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1 | /* Interface to hashtable implementations. |
2 | Copyright (C) 2006-2019 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of libctf. | |
5 | ||
6 | libctf is free software; you can redistribute it and/or modify it under | |
7 | the terms of the GNU General Public License as published by the Free | |
8 | Software Foundation; either version 3, or (at your option) any later | |
9 | version. | |
10 | ||
11 | This program is distributed in the hope that it will be useful, but | |
12 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | |
14 | See the GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with this program; see the file COPYING. If not see | |
18 | <http://www.gnu.org/licenses/>. */ | |
19 | ||
20 | #include <ctf-impl.h> | |
21 | #include <string.h> | |
22 | #include "libiberty.h" | |
23 | #include "hashtab.h" | |
24 | ||
25 | /* We have two hashtable implementations: one, ctf_dynhash_*(), is an interface to | |
26 | a dynamically-expanding hash with unknown size that should support addition | |
27 | of large numbers of items, and removal as well, and is used only at | |
28 | type-insertion time; the other, ctf_dynhash_*(), is an interface to a | |
29 | fixed-size hash from const char * -> ctf_id_t with number of elements | |
30 | specified at creation time, that should support addition of items but need | |
31 | not support removal. These can be implemented by the same underlying hashmap | |
32 | if you wish. */ | |
33 | ||
34 | typedef struct ctf_helem | |
35 | { | |
36 | void *key; /* Either a pointer, or a coerced ctf_id_t. */ | |
37 | void *value; /* The value (possibly a coerced int). */ | |
38 | ctf_hash_free_fun key_free; | |
39 | ctf_hash_free_fun value_free; | |
40 | } ctf_helem_t; | |
41 | ||
42 | struct ctf_dynhash | |
43 | { | |
44 | struct htab *htab; | |
45 | ctf_hash_free_fun key_free; | |
46 | ctf_hash_free_fun value_free; | |
47 | }; | |
48 | ||
49 | /* Hash functions. */ | |
50 | ||
51 | unsigned int | |
52 | ctf_hash_integer (const void *ptr) | |
53 | { | |
54 | ctf_helem_t *hep = (ctf_helem_t *) ptr; | |
55 | ||
56 | return htab_hash_pointer (hep->key); | |
57 | } | |
58 | ||
59 | int | |
60 | ctf_hash_eq_integer (const void *a, const void *b) | |
61 | { | |
62 | ctf_helem_t *hep_a = (ctf_helem_t *) a; | |
63 | ctf_helem_t *hep_b = (ctf_helem_t *) b; | |
64 | ||
65 | return htab_eq_pointer (hep_a->key, hep_b->key); | |
66 | } | |
67 | ||
68 | unsigned int | |
69 | ctf_hash_string (const void *ptr) | |
70 | { | |
71 | ctf_helem_t *hep = (ctf_helem_t *) ptr; | |
72 | ||
73 | return htab_hash_string (hep->key); | |
74 | } | |
75 | ||
76 | int | |
77 | ctf_hash_eq_string (const void *a, const void *b) | |
78 | { | |
79 | ctf_helem_t *hep_a = (ctf_helem_t *) a; | |
80 | ctf_helem_t *hep_b = (ctf_helem_t *) b; | |
81 | ||
82 | return !strcmp((const char *) hep_a->key, (const char *) hep_b->key); | |
83 | } | |
84 | ||
85 | /* The dynhash, used for hashes whose size is not known at creation time. */ | |
86 | ||
87 | /* Free a single ctf_helem. */ | |
88 | ||
89 | static void | |
90 | ctf_dynhash_item_free (void *item) | |
91 | { | |
92 | ctf_helem_t *helem = item; | |
93 | ||
94 | if (helem->key_free && helem->key) | |
95 | helem->key_free (helem->key); | |
96 | if (helem->value_free && helem->value) | |
97 | helem->value_free (helem->value); | |
98 | free (helem); | |
99 | } | |
100 | ||
101 | ctf_dynhash_t * | |
102 | ctf_dynhash_create (ctf_hash_fun hash_fun, ctf_hash_eq_fun eq_fun, | |
103 | ctf_hash_free_fun key_free, ctf_hash_free_fun value_free) | |
104 | { | |
105 | ctf_dynhash_t *dynhash; | |
106 | ||
107 | dynhash = malloc (sizeof (ctf_dynhash_t)); | |
108 | if (!dynhash) | |
109 | return NULL; | |
110 | ||
111 | /* 7 is arbitrary and untested for now.. */ | |
112 | if ((dynhash->htab = htab_create_alloc (7, (htab_hash) hash_fun, eq_fun, | |
113 | ctf_dynhash_item_free, xcalloc, free)) == NULL) | |
114 | { | |
115 | free (dynhash); | |
116 | return NULL; | |
117 | } | |
118 | ||
119 | dynhash->key_free = key_free; | |
120 | dynhash->value_free = value_free; | |
121 | ||
122 | return dynhash; | |
123 | } | |
124 | ||
125 | static ctf_helem_t ** | |
126 | ctf_hashtab_lookup (struct htab *htab, const void *key, enum insert_option insert) | |
127 | { | |
128 | ctf_helem_t tmp = { .key = (void *) key }; | |
