protobuf是一个语言无关、平台无关的序列化协议，由谷歌开源提供。再加上其高性能、存储占用更小等特点，在云原生的应用中越来越广泛。
在C#中主要有两种方法来使用protobuf协议，nuget包分别为Google.Protobuf和protobuf-net，其中Google.Protobuf由谷歌官方提供。本文简要记录和展示Google.Protobuf的使用方法和特点。
项目资料及文档
- 项目官网：https://developers.google.cn/protocol-buffers?hl=zh-cn
- github主页：https://github.com/protocolbuffers/protobuf/
- 官方文档：https://developers.google.cn/protocol-buffers/docs/overview?hl=zh-cn
- 该nuget包支持.NETFramework 4.5、.NETStandard1.1、.net5等
准备工作
需要用到的nuget有如下两个：Google.Protobuf、Google.Protobuf.Tools，其中Google.Protobuf是主类库，运行时要用到。Google.Protobuf.Tools提供了命令行工具，用于根据.proto文件转为目标语言的类型，仅开发时使用，运行时不需要。
本次Demo使用的.proto文件内容如下：
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syntax = "proto3";option cc_enable_arenas = true;package Tccc.Demo.Protobuf;message ErrorLog { string LogID = 1; string Context = 2; string Stack = 3;} |
首先需要根据.proto文件生成目标类型，操作如下：
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./google.protobuf.tools\3.19.1\tools\windows_x64\protoc.exe --csharp_out=./generatedCode ./proto/ErrorLog.proto |
其中--csharp_out选项是生成C#语言的目标类型，运行protoc.exe -h 查看帮助信息，可以看到还支持一下几种选项：
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--proto_path=PATH--cpp_out=OUT_DIR Generate C++ header and source.--csharp_out=OUT_DIR Generate C# source file.--java_out=OUT_DIR Generate Java source file.--js_out=OUT_DIR Generate JavaScript source.--kotlin_out=OUT_DIR Generate Kotlin file.--objc_out=OUT_DIR Generate Objective-C header and source.--php_out=OUT_DIR Generate PHP source file.--python_out=OUT_DIR Generate Python source file.--ruby_out=OUT_DIR Generate Ruby source file. |
运行上述命令，会根据指定的ErrorLog.proto文件生成ErrorLog.cs文件，文件中就是C#类型ErrorLog。生成的代码中会给此类型增加方法void WriteTo(CodedOutputStream output)和只读属性Parser，接下来进行序列化和反序列化的关键。
生成的ErrorLog类的完整代码：
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// <auto-generated>// Generated by the protocol buffer compiler. DO NOT EDIT!// source: ProtoFiles/ErrorLog.proto// </auto-generated>#pragma warning disable 1591, 0612, 3021#region Designer generated codeusing pb = global::Google.Protobuf;using pbc = global::Google.Protobuf.Collections;using pbr = global::Google.Protobuf.Reflection;using scg = global::System.Collections.Generic;namespace Tccc.Demo.Protobuf { /// <summary>Holder for reflection information generated from ProtoFiles/ErrorLog.proto</summary> public static partial class ErrorLogReflection { #region Descriptor /// <summary>File descriptor for ProtoFiles/ErrorLog.proto</summary> public static pbr::FileDescriptor Descriptor { get { return descriptor; } } private static pbr::FileDescriptor descriptor; static ErrorLogReflection() { byte[] descriptorData = global::System.Convert.FromBase64String( string.Concat( "ChlQcm90b0ZpbGVzL0Vycm9yTG9nLnByb3RvEhJUY2NjLkRlbW8uUHJvdG9i", "dWYiOQoIRXJyb3JMb2cSDQoFTG9nSUQYASABKAkSDwoHQ29udGV4dBgCIAEo", "CRINCgVTdGFjaxgDIAEoCUID+AEBYgZwcm90bzM=")); descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData, new pbr::FileDescriptor[] { }, new pbr::GeneratedClrTypeInfo(null, null, new pbr::GeneratedClrTypeInfo[] { new pbr::GeneratedClrTypeInfo(typeof(global::Tccc.Demo.Protobuf.ErrorLog), global::Tccc.Demo.Protobuf.ErrorLog.Parser, new[]{ "LogID", "Context", "Stack" }, null, null, null, null) })); } #endregion } #region Messages public sealed partial class ErrorLog : pb::IMessage<ErrorLog> #if !GOOGLE_PROTOBUF_REFSTRUCT_COMPATIBILITY_MODE , pb::IBufferMessage #endif { private static readonly pb::MessageParser<ErrorLog> _parser = new pb::MessageParser<ErrorLog>(() => new ErrorLog()); private pb::UnknownFieldSet _unknownFields; [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] public static pb::MessageParser<ErrorLog> Parser { get { return _parser; } } [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] public static pbr::MessageDescriptor Descriptor { get { return global::Tccc.Demo.Protobuf.ErrorLogReflection.Descriptor.MessageTypes[0]; } } [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] pbr::MessageDescriptor pb::IMessage.Descriptor { get { return Descriptor; } } [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] public ErrorLog() { OnConstruction(); } partial void OnConstruction(); [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] public ErrorLog(ErrorLog other) : this() { logID_ = other.logID_; context_ = other.context_; stack_ = other.stack_; _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields); } [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] public ErrorLog Clone() { return new ErrorLog(this); } /// <summary>Field number for the "LogID" field.</summary> public const int LogIDFieldNumber = 1; private string logID_ = ""; [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] public string LogID { get { return logID_; } set { logID_ = pb::ProtoPreconditions.CheckNotNull(value, "value"); } } /// <summary>Field number for the "Context" field.