tools/brcm/K24/hndtools-mipsel-uclibc-4.1.2/include/linux/zutil.h

   1 /* zutil.h -- internal interface and configuration of the compression library
   2  * Copyright (C) 1995-1998 Jean-loup Gailly.
   3  * For conditions of distribution and use, see copyright notice in zlib.h
   4  */
   5
   6 /* WARNING: this file should *not* be used by applications. It is
   7    part of the implementation of the compression library and is
   8    subject to change. Applications should only use zlib.h.
   9  */
  10
  11 /* @(#) $Id: zutil.h,v 1.1 2000/01/01 03:32:23 davem Exp $ */
  12
  13 #ifndef _Z_UTIL_H
  14 #define _Z_UTIL_H
  15
  16 #include <linux/zlib.h>
  17 #include <linux/string.h>
  18 #include <linux/errno.h>
  19 #include <linux/kernel.h>
  20
  21 #ifndef local
  22 #  define local static
  23 #endif
  24 /* compile with -Dlocal if your debugger can't find static symbols */
  25
  26 typedef unsigned char  uch;
  27 typedef uch FAR uchf;
  28 typedef unsigned short ush;
  29 typedef ush FAR ushf;
  30 typedef unsigned long  ulg;
  31
  32         /* common constants */
  33
  34 #ifndef DEF_WBITS
  35 #  define DEF_WBITS MAX_WBITS
  36 #endif
  37 /* default windowBits for decompression. MAX_WBITS is for compression only */
  38
  39 #if MAX_MEM_LEVEL >= 8
  40 #  define DEF_MEM_LEVEL 8
  41 #else
  42 #  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
  43 #endif
  44 /* default memLevel */
  45
  46 #define STORED_BLOCK 0
  47 #define STATIC_TREES 1
  48 #define DYN_TREES    2
  49 /* The three kinds of block type */
  50
  51 #define MIN_MATCH  3
  52 #define MAX_MATCH  258
  53 /* The minimum and maximum match lengths */
  54
  55 #define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */
  56
  57         /* target dependencies */
  58
  59         /* Common defaults */
  60
  61 #ifndef OS_CODE
  62 #  define OS_CODE  0x03  /* assume Unix */
  63 #endif
  64
  65          /* functions */
  66
  67 typedef uLong (ZEXPORT *check_func) OF((uLong check, const Bytef *buf,
  68                                        uInt len));
  69
  70
  71                         /* checksum functions */
  72
  73 #define BASE 65521L /* largest prime smaller than 65536 */
  74 #define NMAX 5552
  75 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
  76
  77 #define DO1(buf,i)  {s1 += buf[i]; s2 += s1;}
  78 #define DO2(buf,i)  DO1(buf,i); DO1(buf,i+1);
  79 #define DO4(buf,i)  DO2(buf,i); DO2(buf,i+2);
  80 #define DO8(buf,i)  DO4(buf,i); DO4(buf,i+4);
  81 #define DO16(buf)   DO8(buf,0); DO8(buf,8);
  82
  83 /* ========================================================================= */
  84 /*
  85      Update a running Adler-32 checksum with the bytes buf[0..len-1] and
  86    return the updated checksum. If buf is NULL, this function returns
  87    the required initial value for the checksum.
  88    An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
  89    much faster. Usage example:
  90
  91      uLong adler = adler32(0L, Z_NULL, 0);
  92
  93      while (read_buffer(buffer, length) != EOF) {
  94        adler = adler32(adler, buffer, length);
  95      }
  96      if (adler != original_adler) error();
  97 */
  98 static inline uLong zlib_adler32(uLong adler,
  99                                  const Bytef *buf,
 100                                  uInt len)
 101 {
 102     unsigned long s1 = adler & 0xffff;
 103     unsigned long s2 = (adler >> 16) & 0xffff;
 104     int k;
 105
 106     if (buf == Z_NULL) return 1L;
 107
 108     while (len > 0) {
 109         k = len < NMAX ? len : NMAX;
 110         len -= k;
 111         while (k >= 16) {
 112             DO16(buf);
 113             buf += 16;
 114             k -= 16;
 115         }
 116         if (k != 0) do {
 117             s1 += *buf++;
 118             s2 += s1;
 119         } while (--k);
 120         s1 %= BASE;
 121         s2 %= BASE;
 122     }
 123     return (s2 << 16) | s1;
 124 }
 125
 126 #endif /* _Z_UTIL_H */