| /** |
| * 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._ |
| import java.nio.channels.GatheringByteChannel |
| import kafka.common._ |
| import org.apache.kafka.common.network.TransportLayer |
| |
| /** |
| * Helper functions specific to parsing or serializing requests and responses |
| */ |
| object ApiUtils { |
| |
| val ProtocolEncoding = "UTF-8" |
| |
| /** |
| * Read size prefixed string where the size is stored as a 2 byte short. |
| * @param buffer The buffer to read from |
| */ |
| def readShortString(buffer: ByteBuffer): String = { |
| val size: Int = buffer.getShort() |
| if(size < 0) |
| return null |
| val bytes = new Array[Byte](size) |
| buffer.get(bytes) |
| new String(bytes, ProtocolEncoding) |
| } |
| |
| /** |
| * Write a size prefixed string where the size is stored as a 2 byte short |
| * @param buffer The buffer to write to |
| * @param string The string to write |
| */ |
| def writeShortString(buffer: ByteBuffer, string: String) { |
| if(string == null) { |
| buffer.putShort(-1) |
| } else { |
| val encodedString = string.getBytes(ProtocolEncoding) |
| if(encodedString.length > Short.MaxValue) { |
| throw new KafkaException("String exceeds the maximum size of " + Short.MaxValue + ".") |
| } else { |
| buffer.putShort(encodedString.length.asInstanceOf[Short]) |
| buffer.put(encodedString) |
| } |
| } |
| } |
| |
| /** |
| * Return size of a size prefixed string where the size is stored as a 2 byte short |
| * @param string The string to write |
| */ |
| def shortStringLength(string: String): Int = { |
| if(string == null) { |
| 2 |
| } else { |
| val encodedString = string.getBytes(ProtocolEncoding) |
| if(encodedString.length > Short.MaxValue) { |
| throw new KafkaException("String exceeds the maximum size of " + Short.MaxValue + ".") |
| } else { |
| 2 + encodedString.length |
| } |
| } |
| } |
| |
| /** |
| * Read an integer out of the bytebuffer from the current position and check that it falls within the given |
| * range. If not, throw KafkaException. |
| */ |
| def readIntInRange(buffer: ByteBuffer, name: String, range: (Int, Int)): Int = { |
| val value = buffer.getInt |
| if(value < range._1 || value > range._2) |
| throw new KafkaException(name + " has value " + value + " which is not in the range " + range + ".") |
| else value |
| } |
| |
| /** |
| * Read a short out of the bytebuffer from the current position and check that it falls within the given |
| * range. If not, throw KafkaException. |
| */ |
| def readShortInRange(buffer: ByteBuffer, name: String, range: (Short, Short)): Short = { |
| val value = buffer.getShort |
| if(value < range._1 || value > range._2) |
| throw new KafkaException(name + " has value " + value + " which is not in the range " + range + ".") |
| else value |
| } |
| |
| /** |
| * Read a long out of the bytebuffer from the current position and check that it falls within the given |
| * range. If not, throw KafkaException. |
| */ |
| def readLongInRange(buffer: ByteBuffer, name: String, range: (Long, Long)): Long = { |
| val value = buffer.getLong |
| if(value < range._1 || value > range._2) |
| throw new KafkaException(name + " has value " + value + " which is not in the range " + range + ".") |
| else value |
| } |
| |
| private[api] def hasPendingWrites(channel: GatheringByteChannel): Boolean = channel match { |
| case t: TransportLayer => t.hasPendingWrites |
| case _ => false |
| } |
| |
| } |