xref: /openbsd-src/lib/libcurses/tinfo/comp_hash.c (revision 92dd1ec0a89df25171bc5d61a3d95ea1a68cef0b)
1 /*	$OpenBSD: comp_hash.c,v 1.1 1999/01/18 19:10:14 millert Exp $	*/
2 
3 /****************************************************************************
4  * Copyright (c) 1998 Free Software Foundation, Inc.                        *
5  *                                                                          *
6  * Permission is hereby granted, free of charge, to any person obtaining a  *
7  * copy of this software and associated documentation files (the            *
8  * "Software"), to deal in the Software without restriction, including      *
9  * without limitation the rights to use, copy, modify, merge, publish,      *
10  * distribute, distribute with modifications, sublicense, and/or sell       *
11  * copies of the Software, and to permit persons to whom the Software is    *
12  * furnished to do so, subject to the following conditions:                 *
13  *                                                                          *
14  * The above copyright notice and this permission notice shall be included  *
15  * in all copies or substantial portions of the Software.                   *
16  *                                                                          *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
20  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
21  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
22  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
23  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
24  *                                                                          *
25  * Except as contained in this notice, the name(s) of the above copyright   *
26  * holders shall not be used in advertising or otherwise to promote the     *
27  * sale, use or other dealings in this Software without prior written       *
28  * authorization.                                                           *
29  ****************************************************************************/
30 
31 /****************************************************************************
32  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
33  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
34  ****************************************************************************/
35 
36 
37 /*
38  *	comp_hash.c --- Routines to deal with the hashtable of capability
39  *			names.
40  *
41  */
42 
43 #include <curses.priv.h>
44 
45 #include <tic.h>
46 #include <hashsize.h>
47 
48 #ifdef MAIN_PROGRAM
49 #include <ctype.h>
50 #undef  DEBUG
51 #define DEBUG(level, params) /*nothing*/
52 #endif
53 
54 MODULE_ID("$From: comp_hash.c,v 1.18 1998/08/22 18:01:18 tom Exp $")
55 
56 static  int hash_function(const char *);
57 
58 /*
59  *	_nc_make_hash_table()
60  *
61  *	Takes the entries in table[] and hashes them into hash_table[]
62  *	by name.  There are CAPTABSIZE entries in table[] and HASHTABSIZE
63  *	slots in hash_table[].
64  *
65  */
66 
67 #ifdef MAIN_PROGRAM
68 static void _nc_make_hash_table(struct name_table_entry *table,
69 		     struct name_table_entry **hash_table)
70 {
71 int	i;
72 int	hashvalue;
73 int	collisions = 0;
74 
75 	for (i = 0; i < CAPTABSIZE; i++) {
76 	    hashvalue = hash_function(table[i].nte_name);
77 
78 	    if (hash_table[hashvalue] != (struct name_table_entry *) 0)
79 		collisions++;
80 
81 	    if (hash_table[hashvalue] != 0)
82 		table[i].nte_link = (short)(hash_table[hashvalue] - table);
83 	    hash_table[hashvalue] = &table[i];
84 	}
85 
86 	DEBUG(4, ("Hash table complete: %d collisions out of %d entries", collisions, CAPTABSIZE));
87 }
88 #endif
89 
90 
91 /*
92  *	int hash_function(string)
93  *
94  *	Computes the hashing function on the given string.
95  *
96  *	The current hash function is the sum of each consectutive pair
97  *	of characters, taken as two-byte integers, mod Hashtabsize.
98  *
99  */
100 
101 static
102 int
103 hash_function(const char *string)
104 {
105 long	sum = 0;
106 
107 	DEBUG(9, ("hashing %s", string));
108 	while (*string) {
109 	    sum += (long)(*string + (*(string + 1) << 8));
110 	    string++;
111 	}
112 
113 	DEBUG(9, ("sum is %ld", sum));
114 	return (int)(sum % HASHTABSIZE);
115 }
116 
117 
118 /*
119  *	struct name_table_entry *
120  *	find_entry(string)
121  *
122  *	Finds the entry for the given string in the hash table if present.
