Function addCursorCondition

internal/database/postgres.go:157–174

addCursorCondition adds pagination cursor condition to WHERE clause. The compound cursor uses a row-constructor comparison so PostgreSQL can seek directly into the (server_name, version) B-tree index. The OR-decomposed form `server_name > X OR (server_name = X AND version > Y)` is logically equival

(cursor string, argIndex int)

// prod). The row-constructor form `(server_name, version) > (X, Y)` is special-
// cased and stays constant-time regardless of cursor depth.
func addCursorCondition(cursor string, argIndex int) (string, []any, int) {
	if cursor == "" {
		return "", nil, argIndex
	}

	// Parse cursor format: "serverName:version"
	parts := strings.SplitN(cursor, ":", 2)
	if len(parts) == 2 {
		cursorServerName := parts[0]
		cursorVersion := parts[1]
		condition := fmt.Sprintf("(server_name, version) > ($%d, $%d)", argIndex, argIndex+1)
		return condition, []any{cursorServerName, cursorVersion}, argIndex + 2
	}

	// Fallback for malformed cursor - treat as server name only for backwards compatibility
	condition := fmt.Sprintf("server_name > $%d", argIndex)
	return condition, []any{cursor}, argIndex + 1
}

func (db *PostgreSQL) ListServers(
	ctx context.Context,