#include <string>
#include <algorithm>

class BufferedReader {
 public:
  explicit BufferedReader(PackageStream* stream): stream_(stream) {}
  int32_t Read(char* output_buffer, int32_t buffer_len) {
    int len = stream_->PackageLen();
    char* chararray = new char[len];
    while (data_.length() < (size_t) buffer_len) {
      int temp = stream_->ReadPackage(chararray);
      for (int i = 0; i < temp; i++) {
        data_ += chararray[i];
      }
      if (temp < len) {
        break;
      }
    }
    int length_buf = std::min<int>(buffer_len, data_.length());
    for (int i = 0; i < length_buf; ++i) {
      output_buffer[i] = data_[i];
    }
    data_.erase(data_.begin(), data_.begin() + length_buf);
    return length_buf;
  }

 private:
  PackageStream* stream_;
  std::string data_;
};