1 /****************************************************************************
2  * Copyright (c) 1998 Free Software Foundation, Inc.                        *
3  *                                                                          *
4  * Permission is hereby granted, free of charge, to any person obtaining a  *
5  * copy of this software and associated documentation files (the            *
6  * "Software"), to deal in the Software without restriction, including      *
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8  * distribute, distribute with modifications, sublicense, and/or sell       *
9  * copies of the Software, and to permit persons to whom the Software is    *
10  * furnished to do so, subject to the following conditions:                 *
11  *                                                                          *
12  * The above copyright notice and this permission notice shall be included  *
13  * in all copies or substantial portions of the Software.                   *
14  *                                                                          *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
16  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
18  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
19  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
20  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
21  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
22  *                                                                          *
23  * Except as contained in this notice, the name(s) of the above copyright   *
24  * holders shall not be used in advertising or otherwise to promote the     *
25  * sale, use or other dealings in this Software without prior written       *
26  * authorization.                                                           *
27  ****************************************************************************/
28 
29 /****************************************************************************
30  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
31  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
32  ****************************************************************************/
33 
34 
35 /*
36  *	comp_hash.c --- Routines to deal with the hashtable of capability
37  *			names.
38  *
39  */
40 
41 #include <curses.priv.h>
42 
43 #include <tic.h>
44 #include <hashsize.h>
45 
46 #ifdef MAIN_PROGRAM
47 #include <ctype.h>
48 #undef  DEBUG
49 #define DEBUG(level, params) /*nothing*/
50 #endif
51 
52 MODULE_ID("$Id: comp_hash.c,v 1.21 1999/06/26 21:25:11 tom Exp $")
53 
54 static  int hash_function(const char *);
55 
56 /*
57  *	_nc_make_hash_table()
58  *
59  *	Takes the entries in table[] and hashes them into hash_table[]
60  *	by name.  There are CAPTABSIZE entries in table[] and HASHTABSIZE
61  *	slots in hash_table[].
62  *
63  */
64 
65 #ifdef MAIN_PROGRAM
66 
67 #undef MODULE_ID
68 #define MODULE_ID(id) /*nothing*/
69 #include <tinfo/doalloc.c>
70 
71 static void _nc_make_hash_table(struct name_table_entry *table,
72 		     struct name_table_entry **hash_table)
73 {
74 int	i;
75 int	hashvalue;
76 int	collisions = 0;
77 
78 	for (i = 0; i < CAPTABSIZE; i++) {
79 	    hashvalue = hash_function(table[i].nte_name);
80 
81 	    if (hash_table[hashvalue] != (struct name_table_entry *) 0)
82 		collisions++;
83 
84 	    if (hash_table[hashvalue] != 0)
85 		table[i].nte_link = (short)(hash_table[hashvalue] - table);
86 	    hash_table[hashvalue] = &table[i];
87 	}
88 
89 	DEBUG(4, ("Hash table complete: %d collisions out of %d entries", collisions, CAPTABSIZE));
90 }
91 #endif
92 
93 
94 /*
95  *	int hash_function(string)
96  *
97  *	Computes the hashing function on the given string.
98  *
99  *	The current hash function is the sum of each consectutive pair
100  *	of characters, taken as two-byte integers, mod Hashtabsize.
101  *
102  */
103 
104 static
105 int
106 hash_function(const char *string)
107 {
108 long	sum = 0;
109 
110 	DEBUG(9, ("hashing %s", string));
111 	while (*string) {
112 	    sum += (long)(*string + (*(string + 1) << 8));
113 	    string++;
114 	}
115 
116 	DEBUG(9, ("sum is %ld", sum));
117 	return (int)(sum % HASHTABSIZE);
118 }
119 
120 
121 /*
122  *	struct name_table_entry *
123  *	find_entry(string)
124  *
125  *	Finds the entry for the given string in the hash table if present.
126  *	Returns a pointer to the entry in the table or 0 if not found.
127  *
128  */
129 
130 #ifndef MAIN_PROGRAM
131 struct name_table_entry const *
132 _nc_find_entry(const char *string, const struct name_table_entry *const *hash_table)
133 {
134 int	hashvalue;
135 struct name_table_entry	const *ptr;
136 
137 	hashvalue = hash_function(string);
138 
139 	if ((ptr = hash_table[hashvalue]) != 0) {
140 		while (strcmp(ptr->nte_name, string) != 0) {
141 			if (ptr->nte_link < 0)
142 				return 0;
143 			ptr = ptr->nte_link + hash_table[HASHTABSIZE];
144 		}
145 	}
146 
147 	return (ptr);
148 }
149 
150 /*
151  *	struct name_table_entry *
152  *	find_type_entry(string, type, table)
153  *
154  *	Finds the first entry for the given name with the given type in the
155  *	given table if present (as distinct from find_entry, which finds the
156  *	the last entry regardless of type).  You can use this if you detect
157  *	a name clash.  It's slower, though.  Returns a pointer to the entry
158  *	in the table or 0 if not found.
159  */
160 
161 struct name_table_entry const *
162 _nc_find_type_entry(const char *string,
163 		    int type,
164 		    const struct name_table_entry *table)
165 {
166 struct name_table_entry	const *ptr;
167 
168 	for (ptr = table; ptr < table + CAPTABSIZE; ptr++) {
169 	    if (ptr->nte_type == type && strcmp(string, ptr->nte_name) == 0)
170 		return(ptr);
171 	}
172 
173 	return ((struct name_table_entry *)NULL);
174 }
175 #endif
176 
177 #ifdef MAIN_PROGRAM
178 /*
179  * This filter reads from standard input a list of tab-delimited columns,
180  * (e.g., from Caps.filtered) computes the hash-value of a specified column and
181  * writes the hashed tables to standard output.
