add registrar/ethreg (forgotten)

common/registrar/ethreg/ethreg.go

@@ -0,0 +1,32 @@
+package ethreg
+
+import (
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/common/registrar"
+	"github.com/ethereum/go-ethereum/xeth"
+)
+
+// implements a versioned Registrar on an archiving full node
+type EthReg struct {
+	backend  *xeth.XEth
+	registry *registrar.Registrar
+}
+
+func New(xe *xeth.XEth) (self *EthReg) {
+	self = &EthReg{backend: xe}
+	self.registry = registrar.New(xe)
+	return
+}
+
+func (self *EthReg) Registry() *registrar.Registrar {
+	return self.registry
+}
+
+func (self *EthReg) Resolver(n *big.Int) *registrar.Registrar {
+	xe := self.backend
+	if n != nil {
+		xe = self.backend.AtStateNum(n.Int64())
+	}
+	return registrar.New(xe)
+}