network: add MPT-related P2P payloads

pkg/network/payload/state_root.go

@@ -0,0 +1,43 @@
+package payload
+
+import (
+	"github.com/nspcc-dev/neo-go/pkg/core/state"
+	"github.com/nspcc-dev/neo-go/pkg/io"
+)
+
+// MaxStateRootsAllowed is a maxumum amount of state roots
+// which can be sent in a single payload.
+const MaxStateRootsAllowed = 2000
+
+// StateRoots contains multiple StateRoots.
+type StateRoots struct {
+	Roots []state.MPTRoot
+}
+
+// GetStateRoots represents request for state roots.
+type GetStateRoots struct {
+	Start uint32
+	Count uint32
+}
+
+// EncodeBinary implements io.Serializable.
+func (s *StateRoots) EncodeBinary(w *io.BinWriter) {
+	w.WriteArray(s.Roots)
+}
+
+// DecodeBinary implements io.Serializable.
+func (s *StateRoots) DecodeBinary(r *io.BinReader) {
+	r.ReadArray(&s.Roots, MaxStateRootsAllowed)
+}
+
+// DecodeBinary implements io.Serializable.
+func (g *GetStateRoots) DecodeBinary(r *io.BinReader) {
+	g.Start = r.ReadU32LE()
+	g.Count = r.ReadU32LE()
+}
+
+// EncodeBinary implements io.Serializable.
+func (g *GetStateRoots) EncodeBinary(w *io.BinWriter) {
+	w.WriteU32LE(g.Start)
+	w.WriteU32LE(g.Count)
+}