phoenix-firestorm/indra/llcommon/llmemorystream.h

64 lines
1.6 KiB
C++

/**
* @file llmemorystream.h
* @author Phoenix
* @date 2005-06-03
* @brief Implementation of a simple fixed memory stream
*
* Copyright (c) 2005-$CurrentYear$, Linden Research, Inc.
* $License$
*/
#ifndef LL_LLMEMORYSTREAM_H
#define LL_LLMEMORYSTREAM_H
/**
* This is a simple but effective optimization when you want to treat
* a chunk of memory as an istream. I wrote this to avoid turing a
* buffer into a string, and then throwing the string into an
* iostringstream just to parse it into another datatype, eg, LLSD.
*/
#include <iostream>
/**
* @class LLMemoryStreamBuf
* @brief This implements a wrapper around a piece of memory for istreams
*
* The memory passed in is NOT owned by an instance. The caller must
* be careful to always pass in a valid memory location that exists
* for at least as long as this streambuf.
*/
class LLMemoryStreamBuf : public std::streambuf
{
public:
LLMemoryStreamBuf(const U8* start, S32 length);
~LLMemoryStreamBuf();
void reset(const U8* start, S32 length);
protected:
int underflow();
//std::streamsize xsgetn(char* dest, std::streamsize n);
};
/**
* @class LLMemoryStream
* @brief This implements a wrapper around a piece of memory for istreams
*
* The memory passed in is NOT owned by an instance. The caller must
* be careful to always pass in a valid memory location that exists
* for at least as long as this streambuf.
*/
class LLMemoryStream : public std::istream
{
public:
LLMemoryStream(const U8* start, S32 length);
~LLMemoryStream();
protected:
LLMemoryStreamBuf mStreamBuf;
};
#endif // LL_LLMEMORYSTREAM_H