Make schemaDescriber solely owner of tablets metadata

conn.go

@@ -1522,7 +1522,7 @@ func (c *Conn) executeQuery(ctx context.Context, qry *Query) *Iter {
 			tablet.keyspaceName = qry.routingInfo.keyspace
 			tablet.tableName = qry.routingInfo.table
 
-			c.session.addTablet(&tablet)
+			c.session.schemaDescriber.addTablet(&tablet)
 		}
 	}
 

events.go

@@ -128,14 +128,14 @@ func (s *Session) handleSchemaEvent(frames []frame) {
 func (s *Session) handleKeyspaceChange(keyspace, change string) {
 	s.control.awaitSchemaAgreement()
 	if change == "DROPPED" || change == "UPDATED" {
-		s.removeTabletsWithKeyspace(keyspace)
+		s.schemaDescriber.removeTabletsWithKeyspace(keyspace)
 	}
 	s.policy.KeyspaceChanged(KeyspaceUpdateEvent{Keyspace: keyspace, Change: change})
 }
 
 func (s *Session) handleTableChange(keyspace, table, change string) {
 	if change == "DROPPED" || change == "UPDATED" {
-		s.removeTabletsWithTable(keyspace, table)
+		s.schemaDescriber.removeTabletsWithTable(keyspace, table)
 	}
 }
 

host_source.go

@@ -504,180 +504,6 @@ func (h *HostInfo) ScyllaShardAwarePortTLS() uint16 {
 	return h.scyllaShardAwarePortTLS
 }
 
-type ReplicaInfo struct {
-	hostId  UUID
-	shardId int
-}
-
-type TabletInfo struct {
-	keyspaceName string
-	tableName    string
-	firstToken   int64
-	lastToken    int64
-	replicas     []ReplicaInfo
-}
-
-func (t *TabletInfo) KeyspaceName() string {
-	return t.keyspaceName
-}
-
-func (t *TabletInfo) FirstToken() int64 {
-	return t.firstToken
-}
-
-func (t *TabletInfo) LastToken() int64 {
-	return t.lastToken
-}
-
-func (t *TabletInfo) TableName() string {
-	return t.tableName
-}
-
-func (t *TabletInfo) Replicas() []ReplicaInfo {
-	return t.replicas
-}
-
-type TabletInfoList []*TabletInfo
-
-// Search for place in tablets table with specific Keyspace and Table name
-func (t TabletInfoList) findTablets(keyspace string, table string) (int, int) {
-	l := -1
-	r := -1
-	for i, tablet := range t {
-		if tablet.KeyspaceName() == keyspace && tablet.TableName() == table {
-			if l == -1 {
-				l = i
-			}
-			r = i
-		} else if l != -1 {
-			break
-		}
-	}
-
-	return l, r
-}
-
-func (t TabletInfoList) addTabletToTabletsList(tablet *TabletInfo) TabletInfoList {
-	l, r := t.findTablets(tablet.keyspaceName, tablet.tableName)
-	if l == -1 && r == -1 {
-		l = 0
-		r = 0
-	} else {
-		r = r + 1
-	}
-
-	l1, r1 := l, r
-	l2, r2 := l1, r1
-
-	// find first overlaping range
-	for l1 < r1 {
-		mid := (l1 + r1) / 2
-		if t[mid].FirstToken() < tablet.FirstToken() {
-			l1 = mid + 1
-		} else {
-			r1 = mid
-		}
-	}
-	start := l1
-
-	if start > l && t[start-1].LastToken() > tablet.FirstToken() {
-		start = start - 1
-	}
-
-	// find last overlaping range
-	for l2 < r2 {
-		mid := (l2 + r2) / 2
-		if t[mid].LastToken() < tablet.LastToken() {
-			l2 = mid + 1
-		} else {
-			r2 = mid
-		}
-	}
-	end := l2
-	if end < r && t[end].FirstToken() >= tablet.LastToken() {
-		end = end - 1
-	}
-	if end == len(t) {
-		end = end - 1
-	}
-
-	updated_tablets := t
-	if start <= end {
-		// Delete elements from index start to end
-		updated_tablets = append(t[:start], t[end+1:]...)
-	}
-	// Insert tablet element at index start
-	t = append(updated_tablets[:start], append([]*TabletInfo{tablet}, updated_tablets[start:]...)...)
-	return t
-}
-
-// Remove all tablets that have given host as a replica
-func (t TabletInfoList) removeTabletsWithHostFromTabletsList(host *HostInfo) TabletInfoList {
-	filteredTablets := make([]*TabletInfo, 0, len(t)) // Preallocate for efficiency
-
-	for _, tablet := range t {
-		// Check if any replica matches the given host ID
-		shouldExclude := false
-		for _, replica := range tablet.replicas {
-			if replica.hostId.String() == host.HostID() {
-				shouldExclude = true
-				break
-			}
-		}
-		if !shouldExclude {
-			filteredTablets = append(filteredTablets, tablet)
-		}
-	}
-
-	t = filteredTablets
-	return t
-}
-
-func (t TabletInfoList) removeTabletsWithKeyspaceFromTabletsList(keyspace string) TabletInfoList {
-	filteredTablets := make([]*TabletInfo, 0, len(t))
-
-	for _, tablet := range t {
-		if tablet.keyspaceName != keyspace {
-			filteredTablets = append(filteredTablets, tablet)
-		}
-	}
-
-	t = filteredTablets
-	return t
-}
-
-func (t TabletInfoList) removeTabletsWithTableFromTabletsList(keyspace string, table string) TabletInfoList {
-	filteredTablets := make([]*TabletInfo, 0, len(t))
-
-	for _, tablet := range t {
-		if !(tablet.keyspaceName == keyspace && tablet.tableName == table) {
-			filteredTablets = append(filteredTablets, tablet)
-		}
-	}
-
-	t = filteredTablets
-	return t
-}
-
-// Search for place in tablets table for token starting from index l to index r
-func (t TabletInfoList) findTabletForToken(token Token, l int, r int) *TabletInfo {
-	for l < r {
-		var m int
-		if r*l > 0 {
-			m = l + (r-l)/2
-		} else {
-			m = (r + l) / 2
-		}
-		if int64Token(t[m].LastToken()).Less(token) {
-			l = m + 1
-		} else {
-			r = m
-		}
-	}
-
-	return t[l]
-}
-
 // Polls system.peers at a specific interval to find new hosts
 type ringDescriber struct {
 	session         *Session
@@ -1051,7 +877,7 @@ func refreshRing(r *ringDescriber) error {
 	}
 
