Function prepare_content_receiver

dependencies/httplib/httplib.h:3390–3435

template <typename T, typename U>
bool prepare_content_receiver(T &x, int &status,
                              ContentReceiverWithProgress receiver,
                              bool decompress, U callback) {
  if (decompress) {
    std::string encoding = x.get_header_value("Content-Encoding");
    std::unique_ptr<decompressor> decompressor;

    if (encoding == "gzip" || encoding == "deflate") {
#ifdef CPPHTTPLIB_ZLIB_SUPPORT
      decompressor = detail::make_unique<gzip_decompressor>();
#else
      status = 415;
      return false;
#endif
    } else if (encoding.find("br") != std::string::npos) {
#ifdef CPPHTTPLIB_BROTLI_SUPPORT
      decompressor = detail::make_unique<brotli_decompressor>();
#else
      status = 415;
      return false;
#endif
    }

    if (decompressor) {
      if (decompressor->is_valid()) {
        ContentReceiverWithProgress out = [&](const char *buf, size_t n,
                                              uint64_t off, uint64_t len) {
          return decompressor->decompress(buf, n,
                                          [&](const char *buf2, size_t n2) {
                                            return receiver(buf2, n2, off, len);
                                          });
        };
        return callback(std::move(out));
      } else {
        status = 500;
        return false;
      }
    }
  }

  ContentReceiverWithProgress out = [&](const char *buf, size_t n, uint64_t off,
                                        uint64_t len) {
    return receiver(buf, n, off, len);
  };
  return callback(std::move(out));
}

template <typename T>
bool read_content(Stream &strm, T &x, size_t payload_max_length, int &status,