xref: /openbsd-src/lib/libcurses/tinfo/comp_hash.c (revision 6dfa96fc5df5bbdeae7620249cdda1e18dca48b7)
1 /*	$OpenBSD: comp_hash.c,v 1.3 1999/03/15 19:12:22 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 1.20 1999/03/14 12:23:26 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 
69 #undef USE_RCS_IDS
70 #include <tinfo/doalloc.c>
71 
72 static void _nc_make_hash_table(struct name_table_entry *table,
73 		     struct name_table_entry **hash_table)
74 {
75 int	i;
76 int	hashvalue;
77 int	collisions = 0;
78 
79 	for (i = 0; i < CAPTABSIZE; i++) {
80 	    hashvalue = hash_function(table[i].nte_name);
81 
82 	    if (hash_table[hashvalue] != (struct name_table_entry *) 0)
83 		collisions++;
84 
85 	    if (hash_table[hashvalue] != 0)
86 		table[i].nte_link = (short)(hash_table[hashvalue] - table);
87 	    hash_table[hashvalue] = &table[i];
88 	}
89 
90 	DEBUG(4, ("Hash table complete: %d collisions out of %d entries", collisions, CAPTABSIZE));
91 }
92 #endif
93 
94 
95 /*
96  *	int hash_function(string)
97  *
98  *	Computes the hashing function on the given string.
99  *
100  *	The current hash function is the sum of each consectutive pair
101  *	of characters, taken as two-byte integers, mod Hashtabsize.
102  *
103  */
104 
105 static
106 int
107 hash_function(const char *string)
108 {
109 long	sum = 0;
110 
111 	DEBUG(9, ("hashing %s", string));
112 	while (*string) {
113 	    sum += (long)(*string + (*(string + 1) << 8));
114 	    string++;
115 	}
116 
117 	DEBUG(9, ("sum is %ld", sum));
118 	return (int)(sum % HASHTABSIZE);
119 }
120 
121 
122 /*
123  *	struct name_table_entry *
124  *	find_entry(string)
125  *
126  *	Finds the entry for the given string in the hash table if present.
127  *	Returns a pointer to the entry in the table or 0 if not found.
128  *
129  */
130 
131 #ifndef MAIN_PROGRAM
132 struct name_table_entry const *
133 _nc_find_entry(const char *string, const struct name_table_entry *const *hash_table)
134 {
135 int	hashvalue;
136 struct name_table_entry	const *ptr;
137 
138 	hashvalue = hash_function(string);
139 
140 	if ((ptr = hash_table[hashvalue]) != 0) {
141 		while (strcmp(ptr->nte_name, string) != 0) {
142 			if (ptr->nte_link < 0)
143 				return 0;
144 			ptr = ptr->nte_link + hash_table[HASHTABSIZE];
145 		}
146 	}
147 
148 	return (ptr);
149 }
150 
151 /*
152  *	struct name_table_entry *
153  *	find_type_entry(string, type, table)
154  *
155  *	Finds the first entry for the given name with the given type in the
156  *	given table if present (as distinct from find_entry, which finds the
157  *	the last entry regardless of type).  You can use this if you detect
158  *	a name clash.  It's slower, though.  Returns a pointer to the entry
159  *	in the table or 0 if not found.
160  */
161 
162 struct name_table_entry const *
163 _nc_find_type_entry(const char *string,
164 		    int type,
165 		    const struct name_table_entry *table)
166 {
167 struct name_table_entry	const *ptr;
168 
169 	for (ptr = table; ptr < table + CAPTABSIZE; ptr++) {
170 	    if (ptr->nte_type == type && strcmp(string, ptr->nte_name) == 0)
171 		return(ptr);
172 	}
173 
174 	return ((struct name_table_entry *)NULL);
175 }
176 #endif
177 
178 #ifdef MAIN_PROGRAM
179 /*
180  * This filter reads from standard input a list of tab-delimited columns,
181  * (e.g., from Caps.filtered) computes the hash-value of a specified column and
182  * writes the hashed tables to standard output.
183  *
184  * By compiling the hash table at build time, we're able to make the entire
185  * set of terminfo and termcap tables readonly (and also provide some runtime
186  * performance enhancement).