182  *
183  * By compiling the hash table at build time, we're able to make the entire
184  * set of terminfo and termcap tables readonly (and also provide some runtime
185  * performance enhancement).
186  */
187 
188 #define MAX_COLUMNS BUFSIZ	/* this _has_ to be worst-case */
189 
190 static char **parse_columns(char *buffer)
191 {
192 	static char **list;
193 
194 	int col = 0;
195 
196 	if (list == 0 && (list = typeCalloc(char *, MAX_COLUMNS)) == 0)
197 		return(0);
198 
199 	if (*buffer != '#') {
200 		while (*buffer != '\0') {
201 			char *s;
202 			for (s = buffer; (*s != '\0') && !isspace(*s); s++)
203 				/*EMPTY*/;
204 			if (s != buffer) {
205 				char mark = *s;
206 				*s = '\0';
207 				if ((s - buffer) > 1
208 				 && (*buffer == '"')
209 				 && (s[-1] == '"')) {	/* strip the quotes */
210 					buffer++;
211 					s[-1] = '\0';
212 				}
213 				list[col] = buffer;
214 				col++;
215 				if (mark == '\0')
216 					break;
217 				while (*++s && isspace(*s))
218 					/*EMPTY*/;
219 				buffer = s;
220 			} else
221 				break;
222 		}
223 	}
224 	return col ? list : 0;
225 }
226 
227 int main(int argc, char **argv)
228 {
229 	struct name_table_entry *name_table = typeCalloc(struct name_table_entry, CAPTABSIZE);
230 	struct name_table_entry **hash_table = typeCalloc(struct name_table_entry *, HASHTABSIZE);
231 	const char *root_name = "";
232 	int  column = 0;
233 	int  n;
234 	char buffer[BUFSIZ];
235 
236 	static const char * typenames[] = { "BOOLEAN", "NUMBER", "STRING" };
237 
238 	short BoolCount = 0;
239 	short NumCount  = 0;
240 	short StrCount  = 0;
241 
242 	/* The first argument is the column-number (starting with 0).
243 	 * The second is the root name of the tables to generate.
244 	 */
245 	if (argc <= 2
246 	 || (column = atoi(argv[1])) <= 0
247 	 || (column >= MAX_COLUMNS)
248 	 || *(root_name = argv[2]) == 0) {
249 		fprintf(stderr, "usage: make_hash column root_name\n");
250 		exit(EXIT_FAILURE);
251 	}
252 
253 	/*
254 	 * Read the table into our arrays.
255 	 */
256 	for (n = 0; (n < CAPTABSIZE) && fgets(buffer, BUFSIZ, stdin); ) {
257 		char **list, *nlp = strchr(buffer, '\n');
258 		if (nlp)
259 		    *nlp = '\0';
260 		list = parse_columns(buffer);
261 		if (list == 0)	/* blank or comment */
262 		    continue;
263 		name_table[n].nte_link = -1;	/* end-of-hash */
264 		name_table[n].nte_name = strdup(list[column]);
265 		if (!strcmp(list[2], "bool")) {
266 			name_table[n].nte_type  = BOOLEAN;
267 			name_table[n].nte_index = BoolCount++;
268 		} else if (!strcmp(list[2], "num")) {
269 			name_table[n].nte_type  = NUMBER;
270 			name_table[n].nte_index = NumCount++;
271 		} else if (!strcmp(list[2], "str")) {
272 			name_table[n].nte_type  = STRING;
273 			name_table[n].nte_index = StrCount++;
274 		} else {
275 			fprintf(stderr, "Unknown type: %s\n", list[2]);
276 			exit(EXIT_FAILURE);
277 		}
278 		n++;
279 	}
280 	_nc_make_hash_table(name_table, hash_table);
281 
282 	/*
283 	 * Write the compiled tables to standard output
284 	 */
285 	printf("static struct name_table_entry const _nc_%s_table[] =\n",
286 		root_name);
287 	printf("{\n");
288 	for (n = 0; n < CAPTABSIZE; n++) {
289 		sprintf(buffer, "\"%s\"",
290 			name_table[n].nte_name);
291 		printf("\t{ %15s,\t%10s,\t%3d, %3d }%c\n",
292 			buffer,
293 			typenames[name_table[n].nte_type],
294 			name_table[n].nte_index,
295 			name_table[n].nte_link,
296 			n < CAPTABSIZE - 1 ? ',' : ' ');
297 	}
298 	printf("};\n\n");
299 
300 	printf("const struct name_table_entry * const _nc_%s_hash_table[%d] =\n",
301 		root_name,
302 		HASHTABSIZE+1);
303 	printf("{\n");
304 	for (n = 0; n < HASHTABSIZE; n++) {
305 		if (hash_table[n] != 0) {
306 			sprintf(buffer, "_nc_%s_table + %3ld",
307 				root_name,
308 				(long) (hash_table[n] - name_table));
309 		} else {
310 			strcpy(buffer, "0");
311 		}
312 		printf("\t%s,\n", buffer);
313 	}
314 	printf("\t_nc_%s_table\t/* base-of-table */\n", root_name);
315 	printf("};\n\n");
316 
317 	printf("#if (BOOLCOUNT!=%d)||(NUMCOUNT!=%d)||(STRCOUNT!=%d)\n",
318 		BoolCount, NumCount, StrCount);
319 	printf("#error\t--> term.h and comp_captab.c disagree about the <--\n");
320 	printf("#error\t--> numbers of booleans, numbers and/or strings <--\n");
321 	printf("#endif\n\n");
322 
323 	return EXIT_SUCCESS;
324 }
325 #endif
326