/** * @file llmemorystream.h * @author Phoenix * @date 2005-06-03 * @brief Implementation of a simple fixed memory stream * * $LicenseInfo:firstyear=2005&license=viewergpl$ * * Copyright (c) 2005-2009, Linden Research, Inc. * * Second Life Viewer Source Code * The source code in this file ("Source Code") is provided by Linden Lab * to you under the terms of the GNU General Public License, version 2.0 * ("GPL"), unless you have obtained a separate licensing agreement * ("Other License"), formally executed by you and Linden Lab. Terms of * the GPL can be found in doc/GPL-license.txt in this distribution, or * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2 * * There are special exceptions to the terms and conditions of the GPL as * it is applied to this Source Code. View the full text of the exception * in the file doc/FLOSS-exception.txt in this software distribution, or * online at * http://secondlifegrid.net/programs/open_source/licensing/flossexception * * By copying, modifying or distributing this software, you acknowledge * that you have read and understood your obligations described above, * and agree to abide by those obligations. * * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY, * COMPLETENESS OR PERFORMANCE. * $/LicenseInfo$ */ #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 LL_COMMON_API 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 LL_COMMON_API LLMemoryStream : public std::istream { public: LLMemoryStream(const U8* start, S32 length); ~LLMemoryStream(); protected: LLMemoryStreamBuf mStreamBuf; }; #endif // LL_LLMEMORYSTREAM_H