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real_path: clarify return value ownership
[git.git] / khash.h
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1 /* The MIT License
2
3 Copyright (c) 2008, 2009, 2011 by Attractive Chaos <attractor@live.co.uk>
4
5 Permission is hereby granted, free of charge, to any person obtaining
6 a copy of this software and associated documentation files (the
7 "Software"), to deal in the Software without restriction, including
8 without limitation the rights to use, copy, modify, merge, publish,
9 distribute, sublicense, and/or sell copies of the Software, and to
10 permit persons to whom the Software is furnished to do so, subject to
11 the following conditions:
12
13 The above copyright notice and this permission notice shall be
14 included in all copies or substantial portions of the Software.
15
16 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
19 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
20 BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
21 ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 SOFTWARE.
24 */
25
26 #ifndef __AC_KHASH_H
27 #define __AC_KHASH_H
28
29 #define AC_VERSION_KHASH_H "0.2.8"
30
31 typedef uint32_t khint32_t;
32 typedef uint64_t khint64_t;
33
34 typedef khint32_t khint_t;
35 typedef khint_t khiter_t;
36
37 #define __ac_isempty(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&2)
38 #define __ac_isdel(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&1)
39 #define __ac_iseither(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&3)
40 #define __ac_set_isdel_false(flag, i) (flag[i>>4]&=~(1ul<<((i&0xfU)<<1)))
41 #define __ac_set_isempty_false(flag, i) (flag[i>>4]&=~(2ul<<((i&0xfU)<<1)))
42 #define __ac_set_isboth_false(flag, i) (flag[i>>4]&=~(3ul<<((i&0xfU)<<1)))
43 #define __ac_set_isdel_true(flag, i) (flag[i>>4]|=1ul<<((i&0xfU)<<1))
44
45 #define __ac_fsize(m) ((m) < 16? 1 : (m)>>4)
46
47 #define kroundup32(x) (--(x), (x)|=(x)>>1, (x)|=(x)>>2, (x)|=(x)>>4, (x)|=(x)>>8, (x)|=(x)>>16, ++(x))
48
49 static inline khint_t __ac_X31_hash_string(const char *s)
50 {
51 khint_t h = (khint_t)*s;
52 if (h) for (++s ; *s; ++s) h = (h << 5) - h + (khint_t)*s;
53 return h;
54 }
55
56 #define kh_str_hash_func(key) __ac_X31_hash_string(key)
57 #define kh_str_hash_equal(a, b) (strcmp(a, b) == 0)
58
59 static const double __ac_HASH_UPPER = 0.77;
60
61 #define __KHASH_TYPE(name, khkey_t, khval_t) \
62 typedef struct { \
63 khint_t n_buckets, size, n_occupied, upper_bound; \
64 khint32_t *flags; \
65 khkey_t *keys; \
66 khval_t *vals; \
67 } kh_##name##_t;
68
69 #define __KHASH_PROTOTYPES(name, khkey_t, khval_t) \
70 extern kh_##name##_t *kh_init_##name(void); \
71 extern void kh_destroy_##name(kh_##name##_t *h); \
72 extern void kh_clear_##name(kh_##name##_t *h); \
73 extern khint_t kh_get_##name(const kh_##name##_t *h, khkey_t key); \
74 extern int kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets); \
75 extern khint_t kh_put_##name(kh_##name##_t *h, khkey_t key, int *ret); \
76 extern void kh_del_##name(kh_##name##_t *h, khint_t x);
77
78 #define __KHASH_IMPL(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \
79 SCOPE kh_##name##_t *kh_init_##name(void) { \
80 return (kh_##name##_t*)xcalloc(1, sizeof(kh_##name##_t)); \
81 } \
82 SCOPE void kh_destroy_##name(kh_##name##_t *h) \
83 { \
84 if (h) { \
85 free((void *)h->keys); free(h->flags); \
86 free((void *)h->vals); \
87 free(h); \
88 } \
89 } \
90 SCOPE void kh_clear_##name(kh_##name##_t *h) \
91 { \
92 if (h && h->flags) { \
93 memset(h->flags, 0xaa, __ac_fsize(h->n_buckets) * sizeof(khint32_t)); \
94 h->size = h->n_occupied = 0; \
95 } \
96 } \
97 SCOPE khint_t kh_get_##name(const kh_##name##_t *h, khkey_t key) \
98 { \
99 if (h->n_buckets) { \
100 khint_t k, i, last, mask, step = 0; \
101 mask = h->n_buckets - 1; \
102 k = __hash_func(key); i = k & mask; \
103 last = i; \
104 while (!__ac_isempty(h->flags, i) && (__ac_isdel(h->flags, i) || !__hash_equal(h->keys[i], key))) { \
105 i = (i + (++step)) & mask; \
106 if (i == last) return h->n_buckets; \
107 } \
108 return __ac_iseither(h->flags, i)? h->n_buckets : i; \
109 } else return 0; \
110 } \
111 SCOPE int kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets) \
112 { /* This function uses 0.25*n_buckets bytes of working space instead of [sizeof(key_t+val_t)+.25]*n_buckets. */ \
113 khint32_t *new_flags = NULL; \
114 khint_t j = 1; \
115 { \
116 kroundup32(new_n_buckets); \
117 if (new_n_buckets < 4) new_n_buckets = 4; \
