fs/hfs/string.c

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 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 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 longhfs_strhash(const struct hfs_name *cname)
 85 {
 86 unsigned long hash =init_name_hash();
 87 unsigned int i;
 88 for(i =0; i < cname->Len; i++) {
 89  hash =partial_name_hash(caseorder[cname->Name[i]], hash);
 90 }
 91 returnend_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 inthfs_strcmp(const struct hfs_name *s1,const struct hfs_name *s2)
 102 {
 103 int len, tmp;
 104 const unsigned char*p1, *p2;
 105
 106 if(!s1 || !s2) {
 107 return0;
 108 }
 109
 110  len = (s1->Len > s2->Len) ? s2->Len : s1->Len;
 111  p1 = s1->Name;
 112  p2 = s2->Name;
 113
 114 while(len--) {
 115 if((tmp = (int)caseorder[*(p1++)]-(int)caseorder[*(p2++)])) {
 116 return tmp;
 117 }
 118 }
 119 return s1->Len - s2->Len;
 120 }
 121
 122 /*
 123  * Test for equality of two strings in the HFS filename character ordering.
 124  */
 125 inthfs_streq(const struct hfs_name *s1,const struct hfs_name *s2)
 126 {
 127 int len;
 128 const unsigned char*p1, *p2;
 129
 130 if(!s1 || !s2 || (s1->Len != s2->Len)) {
 131 return0;
 132 }
 133
 134  len = s1->Len;
 135  p1 = s1->Name;
 136  p2 = s2->Name;
 137
 138 while(len--) {
 139 if(caseorder[*(p1++)] != caseorder[*(p2++)]) {
 140 return0;
 141 }
 142 }
 143 return1;
 144 }
 145
 146 /*
 147  * Convert a string to the Macintosh version of lower case.
 148  */
 149 voidhfs_tolower(unsigned char*p,int len)
 150 {
 151 while(len--) {
 152 *p = casefold[*p];
 153 ++p;
 154 }
 155 }