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2  * Copyright (c) 1998-2007,2008 Free Software Foundation, Inc.              *
3  *                                                                          *
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5  * copy of this software and associated documentation files (the            *
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14  *                                                                          *
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22  *                                                                          *
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28 
29 /****************************************************************************
30  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
31  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
32  *     and: Thomas E. Dickey                        1996-on                 *
33  ****************************************************************************/
34 
35 /*
36  *	comp_hash.c --- Routines to deal with the hashtable of capability
37  *			names.
38  *
39  */
40 
41 #define USE_TERMLIB 1
42 #include <curses.priv.h>
43 
44 #include <tic.h>
45 #include <hashsize.h>
46 
47 #ifdef MAIN_PROGRAM
48 #include <ctype.h>
49 #undef  DEBUG
50 #define DEBUG(level, params)	/*nothing */
51 #endif
52 
53 MODULE_ID("$Id: comp_hash.c,v 1.36 2008/08/16 17:06:53 tom Exp $")
54 
55 static int hash_function(const char *);
56 
57 /*
58  *	_nc_make_hash_table()
59  *
60  *	Takes the entries in table[] and hashes them into hash_table[]
61  *	by name.  There are CAPTABSIZE entries in table[] and HASHTABSIZE
62  *	slots in hash_table[].
63  *
64  */
65 
66 #ifdef MAIN_PROGRAM
67 
68 #undef MODULE_ID
69 #define MODULE_ID(id)		/*nothing */
70 #include <tinfo/doalloc.c>
71 
72 static void
73 _nc_make_hash_table(struct name_table_entry *table,
74 		    short *hash_table)
75 {
76     short i;
77     int hashvalue;
78     int collisions = 0;
79 
80     for (i = 0; i < HASHTABSIZE; i++) {
81 	hash_table[i] = -1;
82     }
83     for (i = 0; i < CAPTABSIZE; i++) {
84 	hashvalue = hash_function(table[i].nte_name);
85 
86 	if (hash_table[hashvalue] >= 0)
87 	    collisions++;
88 
89 	if (hash_table[hashvalue] != 0)
90 	    table[i].nte_link = hash_table[hashvalue];
91 	hash_table[hashvalue] = i;
92     }
93 
94     DEBUG(4, ("Hash table complete: %d collisions out of %d entries",
95 	      collisions, CAPTABSIZE));
96 }
97 #endif
98 
99 /*
100  *	int hash_function(string)
101  *
102  *	Computes the hashing function on the given string.
103  *
104  *	The current hash function is the sum of each consectutive pair
105  *	of characters, taken as two-byte integers, mod HASHTABSIZE.
106  *
107  */
108 
109 static int
110 hash_function(const char *string)
111 {
112     long sum = 0;
113 
114     DEBUG(9, ("hashing %s", string));
115     while (*string) {
116 	sum += (long) (*string + (*(string + 1) << 8));
117 	string++;
118     }
119 
120     DEBUG(9, ("sum is %ld", sum));
121     return (int) (sum % HASHTABSIZE);
122 }
123 
124 /*
125  *	struct name_table_entry *
126  *	find_entry(string)
127  *
128  *	Finds the entry for the given string in the hash table if present.
129  *	Returns a pointer to the entry in the table or 0 if not found.
130  *
131  */
132 
133 #ifndef MAIN_PROGRAM
134 NCURSES_EXPORT(struct name_table_entry const *)
135 _nc_find_entry(const char *string,
136 	       const short *hash_table)
137 {
138     int hashvalue;
139     struct name_table_entry const *ptr = 0;
140     struct name_table_entry const *real_table;
141 
142     hashvalue = hash_function(string);
143 
144     if (hash_table[hashvalue] >= 0) {
145 	real_table = _nc_get_table(hash_table != _nc_get_hash_table(FALSE));
146 	ptr = real_table + hash_table[hashvalue];
147 	while (strcmp(ptr->nte_name, string) != 0) {
148 	    if (ptr->nte_link < 0)
149 		return 0;
150 	    ptr = real_table + (ptr->nte_link + hash_table[HASHTABSIZE]);
151 	}
152     }
153 
154     return (ptr);
155 }
156 
157 /*
158  *	struct name_table_entry *
159  *	find_type_entry(string, type, table)
160  *
161  *	Finds the first entry for the given name with the given type in the
162  *	given table if present (as distinct from find_entry, which finds the
163  *	the last entry regardless of type).  You can use this if you detect
164  *	a name clash.  It's slower, though.  Returns a pointer to the entry
165  *	in the table or 0 if not found.
