1 /* $Vendor-Id: chars.c,v 1.17 2010/03/23 13:25:01 kristaps Exp $ */ 2 /* 3 * Copyright (c) 2009 Kristaps Dzonsons <kristaps@kth.se> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 #ifdef HAVE_CONFIG_H 18 #include "config.h" 19 #endif 20 21 #include <assert.h> 22 #include <stdio.h> 23 #include <stdlib.h> 24 #include <string.h> 25 26 #include "chars.h" 27 28 #define PRINT_HI 126 29 #define PRINT_LO 32 30 31 struct ln { 32 struct ln *next; 33 const char *code; 34 const char *ascii; 35 const char *html; 36 size_t codesz; 37 size_t asciisz; 38 size_t htmlsz; 39 int type; 40 #define CHARS_CHAR (1 << 0) 41 #define CHARS_STRING (1 << 1) 42 #define CHARS_BOTH (CHARS_CHAR | CHARS_STRING) 43 }; 44 45 #define LINES_MAX 369 46 47 #define CHAR(w, x, y, z, a, b) \ 48 { NULL, (w), (y), (a), (x), (z), (b), CHARS_CHAR }, 49 #define STRING(w, x, y, z, a, b) \ 50 { NULL, (w), (y), (a), (x), (z), (b), CHARS_STRING }, 51 #define BOTH(w, x, y, z, a, b) \ 52 { NULL, (w), (y), (a), (x), (z), (b), CHARS_BOTH }, 53 54 #define CHAR_TBL_START static struct ln lines[LINES_MAX] = { 55 #define CHAR_TBL_END }; 56 57 #include "chars.in" 58 59 struct tbl { 60 enum chars type; 61 struct ln **htab; 62 }; 63 64 static inline int match(const struct ln *, 65 const char *, size_t, int); 66 static const char *find(struct tbl *, const char *, 67 size_t, size_t *, int); 68 69 70 void 71 chars_free(void *arg) 72 { 73 struct tbl *tab; 74 75 tab = (struct tbl *)arg; 76 77 free(tab->htab); 78 free(tab); 79 } 80 81 82 void * 83 chars_init(enum chars type) 84 { 85 struct tbl *tab; 86 struct ln **htab; 87 struct ln *pp; 88 int i, hash; 89 90 /* 91 * Constructs a very basic chaining hashtable. The hash routine 92 * is simply the integral value of the first character. 93 * Subsequent entries are chained in the order they're processed 94 * (they're in-line re-ordered during lookup). 95 */ 96 97 tab = malloc(sizeof(struct tbl)); 98 if (NULL == tab) { 99 perror(NULL); 100 exit(EXIT_FAILURE); 101 } 102 103 htab = calloc(PRINT_HI - PRINT_LO + 1, sizeof(struct ln **)); 104 if (NULL == htab) { 105 perror(NULL); 106 exit(EXIT_FAILURE); 107 } 108 109 for (i = 0; i < LINES_MAX; i++) { 110 hash = (int)lines[i].code[0] - PRINT_LO; 111 112 if (NULL == (pp = htab[hash])) { 113 htab[hash] = &lines[i]; 114 continue; 115 } 116 117 for ( ; pp->next; pp = pp->next) 118 /* Scan ahead. */ ; 119 pp->next = &lines[i]; 120 } 121 122 tab->htab = htab; 123 tab->type = type; 124 return(tab); 125 } 126 127 128 const char * 129 chars_a2ascii(void *arg, const char *p, size_t sz, size_t *rsz) 130 { 131 132 return(find((struct tbl *)arg, p, sz, rsz, CHARS_CHAR)); 133 } 134 135 136 const char * 137 chars_a2res(void *arg, const char *p, size_t sz, size_t *rsz) 138 { 139 140 return(find((struct tbl *)arg, p, sz, rsz, CHARS_STRING)); 141 } 142 143 144 static const char * 145 find(struct tbl *tab, const char *p, size_t sz, size_t *rsz, int type) 146 { 147 struct ln *pp, *prev; 148 struct ln **htab; 149 int hash; 150 151 assert(p); 152 assert(sz > 0); 153 154 if (p[0] < PRINT_LO || p[0] > PRINT_HI) 155 return(NULL); 156 157 /* 158 * Lookup the symbol in the symbol hash. See ascii2htab for the 159 * hashtable specs. This dynamically re-orders the hash chain 160 * to optimise for repeat hits. 161 */ 162 163 hash = (int)p[0] - PRINT_LO; 164 htab = tab->htab; 165 166 if (NULL == (pp = htab[hash])) 167 return(NULL); 168 169 for (prev = NULL; pp; pp = pp->next) { 170 if ( ! match(pp, p, sz, type)) { 171 prev = pp; 172 continue; 173 } 174 175 if (prev) { 176 prev->next = pp->next; 177 pp->next = htab[hash]; 178 htab[hash] = pp; 179 } 180 181 if (CHARS_HTML == tab->type) { 182 *rsz = pp->htmlsz; 183 return(pp->html); 184 } 185 *rsz = pp->asciisz; 186 return(pp->ascii); 187 } 188 189 return(NULL); 190 } 191 192 193 static inline int 194 match(const struct ln *ln, const char *p, size_t sz, int type) 195 { 196 197 if ( ! (ln->type & type)) 198 return(0); 199 if (ln->codesz != sz) 200 return(0); 201 return(0 == strncmp(ln->code, p, sz)); 202 } 203