fs/hfs/string.c

   1 /*
   2  * linux/fs/hfs/string.c
   3  *
   4  * Copyright (C) 1995-1997  Paul H. Hargrove
   5  * This file may be distributed under the terms of the GNU General Public License.
   6  *
   7  * This file contains the string comparison function for the
   8  * Macintosh character set.
   9  *
  10  * The code in this file is derived from code which is copyright
  11  * 1986, 1989, 1990 by Abacus Research and Development, Inc. (ARDI)
  12  * It is used here by the permission of ARDI's president Cliff Matthews.
  13  *
  14  * If you discover bugs in this code please notify both the author of the
  15  * Linux HFS file system: hargrove@sccm.stanford.edu (Paul H. Hargrove)
  16  * and the author of ARDI's HFS code: ctm@ardi.com (Clifford T. Matthews)
  17  *
  18  * "XXX" in a comment is a note to myself to consider changing something.
  19  */
  20
  21 #include "hfs.h"
  22
  23 /*================ File-local variables ================*/
  24
  25 /*
  26  * unsigned char caseorder[]
  27  *
  28  * Defines the lexical ordering of characters on the Macintosh
  29  *
  30  * Composition of the 'casefold' and 'order' tables from ARDI's code
  31  * with the entry for 0x20 changed to match that for 0xCA to remove
  32  * special case for those two characters.
  33  */
  34 static unsigned char caseorder[256] = {
  35 0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,
  36 0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F,
  37 0x20,0x22,0x23,0x28,0x29,0x2A,0x2B,0x2C,0x2F,0x30,0x31,0x32,0x33,0x34,0x35,0x36,
  38 0x37,0x38,0x39,0x3A,0x3B,0x3C,0x3D,0x3E,0x3F,0x40,0x41,0x42,0x43,0x44,0x45,0x46,
  39 0x47,0x48,0x57,0x59,0x5D,0x5F,0x66,0x68,0x6A,0x6C,0x72,0x74,0x76,0x78,0x7A,0x7E,
  40 0x8C,0x8E,0x90,0x92,0x95,0x97,0x9E,0xA0,0xA2,0xA4,0xA7,0xA9,0xAA,0xAB,0xAC,0xAD,
  41 0x4E,0x48,0x57,0x59,0x5D,0x5F,0x66,0x68,0x6A,0x6C,0x72,0x74,0x76,0x78,0x7A,0x7E,
  42 0x8C,0x8E,0x90,0x92,0x95,0x97,0x9E,0xA0,0xA2,0xA4,0xA7,0xAF,0xB0,0xB1,0xB2,0xB3,
  43 0x4A,0x4C,0x5A,0x60,0x7B,0x7F,0x98,0x4F,0x49,0x51,0x4A,0x4B,0x4C,0x5A,0x60,0x63,
  44 0x64,0x65,0x6E,0x6F,0x70,0x71,0x7B,0x84,0x85,0x86,0x7F,0x80,0x9A,0x9B,0x9C,0x98,
  45 0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,0x94,0xBB,0xBC,0xBD,0xBE,0xBF,0xC0,0x4D,0x81,
  46 0xC1,0xC2,0xC3,0xC4,0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0xCB,0x55,0x8A,0xCC,0x4D,0x81,
  47 0xCD,0xCE,0xCF,0xD0,0xD1,0xD2,0xD3,0x26,0x27,0xD4,0x20,0x49,0x4B,0x80,0x82,0x82,
  48 0xD5,0xD6,0x24,0x25,0x2D,0x2E,0xD7,0xD8,0xA6,0xD9,0xDA,0xDB,0xDC,0xDD,0xDE,0xDF,
  49 0xE0,0xE1,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,0xEA,0xEB,0xEC,0xED,0xEE,0xEF,
  50 0xF0,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8,0xF9,0xFA,0xFB,0xFC,0xFD,0xFE,0xFF
  51 };
  52
  53 /*
  54  * unsigned char casefold[]
  55  *
  56  * Defines the mapping to lowercase characters on the Macintosh
  57  *
  58  * "Inverse" of the 'casefold' from ARDI's code.
