Annotation of embedaddon/rsync/byteorder.h, revision 1.1
1.1 ! misho 1: /*
! 2: * Simple byteorder handling.
! 3: *
! 4: * Copyright (C) 1992-1995 Andrew Tridgell
! 5: * Copyright (C) 2007-2008 Wayne Davison
! 6: *
! 7: * This program is free software; you can redistribute it and/or modify
! 8: * it under the terms of the GNU General Public License as published by
! 9: * the Free Software Foundation; either version 3 of the License, or
! 10: * (at your option) any later version.
! 11: *
! 12: * This program is distributed in the hope that it will be useful,
! 13: * but WITHOUT ANY WARRANTY; without even the implied warranty of
! 14: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
! 15: * GNU General Public License for more details.
! 16: *
! 17: * You should have received a copy of the GNU General Public License along
! 18: * with this program; if not, visit the http://fsf.org website.
! 19: */
! 20:
! 21: #undef CAREFUL_ALIGNMENT
! 22: #undef AVOID_BYTEORDER_INLINE
! 23:
! 24: /* We know that the x86 can handle misalignment and has the same
! 25: * byte order (LSB-first) as the 32-bit numbers we transmit. */
! 26: #ifdef __i386__
! 27: #define CAREFUL_ALIGNMENT 0
! 28: #endif
! 29:
! 30: #ifndef CAREFUL_ALIGNMENT
! 31: #define CAREFUL_ALIGNMENT 1
! 32: #endif
! 33:
! 34: #define CVAL(buf,pos) (((unsigned char *)(buf))[pos])
! 35: #define UVAL(buf,pos) ((uint32)CVAL(buf,pos))
! 36:
! 37: #if CAREFUL_ALIGNMENT
! 38:
! 39: #define PVAL(buf,pos) (UVAL(buf,pos)|UVAL(buf,(pos)+1)<<8)
! 40: #define IVAL(buf,pos) (PVAL(buf,pos)|PVAL(buf,(pos)+2)<<16)
! 41: #define SSVALX(buf,pos,val) (CVAL(buf,pos)=(val)&0xFF,CVAL(buf,pos+1)=(val)>>8)
! 42: #define SIVALX(buf,pos,val) (SSVALX(buf,pos,val&0xFFFF),SSVALX(buf,pos+2,val>>16))
! 43: #define SIVAL(buf,pos,val) SIVALX((buf),(pos),((uint32)(val)))
! 44:
! 45: #define IVALu(buf,pos) IVAL(buf,pos)
! 46: #define SIVALu(buf,pos,val) SIVAL(buf,pos,val)
! 47:
! 48: #else /* !CAREFUL_ALIGNMENT */
! 49:
! 50: /* This handles things for architectures like the 386 that can handle alignment errors.
! 51: * WARNING: This section is dependent on the length of an int32 (and thus a uint32)
! 52: * being correct (4 bytes)! Set CAREFUL_ALIGNMENT if it is not. */
! 53:
! 54: # ifdef AVOID_BYTEORDER_INLINE
! 55:
! 56: #define IVAL(buf,pos) (*(uint32 *)((char *)(buf) + (pos)))
! 57: #define SIVAL(buf,pos,val) IVAL(buf,pos)=((uint32)(val))
! 58:
! 59: #define IVALu(buf,pos) IVAL(buf,pos)
! 60: #define SIVALu(buf,pos,val) SIVAL(buf,pos,val)
! 61:
! 62: # else /* !AVOID_BYTEORDER_INLINE */
! 63:
! 64: static inline uint32
! 65: IVALu(const uchar *buf, int pos)
! 66: {
! 67: union {
! 68: const uchar *b;
! 69: const uint32 *num;
! 70: } u;
! 71: u.b = buf + pos;
! 72: return *u.num;
! 73: }
! 74:
! 75: static inline void
! 76: SIVALu(uchar *buf, int pos, uint32 val)
! 77: {
! 78: union {
! 79: uchar *b;
! 80: uint32 *num;
! 81: } u;
! 82: u.b = buf + pos;
! 83: *u.num = val;
! 84: }
! 85:
! 86: static inline uint32
! 87: IVAL(const char *buf, int pos)
! 88: {
! 89: return IVALu((uchar*)buf, pos);
! 90: }
! 91:
! 92: static inline void
! 93: SIVAL(char *buf, int pos, uint32 val)
! 94: {
! 95: SIVALu((uchar*)buf, pos, val);
! 96: }
! 97:
! 98: # endif /* !AVOID_BYTEORDER_INLINE */
! 99:
! 100: #endif /* !CAREFUL_ALIGNMENT */
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