filereadstream.h
// Tencent is pleased to support the open source community by making RapidJSON available.
//
// Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved.
//
// Licensed under the MIT License (the "License"); you may not use this file except
// in compliance with the License. You may obtain a copy of the License at
//
// http://opensource.org/licenses/MIT
//
// Unless required by applicable law or agreed to in writing, software distributed
// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
// CONDITIONS OF ANY KIND, either express or implied. See the License for the
// specific language governing permissions and limitations under the License.
#ifndef RAPIDJSON_FILEREADSTREAM_H_
#define RAPIDJSON_FILEREADSTREAM_H_
#include "stream.h"
#include <cstdio>
#ifdef __clang__
RAPIDJSON_DIAG_PUSH
RAPIDJSON_DIAG_OFF(padded)
RAPIDJSON_DIAG_OFF(unreachable-code)
RAPIDJSON_DIAG_OFF(missing-noreturn)
#endif
RAPIDJSON_NAMESPACE_BEGIN
//! 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(std::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;
}
}
}
std::FILE* fp_;
Ch *buffer_;
size_t bufferSize_;
Ch *bufferLast_;
Ch *current_;
size_t readCount_;
size_t count_; //!< Number of characters read
bool eof_;
};
RAPIDJSON_NAMESPACE_END
#ifdef __clang__
RAPIDJSON_DIAG_POP
#endif
#endif // RAPIDJSON_FILESTREAM_H_
rapidjson::FileReadStream::FileReadStream
FileReadStream(std::FILE *fp, char *buffer, size_t bufferSize)
Constructor.
Definition: filereadstream.h:44
rapidjson::FileReadStream
File byte stream for input using fread().
Definition: filereadstream.h:34
rapidjson::FileReadStream::Ch
char Ch
Character type (byte).
Definition: filereadstream.h:36
RAPIDJSON_ASSERT
#define RAPIDJSON_ASSERT(x)
Assertion.
Definition: rapidjson.h:402