async process()

in src/core/binary_cmap.js [146:323]
170 lines of code
23 McCabe index (conditional complexity)

  async process(data, cMap, extend) {
    const stream = new BinaryCMapStream(data);
    const header = stream.readByte();
    cMap.vertical = !!(header & 1);

    let useCMap = null;
    const start = new Uint8Array(MAX_NUM_SIZE);
    const end = new Uint8Array(MAX_NUM_SIZE);
    const char = new Uint8Array(MAX_NUM_SIZE);
    const charCode = new Uint8Array(MAX_NUM_SIZE);
    const tmp = new Uint8Array(MAX_NUM_SIZE);
    let code;

    let b;
    while ((b = stream.readByte()) >= 0) {
      const type = b >> 5;
      if (type === 7) {
        // metadata, e.g. comment or usecmap
        switch (b & 0x1f) {
          case 0:
            stream.readString(); // skipping comment
            break;
          case 1:
            useCMap = stream.readString();
            break;
        }
        continue;
      }
      const sequence = !!(b & 0x10);
      const dataSize = b & 15;

      if (dataSize + 1 > MAX_NUM_SIZE) {
        throw new Error("BinaryCMapReader.process: Invalid dataSize.");
      }

      const ucs2DataSize = 1;
      const subitemsCount = stream.readNumber();
      switch (type) {
        case 0: // codespacerange
          stream.readHex(start, dataSize);
          stream.readHexNumber(end, dataSize);
          addHex(end, start, dataSize);
          cMap.addCodespaceRange(
            dataSize + 1,
            hexToInt(start, dataSize),
            hexToInt(end, dataSize)
          );
          for (let i = 1; i < subitemsCount; i++) {
            incHex(end, dataSize);
            stream.readHexNumber(start, dataSize);
            addHex(start, end, dataSize);
            stream.readHexNumber(end, dataSize);
            addHex(end, start, dataSize);
            cMap.addCodespaceRange(
              dataSize + 1,
              hexToInt(start, dataSize),
              hexToInt(end, dataSize)
            );
          }
          break;
        case 1: // notdefrange
          stream.readHex(start, dataSize);
          stream.readHexNumber(end, dataSize);
          addHex(end, start, dataSize);
          stream.readNumber(); // code
          // undefined range, skipping
          for (let i = 1; i < subitemsCount; i++) {
            incHex(end, dataSize);
            stream.readHexNumber(start, dataSize);
            addHex(start, end, dataSize);
            stream.readHexNumber(end, dataSize);
            addHex(end, start, dataSize);
            stream.readNumber(); // code
            // nop
          }
          break;
        case 2: // cidchar
          stream.readHex(char, dataSize);
          code = stream.readNumber();
          cMap.mapOne(hexToInt(char, dataSize), code);
          for (let i = 1; i < subitemsCount; i++) {
            incHex(char, dataSize);
            if (!sequence) {
              stream.readHexNumber(tmp, dataSize);
              addHex(char, tmp, dataSize);
            }
            code = stream.readSigned() + (code + 1);
            cMap.mapOne(hexToInt(char, dataSize), code);
          }
          break;
        case 3: // cidrange
          stream.readHex(start, dataSize);
          stream.readHexNumber(end, dataSize);
          addHex(end, start, dataSize);
          code = stream.readNumber();
          cMap.mapCidRange(
            hexToInt(start, dataSize),
            hexToInt(end, dataSize),
            code
          );
          for (let i = 1; i < subitemsCount; i++) {
            incHex(end, dataSize);
            if (!sequence) {
              stream.readHexNumber(start, dataSize);
              addHex(start, end, dataSize);
            } else {
              start.set(end);
            }
            stream.readHexNumber(end, dataSize);
            addHex(end, start, dataSize);
            code = stream.readNumber();
            cMap.mapCidRange(
              hexToInt(start, dataSize),
              hexToInt(end, dataSize),
              code
            );
          }
          break;
        case 4: // bfchar
          stream.readHex(char, ucs2DataSize);
          stream.readHex(charCode, dataSize);
          cMap.mapOne(
            hexToInt(char, ucs2DataSize),
            hexToStr(charCode, dataSize)
          );
          for (let i = 1; i < subitemsCount; i++) {
            incHex(char, ucs2DataSize);
            if (!sequence) {
              stream.readHexNumber(tmp, ucs2DataSize);
              addHex(char, tmp, ucs2DataSize);
            }
            incHex(charCode, dataSize);
            stream.readHexSigned(tmp, dataSize);
            addHex(charCode, tmp, dataSize);
            cMap.mapOne(
              hexToInt(char, ucs2DataSize),
              hexToStr(charCode, dataSize)
            );
          }
          break;
        case 5: // bfrange
          stream.readHex(start, ucs2DataSize);
          stream.readHexNumber(end, ucs2DataSize);
          addHex(end, start, ucs2DataSize);
          stream.readHex(charCode, dataSize);
          cMap.mapBfRange(
            hexToInt(start, ucs2DataSize),
            hexToInt(end, ucs2DataSize),
            hexToStr(charCode, dataSize)
          );
          for (let i = 1; i < subitemsCount; i++) {
            incHex(end, ucs2DataSize);
            if (!sequence) {
              stream.readHexNumber(start, ucs2DataSize);
              addHex(start, end, ucs2DataSize);
            } else {
              start.set(end);
            }
            stream.readHexNumber(end, ucs2DataSize);
            addHex(end, start, ucs2DataSize);
            stream.readHex(charCode, dataSize);
            cMap.mapBfRange(
              hexToInt(start, ucs2DataSize),
              hexToInt(end, ucs2DataSize),
              hexToStr(charCode, dataSize)
            );
          }
          break;
        default:
          throw new Error(`BinaryCMapReader.process - unknown type: ${type}`);
      }
    }

    if (useCMap) {
      return extend(useCMap);
    }
    return cMap;
  }