 	for _, host := range prevHosts {
-		r.session.removeTabletsWithHost(host)
+		r.session.schemaDescriber.removeTabletsWithHost(host)
 		r.session.removeHost(host)
 	}
 
@@ -1061,54 +887,6 @@ func refreshRing(r *ringDescriber) error {
 	return nil
 }
 
-func (s *Session) addTablet(tablet *TabletInfo) error {
-	tablets := s.getTablets()
-	tablets = tablets.addTabletToTabletsList(tablet)
-
-	s.ring.setTablets(tablets)
-	s.policy.SetTablets(tablets)
-
-	s.schemaDescriber.refreshTabletsSchema()
-
-	return nil
-}
-
-func (s *Session) removeTabletsWithHost(host *HostInfo) error {
-	tablets := s.getTablets()
-	tablets = tablets.removeTabletsWithHostFromTabletsList(host)
-
-	s.ring.setTablets(tablets)
-	s.policy.SetTablets(tablets)
-
-	s.schemaDescriber.refreshTabletsSchema()
-
-	return nil
-}
-
-func (s *Session) removeTabletsWithKeyspace(keyspace string) error {
-	tablets := s.getTablets()
-	tablets = tablets.removeTabletsWithKeyspaceFromTabletsList(keyspace)
-
-	s.ring.setTablets(tablets)
-	s.policy.SetTablets(tablets)
-
-	s.schemaDescriber.refreshTabletsSchema()
-
-	return nil
-}
-
-func (s *Session) removeTabletsWithTable(keyspace string, table string) error {
-	tablets := s.getTablets()
-	tablets = tablets.removeTabletsWithTableFromTabletsList(keyspace, table)
-
-	s.ring.setTablets(tablets)
-	s.policy.SetTablets(tablets)
-
-	s.schemaDescriber.refreshTabletsSchema()
-
-	return nil
-}
-
 const (
 	ringRefreshDebounceTime = 1 * time.Second
 )