monero/external/rapidjson/filereadstream.h
2014-12-01 21:15:50 +02:00

95 lines
3.2 KiB
C++

// Copyright (C) 2011 Milo Yip
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#ifndef RAPIDJSON_FILEREADSTREAM_H_
#define RAPIDJSON_FILEREADSTREAM_H_
#include "rapidjson.h"
#include <cstdio>
namespace rapidjson {
//! File byte stream for input using fread().
/*!
\note implements Stream concept
*/
class FileReadStream {
public:
typedef char Ch; //!< Character type (byte).
//! Constructor.
/*!
\param fp File pointer opened for read.
\param buffer user-supplied buffer.
\param bufferSize size of buffer in bytes. Must >=4 bytes.
*/
FileReadStream(FILE* fp, char* buffer, size_t bufferSize) : fp_(fp), buffer_(buffer), bufferSize_(bufferSize), bufferLast_(0), current_(buffer_), readCount_(0), count_(0), eof_(false) {
RAPIDJSON_ASSERT(fp_ != 0);
RAPIDJSON_ASSERT(bufferSize >= 4);
Read();
}
Ch Peek() const { return *current_; }
Ch Take() { Ch c = *current_; Read(); return c; }
size_t Tell() const { return count_ + static_cast<size_t>(current_ - buffer_); }
// Not implemented
void Put(Ch) { RAPIDJSON_ASSERT(false); }
void Flush() { RAPIDJSON_ASSERT(false); }
Ch* PutBegin() { RAPIDJSON_ASSERT(false); return 0; }
size_t PutEnd(Ch*) { RAPIDJSON_ASSERT(false); return 0; }
// For encoding detection only.
const Ch* Peek4() const {
return (current_ + 4 <= bufferLast_) ? current_ : 0;
}
private:
void Read() {
if (current_ < bufferLast_)
++current_;
else if (!eof_) {
count_ += readCount_;
readCount_ = fread(buffer_, 1, bufferSize_, fp_);
bufferLast_ = buffer_ + readCount_ - 1;
current_ = buffer_;
if (readCount_ < bufferSize_) {
buffer_[readCount_] = '\0';
++bufferLast_;
eof_ = true;
}
}
}
FILE* fp_;
Ch *buffer_;
size_t bufferSize_;
Ch *bufferLast_;
Ch *current_;
size_t readCount_;
size_t count_; //!< Number of characters read
bool eof_;
};
} // namespace rapidjson
#endif // RAPIDJSON_FILESTREAM_H_