129 | return (ctf_helem_t **) htab_find_slot (htab, &tmp, insert); | |
130 | } | |
131 | ||
132 | static ctf_helem_t * | |
133 | ctf_hashtab_insert (struct htab *htab, void *key, void *value) | |
134 | { | |
135 | ctf_helem_t **slot; | |
136 | ||
137 | slot = ctf_hashtab_lookup (htab, key, INSERT); | |
138 | ||
139 | if (!slot) | |
140 | { | |
141 | errno = -ENOMEM; | |
142 | return NULL; | |
143 | } | |
144 | ||
145 | if (!*slot) | |
146 | { | |
147 | *slot = malloc (sizeof (ctf_helem_t)); | |
148 | if (!*slot) | |
149 | return NULL; | |
150 | (*slot)->key = key; | |
151 | } | |
152 | (*slot)->value = value; | |
153 | return *slot; | |
154 | } | |
155 | ||
156 | int | |
157 | ctf_dynhash_insert (ctf_dynhash_t *hp, void *key, void *value) | |
158 | { | |
159 | ctf_helem_t *slot; | |
160 | ||
161 | slot = ctf_hashtab_insert (hp->htab, key, value); | |
162 | ||
163 | if (!slot) | |
164 | return errno; | |
165 | ||
166 | /* We need to keep the key_free and value_free around in each item because the | |
167 | del function has no visiblity into the hash as a whole, only into the | |
168 | individual items. */ | |
169 | ||
170 | slot->key_free = hp->key_free; | |
171 | slot->value_free = hp->value_free; | |
172 | ||
173 | return 0; | |
174 | } | |
175 | ||
176 | void | |
177 | ctf_dynhash_remove (ctf_dynhash_t *hp, const void *key) | |
178 | { | |
179 | htab_remove_elt (hp->htab, (void *) key); | |
180 | } | |
181 | ||
182 | void * | |
183 | ctf_dynhash_lookup (ctf_dynhash_t *hp, const void *key) | |
184 | { | |
185 | ctf_helem_t **slot; | |
186 | ||
187 | slot = ctf_hashtab_lookup (hp->htab, key, NO_INSERT); | |
188 | ||
189 | if (slot) | |
190 | return (*slot)->value; | |
191 | ||
192 | return NULL; | |
193 | } | |
194 | ||
195 | void | |
196 | ctf_dynhash_destroy (ctf_dynhash_t *hp) | |
197 | { | |
198 | if (hp != NULL) | |
199 | htab_delete (hp->htab); | |
200 | free (hp); | |
201 | } | |
202 | ||
203 | /* ctf_hash, used for fixed-size maps from const char * -> ctf_id_t without | |
204 | removal. This is a straight cast of a hashtab. */ | |
205 | ||
206 | ctf_hash_t * | |
207 | ctf_hash_create (unsigned long nelems, ctf_hash_fun hash_fun, | |
208 | ctf_hash_eq_fun eq_fun) | |
209 | { | |
210 | return (ctf_hash_t *) htab_create_alloc (nelems, (htab_hash) hash_fun, | |
211 | eq_fun, free, xcalloc, free); | |
212 | } | |
213 | ||
214 | uint32_t | |
215 | ctf_hash_size (const ctf_hash_t *hp) | |
216 | { | |
217 | return htab_elements ((struct htab *) hp); | |
218 | } | |
219 | ||
220 | int | |
221 | ctf_hash_insert_type (ctf_hash_t *hp, ctf_file_t *fp, uint32_t type, | |
222 | uint32_t name) | |
223 | { | |
224 | ctf_strs_t *ctsp = &fp->ctf_str[CTF_NAME_STID (name)]; | |
225 | const char *str = ctsp->cts_strs + CTF_NAME_OFFSET (name); | |
226 | ||
227 | if (type == 0) | |
228 | return EINVAL; | |
229 | ||
230 | if (ctsp->cts_strs == NULL) | |
231 | return ECTF_STRTAB; | |
232 | ||
233 | if (ctsp->cts_len <= CTF_NAME_OFFSET (name)) | |
234 | return ECTF_BADNAME; | |
235 | ||
236 | if (str[0] == '\0') | |
237 | return 0; /* Just ignore empty strings on behalf of caller. */ | |
238 | ||
239 | if (ctf_hashtab_insert ((struct htab *) hp, (char *) str, | |
240 | (void *) (ptrdiff_t) type) != NULL) | |
241 | return 0; | |
242 | return errno; | |
243 | } | |
244 | ||
245 | /* if the key is already in the hash, override the previous definition with | |
246 | this new official definition. If the key is not present, then call | |
247 | ctf_hash_insert_type() and hash it in. */ | |
248 | int | |
249 | ctf_hash_define_type (ctf_hash_t *hp, ctf_file_t *fp, uint32_t type, | |
250 | uint32_t name) | |
251 | { | |
252 | /* This matches the semantics of ctf_hash_insert_type() in this | |
253 | implementation anyway. */ | |
254 | ||
255 | return ctf_hash_insert_type (hp, fp, type, name); | |
256 | } | |
257 | ||
258 | ctf_id_t | |
259 | ctf_hash_lookup_type (ctf_hash_t *hp, ctf_file_t *fp __attribute__ ((__unused__)), | |
260 | const char *key) | |
261 | { | |
262 | ctf_helem_t **slot; | |
263 | ||
264 | slot = ctf_hashtab_lookup ((struct htab *) hp, key, NO_INSERT); | |
265 | ||
266 | if (slot) | |
267 | return (ctf_id_t) ((*slot)->value); | |
268 | ||
269 | return 0; | |
270 | } | |
271 | ||
272 | void | |
273 | ctf_hash_destroy (ctf_hash_t *hp) | |
274 | { | |
275 | if (hp != NULL) | |
276 | htab_delete ((struct htab *) hp); | |
277 | } |