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[git.git] / khash.h
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1 /* The MIT License
3 Copyright (c) 2008, 2009, 2011 by Attractive Chaos <attractor@live.co.uk>
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:
13 The above copyright notice and this permission notice shall be
14 included in all copies or substantial portions of the Software.
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.
26 #ifndef __AC_KHASH_H
27 #define __AC_KHASH_H
29 #define AC_VERSION_KHASH_H "0.2.8"
31 typedef uint32_t khint32_t;
32 typedef uint64_t khint64_t;
34 typedef khint32_t khint_t;
35 typedef khint_t khiter_t;
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))
45 #define __ac_fsize(m) ((m) < 16? 1 : (m)>>4)
47 #define kroundup32(x) (--(x), (x)|=(x)>>1, (x)|=(x)>>2, (x)|=(x)>>4, (x)|=(x)>>8, (x)|=(x)>>16, ++(x))
49 static inline khint_t __ac_X31_hash_string(const char *s)
51 khint_t h = (khint_t)*s;
52 if (h) for (++s ; *s; ++s) h = (h << 5) - h + (khint_t)*s;
53 return h;
56 #define kh_str_hash_func(key) __ac_X31_hash_string(key)
57 #define kh_str_hash_equal(a, b) (strcmp(a, b) == 0)
59 static const double __ac_HASH_UPPER = 0.77;
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;
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);
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; \
108 return __ac_iseither(h->flags, i)? h->n_buckets : i; \
109 } else return 0; \
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; \
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 new_flags = (khint32_t*)xmalloc(__ac_fsize(new_n_buckets) * sizeof(khint32_t)); \
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 khkey_t *new_keys = (khkey_t*)xrealloc((void *)h->keys, new_n_buckets * sizeof(khkey_t)); \
125 if (!new_keys) return -1; \
126 h->keys = new_keys; \
127 if (kh_is_map) { \
128 khval_t *new_vals = (khval_t*)xrealloc((void *)h->vals, new_n_buckets * sizeof(khval_t)); \
129 if (!new_vals) return -1; \
130 h->vals = new_vals; \
132 } /* otherwise shrink */ \
135 if (j) { /* rehashing is needed */ \
136 for (j = 0; j != h->n_buckets; ++j) { \
137 if (__ac_iseither(h->flags, j) == 0) { \
138 khkey_t key = h->keys[j]; \
139 khval_t val; \
140 khint_t new_mask; \
141 new_mask = new_n_buckets - 1; \
142 if (kh_is_map) val = h->vals[j]; \
143 __ac_set_isdel_true(h->flags, j); \
144 while (1) { /* kick-out process; sort of like in Cuckoo hashing */ \
145 khint_t k, i, step = 0; \
146 k = __hash_func(key); \
147 i = k & new_mask; \
148 while (!__ac_isempty(new_flags, i)) i = (i + (++step)) & new_mask; \
149 __ac_set_isempty_false(new_flags, i); \
150 if (i < h->n_buckets && __ac_iseither(h->flags, i) == 0) { /* kick out the existing element */ \
151 { khkey_t tmp = h->keys[i]; h->keys[i] = key; key = tmp; } \
152 if (kh_is_map) { khval_t tmp = h->vals[i]; h->vals[i] = val; val = tmp; } \
153 __ac_set_isdel_true(h->flags, i); /* mark it as deleted in the old hash table */ \
154 } else { /* write the element and jump out of the loop */ \
155 h->keys[i] = key; \
156 if (kh_is_map) h->vals[i] = val; \
157 break; \
162 if (h->n_buckets > new_n_buckets) { /* shrink the hash table */ \
163 h->keys = (khkey_t*)xrealloc((void *)h->keys, new_n_buckets * sizeof(khkey_t)); \
164 if (kh_is_map) h->vals = (khval_t*)xrealloc((void *)h->vals, new_n_buckets * sizeof(khval_t)); \
166 free(h->flags); /* free the working space */ \
167 h->flags = new_flags; \
168 h->n_buckets = new_n_buckets; \
169 h->n_occupied = h->size; \
170 h->upper_bound = (khint_t)(h->n_buckets * __ac_HASH_UPPER + 0.5); \
172 return 0; \
174 SCOPE khint_t kh_put_##name(kh_##name##_t *h, khkey_t key, int *ret) \
176 khint_t x; \
177 if (h->n_occupied >= h->upper_bound) { /* update the hash table */ \
178 if (h->n_buckets > (h->size<<1)) { \
179 if (kh_resize_##name(h, h->n_buckets - 1) < 0) { /* clear "deleted" elements */ \
180 *ret = -1; return h->n_buckets; \
182 } else if (kh_resize_##name(h, h->n_buckets + 1) < 0) { /* expand the hash table */ \
183 *ret = -1; return h->n_buckets; \
185 } /* TODO: to implement automatically shrinking; resize() already support shrinking */ \
187 khint_t k, i, site, last, mask = h->n_buckets - 1, step = 0; \
188 x = site = h->n_buckets; k = __hash_func(key); i = k & mask; \
189 if (__ac_isempty(h->flags, i)) x = i; /* for speed up */ \
190 else { \
191 last = i; \
192 while (!__ac_isempty(h->flags, i) && (__ac_isdel(h->flags, i) || !__hash_equal(h->keys[i], key))) { \
193 if (__ac_isdel(h->flags, i)) site = i; \
