[NOD-1117] Write interfaces for P2P layer (#784)

* [NOD-1117] Write interfaces for P2P layer

* [NOD-1117] Add logs

logger/logger.go

@@ -46,6 +46,9 @@ var (
 	txmpLog = BackendLog.Logger("TXMP")
 	utilLog = BackendLog.Logger("UTIL")
 	profLog = BackendLog.Logger("PROF")
+	protLog = BackendLog.Logger("PROT")
+	muxxLog = BackendLog.Logger("MUXX")
+	p2psLog = BackendLog.Logger("P2PS")
 )
 
 // SubsystemTags is an enum of all sub system tags
@@ -67,7 +70,10 @@ var SubsystemTags = struct {
 	SYNC,
 	TXMP,
 	UTIL,
-	PROF string
+	PROF,
+	PROT,
+	MUXX,
+	P2PS string
 }{
 	ADXR: "ADXR",
 	AMGR: "AMGR",
@@ -87,6 +93,9 @@ var SubsystemTags = struct {
 	TXMP: "TXMP",
 	UTIL: "UTIL",
 	PROF: "PROF",
+	PROT: "PROT",
+	MUXX: "MUXX",
+	P2PS: "P2PS",
 }
 
 // subsystemLoggers maps each subsystem identifier to its associated logger.
@@ -109,6 +118,9 @@ var subsystemLoggers = map[string]*logs.Logger{
 	SubsystemTags.TXMP: txmpLog,
 	SubsystemTags.UTIL: utilLog,
 	SubsystemTags.PROF: profLog,
+	SubsystemTags.PROT: protLog,
+	SubsystemTags.MUXX: muxxLog,
+	SubsystemTags.P2PS: p2psLog,
 }
 
 // InitLog attaches log file and error log file to the backend log.

messagemux/messagemux.go

@@ -0,0 +1,8 @@
+package messagemux
+
+import "github.com/kaspanet/kaspad/wire"
+
+// Mux represents a p2p message multiplexer.
+type Mux interface {
+	AddFlow(msgTypes []string, ch chan<- wire.Message)
+}

p2pserver/p2pserver.go

@@ -0,0 +1,16 @@
+package p2pserver
+
+import "github.com/kaspanet/kaspad/wire"
+
+// Server represents a p2p server.
+type Server interface {
+	Connect(address string) (Connection, error)
+	Connections() []Connection
+}
+
+// Connection represents a p2p server connection.
+type Connection interface {
+	Send(message wire.Message) error
+	Receive() (wire.Message, error)
+	Disconnect() error
+}

protocol/log.go

@@ -0,0 +1,9 @@
+package protocol
+
+import (
+	"github.com/kaspanet/kaspad/logger"
+	"github.com/kaspanet/kaspad/util/panics"
+)
+
+var log, _ = logger.Get(logger.SubsystemTags.PROT)
+var spawn = panics.GoroutineWrapperFunc(log)

protocol/protocol.go

@@ -0,0 +1,24 @@
+package protocol
+
+import (
+	"github.com/kaspanet/kaspad/blockdag"
+	"github.com/kaspanet/kaspad/messagemux"
+	"github.com/kaspanet/kaspad/p2pserver"
+	"github.com/kaspanet/kaspad/wire"
+)
+
+// StartProtocol starts the p2p protocol for a given connection
+func StartProtocol(server p2pserver.Server, mux messagemux.Mux, connection p2pserver.Connection,
+	dag *blockdag.BlockDAG) {
+
+	mux.AddFlow([]string{wire.CmdTx}, startDummy(server, connection, dag))
+}
+
+func startDummy(server p2pserver.Server, connection p2pserver.Connection, dag *blockdag.BlockDAG) chan<- wire.Message {
+	ch := make(chan wire.Message)
+	spawn(func() {
+		for range ch {
+		}
+	})
+	return ch
+}