Function loadPreviewSpans

modules/sentry/api_exceptions.go:402–443

loadPreviewSpans loads the top N spans by duration for mini-waterfall preview.

(db *sql.DB, traceID string, txnStartTS sql.NullString, limit int)

// loadPreviewSpans loads the top N spans by duration for mini-waterfall preview.
func loadPreviewSpans(db *sql.DB, traceID string, txnStartTS sql.NullString, limit int) []map[string]any {
	rows, err := db.Query(
		fmt.Sprintf(`SELECT span_id, op, description, start_ts, duration_ms, is_error, peer_type
		FROM sentry_spans WHERE trace_id = ? ORDER BY duration_ms DESC LIMIT %d`, limit), traceID,
	)
	if err != nil {
		return []map[string]any{}
	}
	defer rows.Close()

	var result []map[string]any
	for rows.Next() {
		var (
			spanID, op  string
			description sql.NullString
			sStartTS    sql.NullString
			durationMS  sql.NullInt64
			isError     int
			peerType    sql.NullString
		)
		if err := rows.Scan(&spanID, &op, &description, &sStartTS, &durationMS, &isError, &peerType); err != nil {
			continue
		}

		startOffsetMS := computeOffsetMS(txnStartTS, sStartTS)

		result = append(result, map[string]any{
			"span_id":         spanID,
			"op":              op,
			"description":     scanNullString(description),
			"start_offset_ms": startOffsetMS,
			"duration_ms":     scanNullInt(durationMS),
			"is_error":        isError != 0,
			"peer_type":       scanNullString(peerType),
		})
	}

	if result == nil {
		result = []map[string]any{}
	}
	return result
}

// computeOffsetMS calculates the offset in ms between two RFC3339 timestamps.
func computeOffsetMS(baseTSStr, spanTSStr sql.NullString) int {