grpc-pb字段顺序

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我是靠谱客的博主热心硬币，这篇文章主要介绍grpc-pb字段顺序，现在分享给大家，希望可以做个参考。

简介

grpc序列化时,如果服务提供方和服务调用方请求字段的数量和顺序不一致时，发生的情况

1.基本代码

pb文件

复制代码

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syntax = "proto3"; // 版本声明，使用Protocol Buffers v3版本
package serialize; // 包名
// 定义一个服务
service SerializeService {
//
方法
rpc SendMsg (MsgRequest) returns (MsgReply) {}
}
message MsgRequest {
string name = 1;
int32 id = 2;
bool isUser = 3;
}
message MsgReply {
int32 code = 1;
string message = 2;
}

服务端

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type SerializeService struct {
}
const Success = 0
const failure = 1
func (s *SerializeService) SendMsg(ctx context.Context, req *serialize.MsgRequest) (*serialize.MsgReply, error) {
fmt.Printf("serializeService.SendMsg|req:%+v", req)
rsp := &serialize.MsgReply{Code: Success, Message: "success"}
if req.Name == "fail" {
rsp.Code = failure
rsp.Message = "failure"
}
return rsp, nil
}

服务端会打印序列化后的请求。

2.情况

服务端与客户端-pb一致
- 客户端请求
复制代码 req := serialize.MsgRequest{ Name: "LiHua", Id: 5, IsUser: true, } client.SendMsg(context.Background(), &req)
```
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	req := serialize.MsgRequest{
Name:
"LiHua",
Id:
5,
IsUser: true,
}
client.SendMsg(context.Background(), &req)
```
- 输出
  复制代码serializeService.SendMsg|req:name:"LiHua" id:5 isUser:true
```
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serializeService.SendMsg|req:name:"LiHua" id:5 isUser:true
```
服务端减少pb字段
- 服务端
  复制代码message MsgRequest { int32 id = 2; bool isUser = 3; }
```
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message MsgRequest {
int32 id = 2;
bool isUser = 3;
}
```
- 客户端
复制代码message MsgRequest { string name = 1; int32 id = 2; bool isUser = 3; }
```
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message MsgRequest {
string name = 1;
int32 id = 2;
bool isUser = 3;
}
```
输出
复制代码serializeService.SendMsg|req:id:5 isUser:true 1:"LiHua"
```
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serializeService.SendMsg|req:id:5 isUser:true 1:"LiHua"
```
当去除字段name，服务端进行反序列化时，无法识别这个字段，所以出现了一个意外的输出1:"LiHua"。
当客户端减少pb字段
- 服务端
  复制代码message MsgRequest { string name = 1; int32 id = 2; bool isUser = 3; }
```
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message MsgRequest {
string name = 1;
int32 id = 2;
bool isUser = 3;
}
```
- 客户端
  复制代码message MsgRequest { int32 id = 2; bool isUser = 3; }
```
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message MsgRequest {
int32 id = 2;
bool isUser = 3;
}
```
- 输出
  复制代码serializeService.SendMsg|req:id:5 isUser:true
```
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serializeService.SendMsg|req:id:5 isUser:true
```
  当客户端pb减少字段name时，并不会影响反序列化结果。
客户端修改字段顺序
- 服务端
  复制代码message MsgRequest { string name = 1; int32 id = 2; bool isUser = 3; }
```
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message MsgRequest {
string name = 1;
int32 id = 2;
bool isUser = 3;
}
```
- 客户端
  复制代码message MsgRequest { string name = 2; int32 id = 1; bool isUser = 3; }
```
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message MsgRequest {
string name = 2;
int32 id = 1;
bool
isUser = 3;
}
```
- 输出
  复制代码serializeService.SendMsg|req:isUser:true 1:5 2:"LiHua" /*添加打印后，发现无法获取name的值*/ name: isUser:true
```
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serializeService.SendMsg|req:isUser:true 1:5 2:"LiHua"
/*添加打印后，发现无法获取name的值*/
name:
isUser:true
```
  当交换字段时，会导致反序列化后，无法取到正常的值。