filewritestream.h 1.6 KB

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  1. #ifndef RAPIDJSON_FILEWRITESTREAM_H_
  2. #define RAPIDJSON_FILEWRITESTREAM_H_
  3. #include "rapidjson.h"
  4. #include <cstdio>
  5. namespace rapidjson {
  6. //! Wrapper of C file stream for input using fread().
  7. /*!
  8. \implements Stream
  9. */
  10. class FileWriteStream {
  11. public:
  12. typedef char Ch; //!< Character type. Only support char.
  13. FileWriteStream(FILE* fp, char* buffer, size_t bufferSize) : fp_(fp), buffer_(buffer), bufferEnd_(buffer + bufferSize), current_(buffer_) {
  14. RAPIDJSON_ASSERT(fp_ != 0);
  15. }
  16. void Put(char c) {
  17. if (current_ >= bufferEnd_)
  18. Flush();
  19. *current_++ = c;
  20. }
  21. void PutN(char c, size_t n) {
  22. size_t avail = bufferEnd_ - current_;
  23. while (n > avail) {
  24. memset(current_, c, avail);
  25. current_ += avail;
  26. Flush();
  27. n -= avail;
  28. avail = bufferEnd_ - current_;
  29. }
  30. if (n > 0) {
  31. memset(current_, c, n);
  32. current_ += n;
  33. }
  34. }
  35. void Flush() {
  36. if (current_ != buffer_) {
  37. fwrite(buffer_, 1, current_ - buffer_, fp_);
  38. current_ = buffer_;
  39. }
  40. }
  41. // Not implemented
  42. char Peek() const { RAPIDJSON_ASSERT(false); return 0; }
  43. char Take() { RAPIDJSON_ASSERT(false); return 0; }
  44. size_t Tell() const { RAPIDJSON_ASSERT(false); return 0; }
  45. char* PutBegin() { RAPIDJSON_ASSERT(false); return 0; }
  46. size_t PutEnd(char*) { RAPIDJSON_ASSERT(false); return 0; }
  47. private:
  48. FILE* fp_;
  49. char *buffer_;
  50. char *bufferEnd_;
  51. char *current_;
  52. };
  53. //! Implement specialized version of PutN() with memset() for better performance.
  54. template<>
  55. inline void PutN(FileWriteStream& stream, char c, size_t n) {
  56. stream.PutN(c, n);
  57. }
  58. } // namespace rapidjson
  59. #endif // RAPIDJSON_FILESTREAM_H_