rapidjson/include/rapidjson/filewritestream.h
2014-06-25 16:06:00 +08:00

74 lines
1.7 KiB
C++

#ifndef RAPIDJSON_FILEWRITESTREAM_H_
#define RAPIDJSON_FILEWRITESTREAM_H_
#include "rapidjson.h"
#include <cstdio>
namespace rapidjson {
//! Wrapper of C file stream for input using fread().
/*!
\note implements Stream concept
*/
class FileWriteStream {
public:
typedef char Ch; //!< Character type. Only support char.
FileWriteStream(FILE* fp, char* buffer, size_t bufferSize) : fp_(fp), buffer_(buffer), bufferEnd_(buffer + bufferSize), current_(buffer_) {
RAPIDJSON_ASSERT(fp_ != 0);
}
void Put(char c) {
if (current_ >= bufferEnd_)
Flush();
*current_++ = c;
}
void PutN(char c, size_t n) {
size_t avail = static_cast<size_t>(bufferEnd_ - current_);
while (n > avail) {
memset(current_, c, avail);
current_ += avail;
Flush();
n -= avail;
avail = static_cast<size_t>(bufferEnd_ - current_);
}
if (n > 0) {
memset(current_, c, n);
current_ += n;
}
}
void Flush() {
if (current_ != buffer_) {
fwrite(buffer_, 1, static_cast<size_t>(current_ - buffer_), fp_);
current_ = buffer_;
}
}
// Not implemented
char Peek() const { RAPIDJSON_ASSERT(false); return 0; }
char Take() { RAPIDJSON_ASSERT(false); return 0; }
size_t Tell() const { RAPIDJSON_ASSERT(false); return 0; }
char* PutBegin() { RAPIDJSON_ASSERT(false); return 0; }
size_t PutEnd(char*) { RAPIDJSON_ASSERT(false); return 0; }
private:
FILE* fp_;
char *buffer_;
char *bufferEnd_;
char *current_;
};
//! Implement specialized version of PutN() with memset() for better performance.
template<>
inline void PutN(FileWriteStream& stream, char c, size_t n) {
stream.PutN(c, n);
}
} // namespace rapidjson
#endif // RAPIDJSON_FILESTREAM_H_