1/****************************************************************************
2 * Copyright (c) 1998-2003,2005 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      *
7 * without limitation the rights to use, copy, modify, merge, publish,      *
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 *     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
53MODULE_ID("$Id: comp_hash.c,v 1.28 2005/08/20 19:58:18 tom Exp $")
54
55static 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
72static void
73_nc_make_hash_table(struct name_table_entry *table,
74		    struct name_table_entry **hash_table)
75{
76    int i;
77    int hashvalue;
78    int collisions = 0;
79
80    for (i = 0; i < CAPTABSIZE; i++) {
81	hashvalue = hash_function(table[i].nte_name);
82
83	if (hash_table[hashvalue] != (struct name_table_entry *) 0)
84	    collisions++;
85
86	if (hash_table[hashvalue] != 0)
87	    table[i].nte_link = (short) (hash_table[hashvalue] - table);
88	hash_table[hashvalue] = &table[i];
89    }
90
91    DEBUG(4, ("Hash table complete: %d collisions out of %d entries",
92	      collisions, CAPTABSIZE));
93}
94#endif
95
96/*
97 *	int hash_function(string)
98 *
99 *	Computes the hashing function on the given string.
100 *
101 *	The current hash function is the sum of each consectutive pair
102 *	of characters, taken as two-byte integers, mod HASHTABSIZE.
103 *
104 */
105
106static int
107hash_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 *	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
131NCURSES_EXPORT(struct name_table_entry const *)
132_nc_find_entry(const char *string,
133	       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
162NCURSES_EXPORT(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
191static char **
192parse_columns(char *buffer)
193{
194    static char **list;
195
196    int col = 0;
197
198    if (list == 0 && (list = typeCalloc(char *, MAX_COLUMNS)) == 0)
199	  return (0);
200
201    if (*buffer != '#') {
202	while (*buffer != '\0') {
203	    char *s;
204	    for (s = buffer; (*s != '\0') && !isspace(UChar(*s)); s++)
205		/*EMPTY */ ;
206	    if (s != buffer) {
207		char mark = *s;
208		*s = '\0';
209		if ((s - buffer) > 1
210		    && (*buffer == '"')
211		    && (s[-1] == '"')) {	/* strip the quotes */
212		    buffer++;
213		    s[-1] = '\0';
214		}
215		list[col] = buffer;
216		col++;
217		if (mark == '\0')
218		    break;
219		while (*++s && isspace(UChar(*s)))
220		    /*EMPTY */ ;
221		buffer = s;
222	    } else
223		break;
224	}
225    }
226    return col ? list : 0;
227}
228
229int
230main(int argc, char **argv)
231{
232    struct name_table_entry *name_table = typeCalloc(struct
233						     name_table_entry, CAPTABSIZE);
234    struct name_table_entry **hash_table = typeCalloc(struct name_table_entry
235						      *, HASHTABSIZE);
236    const char *root_name = "";
237    int column = 0;
238    int n;
239    char buffer[BUFSIZ];
240
241    static const char *typenames[] =
242    {"BOOLEAN", "NUMBER", "STRING"};
243
244    short BoolCount = 0;
245    short NumCount = 0;
246    short StrCount = 0;
247
248    /* The first argument is the column-number (starting with 0).
249     * The second is the root name of the tables to generate.
250     */
251    if (argc <= 2
252	|| (column = atoi(argv[1])) <= 0
253	|| (column >= MAX_COLUMNS)
254	|| *(root_name = argv[2]) == 0) {
255	fprintf(stderr, "usage: make_hash column root_name\n");
256	exit(EXIT_FAILURE);
257    }
258
259    /*
260     * Read the table into our arrays.
261     */
262    for (n = 0; (n < CAPTABSIZE) && fgets(buffer, BUFSIZ, stdin);) {
263	char **list, *nlp = strchr(buffer, '\n');
264	if (nlp)
265	    *nlp = '\0';
266	list = parse_columns(buffer);
267	if (list == 0)		/* blank or comment */
268	    continue;
269	name_table[n].nte_link = -1;	/* end-of-hash */
270	name_table[n].nte_name = strdup(list[column]);
271	if (!strcmp(list[2], "bool")) {
272	    name_table[n].nte_type = BOOLEAN;
273	    name_table[n].nte_index = BoolCount++;
274	} else if (!strcmp(list[2], "num")) {
275	    name_table[n].nte_type = NUMBER;
276	    name_table[n].nte_index = NumCount++;
277	} else if (!strcmp(list[2], "str")) {
278	    name_table[n].nte_type = STRING;
279	    name_table[n].nte_index = StrCount++;
280	} else {
281	    fprintf(stderr, "Unknown type: %s\n", list[2]);
282	    exit(EXIT_FAILURE);
283	}
284	n++;
285    }
286    _nc_make_hash_table(name_table, hash_table);
287
288    /*
289     * Write the compiled tables to standard output
290     */
291    printf("static struct name_table_entry const _nc_%s_table[] =\n",
292	   root_name);
293    printf("{\n");
294    for (n = 0; n < CAPTABSIZE; n++) {
295	sprintf(buffer, "\"%s\"",
296		name_table[n].nte_name);
297	printf("\t{ %15s,\t%10s,\t%3d, %3d }%c\n",
298	       buffer,
299	       typenames[name_table[n].nte_type],
300	       name_table[n].nte_index,
301	       name_table[n].nte_link,
302	       n < CAPTABSIZE - 1 ? ',' : ' ');
303    }
304    printf("};\n\n");
305
306    printf("const struct name_table_entry * const _nc_%s_hash_table[%d] =\n",
307	   root_name,
308	   HASHTABSIZE + 1);
309    printf("{\n");
310    for (n = 0; n < HASHTABSIZE; n++) {
311	if (hash_table[n] != 0) {
312	    sprintf(buffer, "_nc_%s_table + %3ld",
313		    root_name,
314		    (long) (hash_table[n] - name_table));
315	} else {
316	    strcpy(buffer, "0");
317	}
318	printf("\t%s,\n", buffer);
319    }
320    printf("\t_nc_%s_table\t/* base-of-table */\n", root_name);
321    printf("};\n\n");
322
323    printf("#if (BOOLCOUNT!=%d)||(NUMCOUNT!=%d)||(STRCOUNT!=%d)\n",
324	   BoolCount, NumCount, StrCount);
325    printf("#error\t--> term.h and comp_captab.c disagree about the <--\n");
326    printf("#error\t--> numbers of booleans, numbers and/or strings <--\n");
327    printf("#endif\n\n");
328
329    return EXIT_SUCCESS;
330}
331#endif
332