118 if (h->size >= (khint_t)(new_n_buckets * __ac_HASH_UPPER + 0.5)) j = 0; /* requested size is too small */ \
119 else { /* hash table size to be changed (shrink or expand); rehash */ \
120 ALLOC_ARRAY(new_flags, __ac_fsize(new_n_buckets)); \
121 if (!new_flags) return -1; \
122 memset(new_flags, 0xaa, __ac_fsize(new_n_buckets) * sizeof(khint32_t)); \
123 if (h->n_buckets < new_n_buckets) { /* expand */ \
124 REALLOC_ARRAY(h->keys, new_n_buckets); \
125 if (kh_is_map) { \
126 REALLOC_ARRAY(h->vals, new_n_buckets); \
127 } \
128 } /* otherwise shrink */ \
129 } \
130 } \
131 if (j) { /* rehashing is needed */ \
132 for (j = 0; j != h->n_buckets; ++j) { \
133 if (__ac_iseither(h->flags, j) == 0) { \
134 khkey_t key = h->keys[j]; \
135 khval_t val; \
136 khint_t new_mask; \
137 new_mask = new_n_buckets - 1; \
138 if (kh_is_map) val = h->vals[j]; \
139 __ac_set_isdel_true(h->flags, j); \
140 while (1) { /* kick-out process; sort of like in Cuckoo hashing */ \
141 khint_t k, i, step = 0; \
142 k = __hash_func(key); \
143 i = k & new_mask; \
144 while (!__ac_isempty(new_flags, i)) i = (i + (++step)) & new_mask; \
145 __ac_set_isempty_false(new_flags, i); \
146 if (i < h->n_buckets && __ac_iseither(h->flags, i) == 0) { /* kick out the existing element */ \
147 { khkey_t tmp = h->keys[i]; h->keys[i] = key; key = tmp; } \
148 if (kh_is_map) { khval_t tmp = h->vals[i]; h->vals[i] = val; val = tmp; } \
149 __ac_set_isdel_true(h->flags, i); /* mark it as deleted in the old hash table */ \
150 } else { /* write the element and jump out of the loop */ \
151 h->keys[i] = key; \
152 if (kh_is_map) h->vals[i] = val; \
153 break; \
154 } \
155 } \
156 } \
157 } \
158 if (h->n_buckets > new_n_buckets) { /* shrink the hash table */ \
159 REALLOC_ARRAY(h->keys, new_n_buckets); \
160 if (kh_is_map) REALLOC_ARRAY(h->vals, new_n_buckets); \
161 } \
162 free(h->flags); /* free the working space */ \
163 h->flags = new_flags; \
164 h->n_buckets = new_n_buckets; \
165 h->n_occupied = h->size; \
166 h->upper_bound = (khint_t)(h->n_buckets * __ac_HASH_UPPER + 0.5); \
167 } \
168 return 0; \
169 } \
170 SCOPE khint_t kh_put_##name(kh_##name##_t *h, khkey_t key, int *ret) \
171 { \
172 khint_t x; \
173 if (h->n_occupied >= h->upper_bound) { /* update the hash table */ \
174 if (h->n_buckets > (h->size<<1)) { \
175 if (kh_resize_##name(h, h->n_buckets - 1) < 0) { /* clear "deleted" elements */ \
176 *ret = -1; return h->n_buckets; \
177 } \
178 } else if (kh_resize_##name(h, h->n_buckets + 1) < 0) { /* expand the hash table */ \
179 *ret = -1; return h->n_buckets; \
180 } \
181 } /* TODO: to implement automatically shrinking; resize() already support shrinking */ \
182 { \
183 khint_t k, i, site, last, mask = h->n_buckets - 1, step = 0; \
184 x = site = h->n_buckets; k = __hash_func(key); i = k & mask; \
185 if (__ac_isempty(h->flags, i)) x = i; /* for speed up */ \
186 else { \
187 last = i; \
188 while (!__ac_isempty(h->flags, i) && (__ac_isdel(h->flags, i) || !__hash_equal(h->keys[i], key))) { \
189 if (__ac_isdel(h->flags, i)) site = i; \
190 i = (i + (++step)) & mask; \
191 if (i == last) { x = site; break; } \
192 } \
193 if (x == h->n_buckets) { \
194 if (__ac_isempty(h->flags, i) && site != h->n_buckets) x = site; \
195 else x = i; \
196 } \
197 } \
198 } \
199 if (__ac_isempty(h->flags, x)) { /* not present at all */ \
200 h->keys[x] = key; \
201 __ac_set_isboth_false(h->flags, x); \
202 ++h->size; ++h->n_occupied; \
203 *ret = 1; \
204 } else if (__ac_isdel(h->flags, x)) { /* deleted */ \
205 h->keys[x] = key; \
206 __ac_set_isboth_false(h->flags, x); \
207 ++h->size; \
208 *ret = 2; \
209 } else *ret = 0; /* Don't touch h->keys[x] if present and not deleted */ \
210 return x; \
211 } \
212 SCOPE void kh_del_##name(kh_##name##_t *h, khint_t x) \
213 { \
214 if (x != h->n_buckets && !__ac_iseither(h->flags, x)) { \
215 __ac_set_isdel_true(h->flags, x); \
216 --h->size; \
217 } \
218 }
219
220 #define KHASH_DECLARE(name, khkey_t, khval_t) \
221 __KHASH_TYPE(name, khkey_t, khval_t) \
222 __KHASH_PROTOTYPES(name, khkey_t, khval_t)
223
224 #define KHASH_INIT2(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \
225 __KHASH_TYPE(name, khkey_t, khval_t) \
226 __KHASH_IMPL(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal)
227
228 #define KHASH_INIT(name, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \
229 KHASH_INIT2(name, static inline, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal)
230
231 /* Other convenient macros... */
232
233 /*! @function
234 @abstract Test whether a bucket contains data.
