void onIngress()

in proxygen/lib/http/codec/compress/experimental/interop/QPACKInterop.cpp [319:382]
64 lines of code
17 McCabe index (conditional complexity)

  void onIngress(folly::IOBufQueue& input) override {
    Cursor c(input.front());
    while (!c.isAtEnd()) {
      switch (state_) {
        case LINESTART: {
          seenR = false;
          auto p = c.peek();
          switch (p.first[0]) {
            case '#':
              state_ = COMMENT;
              break;
            case '\r':
            case '\n':
              if (!blocks.back().empty()) {
                blocks.emplace_back();
              }
              state_ = EOL;
              break;
            default:
              state_ = NAME;
              strings.emplace_back();
          }
          break;
        }
        case COMMENT:
          c.skipWhile([](uint8_t ch) { return !iseol(ch); });
          if (!c.isAtEnd()) {
            state_ = EOL;
          }
          break;
        case EOL: {
          auto p = c.peek();
          if (p.first[0] == '\n') {
            c.skip(1);
            state_ = LINESTART;
          } else if (seenR) { // \r followed by anything but \n -> mac newline
            state_ = LINESTART;
          } else if (p.first[0] == '\r') {
            c.skip(1);
            seenR = true;
          }
          break;
        }
        case NAME:
          strings.back() += c.readWhile([](uint8_t ch) { return ch != '\t'; });
          if (!c.isAtEnd()) {
            c.skip(1);
            state_ = VALUE;
            strings.emplace_back();
          }
          break;
        case VALUE:
          strings.back() += c.readWhile([](uint8_t ch) { return !iseol(ch); });
          if (!c.isAtEnd()) {
            CHECK_GE(strings.size(), 2);
            blocks.back().emplace_back(compress::Header::makeHeaderForTest(
                *(strings.rbegin() + 1), *strings.rbegin()));
            state_ = EOL;
          }
          break;
      }
    }
    input.move();
  }