187  */
188 
189 #define MAX_COLUMNS BUFSIZ	/* this _has_ to be worst-case */
190 
191 static char **parse_columns(char *buffer)
192 {
193 	static char **list;
194 
195 	int col = 0;
196 
197 	if (list == 0 && (list = typeCalloc(char *, MAX_COLUMNS)) == 0)
198 		return(0);
199 
200 	if (*buffer != '#') {
201 		while (*buffer != '\0') {
202 			char *s;
203 			for (s = buffer; (*s != '\0') && !isspace(*s); s++)
204 				/*EMPTY*/;
205 			if (s != buffer) {
206 				char mark = *s;
207 				*s = '\0';
208 				if ((s - buffer) > 1
209 				 && (*buffer == '"')
210 				 && (s[-1] == '"')) {	/* strip the quotes */
211 					buffer++;
212 					s[-1] = '\0';
213 				}
214 				list[col] = buffer;
215 				col++;
216 				if (mark == '\0')
217 					break;
218 				while (*++s && isspace(*s))
219 					/*EMPTY*/;
220 				buffer = s;
221 			} else
222 				break;
223 		}
224 	}
225 	return col ? list : 0;
226 }
227 
228 int main(int argc, char **argv)
229 {
230 	struct name_table_entry *name_table = typeCalloc(struct name_table_entry, CAPTABSIZE);
231 	struct name_table_entry **hash_table = typeCalloc(struct name_table_entry *, HASHTABSIZE);
232 	const char *root_name = "";
233 	int  column = 0;
234 	int  n;
235 	char buffer[BUFSIZ];
236 
237 	static const char * typenames[] = { "BOOLEAN", "NUMBER", "STRING" };
238 
239 	short BoolCount = 0;
240 	short NumCount  = 0;
241 	short StrCount  = 0;
242 
243 	/* The first argument is the column-number (starting with 0).
244 	 * The second is the root name of the tables to generate.
245 	 */
246 	if (argc <= 2
247 	 || (column = atoi(argv[1])) <= 0
248 	 || (column >= MAX_COLUMNS)
249 	 || *(root_name = argv[2]) == 0) {
250 		fprintf(stderr, "usage: make_hash column root_name\n");
251 		exit(EXIT_FAILURE);
252 	}
253 
254 	/*
255 	 * Read the table into our arrays.
256 	 */
257 	for (n = 0; (n < CAPTABSIZE) && fgets(buffer, BUFSIZ, stdin); ) {
258 		char **list, *nlp = strchr(buffer, '\n');
259 		if (nlp)
260 		    *nlp = '\0';
261 		list = parse_columns(buffer);
262 		if (list == 0)	/* blank or comment */
263 		    continue;
264 		name_table[n].nte_link = -1;	/* end-of-hash */
265 		name_table[n].nte_name = strdup(list[column]);
266 		if (!strcmp(list[2], "bool")) {
267 			name_table[n].nte_type  = BOOLEAN;
268 			name_table[n].nte_index = BoolCount++;
269 		} else if (!strcmp(list[2], "num")) {
270 			name_table[n].nte_type  = NUMBER;
271 			name_table[n].nte_index = NumCount++;
272 		} else if (!strcmp(list[2], "str")) {
273 			name_table[n].nte_type  = STRING;
274 			name_table[n].nte_index = StrCount++;
275 		} else {
276 			fprintf(stderr, "Unknown type: %s\n", list[2]);
277 			exit(EXIT_FAILURE);
278 		}
279 		n++;
280 	}
281 	_nc_make_hash_table(name_table, hash_table);
282 
283 	/*
284 	 * Write the compiled tables to standard output
285 	 */
286 	printf("static struct name_table_entry const _nc_%s_table[] =\n",
287 		root_name);
288 	printf("{\n");
289 	for (n = 0; n < CAPTABSIZE; n++) {
290 		sprintf(buffer, "\"%s\"",
291 			name_table[n].nte_name);
292 		printf("\t{ %15s,\t%10s,\t%3d, %3d }%c\n",
293 			buffer,
294 			typenames[name_table[n].nte_type],
295 			name_table[n].nte_index,
296 			name_table[n].nte_link,
297 			n < CAPTABSIZE - 1 ? ',' : ' ');
298 	}
299 	printf("};\n\n");
300 
301 	printf("const struct name_table_entry * const _nc_%s_hash_table[%d] =\n",
302 		root_name,
303 		HASHTABSIZE+1);
304 	printf("{\n");
305 	for (n = 0; n < HASHTABSIZE; n++) {
306 		if (hash_table[n] != 0) {
307 			sprintf(buffer, "_nc_%s_table + %3ld",
308 				root_name,
309 				(long) (hash_table[n] - name_table));
310 		} else {
311 			strcpy(buffer, "0");
312 		}
313 		printf("\t%s,\n", buffer);
314 	}
315 	printf("\t_nc_%s_table\t/* base-of-table */\n", root_name);
316 	printf("};\n\n");
317 
318 	printf("#if (BOOLCOUNT!=%d)||(NUMCOUNT!=%d)||(STRCOUNT!=%d)\n",
319 		BoolCount, NumCount, StrCount);
320 	printf("#error\t--> term.h and comp_captab.c disagree about the <--\n");
321 	printf("#error\t--> numbers of booleans, numbers and/or strings <--\n");
322 	printf("#endif\n\n");
323 
324 	return EXIT_SUCCESS;
325 }
326 #endif
327