123  *	Returns a pointer to the entry in the table or 0 if not found.
124  *
125  */
126 
127 #ifndef MAIN_PROGRAM
128 struct name_table_entry const *
129 _nc_find_entry(const char *string, const struct name_table_entry *const *hash_table)
130 {
131 int	hashvalue;
132 struct name_table_entry	const *ptr;
133 
134 	hashvalue = hash_function(string);
135 
136 	if ((ptr = hash_table[hashvalue]) != 0) {
137 		while (strcmp(ptr->nte_name, string) != 0) {
138 			if (ptr->nte_link < 0)
139 				return 0;
140 			ptr = ptr->nte_link + hash_table[HASHTABSIZE];
141 		}
142 	}
143 
144 	return (ptr);
145 }
146 
147 /*
148  *	struct name_table_entry *
149  *	find_type_entry(string, type, table)
150  *
151  *	Finds the first entry for the given name with the given type in the
152  *	given table if present (as distinct from find_entry, which finds the
153  *	the last entry regardless of type).  You can use this if you detect
154  *	a name clash.  It's slower, though.  Returns a pointer to the entry
155  *	in the table or 0 if not found.
156  */
157 
158 struct name_table_entry const *
159 _nc_find_type_entry(const char *string,
160 		    int type,
161 		    const struct name_table_entry *table)
162 {
163 struct name_table_entry	const *ptr;
164 
165 	for (ptr = table; ptr < table + CAPTABSIZE; ptr++) {
166 	    if (ptr->nte_type == type && strcmp(string, ptr->nte_name) == 0)
167 		return(ptr);
168 	}
169 
170 	return ((struct name_table_entry *)NULL);
171 }
172 #endif
173 
174 #ifdef MAIN_PROGRAM
175 /*
176  * This filter reads from standard input a list of tab-delimited columns,
177  * (e.g., from Caps.filtered) computes the hash-value of a specified column and
178  * writes the hashed tables to standard output.
179  *
180  * By compiling the hash table at build time, we're able to make the entire
181  * set of terminfo and termcap tables readonly (and also provide some runtime
182  * performance enhancement).
183  */
184 
185 #if !HAVE_STRDUP
186 static char *strdup (char *s)
187 {
188   char *p;
189 
190   p = malloc(strlen(s)+1);
191   if (p)
192     strcpy(p,s);
193   return(p);
194 }
195 #endif /* not HAVE_STRDUP */
196 
197 #define MAX_COLUMNS BUFSIZ	/* this _has_ to be worst-case */
198 
199 static char **parse_columns(char *buffer)
200 {
201 	static char **list;
202 
203 	int col = 0;
204 
205 	if (list == 0 && (list = typeCalloc(char *, MAX_COLUMNS)) == 0)
206 		return(0);
207 
208 	if (*buffer != '#') {
209 		while (*buffer != '\0') {
210 			char *s;
211 			for (s = buffer; (*s != '\0') && !isspace(*s); s++)
212 				/*EMPTY*/;
213 			if (s != buffer) {
214 				char mark = *s;
215 				*s = '\0';
216 				if ((s - buffer) > 1
217 				 && (*buffer == '"')
218 				 && (s[-1] == '"')) {	/* strip the quotes */
219 					buffer++;
220 					s[-1] = '\0';
221 				}
222 				list[col] = buffer;
223 				col++;
224 				if (mark == '\0')
225 					break;
226 				while (*++s && isspace(*s))
227 					/*EMPTY*/;
228 				buffer = s;
229 			} else
230 				break;
231 		}
232 	}
233 	return col ? list : 0;
234 }
235 
236 int main(int argc, char **argv)
237 {
238 	struct name_table_entry *name_table = typeCalloc(struct name_table_entry, CAPTABSIZE);
239 	struct name_table_entry **hash_table = typeCalloc(struct name_table_entry *, HASHTABSIZE);
240 	const char *root_name = "";
241 	int  column = 0;
242 	int  n;
243 	char buffer[BUFSIZ];
244 
245 	static const char * typenames[] = { "BOOLEAN", "NUMBER", "STRING" };
246 
247 	short BoolCount = 0;
248 	short NumCount  = 0;
249 	short StrCount  = 0;
250 
251 	/* The first argument is the column-number (starting with 0).
