oracle: split broadcaster into parts

1. Generic parallel sending part can be reused by state service.
2. Specific oracle marshaling is implemented on top of (1).

pkg/services/helpers/rpcbroadcaster/broadcaster.go

@@ -0,0 +1,55 @@
+package rpcbroadcaster
+
+import (
+	"time"
+
+	"github.com/nspcc-dev/neo-go/pkg/rpc/request"
+	"go.uber.org/zap"
+)
+
+// RPCBroadcaster represent generic RPC broadcaster.
+type RPCBroadcaster struct {
+	Clients   map[string]*RPCClient
+	Log       *zap.Logger
+	Responses chan request.RawParams
+
+	close       chan struct{}
+	sendTimeout time.Duration
+}
+
+// NewRPCBroadcaster returns new RPC broadcaster instance.
+func NewRPCBroadcaster(log *zap.Logger, sendTimeout time.Duration) *RPCBroadcaster {
+	return &RPCBroadcaster{
+		Clients:     make(map[string]*RPCClient),
+		Log:         log,
+		close:       make(chan struct{}),
+		Responses:   make(chan request.RawParams),
+		sendTimeout: sendTimeout,
+	}
+}
+
+// Run implements oracle.Broadcaster.
+func (r *RPCBroadcaster) Run() {
+	for _, c := range r.Clients {
+		go c.run()
+	}
+	for {
+		select {
+		case <-r.close:
+			return
+		case ps := <-r.Responses:
+			for _, c := range r.Clients {
+				select {
+				case c.responses <- ps:
+				default:
+					c.log.Error("can't send response, channel is full")
+				}
+			}
+		}
+	}
+}
+
+// Shutdown implements oracle.Broadcaster.
+func (r *RPCBroadcaster) Shutdown() {
+	close(r.close)
+}

pkg/services/helpers/rpcbroadcaster/client.go

@@ -1,4 +1,4 @@
-package broadcaster
+package rpcbroadcaster
 
 import (
 	"context"
@@ -9,26 +9,33 @@ import (
 	"go.uber.org/zap"
 )
 
-type oracleClient struct {
+// RPCClient represent rpc client for a single node.
+type RPCClient struct {
 	client      *client.Client
 	addr        string
 	close       chan struct{}
 	responses   chan request.RawParams
 	log         *zap.Logger
 	sendTimeout time.Duration
+	method      SendMethod
 }
 
-func (r *rpcBroascaster) newOracleClient(addr string, timeout time.Duration, ch chan request.RawParams) *oracleClient {
-	return &oracleClient{
+// SendMethod represents rpc method for sending data to other nodes.
+type SendMethod func(*client.Client, request.RawParams) error
+
+// NewRPCClient returns new rpc client for provided address and method.
+func (r *RPCBroadcaster) NewRPCClient(addr string, method SendMethod, timeout time.Duration, ch chan request.RawParams) *RPCClient {
+	return &RPCClient{
 		addr:        addr,
 		close:       r.close,
 		responses:   ch,
-		log:         r.log.With(zap.String("address", addr)),
+		log:         r.Log.With(zap.String("address", addr)),
 		sendTimeout: timeout,
+		method:      method,
 	}
 }
 
-func (c *oracleClient) run() {
+func (c *RPCClient) run() {
 	// We ignore error as not every node can be available on startup.
 	c.client, _ = client.New(context.Background(), "http://"+c.addr, client.Options{
 		DialTimeout:    c.sendTimeout,
@@ -49,7 +56,7 @@ func (c *oracleClient) run() {
 					continue
 				}
 			}
-			err := c.client.SubmitRawOracleResponse(ps)
+			err := c.method(c.client, ps)
 			if err != nil {
 				c.log.Error("error while submitting oracle response", zap.Error(err))
 			}

pkg/services/oracle/broadcaster/oracle.go

@@ -8,72 +8,40 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/config"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
+	"github.com/nspcc-dev/neo-go/pkg/rpc/client"
 	"github.com/nspcc-dev/neo-go/pkg/rpc/request"
+	"github.com/nspcc-dev/neo-go/pkg/services/helpers/rpcbroadcaster"
 	"github.com/nspcc-dev/neo-go/pkg/services/oracle"
 	"go.uber.org/zap"
 )
 
-type rpcBroascaster struct {
-	clients map[string]*oracleClient
-	log     *zap.Logger
-
-	close       chan struct{}
-	responses   chan request.RawParams
-	sendTimeout time.Duration
-}
-
 const (
 	defaultSendTimeout = time.Second * 4
 
 	defaultChanCapacity = 16
 )
 
+type oracleBroadcaster struct {
+	rpcbroadcaster.RPCBroadcaster
+}
+
 // New returns new struct capable of broadcasting oracle responses.
 func New(cfg config.OracleConfiguration, log *zap.Logger) oracle.Broadcaster {
 	if cfg.ResponseTimeout == 0 {
 		cfg.ResponseTimeout = defaultSendTimeout
 	}
-	r := &rpcBroascaster{
-		clients:     make(map[string]*oracleClient, len(cfg.Nodes)),
-		log:         log,
-		close:       make(chan struct{}),
-		responses:   make(chan request.RawParams),
-		sendTimeout: cfg.ResponseTimeout,
+	r := &oracleBroadcaster{
+		RPCBroadcaster: *rpcbroadcaster.NewRPCBroadcaster(log, cfg.ResponseTimeout),
 	}
 	for i := range cfg.Nodes {
-		r.clients[cfg.Nodes[i]] = r.newOracleClient(cfg.Nodes[i], cfg.ResponseTimeout, make(chan request.RawParams, defaultChanCapacity))
+		r.Clients[cfg.Nodes[i]] = r.NewRPCClient(cfg.Nodes[i], (*client.Client).SubmitRawOracleResponse,
+			cfg.ResponseTimeout, make(chan request.RawParams, defaultChanCapacity))
 	}
 	return r
 }
 
-// Run implements oracle.Broadcaster.
-func (r *rpcBroascaster) Run() {
-	for _, c := range r.clients {
-		go c.run()
-	}
-	for {
-		select {
-		case <-r.close:
-			return
-		case ps := <-r.responses:
-			for _, c := range r.clients {
-				select {
-				case c.responses <- ps:
-				default:
-					c.log.Error("can't send response, channel is full")
-				}
-			}
-		}
-	}
-}
-
-// Shutdown implements oracle.Broadcaster.
-func (r *rpcBroascaster) Shutdown() {
-	close(r.close)
-}
-
 // SendResponse implements interfaces.Broadcaster.
-func (r *rpcBroascaster) SendResponse(priv *keys.PrivateKey, resp *transaction.OracleResponse, txSig []byte) {
+func (r *oracleBroadcaster) SendResponse(priv *keys.PrivateKey, resp *transaction.OracleResponse, txSig []byte) {
 	pub := priv.PublicKey()
 	data := GetMessage(pub.Bytes(), resp.ID, txSig)
 	msgSig := priv.Sign(data)
@@ -83,7 +51,7 @@ func (r *rpcBroascaster) SendResponse(priv *keys.PrivateKey, resp *transaction.O
 		base64.StdEncoding.EncodeToString(txSig),
 		base64.StdEncoding.EncodeToString(msgSig),
 	)
-	r.responses <- params
+	r.Responses <- params
 }
 
 // GetMessage returns data which is signed upon sending response by RPC.