194 i = (i + (++step)) & mask; \
195 if (i == last) { x = site; break; } \
197 if (x == h->n_buckets) { \
198 if (__ac_isempty(h->flags, i) && site != h->n_buckets) x = site; \
199 else x = i; \
203 if (__ac_isempty(h->flags, x)) { /* not present at all */ \
204 h->keys[x] = key; \
205 __ac_set_isboth_false(h->flags, x); \
206 ++h->size; ++h->n_occupied; \
207 *ret = 1; \
208 } else if (__ac_isdel(h->flags, x)) { /* deleted */ \
209 h->keys[x] = key; \
210 __ac_set_isboth_false(h->flags, x); \
211 ++h->size; \
212 *ret = 2; \
213 } else *ret = 0; /* Don't touch h->keys[x] if present and not deleted */ \
214 return x; \
216 SCOPE void kh_del_##name(kh_##name##_t *h, khint_t x) \
218 if (x != h->n_buckets && !__ac_iseither(h->flags, x)) { \
219 __ac_set_isdel_true(h->flags, x); \
220 --h->size; \
224 #define KHASH_DECLARE(name, khkey_t, khval_t) \
225 __KHASH_TYPE(name, khkey_t, khval_t) \
226 __KHASH_PROTOTYPES(name, khkey_t, khval_t)
228 #define KHASH_INIT2(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \
229 __KHASH_TYPE(name, khkey_t, khval_t) \
230 __KHASH_IMPL(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal)
232 #define KHASH_INIT(name, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \
233 KHASH_INIT2(name, static inline, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal)
235 /* Other convenient macros... */
237 /*! @function
238 @abstract Test whether a bucket contains data.
239 @param h Pointer to the hash table [khash_t(name)*]
240 @param x Iterator to the bucket [khint_t]
241 @return 1 if containing data; 0 otherwise [int]
243 #define kh_exist(h, x) (!__ac_iseither((h)->flags, (x)))
245 /*! @function
246 @abstract Get key given an iterator
247 @param h Pointer to the hash table [khash_t(name)*]
248 @param x Iterator to the bucket [khint_t]
249 @return Key [type of keys]
251 #define kh_key(h, x) ((h)->keys[x])
253 /*! @function
254 @abstract Get value given an iterator
255 @param h Pointer to the hash table [khash_t(name)*]
256 @param x Iterator to the bucket [khint_t]
257 @return Value [type of values]
258 @discussion For hash sets, calling this results in segfault.
260 #define kh_val(h, x) ((h)->vals[x])
262 /*! @function
263 @abstract Alias of kh_val()
265 #define kh_value(h, x) ((h)->vals[x])
267 /*! @function
268 @abstract Get the start iterator
269 @param h Pointer to the hash table [khash_t(name)*]
270 @return The start iterator [khint_t]
272 #define kh_begin(h) (khint_t)(0)
274 /*! @function
275 @abstract Get the end iterator
276 @param h Pointer to the hash table [khash_t(name)*]
277 @return The end iterator [khint_t]
279 #define kh_end(h) ((h)->n_buckets)
281 /*! @function
282 @abstract Get the number of elements in the hash table
283 @param h Pointer to the hash table [khash_t(name)*]
284 @return Number of elements in the hash table [khint_t]
286 #define kh_size(h) ((h)->size)
288 /*! @function
289 @abstract Get the number of buckets in the hash table
290 @param h Pointer to the hash table [khash_t(name)*]
291 @return Number of buckets in the hash table [khint_t]
293 #define kh_n_buckets(h) ((h)->n_buckets)
295 /*! @function
296 @abstract Iterate over the entries in the hash table
297 @param h Pointer to the hash table [khash_t(name)*]
298 @param kvar Variable to which key will be assigned
299 @param vvar Variable to which value will be assigned
300 @param code Block of code to execute
302 #define kh_foreach(h, kvar, vvar, code) { khint_t __i; \
303 for (__i = kh_begin(h); __i != kh_end(h); ++__i) { \
304 if (!kh_exist(h,__i)) continue; \
305 (kvar) = kh_key(h,__i); \
306 (vvar) = kh_val(h,__i); \
307 code; \
310 /*! @function
311 @abstract Iterate over the values in the hash table
312 @param h Pointer to the hash table [khash_t(name)*]
313 @param vvar Variable to which value will be assigned
314 @param code Block of code to execute
316 #define kh_foreach_value(h, vvar, code) { khint_t __i; \
317 for (__i = kh_begin(h); __i != kh_end(h); ++__i) { \
318 if (!kh_exist(h,__i)) continue; \
319 (vvar) = kh_val(h,__i); \
320 code; \
323 static inline khint_t __kh_oid_hash(const unsigned char *oid)
325 khint_t hash;
326 memcpy(&hash, oid, sizeof(hash));
327 return hash;
330 #define __kh_oid_cmp(a, b) (hashcmp(a, b) == 0)
332 KHASH_INIT(sha1, const unsigned char *, void *, 1, __kh_oid_hash, __kh_oid_cmp)
333 typedef kh_sha1_t khash_sha1;
335 KHASH_INIT(sha1_pos, const unsigned char *, int, 1, __kh_oid_hash, __kh_oid_cmp)
336 typedef kh_sha1_pos_t khash_sha1_pos;
338 #endif /* __AC_KHASH_H */