252 	 * The second is the root name of the tables to generate.
253 	 */
254 	if (argc <= 2
255 	 || (column = atoi(argv[1])) <= 0
256 	 || (column >= MAX_COLUMNS)
257 	 || *(root_name = argv[2]) == 0) {
258 		fprintf(stderr, "usage: make_hash column root_name\n");
259 		exit(EXIT_FAILURE);
260 	}
261 
262 	/*
263 	 * Read the table into our arrays.
264 	 */
265 	for (n = 0; (n < CAPTABSIZE) && fgets(buffer, BUFSIZ, stdin); ) {
266 		char **list, *nlp = strchr(buffer, '\n');
267 		if (nlp)
268 		    *nlp = '\0';
269 		list = parse_columns(buffer);
270 		if (list == 0)	/* blank or comment */
271 		    continue;
272 		name_table[n].nte_link = -1;	/* end-of-hash */
273 		name_table[n].nte_name = strdup(list[column]);
274 		if (!strcmp(list[2], "bool")) {
275 			name_table[n].nte_type  = BOOLEAN;
276 			name_table[n].nte_index = BoolCount++;
277 		} else if (!strcmp(list[2], "num")) {
278 			name_table[n].nte_type  = NUMBER;
279 			name_table[n].nte_index = NumCount++;
280 		} else if (!strcmp(list[2], "str")) {
281 			name_table[n].nte_type  = STRING;
282 			name_table[n].nte_index = StrCount++;
283 		} else {
284 			fprintf(stderr, "Unknown type: %s\n", list[2]);
285 			exit(EXIT_FAILURE);
286 		}
287 		n++;
288 	}
289 	_nc_make_hash_table(name_table, hash_table);
290 
291 	/*
292 	 * Write the compiled tables to standard output
293 	 */
294 	printf("static struct name_table_entry const _nc_%s_table[] =\n",
295 		root_name);
296 	printf("{\n");
297 	for (n = 0; n < CAPTABSIZE; n++) {
298 		sprintf(buffer, "\"%s\"",
299 			name_table[n].nte_name);
300 		printf("\t{ %15s,\t%10s,\t%3d, %3d }%c\n",
301 			buffer,
302 			typenames[name_table[n].nte_type],
303 			name_table[n].nte_index,
304 			name_table[n].nte_link,
305 			n < CAPTABSIZE - 1 ? ',' : ' ');
306 	}
307 	printf("};\n\n");
308 
309 	printf("const struct name_table_entry * const _nc_%s_hash_table[%d] =\n",
310 		root_name,
311 		HASHTABSIZE+1);
312 	printf("{\n");
313 	for (n = 0; n < HASHTABSIZE; n++) {
314 		if (hash_table[n] != 0) {
315 			sprintf(buffer, "_nc_%s_table + %3ld",
316 				root_name,
317 				(long) (hash_table[n] - name_table));
318 		} else {
319 			strcpy(buffer, "0");
320 		}
321 		printf("\t%s,\n", buffer);
322 	}
323 	printf("\t_nc_%s_table\t/* base-of-table */\n", root_name);
324 	printf("};\n\n");
325 
326 	printf("#if (BOOLCOUNT!=%d)||(NUMCOUNT!=%d)||(STRCOUNT!=%d)\n",
327 		BoolCount, NumCount, StrCount);
328 	printf("#error\t--> term.h and comp_captab.c disagree about the <--\n");
329 	printf("#error\t--> numbers of booleans, numbers and/or strings <--\n");
330 	printf("#endif\n\n");
331 
332 	return EXIT_SUCCESS;
333 }
334 #endif
335