/** | |
* 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.Collections.Generic; | |
using System.Text; | |
using Kafka.Client.Messages; | |
using Kafka.Client.Serialization; | |
using Kafka.Client.Utils; | |
/// <summary> | |
/// Constructs a request to send to Kafka to get the current offset for a given topic | |
/// </summary> | |
public class OffsetRequest : AbstractRequest, IWritable | |
{ | |
/// <summary> | |
/// The latest time constant. | |
/// </summary> | |
public static readonly long LatestTime = -1L; | |
/// <summary> | |
/// The earliest time constant. | |
/// </summary> | |
public static readonly long EarliestTime = -2L; | |
public const string SmallestTime = "smallest"; | |
public const string LargestTime = "largest"; | |
public const byte DefaultTopicSizeSize = 2; | |
public const byte DefaultPartitionSize = 4; | |
public const byte DefaultTimeSize = 8; | |
public const byte DefaultMaxOffsetsSize = 4; | |
public const byte DefaultHeaderSize = DefaultRequestSizeSize + DefaultTopicSizeSize + DefaultPartitionSize + DefaultRequestIdSize + DefaultTimeSize + DefaultMaxOffsetsSize; | |
public static int GetRequestLength(string topic, string encoding = DefaultEncoding) | |
{ | |
short topicLength = GetTopicLength(topic, encoding); | |
return topicLength + DefaultHeaderSize; | |
} | |
/// <summary> | |
/// Initializes a new instance of the OffsetRequest class. | |
/// </summary> | |
public OffsetRequest() | |
{ | |
} | |
/// <summary> | |
/// Initializes a new instance of the OffsetRequest class. | |
/// </summary> | |
/// <param name="topic">The topic to publish to.</param> | |
/// <param name="partition">The partition to publish to.</param> | |
/// <param name="time">The time from which to request offsets.</param> | |
/// <param name="maxOffsets">The maximum amount of offsets to return.</param> | |
public OffsetRequest(string topic, int partition, long time, int maxOffsets) | |
{ | |
Topic = topic; | |
Partition = partition; | |
Time = time; | |
MaxOffsets = maxOffsets; | |
int length = GetRequestLength(topic, DefaultEncoding); | |
this.RequestBuffer = new BoundedBuffer(length); | |
this.WriteTo(this.RequestBuffer); | |
} | |
/// <summary> | |
/// Gets the time. | |
/// </summary> | |
public long Time { get; private set; } | |
/// <summary> | |
/// Gets the maximum number of offsets to return. | |
/// </summary> | |
public int MaxOffsets { get; private set; } | |
public override RequestTypes RequestType | |
{ | |
get | |
{ | |
return RequestTypes.Offsets; | |
} | |
} | |
/// <summary> | |
/// Writes content into given stream | |
/// </summary> | |
/// <param name="output"> | |
/// The output stream. | |
/// </param> | |
public void WriteTo(System.IO.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.Time); | |
writer.Write(this.MaxOffsets); | |
} | |
} | |
} |