[#115] nns: Make 'DeleteDomain' faster

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

nns/nns_contract.go

@@ -44,6 +44,11 @@ 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
+	// prefixCountSubDomains contains information about the number of domains in the zone.
+	// If it is nil, it will definitely be calculated on the first removal.
+	prefixCountSubDomains byte = 0x24
+	// prefixAutoCreated contains a flag indicating whether the TLD domain was created automatically.
+	prefixAutoCreated = 0x25
 )
 
 // Values constraints.
@@ -333,11 +338,12 @@ func Register(name string, owner interop.Hash160, email string, refresh, retry,
 // Register registers a new domain with the specified owner and name if it's available.
 func register(ctx storage.Context, name string, owner interop.Hash160, email string, refresh, retry, expire, ttl int) bool {
 	fragments := splitAndCheck(name)
-	l := len(fragments)
+	isTLD := len(fragments)
-	tldKey := append([]byte{prefixRoot}, []byte(fragments[l-1])...)
+	rootZone := []byte(fragments[isTLD-1])
+	tldKey := append([]byte{prefixRoot}, rootZone...)
 
 	tldBytes := storage.Get(ctx, tldKey)
-	if l == 1 {
+	if isTLD == 1 {
 		checkCommittee()
 		if tldBytes != nil {
 			panic("TLD already exists")
@@ -347,6 +353,8 @@ func register(ctx storage.Context, name string, owner interop.Hash160, email str
 		parent := checkParent(ctx, fragments)
 		if parent == "" {
 			parent = fragments[len(fragments)-1]
+
+			storage.Put(ctx, append([]byte{prefixAutoCreated}, rootZone...), true)
 			register(ctx, parent, owner, email, refresh, retry, expire, ttl)
 		}
 
@@ -398,6 +406,7 @@ func register(ctx storage.Context, name string, owner interop.Hash160, email str
 	}
 	checkAvailableGlobalDomain(ctx, name)
 
+	incrementCountSubDomain(ctx, rootZone, isTLD)
 	putNameStateWithKey(ctx, tokenKey, ns)
 	putSoaRecord(ctx, name, email, refresh, retry, expire, ttl)
 	updateBalance(ctx, []byte(name), owner, +1)
@@ -572,14 +581,23 @@ func DeleteDomain(name string) {
 	deleteDomain(ctx, name)
 }
 
-func deleteDomain(ctx storage.Context, name string) {
+func restoreCountSubDomains(name string) int {
+	countSubDomains := 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")
+			countSubDomains = countSubDomains + 1
 		}
 	}
+	return countSubDomains
+}
+
+func deleteDomain(ctx storage.Context, name string) {
+	fragments := splitAndCheck(name)
+	parent := []byte(fragments[len(fragments)-1])
+	countSubDomainsKey := append([]byte{prefixCountSubDomains}, parent...)
+	autoCreatedPrefix := append([]byte{prefixAutoCreated}, parent...)
 
 	nsKey := append([]byte{prefixName}, getTokenKey([]byte(name))...)
 	nsRaw := storage.Get(ctx, nsKey)
@@ -590,6 +608,21 @@ func deleteDomain(ctx storage.Context, name string) {
 	ns := std.Deserialize(nsRaw.([]byte)).(NameState)
 	ns.checkAdmin()
 
+	countSubDomain := 0
+	countSubDomainRaw := storage.Get(ctx, countSubDomainsKey)
+	if countSubDomainRaw != nil {
+		countSubDomain = common.FromFixedWidth64(countSubDomainRaw.([]byte))
+	} else {
+		countSubDomain = restoreCountSubDomains(fragments[len(fragments)-1])
+	}
+
+	if countSubDomain > 1 && len(fragments) == 1 {
+		panic("can't delete TLD domain that has subdomains")
+	}
+
+	countSubDomain = countSubDomain - 1
+	storage.Put(ctx, countSubDomainsKey, common.ToFixedWidth64(countSubDomain))
+
 	globalNSKey := append([]byte{prefixGlobalDomain}, getTokenKey([]byte(name))...)
 	globalDomainRaw := storage.Get(ctx, globalNSKey)
 	globalDomain := globalDomainRaw.(string)
@@ -603,6 +636,17 @@ func deleteDomain(ctx storage.Context, name string) {
 	deleteRecords(ctx, name, AAAA)
 	storage.Delete(ctx, nsKey)
 	storage.Delete(ctx, append([]byte{prefixRoot}, []byte(name)...))
+
+	isAutoCreated := storage.Get(ctx, autoCreatedPrefix)
+	if countSubDomain == 1 && isAutoCreated != nil {
+		deleteDomain(ctx, fragments[len(fragments)-1])
+	}
+
+	if len(fragments) == 1 {
+		storage.Delete(ctx, countSubDomainsKey)
+		storage.Delete(ctx, autoCreatedPrefix)
+	}
+
 	runtime.Notify("DeleteDomain", name)
 }
 
@@ -1122,3 +1166,16 @@ func getAllRecords(ctx storage.Context, name string) iterator.Iterator {
 	recordsKey := getRecordsKey(tokenID, name)
 	return storage.Find(ctx, recordsKey, storage.ValuesOnly|storage.DeserializeValues)
 }
+
+func incrementCountSubDomain(ctx storage.Context, rootZone []byte, isTLD int) {
+	countSubDomain := 0
+	delInfoRaw := storage.Get(ctx, append([]byte{prefixCountSubDomains}, rootZone...))
+	if delInfoRaw != nil {
+		countSubDomain = common.FromFixedWidth64(delInfoRaw.([]byte))
+	}
+
+	if delInfoRaw != nil || isTLD == 1 {
+		countSubDomain = countSubDomain + 1
+		storage.Put(ctx, append([]byte{prefixCountSubDomains}, rootZone...), common.ToFixedWidth64(countSubDomain))
+	}
+}

tests/nns_test.go

@@ -100,6 +100,18 @@ 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)
+
+	c1.InvokeFail(t, "TLD already exists", "register",
+		"zz", accTop.ScriptHash(),
+		"myemail@frostfs.info", refresh, retry, expire, ttl)
+
+	c1.Invoke(t, true, "register",
+		"xx.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",
@@ -251,10 +263,23 @@ 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.InvokeFail(t, "can't delete TLD domain that has subdomains", "deleteDomain", "com")
-	c1.Invoke(t, stackitem.Null{}, "deleteDomain", "domik.testdomain.com")
 	c1.Invoke(t, stackitem.Null{}, "deleteDomain", "testdomain.com")
 
+	c1.Invoke(t, true, "register",
+		"aa.bb.zz", acc1.ScriptHash(),
+		"myemail@frostfs.info", defaultRefresh, defaultRetry, defaultExpire, defaultTTL)
+
+	c1.InvokeFail(t, "TLD already exists", "register",
+		"zz", acc1.ScriptHash(),
+		"myemail@frostfs.info", defaultRefresh, defaultRetry, defaultExpire, defaultTTL)
+
+	c1.Invoke(t, stackitem.Null{}, "deleteDomain", "aa.bb.zz")
+
+	c1.Invoke(t, true, "register",
+		"zz", acc1.ScriptHash(),
+		"myemail@frostfs.info", defaultRefresh, defaultRetry, defaultExpire, defaultTTL)
+
 	c1.Invoke(t, true, "register",
 		"cn", acc1.ScriptHash(),
 		"myemail@frostfs.info", defaultRefresh, defaultRetry, defaultExpire, defaultTTL)