为什么 gRPC Python 看不到第一个字段？

Question

Python gRPC 消息不序列化第一个字段。我多次更新原型并清理所有内容，但未修复。您可以看到日志，settings_dict 有 stop 字段，但在将这些字段传递给 AgentSetting 后，在日志和服务器端看不到。我也尝试手动传递 stop 字段，但也没有看到。烦人的是，gRPC 不会抛出任何异常，它正在接受 stop 字段，但它不会发送到服务器，它在打印时也不会在 AgentSetting 中看到，但是 stop 字段可以像 agent_setting.stop.

这是我的原型文件：

syntax = 'proto3';

import "base.proto";

message ConnectionCheckRequest {
  string host_name = 1;
}

message RecordChunkRequest {
  string host_name = 1;
  string name = 2;
  bytes chunk = 3;
  uint32 chunk_index = 4;
  uint32 chunk_number = 5;
}

message AgentSetting {
    bool stop = 1;

    bool connection = 2;
    bool registered = 3;

    string image_mode = 4;

    uint32 sending_fail_limit = 5;
    uint64 limit_of_old_records = 6;

    string offline_records_exceed_policy = 7;
}

message AgentSettingRequest {
    AgentSetting agent_setting = 1;
    string host_name = 2;
}

message AgentSettingResponse {
    AgentSetting agent_setting = 1;
}

message AgentRegistryRequest {
    AgentSetting agent_setting = 1;
    string host_name = 2;
}

service Chief {
  rpc agent_update_setting(AgentSettingRequest) returns (AgentSettingResponse) {};
  rpc agent_registry(AgentRegistryRequest) returns (Response) {};
  rpc send (stream RecordChunkRequest) returns (Response) {};
  rpc connection_check (ConnectionCheckRequest) returns (Response) {};
}

这是我的代码片段：

def register():
    try:
        with insecure_channel(settings.server_address) as channel:
            setting_dict = settings.dict()

            logger.info(f'\nSetting Dict: {setting_dict}')

            agent_setting = AgentSetting(**setting_dict)

            logger.info(f'\nAgent Setting Instance: \n{agent_setting}')

            response = ChiefStub(channel).agent_registry(
                AgentRegistryRequest(
                    agent_setting=agent_setting,
                    host_name=settings.host_name
                )
            )
            return response
    except Exception as e:
        logger.exception(f'Register Error: {str(e)}')
        return Response(success=False, message="failure")

日志：

|2020-05-05T18:33:56.931140+0300| |5480| |INFO| |reqs:register:28| 
Setting Dict: {'stop': False, 'connection': True, 'registered': False, 'image_mode': 'RGB', 'sending_fail_limit': 3, 'limit_of_old_records': 5368709120, 'offline_records_exceed_policy': 'OVERWRITE'}
|2020-05-05T18:33:56.932137+0300| |5480| |INFO| |reqs:register:32| 
Agent Setting Instance: 
connection: true
image_mode: "RGB"
sending_fail_limit: 3
limit_of_old_records: 5368709120
offline_records_exceed_policy: "OVERWRITE"

Answer 1

在 proto3 中，未设置的值和默认值被认为是等价的。

所以 stop: false 被认为等同于完全省略 stop。

见Language Guide (proto3)

Note that for scalar message fields, once a message is parsed there's no way of telling whether a field was explicitly set to the default value (for example whether a boolean was set to false) or just not set at all: you should bear this in mind when defining your message types. For example, don't have a boolean that switches on some behaviour when set to false if you don't want that behaviour to also happen by default. Also note that if a scalar message field is set to its default, the value will not be serialized on the wire.

请注意，这与 proto2 不同。

为什么 gRPC Python 看不到第一个字段？

Why gRPC Python does not see first field?

python

grpc

grpc-python