How to return an array in Protobuf service rpc

Shoham picture Shoham · Apr 2, 2017 · Viewed 27.9k times · Source

I have the following schema in my .proto file:

service MyService {
    rpc GetItem (ItemQuery) returns (Item) {
    }
}

message ItemQuery {
    int id = 1;
}
message Item {
    int id = 1;
    string name = 2;
}

Now I want to add another rpc method to return multiple Items. Something like this:

rpc GetItems (ItemsQuery) returns (repeated Item) {
}

Is there a better way to do it than define an Items message?

Answer

Shoham picture Shoham · Apr 2, 2017

Option 1 - Use stream:

rpc GetItems (ItemsQuery) returns (stream Item) {
}

Option 2 - Set a response message which will use a repeated object:

service MyService {
    rpc GetItem (ItemQuery) returns (ItemResponse) {
    }
}

message ItemQuery {
    int id = 1;
}
message ItemResponse {
    repeated Item items = 1;
}
message Item {
    int id = 1;
    string name = 2;
}