Function zip

packages/dev/s2-docs/src/zip.tsx:40–89

(files: {[name: string]: string})

}

export function zip(files: {[name: string]: string}): Blob {
  let records: Uint8Array[] = [];
  let cdrs: Uint8Array[] = [];
  let te = new TextEncoder();

  let offset = 0;
  let cdSz = 0;

  for (let name in files) {
    let fh = new Uint8Array(30 + name.length);
    let fname = te.encode(name);
    let data = te.encode(files[name]);
    let chksum = crc32(data);

    putUint32s(fh, 0, 0x04034b50);
    putUint32s(fh, 14, chksum, data.length, data.length);
    putUint16s(fh, 26, name.length);

    fh.set(fname, 30);

    records.push(fh);
    records.push(data);

    // Create CD records pending flush at the end...
    let cdr = new Uint8Array(46 + name.length);

    putUint32s(cdr, 0, 0x02014b50);
    putUint32s(cdr, 16, chksum, data.length, data.length);
    putUint16s(cdr, 28, name.length);
    putUint32s(cdr, 42, offset);

    cdr.set(fname, 46);
    cdrs.push(cdr);

    cdSz += cdr.length;
    offset += fh.length + data.length;
  }

  // Push all accrued CD records..
  records.push(...cdrs);

  // Add EOCD record...
  let eocd = new Uint8Array(22);
  putUint32s(eocd, 0, 0x06054b50);
  putUint16s(eocd, 8, cdrs.length, cdrs.length);
  putUint32s(eocd, 12, cdSz, offset);
  records.push(eocd);

  return new Blob(records as BlobPart[], {type: 'application/zip'});
}