166  */
167 
168 NCURSES_EXPORT(struct name_table_entry const *)
169 _nc_find_type_entry(const char *string,
170 		    int type,
171 		    const struct name_table_entry *table)
172 {
173     struct name_table_entry const *ptr;
174 
175     for (ptr = table; ptr < table + CAPTABSIZE; ptr++) {
176 	if (ptr->nte_type == type && strcmp(string, ptr->nte_name) == 0)
177 	    return (ptr);
178     }
179 
180     return ((struct name_table_entry *) NULL);
181 }
182 #endif
183 
184 #ifdef MAIN_PROGRAM
185 /*
186  * This filter reads from standard input a list of tab-delimited columns,
187  * (e.g., from Caps.filtered) computes the hash-value of a specified column and
188  * writes the hashed tables to standard output.
189  *
190  * By compiling the hash table at build time, we're able to make the entire
191  * set of terminfo and termcap tables readonly (and also provide some runtime
192  * performance enhancement).
193  */
194 
195 #define MAX_COLUMNS BUFSIZ	/* this _has_ to be worst-case */
196 
197 static char **
198 parse_columns(char *buffer)
199 {
200     static char **list;
201 
202     int col = 0;
203 
204     if (list == 0 && (list = typeCalloc(char *, MAX_COLUMNS)) == 0)
205 	  return (0);
206 
207     if (*buffer != '#') {
208 	while (*buffer != '\0') {
209 	    char *s;
210 	    for (s = buffer; (*s != '\0') && !isspace(UChar(*s)); s++)
211 		/*EMPTY */ ;
212 	    if (s != buffer) {
213 		char mark = *s;
214 		*s = '\0';
215 		if ((s - buffer) > 1
216 		    && (*buffer == '"')
217 		    && (s[-1] == '"')) {	/* strip the quotes */
218 		    assert(s > buffer + 1);
219 		    s[-1] = '\0';
220 		    buffer++;
221 		}
222 		list[col] = buffer;
223 		col++;
224 		if (mark == '\0')
225 		    break;
226 		while (*++s && isspace(UChar(*s)))
227 		    /*EMPTY */ ;
228 		buffer = s;
229 	    } else
230 		break;
231 	}
232     }
233     return col ? list : 0;
234 }
235 
236 int
237 main(int argc, char **argv)
238 {
239     struct name_table_entry *name_table = typeCalloc(struct
240 						     name_table_entry, CAPTABSIZE);
241     short *hash_table = typeCalloc(short, HASHTABSIZE);
242     const char *root_name = "";
243     int column = 0;
244     int bigstring = 0;
245     int n;
246     char buffer[BUFSIZ];
247 
248     static const char *typenames[] =
249     {"BOOLEAN", "NUMBER", "STRING"};
250 
251     short BoolCount = 0;
252     short NumCount = 0;
253     short StrCount = 0;
254 
255     /* The first argument is the column-number (starting with 0).
256      * The second is the root name of the tables to generate.
257      */
258     if (argc <= 3
259 	|| (column = atoi(argv[1])) <= 0
260 	|| (column >= MAX_COLUMNS)
261 	|| *(root_name = argv[2]) == 0
262 	|| (bigstring = atoi(argv[3])) < 0
263 	|| name_table == 0
264 	|| hash_table == 0) {
265 	fprintf(stderr, "usage: make_hash column root_name bigstring\n");
266 	exit(EXIT_FAILURE);
267     }
268 
269     /*
270      * Read the table into our arrays.