235 @param h Pointer to the hash table [khash_t(name)*]
236 @param x Iterator to the bucket [khint_t]
237 @return 1 if containing data; 0 otherwise [int]
238 */
239 #define kh_exist(h, x) (!__ac_iseither((h)->flags, (x)))
240
241 /*! @function
242 @abstract Get key given an iterator
243 @param h Pointer to the hash table [khash_t(name)*]
244 @param x Iterator to the bucket [khint_t]
245 @return Key [type of keys]
246 */
247 #define kh_key(h, x) ((h)->keys[x])
248
249 /*! @function
250 @abstract Get value given an iterator
251 @param h Pointer to the hash table [khash_t(name)*]
252 @param x Iterator to the bucket [khint_t]
253 @return Value [type of values]
254 @discussion For hash sets, calling this results in segfault.
255 */
256 #define kh_val(h, x) ((h)->vals[x])
257
258 /*! @function
259 @abstract Alias of kh_val()
260 */
261 #define kh_value(h, x) ((h)->vals[x])
262
263 /*! @function
264 @abstract Get the start iterator
265 @param h Pointer to the hash table [khash_t(name)*]
266 @return The start iterator [khint_t]
267 */
268 #define kh_begin(h) (khint_t)(0)
269
270 /*! @function
271 @abstract Get the end iterator
272 @param h Pointer to the hash table [khash_t(name)*]
273 @return The end iterator [khint_t]
274 */
275 #define kh_end(h) ((h)->n_buckets)
276
277 /*! @function
278 @abstract Get the number of elements in the hash table
279 @param h Pointer to the hash table [khash_t(name)*]
280 @return Number of elements in the hash table [khint_t]
281 */
282 #define kh_size(h) ((h)->size)
283
284 /*! @function
285 @abstract Get the number of buckets in the hash table
286 @param h Pointer to the hash table [khash_t(name)*]
287 @return Number of buckets in the hash table [khint_t]
288 */
289 #define kh_n_buckets(h) ((h)->n_buckets)
290
291 /*! @function
292 @abstract Iterate over the entries in the hash table
293 @param h Pointer to the hash table [khash_t(name)*]
294 @param kvar Variable to which key will be assigned
295 @param vvar Variable to which value will be assigned
296 @param code Block of code to execute
297 */
298 #define kh_foreach(h, kvar, vvar, code) { khint_t __i; \
299 for (__i = kh_begin(h); __i != kh_end(h); ++__i) { \
300 if (!kh_exist(h,__i)) continue; \
301 (kvar) = kh_key(h,__i); \
302 (vvar) = kh_val(h,__i); \
303 code; \
304 } }
305
306 /*! @function
307 @abstract Iterate over the values in the hash table
308 @param h Pointer to the hash table [khash_t(name)*]
309 @param vvar Variable to which value will be assigned
310 @param code Block of code to execute
311 */
312 #define kh_foreach_value(h, vvar, code) { khint_t __i; \
313 for (__i = kh_begin(h); __i != kh_end(h); ++__i) { \
314 if (!kh_exist(h,__i)) continue; \
315 (vvar) = kh_val(h,__i); \
316 code; \
317 } }
318
319 #define __kh_oid_cmp(a, b) (hashcmp(a, b) == 0)
320
321 KHASH_INIT(sha1, const unsigned char *, void *, 1, sha1hash, __kh_oid_cmp)
322 typedef kh_sha1_t khash_sha1;
323
324 KHASH_INIT(sha1_pos, const unsigned char *, int, 1, sha1hash, __kh_oid_cmp)
325 typedef kh_sha1_pos_t khash_sha1_pos;
326
327 #endif /* __AC_KHASH_H */
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