  59  */
  60 static unsigned char casefold[256] = {
  61 0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,
  62 0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F,
  63 0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,0x28,0x29,0x2A,0x2B,0x2C,0x2D,0x2E,0x2F,
  64 0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0x3A,0x3B,0x3C,0x3D,0x3E,0x3F,
  65 0x40,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,
  66 0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0x5B,0x5C,0x5D,0x5E,0x5F,
  67 0x41,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,
  68 0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0x7B,0x7C,0x7D,0x7E,0x7F,
  69 0x8A,0x8C,0x8D,0x8E,0x96,0x9A,0x9F,0x87,0x88,0x89,0x8A,0x8B,0x8C,0x8D,0x8E,0x8F,
  70 0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9A,0x9B,0x9C,0x9D,0x9E,0x9F,
  71 0xA0,0xA1,0xA2,0xA3,0xA4,0xA5,0xA6,0xA7,0xA8,0xA9,0xAA,0xAB,0xAC,0xAD,0xBE,0xBF,
  72 0xB0,0xB1,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,0xBB,0xBC,0xBD,0xBE,0xBF,
  73 0xC0,0xC1,0xC2,0xC3,0xC4,0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0x88,0x8B,0x9B,0xCF,0xCF,
  74 0xD0,0xD1,0xD2,0xD3,0xD4,0xD5,0xD6,0xD7,0xD8,0xD9,0xDA,0xDB,0xDC,0xDD,0xDE,0xDF,
  75 0xE0,0xE1,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,0xEA,0xEB,0xEC,0xED,0xEE,0xEF,
  76 0xF0,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8,0xF9,0xFA,0xFB,0xFC,0xFD,0xFE,0xFF
  77 };
  78
  79 /*================ Global functions ================*/
  80
  81 /*
  82  * Hash a string to an integer in a case-independent way
  83  */
  84 unsigned int hfs_strhash(const unsigned char *name, unsigned int len)
  85 {
  86         unsigned long hash = init_name_hash();
  87
  88         while (len--)
  89                 hash = partial_name_hash(caseorder[*name++],
  90                                          hash);
  91         return end_name_hash(hash);
  92 }
  93
  94 /*
  95  * Compare two strings in the HFS filename character ordering
  96  * Returns positive, negative, or zero, not just 0 or (+/-)1
  97  *
  98  * Equivalent to ARDI's call:
  99  *      ROMlib_RelString(s1+1, s2+1, true, false, (s1[0]<<16) | s2[0])
 100  */
 101 int hfs_strcmp(const unsigned char *s1, unsigned int len1,
 102                const unsigned char *s2, unsigned int len2)
 103 {
 104         int len, tmp;
 105
 106         len = (len1 > len2) ? len2 : len1;
 107
 108         while (len--) {
 109                 if ((tmp = (int)caseorder[*(s1++)] -
 110                      (int)caseorder[*(s2++)])) {
 111                         return tmp;
 112                 }
 113         }
 114         return len1 - len2;
 115 }
 116
 117 /*
 118  * Test for equality of two strings in the HFS filename character ordering.
 119  */
 120 int hfs_streq(const unsigned char *s1, unsigned int len1,
 121               const unsigned char *s2, unsigned int len2)
 122 {
 123         if (len1 != len2) {
 124                 return 0;
 125         }
 126
 127         while (len1--) {
 128                 if (caseorder[*(s1++)] != caseorder[*(s2++)]) {
 129                         return 0;
 130                 }
 131         }
 132         return 1;
 133 }
 134
 135 /*
 136  * Convert a string to the Macintosh version of lower case.
 137  */
 138 void hfs_tolower(unsigned char *p, int len)
 139 {
 140         while (len--) {
 141                 *p = casefold[*p];
 142                 ++p;
 143         }
 144 }