/** * @file llmemorystream.h * @author Phoenix * @date 2005-06-03 * @brief Implementation of a simple fixed memory stream * * $LicenseInfo:firstyear=2005&license=viewerlgpl$ * Second Life Viewer Source Code * Copyright (C) 2010, Linden Research, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; * version 2.1 of the License only. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA * $/LicenseInfo$ */ #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