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- /* Copyright (C) 2002-2003 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.
- */
-
- //
- // rdr::OutStream marshalls data into a buffer stored in RDR (RFB Data
- // Representation).
- //
-
- #ifndef __RDR_OUTSTREAM_H__
- #define __RDR_OUTSTREAM_H__
-
- #include <rdr/types.h>
- #include <rdr/Exception.h>
- #include <rdr/InStream.h>
- #include <string.h> // for memcpy
-
- namespace rdr {
-
- class OutStream {
-
- protected:
-
- OutStream() : ptr(NULL), end(NULL), corked(false) {}
-
- public:
-
- virtual ~OutStream() {}
-
- // avail() returns the number of bytes that currently be written to the
- // stream without any risk of blocking.
-
- inline size_t avail()
- {
- return end - ptr;
- }
-
- // writeU/SN() methods write unsigned and signed N-bit integers.
-
- inline void writeU8( U8 u) { check(1); *ptr++ = u; }
- inline void writeU16(U16 u) { check(2); *ptr++ = u >> 8; *ptr++ = (U8)u; }
- inline void writeU32(U32 u) { check(4); *ptr++ = u >> 24; *ptr++ = u >> 16;
- *ptr++ = u >> 8; *ptr++ = u; }
-
- inline void writeS8( S8 s) { writeU8((U8)s); }
- inline void writeS16(S16 s) { writeU16((U16)s); }
- inline void writeS32(S32 s) { writeU32((U32)s); }
-
- inline void pad(size_t bytes) {
- while (bytes-- > 0) writeU8(0);
- }
-
- // writeBytes() writes an exact number of bytes.
-
- void writeBytes(const void* data, size_t length) {
- while (length > 0) {
- check(1);
- size_t n = length;
- if (length > avail())
- n = avail();
- memcpy(ptr, data, n);
- ptr += n;
- data = (U8*)data + n;
- length -= n;
- }
- }
-
- // copyBytes() efficiently transfers data between streams
-
- void copyBytes(InStream* is, size_t length) {
- while (length > 0) {
- check(1);
- size_t n = length;
- if (length > avail())
- n = avail();
- is->readBytes(ptr, n);
- ptr += n;
- length -= n;
- }
- }
-
- // writeOpaqueN() writes a quantity without byte-swapping.
-
- inline void writeOpaque8( U8 u) { writeU8(u); }
- inline void writeOpaque16(U16 u) { check(2); *ptr++ = ((U8*)&u)[0];
- *ptr++ = ((U8*)&u)[1]; }
- inline void writeOpaque32(U32 u) { check(4); *ptr++ = ((U8*)&u)[0];
- *ptr++ = ((U8*)&u)[1];
- *ptr++ = ((U8*)&u)[2];
- *ptr++ = ((U8*)&u)[3]; }
-
- // length() returns the length of the stream.
-
- virtual size_t length() = 0;
-
- // flush() requests that the stream be flushed.
-
- virtual void flush() {}
-
- // cork() requests that the stream coalesces flushes in an efficient way
-
- virtual void cork(bool enable) { corked = enable; flush(); }
-
- // getptr() and setptr() are "dirty" methods which allow you direct access
- // to the buffer. This is useful for a stream which is a wrapper around an
- // some other stream API. Note that setptr() should not called with a value
- // larger than the bytes actually written as doing so can result in
- // security issues. Use pad() in such cases instead.
-
- inline U8* getptr(size_t length) { check(length); return ptr; }
- inline void setptr(size_t length) { if (length > avail())
- throw Exception("Output stream overflow");
- ptr += length; }
-
- private:
-
- inline void check(size_t length)
- {
- if (length > avail())
- overrun(length);
- }
-
- // overrun() is implemented by a derived class to cope with buffer overrun.
- // It ensures there are at least needed bytes of buffer space.
-
- virtual void overrun(size_t needed) = 0;
-
- protected:
-
- U8* ptr;
- U8* end;
-
- bool corked;
- };
-
- }
-
- #endif
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