XLSX workbook model

1export interface CompactSheet {
2  name: string;
3  rowCount: number;
4  columnCount: number;
5  /** Sorted row-major indexes for non-empty cells only. */
6  cellIndexes: Uint32Array;
7  /** Length cellIndexes.length + 1; cell i's text is text.slice(textOffsets[i], textOffsets[i + 1]). */
8  textOffsets: Uint32Array;
9  /** Length cellIndexes.length; 1 = numeric/date. */
10  numericFlags: Uint8Array;
11  /** All non-empty display texts concatenated in row-major order. */
12  text: string;
13}
14 
15export interface XlsxCell {
16  /** Display text: the workbook's formatted value when available. */
17  text: string;
18  /** Right-align numbers and dates. */
19  numeric: boolean;
20}
21 
22export interface XlsxSheetMeta {
23  name: string;
24  rowCount: number;
25  columnCount: number;
26  nonEmptyCellCount: number;
27}
28 
29export interface XlsxSource {
30  sheets: XlsxSheetMeta[];
31  getCell(sheetIndex: number, rowIndex: number, columnIndex: number): XlsxCell;
32  dispose?: () => void;
33  estimatedByteSize?: number;
34}
35 
36export interface XlsxCacheOptions {
37  maxEntries?: number;
38  maxBytes?: number;
39}
40 
41export interface XlsxSheetChangeResult {
42  accepted: boolean;
43  changed: boolean;
44  sheetIndex: number;
45}
46 
47interface CacheEntry {
48  promise: Promise<XlsxSource>;
49  source?: XlsxSource;
50  bytes: number;
51}
52 
53export const EMPTY_XLSX_CELL: XlsxCell = { text: "", numeric: false };
54const MAX_COMPACT_CELL_INDEX = 0xffffffff;
55 
56export function resolveXlsxSheetChange({
57  activeSheet,
58  requestedSheet,
59  sheetCount,
60}: {
61  activeSheet: number;
62  requestedSheet: number;
63  sheetCount?: number | null;
64}): XlsxSheetChangeResult {
65  if (!Number.isSafeInteger(requestedSheet) || requestedSheet < 0) {
66    return { accepted: false, changed: false, sheetIndex: activeSheet };
67  }
68  if (
69    sheetCount != null &&
70    (!Number.isSafeInteger(sheetCount) ||
71      sheetCount < 0 ||
72      requestedSheet >= sheetCount)
73  ) {
74    return { accepted: false, changed: false, sheetIndex: activeSheet };
75  }
76  return {
77    accepted: true,
78    changed: requestedSheet !== activeSheet,
79    sheetIndex: requestedSheet,
80  };
81}
82 
83/** Spreadsheet column label: 0 -> A, 25 -> Z, 26 -> AA. */
84export function xlsxColumnLabel(index: number): string {
85  if (!Number.isSafeInteger(index) || index < 0) return "";
86  let i = Math.floor(index) + 1;
87  let label = "";
88  while (i > 0) {
89    const m = (i - 1) % 26;
90    label = String.fromCharCode(65 + m) + label;
91    i = Math.floor((i - 1) / 26);
92  }
93  return label;
94}
95 
96// … truncated