KasmVNC/common/rdr/MemOutStream.h

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/* Copyright (C) 2002-2005 RealVNC Ltd. All Rights Reserved.
*
* This is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This software 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this software; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
* USA.
*/
//
// A MemOutStream grows as needed when data is written to it.
//
#ifndef __RDR_MEMOUTSTREAM_H__
#define __RDR_MEMOUTSTREAM_H__
#include <rdr/Exception.h>
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#include <rdr/OutStream.h>
namespace rdr {
class MemOutStream : public OutStream {
public:
MemOutStream(int len=1024) {
start = ptr = new U8[len];
end = start + len;
}
virtual ~MemOutStream() {
delete [] start;
}
size_t length() { return ptr - start; }
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void clear() { ptr = start; };
void clearAndZero() { memset(start, 0, ptr-start); clear(); }
void reposition(size_t pos) { ptr = start + pos; }
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// data() returns a pointer to the buffer.
const void* data() { return (const void*)start; }
protected:
// overrun() either doubles the buffer or adds enough space for nItems of
// size itemSize bytes.
size_t overrun(size_t itemSize, size_t nItems) {
size_t len = ptr - start + itemSize * nItems;
if (len < (size_t)(end - start) * 2)
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len = (end - start) * 2;
if (len < (size_t)(end - start))
throw Exception("Overflow in MemOutStream::overrun()");
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U8* newStart = new U8[len];
memcpy(newStart, start, ptr - start);
ptr = newStart + (ptr - start);
delete [] start;
start = newStart;
end = newStart + len;
return nItems;
}
U8* start;
};
}
#endif