add common/resolver skeleton

common/resolver/resolver.go

+package resolver
+
+import (
+	"fmt"
+	"net/url"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/xeth"
+)
+
+/*
+Resolver implements the Ethereum DNS mapping
+NameReg : Domain Name (or Code hash of Contract) -> Content Hash
+UrlHint : Content Hash -> Url Hint
+*/
+const (
+	urlHintContractAddress = "urlhint"
+	nameRegContractAddress = "nameReg"
+)
+
+type Resolver struct {
+	xeth *xeth.XEth
+}
+
+func (self *Resolver) NameToContentHash(name string) (hash common.Hash, err error) {
+	// look up in nameReg
+	copy(hash[:], []byte(name)[:32])
+	return
+}
+
+func (self *Resolver) ContentHashToUrl(hash common.Hash) (uri *url.URL, err error) {
+	// look up in nameReg
+	rawurl := fmt.Sprintf("bzz://%x/my/path/mycontract.sud", hash[:])
+	// mime type?
+	return url.Parse(rawurl)
+}
+
+func (self *Resolver) NameToUrl(name string) (uri *url.URL, err error) {
+	// look up in urlHint
+	hash, err := self.NameToContentHash(name)
+	if err != nil {
+		return
+	}
+	return self.ContentHashToUrl(hash)
+}

common/resolver/resolver_test.go

+package resolver
+
+import (
+	"testing"
+)
+
+func TestNameToContentHash(t *testing.T) {
+
+}
+
+func TestContentHashToUrl(t *testing.T) {
+
+}
+
+func TestNameToUrl(t *testing.T) {
+
+}