nuts-foundation/nuts-node

/*
 * Copyright (C) 2021 Nuts community
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 */

package grpc

import (
    "context"
    "github.com/nuts-foundation/nuts-node/network/transport"
    "google.golang.org/grpc"
)

// Protocol defines the API for streaming gRPC protocol implementations.
type Protocol interface {
    transport.Protocol

    // MethodName returns the fully qualified name of the gRPC stream.
    MethodName() string
    // CreateClientStream creates a new client for the gRPC stream.
    CreateClientStream(outgoingContext context.Context, grpcConn grpc.ClientConnInterface) (grpc.ClientStream, error)
    // Register registers the protocol implementation.
    Register(registrar grpc.ServiceRegistrar, acceptor func(stream grpc.ServerStream) error, connectionList ConnectionList, connectionManager transport.ConnectionManager)

    // CreateEnvelope is called to create a new, empty envelope, required for receiving messages.
    CreateEnvelope() interface{}
    // Handle is called with to let the protocol handle a received message.
    Handle(connection Connection, envelope interface{}) error
    // UnwrapMessage is used to extract the inner message from the envelope.
    UnwrapMessage(envelope interface{}) interface{}
    // GetMessageType returns a string key identifying the message type.
    GetMessageType(envelope interface{}) string
}

// Stream bundles common functions from grpc.ServerStream and grpc.ClientStream, providing a common interface.
type Stream interface {
    Context() context.Context
    SendMsg(m interface{}) error
    RecvMsg(m interface{}) error
}

// These interfaces are here for mocking purposes.

// Conn is a wrapper around grpc.ClientConnInterface
type Conn interface {
    grpc.ClientConnInterface
}

// ClientStream is a wrapper around grpc.ClientStream
type ClientStream interface {
    grpc.ClientStream
}