Method _transform

src/parsers/Multipart.js:105–340

(buffer, _, done)

  // eslint-disable-next-line max-statements
  _transform(buffer, _, done) {
    let i = 0;
    let prevIndex = this.index;
    let { index, state, flags } = this;
    const { lookbehind, boundary, boundaryChars } = this;
    const boundaryLength = boundary.length;
    const boundaryEnd = boundaryLength - 1;
    this.bufferLength = buffer.length;
    let c = null;
    let cl = null;

    const setMark = (name, idx) => {
      this[`${name}Mark`] = typeof idx === 'number' ? idx : i;
    };

    const clearMarkSymbol = (name) => {
      delete this[`${name}Mark`];
    };

    const dataCallback = (name, shouldClear) => {
      const markSymbol = `${name}Mark`;
      if (!(markSymbol in this)) {
        return;
      }

      if (!shouldClear) {
        this._handleCallback(name, buffer, this[markSymbol], buffer.length);
        setMark(name, 0);
      } else {
        this._handleCallback(name, buffer, this[markSymbol], i);
        clearMarkSymbol(name);
      }
    };

    for (i = 0; i < this.bufferLength; i++) {
      c = buffer[i];
      switch (state) {
        case STATE.PARSER_UNINITIALIZED:
          done(this._endUnexpected());
          return;
        case STATE.START:
          index = 0;
          state = STATE.START_BOUNDARY;
        case STATE.START_BOUNDARY:
          if (index === boundary.length - 2) {
            if (c === HYPHEN) {
              flags |= FBOUNDARY.LAST_BOUNDARY;
            } else if (c !== CR) {
              done(this._endUnexpected());
              return;
            }
            index++;
            break;
          } else if (index - 1 === boundary.length - 2) {
            if (flags & FBOUNDARY.LAST_BOUNDARY && c === HYPHEN) {
              this._handleCallback('end');
              state = STATE.END;
              flags = 0;