rapidjson/include/rapidjson/memorybuffer.h

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2014-07-27 19:29:57 +08:00
#ifndef RAPIDJSON_MEMORYBUFFER_H_
#define RAPIDJSON_MEMORYBUFFER_H_
#include "rapidjson.h"
#include "internal/stack.h"
namespace rapidjson {
//! Represents an in-memory output byte stream.
/*!
This class is mainly for being wrapped by EncodedOutputStream or AutoUTFOutputStream.
It is similar to FileWriteBuffer but the destination is an in-memory buffer instead of a file.
Differences between MemoryBuffer and StringBuffer:
1. StringBuffer has Encoding but MemoryBuffer is only a byte buffer.
2. StringBuffer::GetString() returns a null-terminated string. MemoryBuffer::GetBuffer() returns a buffer without terminator.
\tparam Allocator type for allocating memory buffer.
\note implements Stream concept
*/
template <typename Allocator = CrtAllocator>
struct GenericMemoryBuffer {
typedef char Ch; // byte
GenericMemoryBuffer(Allocator* allocator = 0, size_t capacity = kDefaultCapacity) : stack_(allocator, capacity) {}
void Put(Ch c) { *stack_.template Push<Ch>() = c; }
void Flush() {}
void Clear() { stack_.Clear(); }
Ch* Push(size_t count) { return stack_.template Push<Ch>(count); }
void Pop(size_t count) { stack_.template Pop<Ch>(count); }
const Ch* GetBuffer() const {
return stack_.template Bottom<Ch>();
}
size_t GetSize() const { return stack_.GetSize(); }
static const size_t kDefaultCapacity = 256;
mutable internal::Stack<Allocator> stack_;
};
typedef GenericMemoryBuffer<> MemoryBuffer;
//! Implement specialized version of PutN() with memset() for better performance.
template<>
inline void PutN(MemoryBuffer& memoryBuffer, char c, size_t n) {
memset(memoryBuffer.stack_.Push<char>(n), c, n * sizeof(c));
}
} // namespace rapidjson
#endif // RAPIDJSON_MEMORYBUFFER_H_