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+//
+// Copyright (C) 2002 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 <string.h> // for memcpy
+
+namespace rdr {
+
+ class OutStream {
+
+ protected:
+
+ OutStream() {}
+
+ public:
+
+ virtual ~OutStream() {}
+
+ // check() ensures there is buffer space for at least one item of size
+ // itemSize bytes. Returns the number of items which fit (up to a maximum
+ // of nItems).
+
+ inline int check(int itemSize, int nItems=1)
+ {
+ if (ptr + itemSize * nItems > end) {
+ if (ptr + itemSize > end)
+ return overrun(itemSize, nItems);
+
+ nItems = (end - ptr) / itemSize;
+ }
+ return nItems;
+ }
+
+ // 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); }
+
+ // writeString() writes a string - a U32 length followed by the data. The
+ // given string should be null-terminated (but the terminating null is not
+ // written to the stream).
+
+ inline void writeString(const char* str) {
+ U32 len = strlen(str);
+ writeU32(len);
+ writeBytes(str, len);
+ }
+
+ inline void pad(int bytes) {
+ while (bytes-- > 0) writeU8(0);
+ }
+
+ inline void skip(int bytes) {
+ while (bytes > 0) {
+ int n = check(1, bytes);
+ ptr += n;
+ bytes -= n;
+ }
+ }
+
+ // writeBytes() writes an exact number of bytes.
+
+ virtual void writeBytes(const void* data, int length) {
+ const U8* dataPtr = (const U8*)data;
+ const U8* dataEnd = dataPtr + length;
+ while (dataPtr < dataEnd) {
+ int n = check(1, dataEnd - dataPtr);
+ memcpy(ptr, dataPtr, n);
+ ptr += n;
+ dataPtr += 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]; }
+ inline void writeOpaque24A(U32 u) { check(3); *ptr++ = ((U8*)&u)[0];
+ *ptr++ = ((U8*)&u)[1];
+ *ptr++ = ((U8*)&u)[2]; }
+ inline void writeOpaque24B(U32 u) { check(3); *ptr++ = ((U8*)&u)[1];
+ *ptr++ = ((U8*)&u)[2];
+ *ptr++ = ((U8*)&u)[3]; }
+
+ // length() returns the length of the stream.
+
+ virtual int length() = 0;
+
+ // flush() requests that the stream be flushed.
+
+ virtual void flush() {}
+
+ // getptr(), getend() and setptr() are "dirty" methods which allow you to
+ // manipulate the buffer directly. This is useful for a stream which is a
+ // wrapper around an underlying stream.
+
+ inline U8* getptr() { return ptr; }
+ inline U8* getend() { return end; }
+ inline void setptr(U8* p) { ptr = p; }
+
+ private:
+
+ // overrun() is implemented by a derived class to cope with buffer overrun.
+ // It ensures there are at least itemSize bytes of buffer space. Returns
+ // the number of items which fit (up to a maximum of nItems). itemSize is
+ // supposed to be "small" (a few bytes).
+
+ virtual int overrun(int itemSize, int nItems) = 0;
+
+ protected:
+
+ U8* ptr;
+ U8* end;
+ };
+
+}
+
+#endif