workbench/devs/diskimage/include/bytepack.h

   1 /* Copyright 2007-2012 Fredrik Wikstrom. All rights reserved.
   2 **
   3 ** Redistribution and use in source and binary forms, with or without
   4 ** modification, are permitted provided that the following conditions
   5 ** are met:
   6 **
   7 ** 1. Redistributions of source code must retain the above copyright
   8 **    notice, this list of conditions and the following disclaimer.
   9 **
  10 ** 2. Redistributions in binary form must reproduce the above copyright
  11 **    notice, this list of conditions and the following disclaimer in the
  12 **    documentation and/or other materials provided with the distribution.
  13 **
  14 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
  15 ** AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16 ** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17 ** ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  18 ** LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  19 ** CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  20 ** SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  21 ** INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  22 ** CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  23 ** ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  24 ** POSSIBILITY OF SUCH DAMAGE.
  25 */
  26
  27 #ifndef BYTEPACK_H
  28 #define BYTEPACK_H
  29
  30 #ifndef EXEC_TYPES_H
  31 #include <exec/types.h>
  32 #endif
  33
  34 #include <string.h>
  35
  36 typedef struct {
  37         UBYTE *start, *current, *end;
  38 } BytePackBuffer;
  39
  40 static inline void BytePackInit (BytePackBuffer *b, APTR addr, ULONG len) {
  41         b->start = b->current = addr;
  42         b->end = (UBYTE *)addr + len;
  43 }
  44
  45 static inline void BytePackWrite8 (BytePackBuffer *b, UBYTE val) {
  46         if (b->current < b->end) {
  47                 *b->current++ = val;
  48         }
  49 }
  50
  51 static inline void BytePackWrite16MSB (BytePackBuffer *b, UWORD val) {
  52         BytePackWrite8(b, val >> 8);
  53         BytePackWrite8(b, val);
  54 }
  55
  56 static inline void BytePackWrite24MSB (BytePackBuffer *b, ULONG val) {
  57         BytePackWrite8(b, val >> 16);
  58         BytePackWrite8(b, val >> 8);
  59         BytePackWrite8(b, val);
  60 }
  61 static inline void BytePackWrite32MSB (BytePackBuffer *b, ULONG val) {
  62         BytePackWrite8(b, val >> 24);
  63         BytePackWrite8(b, val >> 16);
  64         BytePackWrite8(b, val >> 8);
  65         BytePackWrite8(b, val);
  66 }
  67
  68 static inline void BytePackWrite16LSB (BytePackBuffer *b, UWORD val) {
  69         BytePackWrite8(b, val);
  70         BytePackWrite8(b, val >> 8);
  71 }
  72
  73 static inline void BytePackWrite24LSB (BytePackBuffer *b, ULONG val) {
  74         BytePackWrite8(b, val);
  75         BytePackWrite8(b, val >> 8);
  76         BytePackWrite8(b, val >> 16);
  77 }
  78 static inline void BytePackWrite32LSB (BytePackBuffer *b, ULONG val) {
  79         BytePackWrite8(b, val);
  80         BytePackWrite8(b, val >> 8);
  81         BytePackWrite8(b, val >> 16);
  82         BytePackWrite8(b, val >> 24);
  83 }
  84
  85 static inline void BytePackWriteText (BytePackBuffer *b, CONST_STRPTR txt, ULONG len) {
  86         ULONG space = b->end - b->current;
  87         if (len > space) {
  88                 len = space;
  89         }
  90         if (len > 0) {
  91                 strncpy(b->current, txt, len);
  92                 b->current += len;
  93         }
  94 }
  95
  96 static inline ULONG BytePackBytesWritten (BytePackBuffer *b) {
  97         return (ULONG)(b->current - b->start);
  98 }
  99
 100 #endif