[#115] nns: Allow 'Register' register TLD from nested domains

Signed-off-by: Alexander Chuprov <a.chuprov@yadro.com>

nns/nns_contract.go

@@ -44,6 +44,9 @@ const (
 	//prefixGlobalDomain contains a flag indicating that this domain was created using GlobalDomain.
 	//This is necessary to distinguish it from regular CNAME records.
 	prefixGlobalDomain byte = 0x23
+	// prefixZoneCounterSubdomain contains a list of counters that indicate the number of subdomains in the zone.
+	// If it is null, a full scan of all domains must be performed.
+	prefixZoneCounterSubdomain byte = 0x24
 )
 
 // Values constraints.
@@ -240,7 +243,7 @@ func IsAvailable(name string) bool {
 		return true
 	}
 
-	checkParentExists(ctx, fragments)
+	checkParent(ctx, fragments)
 	checkAvailableGlobalDomain(ctx, name)
 	return storage.Get(ctx, append([]byte{prefixName}, getTokenKey([]byte(name))...)) == nil
 }
@@ -304,33 +307,28 @@ func extractCnametgt(ctx storage.Context, name, domain string) string {
 	return fragments[0] + "." + globalDomain
 }
 
-// checkParentExists panics if any domain from fragments doesn't exist or is expired.
-func checkParentExists(ctx storage.Context, fragments []string) {
-	if dom := parentExpired(ctx, fragments); dom != "" {
-		panic("domain does not exist or is expired: " + dom)
-	}
-}
-
-// parentExpired returns domain from fragments that doesn't exist or is expired.
-// first denotes the deepest subdomain to check.
-func parentExpired(ctx storage.Context, fragments []string) string {
+// checkParent returns parent domain or empty string if domain not found.
+func checkParent(ctx storage.Context, fragments []string) string {
 	now := int64(runtime.GetTime())
 	last := len(fragments) - 1
 	name := fragments[last]
+	parent := ""
 	for i := last; i > 0; i-- {
 		if i != last {
 			name = fragments[i] + "." + name
 		}
 		nsBytes := storage.Get(ctx, append([]byte{prefixName}, getTokenKey([]byte(name))...))
 		if nsBytes == nil {
-			return name
+			continue
 		}
+
 		ns := std.Deserialize(nsBytes.([]byte)).(NameState)
 		if now >= ns.Expiration {
-			return name
+			panic("domain expired: " + name)
 		}
+		parent = name
 	}
-	return ""
+	return parent
 }
 
 // Register registers a new domain with the specified owner and name if it's available.
@@ -352,14 +350,19 @@ func register(ctx storage.Context, name string, owner interop.Hash160, email str
 			panic("TLD already exists")
 		}
 		storage.Put(ctx, tldKey, 0)
+		storage.Put(ctx, append([]byte{prefixZoneCounterSubdomain}, []byte(fragments[l-1])...), 0)
 	} else {
-		if tldBytes == nil {
-			panic("TLD not found")
+		parent := checkParent(ctx, fragments)
+		if parent == "" {
+			parent = fragments[len(fragments)-1]
+			register(ctx, parent, owner, email, refresh, retry, expire, ttl)
 		}
-		checkParentExists(ctx, fragments)
 
-		parentKey := getTokenKey([]byte(name[len(fragments[0])+1:]))
+		parentKey := getTokenKey([]byte(parent))
 		nsBytes := storage.Get(ctx, append([]byte{prefixName}, parentKey...))
+		if nsBytes == nil {
+			panic("parent does not exist:" + parent)
+		}
 		ns := std.Deserialize(nsBytes.([]byte)).(NameState)
 		ns.checkAdmin()
 
@@ -408,6 +411,15 @@ func register(ctx storage.Context, name string, owner interop.Hash160, email str
 	updateBalance(ctx, []byte(name), owner, +1)
 	postTransfer(oldOwner, owner, []byte(name), nil)
 	runtime.Notify("RegisterDomain", name)
+
+	if l != 1 {
+		zoneCounterKey := []byte{prefixZoneCounterSubdomain}
+		data := storage.Get(ctx, zoneCounterKey)
+		if data != nil {
+			storage.Put(ctx, zoneCounterKey, data.(int)+1)
+		}
+
+	}
 	return true
 }
 
@@ -577,12 +589,34 @@ func DeleteDomain(name string) {
 	deleteDomain(ctx, name)
 }
 
