Optimize some kv.List requests to not list all children

main.go

@@ -371,7 +371,7 @@ func (server *Server) objectExists(dn string) (bool, error) {
 		return false, err
 	}
 
-	data, _, err := server.kv.List(prefix+"/", nil)
+	data, _, err := server.kv.List(prefix+"/attribute=", nil)
 	if err != nil {
 		return false, err
 	}

read.go

@@ -103,8 +103,13 @@ func (server *Server) handleSearchInternal(state *State, w ldap.ResponseWriter,
 	if err != nil {
 		return ldap.LDAPResultInvalidDNSyntax, err
 	}
+	if r.Scope() == message.SearchRequestScopeBaseObject {
+		basePath += "/attribute="
+	} else {
+		basePath += "/"
+	}
 
-	data, _, err := server.kv.List(basePath+"/", nil)
+	data, _, err := server.kv.List(basePath, nil)
 	if err != nil {
 		return ldap.LDAPResultOperationsError, err
 	}
@@ -114,7 +119,7 @@ func (server *Server) handleSearchInternal(state *State, w ldap.ResponseWriter,
 		return ldap.LDAPResultOperationsError, err
 	}
 
-	server.logger.Tracef("in %s: %#v", basePath+"/", data)
+	server.logger.Tracef("in %s: %#v", basePath, data)
 	server.logger.Tracef("%#v", entries)
 
 	for dn, entry := range entries {