/** | |
* 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. | |
*/ | |
namespace Kafka.Client.Requests | |
{ | |
using System; | |
using System.Globalization; | |
using System.IO; | |
using System.Text; | |
using Kafka.Client.Messages; | |
using Kafka.Client.Serialization; | |
using Kafka.Client.Utils; | |
/// <summary> | |
/// Constructs a request to send to Kafka. | |
/// </summary> | |
public class FetchRequest : AbstractRequest, IWritable | |
{ | |
/// <summary> | |
/// Maximum size. | |
/// </summary> | |
private static readonly int DefaultMaxSize = 1048576; | |
public const byte DefaultTopicSizeSize = 2; | |
public const byte DefaultPartitionSize = 4; | |
public const byte DefaultOffsetSize = 8; | |
public const byte DefaultMaxSizeSize = 4; | |
public const byte DefaultHeaderSize = DefaultRequestSizeSize + DefaultTopicSizeSize + DefaultPartitionSize + DefaultRequestIdSize + DefaultOffsetSize + DefaultMaxSizeSize; | |
public const byte DefaultHeaderAsPartOfMultirequestSize = DefaultTopicSizeSize + DefaultPartitionSize + DefaultOffsetSize + DefaultMaxSizeSize; | |
public static int GetRequestLength(string topic, string encoding = DefaultEncoding) | |
{ | |
short topicLength = GetTopicLength(topic, encoding); | |
return topicLength + DefaultHeaderSize; | |
} | |
public static int GetRequestAsPartOfMultirequestLength(string topic, string encoding = DefaultEncoding) | |
{ | |
short topicLength = GetTopicLength(topic, encoding); | |
return topicLength + DefaultHeaderAsPartOfMultirequestSize; | |
} | |
/// <summary> | |
/// Initializes a new instance of the FetchRequest class. | |
/// </summary> | |
public FetchRequest() | |
{ | |
} | |
/// <summary> | |
/// Initializes a new instance of the FetchRequest class. | |
/// </summary> | |
/// <param name="topic">The topic to publish to.</param> | |
/// <param name="partition">The partition to publish to.</param> | |
/// <param name="offset">The offset in the topic/partition to retrieve from.</param> | |
public FetchRequest(string topic, int partition, long offset) | |
: this(topic, partition, offset, DefaultMaxSize) | |
{ | |
} | |
/// <summary> | |
/// Initializes a new instance of the FetchRequest class. | |
/// </summary> | |
/// <param name="topic">The topic to publish to.</param> | |
/// <param name="partition">The partition to publish to.</param> | |
/// <param name="offset">The offset in the topic/partition to retrieve from.</param> | |
/// <param name="maxSize">The maximum size.</param> | |
public FetchRequest(string topic, int partition, long offset, int maxSize) | |
{ | |
Topic = topic; | |
Partition = partition; | |
Offset = offset; | |
MaxSize = maxSize; | |
int length = GetRequestLength(topic, DefaultEncoding); | |
this.RequestBuffer = new BoundedBuffer(length); | |
this.WriteTo(this.RequestBuffer); | |
} | |
/// <summary> | |
/// Gets or sets the offset to request. | |
/// </summary> | |
public long Offset { get; set; } | |
/// <summary> | |
/// Gets or sets the maximum size to pass in the request. | |
/// </summary> | |
public int MaxSize { get; set; } | |
public override RequestTypes RequestType | |
{ | |
get | |
{ | |
return RequestTypes.Fetch; | |
} | |
} | |
/// <summary> | |
/// Writes content into given stream | |
/// </summary> | |
/// <param name="output"> | |
/// The output stream. | |
/// </param> | |
public void WriteTo(MemoryStream output) | |
{ | |
Guard.NotNull(output, "output"); | |
using (var writer = new KafkaBinaryWriter(output)) | |
{ | |
writer.Write(this.RequestBuffer.Capacity - DefaultRequestSizeSize); | |
writer.Write(this.RequestTypeId); | |
this.WriteTo(writer); | |
} | |
} | |
/// <summary> | |
/// Writes content into given writer | |
/// </summary> | |
/// <param name="writer"> | |
/// The writer. | |
/// </param> | |
public void WriteTo(KafkaBinaryWriter writer) | |
{ | |
Guard.NotNull(writer, "writer"); | |
writer.WriteTopic(this.Topic, DefaultEncoding); | |
writer.Write(this.Partition); | |
writer.Write(this.Offset); | |
writer.Write(this.MaxSize); | |
} | |
public override string ToString() | |
{ | |
return String.Format( | |
CultureInfo.CurrentCulture, | |
"topic: {0}, part: {1}, offset: {2}, maxSize: {3}", | |
this.Topic, | |
this.Partition, | |
this.Offset, | |
this.MaxSize); | |
} | |
} | |
} |