-func deleteDomain(ctx storage.Context, name string) {
+func restoreCountSubDomain(ctx storage.Context, name string, token []byte) int {
+	countSubDomain := 0
 	it := Tokens()
 	for iterator.Next(it) {
 		domain := iterator.Value(it)
 		if std.MemorySearch([]byte(domain.(string)), []byte(name)) > 0 {
-			panic("can't delete a domain that has subdomains")
+			countSubDomain = countSubDomain + 1
+		}
+	}
+
+	storage.Put(ctx, token, countSubDomain)
+	return countSubDomain
+}
+
+func deleteDomain(ctx storage.Context, name string) {
+	fragments := splitAndCheck(name)
+	zoneCounterToken := []byte{prefixZoneCounterSubdomain}
+	countSubDomains := 0
+	if len(fragments) == 1 {
+		countRaw := storage.Get(ctx, zoneCounterToken)
+		if countRaw != nil {
+			countSubDomains = countRaw.(int)
+		} else {
+			countSubDomains = restoreCountSubDomain(ctx, name, zoneCounterToken)
+		}
+
+		if countSubDomains > 0 {
+			panic("can't delete TLD domain that has subdomains")
 		}
 	}
 
@@ -608,6 +642,11 @@ func deleteDomain(ctx storage.Context, name string) {
 	deleteRecords(ctx, name, AAAA)
 	storage.Delete(ctx, nsKey)
 	storage.Delete(ctx, append([]byte{prefixRoot}, []byte(name)...))
+	storage.Put(ctx, zoneCounterToken, countSubDomains-1)
+	if len(fragments) == 1 {
+		storage.Delete(ctx, zoneCounterToken)
+	}
+
 	runtime.Notify("DeleteDomain", name)
 }
 
@@ -681,7 +720,7 @@ func getNameState(ctx storage.Context, tokenID []byte) NameState {
 	tokenKey := getTokenKey(tokenID)
 	ns := getNameStateWithKey(ctx, tokenKey)
 	fragments := std.StringSplit(string(tokenID), ".")
-	checkParentExists(ctx, fragments)
+	checkParent(ctx, fragments)
 	return ns
 }
 

tests/nns_test.go

@@ -100,6 +100,10 @@ func TestNNSRegister(t *testing.T) {
 		"com", accTop.ScriptHash(),
 		"myemail@frostfs.info", refresh, retry, expire, ttl)
 
+	c1.Invoke(t, true, "register",
+		"aa.bb.zz", accTop.ScriptHash(),
+		"myemail@frostfs.info", refresh, retry, expire, ttl)
+
 	acc := c.NewAccount(t)
 	c2 := c.WithSigners(c.Committee, acc)
 	c2.InvokeFail(t, "not witnessed by admin", "register",
@@ -251,9 +255,10 @@ func TestDeleteDomain(t *testing.T) {
 		"myemail@frostfs.info", defaultRefresh, defaultRetry, defaultExpire, defaultTTL)
 
 	c1.InvokeFail(t, "domain not found", "deleteDomain", "ru")
-	c1.InvokeFail(t, "can't delete a domain that has subdomains", "deleteDomain", "testdomain.com")
-	c1.Invoke(t, stackitem.Null{}, "deleteDomain", "domik.testdomain.com")
+	c1.InvokeFail(t, "can't delete TLD domain that has subdomains", "deleteDomain", "com")
 	c1.Invoke(t, stackitem.Null{}, "deleteDomain", "testdomain.com")
+	c1.Invoke(t, stackitem.Null{}, "deleteDomain", "domik.testdomain.com")
+	c1.Invoke(t, stackitem.Null{}, "deleteDomain", "com")
 
 	c1.Invoke(t, true, "register",
 		"cn", acc1.ScriptHash(),
@@ -335,12 +340,6 @@ func TestNNSRegisterMulti(t *testing.T) {
 	cBoth.Invoke(t, true, "register", args...)
 
 	c1 := c.WithSigners(acc)
-	t.Run("parent domain is missing", func(t *testing.T) {
-		msg := "domain does not exist or is expired: fs.neo.com"
-		args[0] = "testnet.fs.neo.com"
-		c1.InvokeFail(t, msg, "register", args...)
-	})
-
 	args[0] = "fs.neo.com"
 	c1.Invoke(t, true, "register", args...)
 
@@ -512,7 +511,6 @@ func TestNNSIsAvailable(t *testing.T) {
 	acc := c.NewAccount(t)
 	c1 := c.WithSigners(c.Committee, acc)
 
-	c1.InvokeFail(t, "domain does not exist or is expired: domain.com", "isAvailable", "dom.domain.com")
 	c1.Invoke(t, true, "register",
 		"domain.com", acc.ScriptHash(),
 		"myemail@frostfs.info", refresh, retry, expire, ttl)
@@ -524,7 +522,6 @@ func TestNNSIsAvailable(t *testing.T) {
 	c.Invoke(t, false, "isAvailable", "domain.com")
 
 	c.Invoke(t, true, "isAvailable", "dom.domain.com")
-	c.InvokeFail(t, "domain does not exist or is expired: dom.domain.com", "isAvailable", "dom.dom.domain.com")
 
 	c1.Invoke(t, true, "register",
 		"dom.domain.com", acc.ScriptHash(),