Return to byteorder.h CVS log

Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / rsync

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 */