123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160 |
- /* 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/InStream.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 size_t check(size_t itemSize, size_t nItems=1)
- {
- size_t nAvail;
-
- if (itemSize > (size_t)(end - ptr))
- return overrun(itemSize, nItems);
-
- nAvail = (end - ptr) / itemSize;
- if (nAvail < nItems)
- return nAvail;
-
- 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(size_t bytes) {
- while (bytes-- > 0) writeU8(0);
- }
-
- inline void skip(size_t bytes) {
- while (bytes > 0) {
- size_t n = check(1, bytes);
- ptr += n;
- bytes -= n;
- }
- }
-
- // writeBytes() writes an exact number of bytes.
-
- void writeBytes(const void* data, size_t length) {
- while (length > 0) {
- size_t n = check(1, length);
- 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) {
- size_t n = check(1, length);
- 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() {}
-
- // 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 size_t overrun(size_t itemSize, size_t nItems) = 0;
-
- protected:
-
- U8* ptr;
- U8* end;
- };
-
- }
-
- #endif
|