riff-rpc.proto

// This protobuf definition defines how riff encodes messages on the wire when doing an RPC function invocation.
syntax = "proto3";

option java_multiple_files = true;
option java_package = "io.projectriff.invoker.rpc";
option java_outer_classname = "Invoker";

option go_package = "rpc";

package streaming;

service Riff {
    rpc Invoke (stream InputSignal) returns (stream OutputSignal) {}
}

// Represents data flowing in when invoking a riff function. A special StartFrame is sent first to specify metadata
// about the invocation
message InputSignal {
    oneof frame {
        StartFrame start = 1;
        InputFrame data = 2;
    }
}

// Contains setup data for an invocation
message StartFrame {
    // The ContentTypes that an invocation is allowed to produce for each output parameter
    repeated string expectedContentTypes = 1;
    // The logical names for input arguments
    repeated string inputNames = 2;
    // The logical names for output arguments
    repeated string outputNames = 3;
}

// Contains actual invocation data, as input events.
message InputFrame {
    // The actual content of the event.
    bytes payload = 1;

    // How to interpret the bytes that make up the payload of this frame.
    string contentType = 2;

    // Additional custom headers.
    map<string, string> headers = 3;

    // The input argument index this frame pertains to.
    int32 argIndex = 4;
}

// Represents data flowing out when invoking a riff function. Represented as a oneof with a single case to allow for
// future extensions
message OutputSignal {
    oneof frame {
        OutputFrame data = 1;
    }
}

// Contains actual function invocation result data, as output events.
message OutputFrame {

    // The actual content of the event.
    bytes payload = 1;

    // How to interpret the bytes that make up the payload of this frame.
    string contentType = 2;

    // Additional custom headers.
    map<string, string> headers = 3;

    // The index of the result this frame pertains to.
    int32 resultIndex = 4;
}