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SingularityViewer/indra/llmessage/llbufferstream.h
2012-08-20 21:18:19 +02:00

167 lines
4.4 KiB
C++

/**
* @file llbufferstream.h
* @author Phoenix
* @date 2005-10-10
* @brief Classes to treat an LLBufferArray as a c++ iostream.
*
* $LicenseInfo:firstyear=2005&license=viewerlgpl$
* 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_LLBUFFERSTREAM_H
#define LL_LLBUFFERSTREAM_H
#include <iosfwd>
#include <iostream>
#include "llbuffer.h"
/**
* @class LLBufferStreamBuf
* @brief This implements the buffer wrapper for an istream
*
* The buffer array passed in is not owned by the stream buf object.
*/
class LLBufferStreamBuf : public std::streambuf
{
public:
LLBufferStreamBuf(
const LLChannelDescriptors& channels,
LLBufferArray* buffer);
virtual ~LLBufferStreamBuf();
protected:
#if( LL_WINDOWS || __GNUC__ > 2 )
typedef std::streambuf::pos_type pos_type;
typedef std::streambuf::off_type off_type;
#endif
/* @name streambuf vrtual implementations
*/
//@{
/*
* @brief called when we hit the end of input
*
* @return Returns the character at the current position or EOF.
*/
virtual int underflow();
/*
* @brief called when we hit the end of output
*
* @param c The character to store at the current put position
* @return Returns EOF if the function failed. Any other value on success.
*/
virtual int overflow(int c);
/*
* @brief synchronize the buffer
*
* @return Returns 0 on success or -1 on failure.
*/
virtual int sync();
/*
* @brief Seek to an offset position in a stream.
*
* @param off Offset value relative to way paramter
* @param way The seek direction. One of ios::beg, ios::cur, and ios::end.
* @param which Which pointer to modify. One of ios::in, ios::out,
* or both masked together.
* @return Returns the new position or an invalid position on failure.
*/
#if( LL_WINDOWS || __GNUC__ > 2)
virtual pos_type seekoff(
off_type off,
std::ios::seekdir way,
std::ios::openmode which);
#else
virtual streampos seekoff(
streamoff off,
std::ios::seekdir way,
std::ios::openmode which);
#endif
/*
* @brief Get s sequence of characters from the input
*
* @param dst Pointer to a block of memory to accept the characters
* @param length Number of characters to be read
* @return Returns the number of characters read
*/
//virtual streamsize xsgetn(char* dst, streamsize length);
/*
* @brief Write some characters to output
*
* @param src Pointer to a sequence of characters to be output
* @param length Number of characters to be put
* @return Returns the number of characters written
*/
//virtual streamsize xsputn(char* src, streamsize length);
//@}
public:
/*
* @brief Return number of bytes in input channel.
*/
S32 count_in(void) const { return mBuffer->count(mChannels.in()); }
/*
* @brief Return number of bytes in output channel.
*/
S32 count_out(void) const { return mBuffer->count(mChannels.out()); }
protected:
// This channels we are working on.
LLChannelDescriptors mChannels;
// The buffer we work on
LLBufferArray* mBuffer;
};
/**
* @class LLBufferStream
* @brief This implements an istream based wrapper around an LLBufferArray.
*
* This class does not own the buffer array, and does not hold a
* shared pointer to it. Since the class itself is fairly ligthweight,
* just make one on the stack when needed and let it fall out of
* scope.
*/
class LLBufferStream : public std::iostream
{
public:
LLBufferStream(
const LLChannelDescriptors& channels,
LLBufferArray* buffer);
~LLBufferStream();
S32 count_in(void) const { return mStreamBuf.count_in(); }
S32 count_out(void) const { return mStreamBuf.count_out(); }
protected:
LLBufferStreamBuf mStreamBuf;
};
#endif // LL_LLBUFFERSTREAM_H