</summary> public const int ContextFieldNumber = 2; private string context_ = ""; [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] public string Context { get { return context_; } set { context_ = pb::ProtoPreconditions.CheckNotNull(value, "value"); } } /// <summary>Field number for the "Stack" field.</summary> public const int StackFieldNumber = 3; private string stack_ = ""; [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] public string Stack { get { return stack_; } set { stack_ = pb::ProtoPreconditions.CheckNotNull(value, "value"); } } [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] public override bool Equals(object other) { return Equals(other as ErrorLog); } [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] public bool Equals(ErrorLog other) { if (ReferenceEquals(other, null)) { return false; } if (ReferenceEquals(other, this)) { return true; } if (LogID != other.LogID) return false; if (Context != other.Context) return false; if (Stack != other.Stack) return false; return Equals(_unknownFields, other._unknownFields); } [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] public override int GetHashCode() { int hash = 1; if (LogID.Length != 0) hash ^= LogID.GetHashCode(); if (Context.Length != 0) hash ^= Context.GetHashCode(); if (Stack.Length != 0) hash ^= Stack.GetHashCode(); if (_unknownFields != null) { hash ^= _unknownFields.GetHashCode(); } return hash; } [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] public override string ToString() { return pb::JsonFormatter.ToDiagnosticString(this); } [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] public void WriteTo(pb::CodedOutputStream output) { #if !GOOGLE_PROTOBUF_REFSTRUCT_COMPATIBILITY_MODE output.WriteRawMessage(this); #else if (LogID.Length != 0) { output.WriteRawTag(10); output.WriteString(LogID); } if (Context.Length != 0) { output.WriteRawTag(18); output.WriteString(Context); } if (Stack.Length != 0) { output.WriteRawTag(26); output.WriteString(Stack); } if (_unknownFields != null) { _unknownFields.WriteTo(output); } #endif } #if !GOOGLE_PROTOBUF_REFSTRUCT_COMPATIBILITY_MODE [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] void pb::IBufferMessage.InternalWriteTo(ref pb::WriteContext output) { if (LogID.Length != 0) { output.WriteRawTag(10); output.WriteString(LogID); } if (Context.Length != 0) { output.WriteRawTag(18); output.WriteString(Context); } if (Stack.Length != 0) { output.WriteRawTag(26); output.WriteString(Stack); } if (_unknownFields != null) { _unknownFields.WriteTo(ref output); } } #endif [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] public int CalculateSize() { int size = 0; if (LogID.Length != 0) { size += 1 + pb::CodedOutputStream.ComputeStringSize(LogID); } if (Context.Length != 0) { size += 1 + pb::CodedOutputStream.ComputeStringSize(Context); } if (Stack.Length != 0) { size += 1 + pb::CodedOutputStream.ComputeStringSize(Stack); } if (_unknownFields != null) { size += _unknownFields.CalculateSize(); } return size; } [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] public void MergeFrom(ErrorLog other) { if (other == null) { return; } if (other.LogID.Length != 0) { LogID = other.LogID; } if (other.Context.Length != 0) { Context = other.Context; } if (other.Stack.Length != 0) { Stack = other.Stack; } _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields); } [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] public void MergeFrom(pb::CodedInputStream input) { #if !GOOGLE_PROTOBUF_REFSTRUCT_COMPATIBILITY_MODE input.ReadRawMessage(this); #else uint tag; while ((tag = input.ReadTag()) != 0) { switch(tag) { default: _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input); break; case 10: { LogID = input.ReadString(); break; } case 18: { Context = input.ReadString(); break; } case 26: { Stack = input.ReadString(); break; } } } #endif } #if !GOOGLE_PROTOBUF_REFSTRUCT_COMPATIBILITY_MODE [global::System.Diagnostics.DebuggerNonUserCodeAttribute] [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)] void pb::IBufferMessage.InternalMergeFrom(ref pb::ParseContext input) { uint tag; while ((tag = input.ReadTag()) != 0) { switch(tag) { default: _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, ref input); break; case 10: { LogID = input.ReadString(); break; } case 18: { Context = input.ReadString(); break; } case 26: { Stack = input.ReadString(); break; } } } } #endif } #endregion}#endregion Designer generated code |
序列化操作
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public static byte[] Serialize(ErrorLog log) { using (MemoryStream output = new MemoryStream()) { log.WriteTo(output); return output.ToArray(); } } |
反序列化操作
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ErrorLog desErrorLog= ErrorLog.Parser.ParseFrom(data); |
使用特点和理解
- protoc.exe是支持生成多语言类型，这对于跨语言的混合编程比较方便。
- 根据上述使用步骤可以看到，必须先使用工具protoc生成目标类型，才能调用序列化和反序列化方法，这有些不符合.net平台的编码习惯。
- 一堆自动生成的C#类在可维护性方面欠佳，当需要调整属性字段时，还要通过工具重新生成，较为麻烦。
到此这篇关于Google.Protobuf工具在C#中的使用方法就介绍到这了。希望对大家的学习有所帮助，也希望大家多多支持服务器之家。
原文链接：https://www.cnblogs.com/chen943354/p/15597270.html
