bytes (including the header size) |
| def responseSize(dataGroupedByTopic: Map[String, Map[TopicAndPartition, FetchResponsePartitionData]], |
| requestVersion: Int): Int = { |
| headerSize(requestVersion) + |
| dataGroupedByTopic.foldLeft(0) { case (folded, (topic, partitionDataMap)) => |
| val topicData = TopicData(topic, partitionDataMap.map { |
| case (topicAndPartition, partitionData) => (topicAndPartition.partition, partitionData) |
| }) |
| folded + topicData.sizeInBytes |
| } |
| } |
| } |
| |
| case class FetchResponse(correlationId: Int, |
| data: Map[TopicAndPartition, FetchResponsePartitionData], |
| requestVersion: Int = 0, |
| throttleTimeMs: Int = 0) |
| extends RequestOrResponse() { |
| |
| /** |
| * Partitions the data into a map of maps (one for each topic). |
| */ |
| lazy val dataGroupedByTopic = data.groupBy{ case (topicAndPartition, fetchData) => topicAndPartition.topic } |
| val headerSizeInBytes = FetchResponse.headerSize(requestVersion) |
| lazy val sizeInBytes = FetchResponse.responseSize(dataGroupedByTopic, requestVersion) |
| |
| /* |
| * Writes the header of the FetchResponse to the input buffer |
| */ |
| def writeHeaderTo(buffer: ByteBuffer) = { |
| buffer.putInt(sizeInBytes) |
| buffer.putInt(correlationId) |
| // Include the throttleTime only if the client can read it |
| if (requestVersion > 0) |
| buffer.putInt(throttleTimeMs) |
| |
| buffer.putInt(dataGroupedByTopic.size) // topic count |
| } |
| /* |
| * FetchResponse uses [sendfile](http://man7.org/linux/man-pages/man2/sendfile.2.html) |
| * api for data transfer through the FetchResponseSend, so `writeTo` aren't actually being used. |
| * It is implemented as an empty function to conform to `RequestOrResponse.writeTo` |
| * abstract method signature. |
| */ |
| def writeTo(buffer: ByteBuffer): Unit = throw new UnsupportedOperationException |
| |
| override def describe(details: Boolean): String = toString |
| |
| private def partitionDataFor(topic: String, partition: Int): FetchResponsePartitionData = { |
| val topicAndPartition = TopicAndPartition(topic, partition) |
| data.get(topicAndPartition) match { |
| case Some(partitionData) => partitionData |
| case _ => |
| throw new IllegalArgumentException( |
| "No partition %s in fetch response %s".format(topicAndPartition, this.toString)) |
| } |
| } |
| |
| def messageSet(topic: String, partition: Int): ByteBufferMessageSet = |
| partitionDataFor(topic, partition).messages.asInstanceOf[ByteBufferMessageSet] |
| |
| def highWatermark(topic: String, partition: Int) = partitionDataFor(topic, partition).hw |
| |
| def hasError = data.values.exists(_.error != Errors.NONE.code) |
| |
| def errorCode(topic: String, partition: Int) = partitionDataFor(topic, partition).error |
| } |
| |
| |
| class FetchResponseSend(val dest: String, val fetchResponse: FetchResponse) extends Send { |
| |
| private val emptyBuffer = ByteBuffer.allocate(0) |
| |
| private val payloadSize = fetchResponse.sizeInBytes |
| |
| private var sent = 0L |
| |
| private var pending = false |
| |
| override def size = 4 /* for size byte */ + payloadSize |
| |
| override def completed = sent >= size && !pending |
| |
| override def destination = dest |
| |
| // The throttleTimeSize will be 0 if the request was made from a client sending a V0 style request |
| private val buffer = ByteBuffer.allocate(4 /* for size */ + fetchResponse.headerSizeInBytes) |
| fetchResponse.writeHeaderTo(buffer) |
| buffer.rewind() |
| |
| private val sends = new MultiSend(dest, JavaConversions.seqAsJavaList(fetchResponse.dataGroupedByTopic.toList.map { |
| case(topic, data) => new TopicDataSend(dest, TopicData(topic, |
| data.map{case(topicAndPartition, message) => (topicAndPartition.partition, message)})) |
| })) |
| |
| override def writeTo(channel: GatheringByteChannel): Long = { |
| if (completed) |
| throw new KafkaException("This operation cannot be completed on a complete request.") |
| |
| var written = 0L |
| |
| if (buffer.hasRemaining) |
| written += channel.write(buffer) |
| if (!buffer.hasRemaining) { |
| if (!sends.completed) |
| written += sends.writeTo(channel) |
| if (sends.completed && hasPendingWrites(channel)) |
| written += channel.write(emptyBuffer) |
| } |
| |
| sent += written |
| pending = hasPendingWrites(channel) |
| |
| written |
| } |
| } |