271      */
272     for (n = 0; (n < CAPTABSIZE) && fgets(buffer, BUFSIZ, stdin);) {
273 	char **list, *nlp = strchr(buffer, '\n');
274 	if (nlp)
275 	    *nlp = '\0';
276 	list = parse_columns(buffer);
277 	if (list == 0)		/* blank or comment */
278 	    continue;
279 	name_table[n].nte_link = -1;	/* end-of-hash */
280 	name_table[n].nte_name = strdup(list[column]);
281 	if (!strcmp(list[2], "bool")) {
282 	    name_table[n].nte_type = BOOLEAN;
283 	    name_table[n].nte_index = BoolCount++;
284 	} else if (!strcmp(list[2], "num")) {
285 	    name_table[n].nte_type = NUMBER;
286 	    name_table[n].nte_index = NumCount++;
287 	} else if (!strcmp(list[2], "str")) {
288 	    name_table[n].nte_type = STRING;
289 	    name_table[n].nte_index = StrCount++;
290 	} else {
291 	    fprintf(stderr, "Unknown type: %s\n", list[2]);
292 	    exit(EXIT_FAILURE);
293 	}
294 	n++;
295     }
296     _nc_make_hash_table(name_table, hash_table);
297 
298     /*
299      * Write the compiled tables to standard output
300      */
301     if (bigstring) {
302 	int len = 0;
303 	int nxt;
304 
305 	printf("static const char %s_names_text[] = \\\n", root_name);
306 	for (n = 0; n < CAPTABSIZE; n++) {
307 	    nxt = (int) strlen(name_table[n].nte_name) + 5;
308 	    if (nxt + len > 72) {
309 		printf("\\\n");
310 		len = 0;
311 	    }
312 	    printf("\"%s\\0\" ", name_table[n].nte_name);
313 	    len += nxt;
314 	}
315 	printf(";\n\n");
316 
317 	len = 0;
318 	printf("static name_table_data const %s_names_data[] =\n",
319 	       root_name);
320 	printf("{\n");
321 	for (n = 0; n < CAPTABSIZE; n++) {
322 	    printf("\t{ %15d,\t%10s,\t%3d, %3d }%c\n",
323 		   len,
324 		   typenames[name_table[n].nte_type],
325 		   name_table[n].nte_index,
326 		   name_table[n].nte_link,
327 		   n < CAPTABSIZE - 1 ? ',' : ' ');
328 	    len += (int) strlen(name_table[n].nte_name) + 1;
329 	}
330 	printf("};\n\n");
331 	printf("static struct name_table_entry *_nc_%s_table = 0;\n\n", root_name);
332     } else {
333 
334 	printf("static struct name_table_entry %s _nc_%s_table[] =\n",
335 	       bigstring ? "" : "const",
336 	       root_name);
337 	printf("{\n");
338 	for (n = 0; n < CAPTABSIZE; n++) {
339 	    sprintf(buffer, "\"%s\"",
340 		    name_table[n].nte_name);
341 	    printf("\t{ %15s,\t%10s,\t%3d, %3d }%c\n",
342 		   buffer,
343 		   typenames[name_table[n].nte_type],
344 		   name_table[n].nte_index,
345 		   name_table[n].nte_link,
346 		   n < CAPTABSIZE - 1 ? ',' : ' ');
347 	}
348 	printf("};\n\n");
349     }
350 
351     printf("static const short _nc_%s_hash_table[%d] =\n",
352 	   root_name,
353 	   HASHTABSIZE + 1);
354     printf("{\n");
355     for (n = 0; n < HASHTABSIZE; n++) {
356 	printf("\t%3d,\n", hash_table[n]);
357     }
358     printf("\t0\t/* base-of-table */\n");
359     printf("};\n\n");
360 
361     printf("#if (BOOLCOUNT!=%d)||(NUMCOUNT!=%d)||(STRCOUNT!=%d)\n",
362 	   BoolCount, NumCount, StrCount);
363     printf("#error\t--> term.h and comp_captab.c disagree about the <--\n");
364     printf("#error\t--> numbers of booleans, numbers and/or strings <--\n");
365     printf("#endif\n\n");
366 
367     free(hash_table);
368     return EXIT_SUCCESS;
369 }
370 #endif
371