xref: /freebsd/contrib/libucl/klib/khash.h (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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 /*
27   An example:
28 
29 #include "khash.h"
30 KHASH_MAP_INIT_INT(32, char)
31 int main() {
32 	int ret, is_missing;
33 	khiter_t k;
34 	khash_t(32) *h = kh_init(32);
35 	k = kh_put(32, h, 5, &ret);
36 	kh_value(h, k) = 10;
37 	k = kh_get(32, h, 10);
38 	is_missing = (k == kh_end(h));
39 	k = kh_get(32, h, 5);
40 	kh_del(32, h, k);
41 	for (k = kh_begin(h); k != kh_end(h); ++k)
42 		if (kh_exist(h, k)) kh_value(h, k) = 1;
43 	kh_destroy(32, h);
44 	return 0;
45 }
46 */
47 
48 /*
49   2013-05-02 (0.2.8):
50 
51 	* Use quadratic probing. When the capacity is power of 2, stepping function
52 	  i*(i+1)/2 guarantees to traverse each bucket. It is better than double
53 	  hashing on cache performance and is more robust than linear probing.
54 
55 	  In theory, double hashing should be more robust than quadratic probing.
56 	  However, my implementation is probably not for large hash tables, because
57 	  the second hash function is closely tied to the first hash function,
58 	  which reduce the effectiveness of double hashing.
59 
60 	Reference: http://research.cs.vt.edu/AVresearch/hashing/quadratic.php
61 
62   2011-12-29 (0.2.7):
63 
64     * Minor code clean up; no actual effect.
65 
66   2011-09-16 (0.2.6):
67 
68 	* The capacity is a power of 2. This seems to dramatically improve the
69 	  speed for simple keys. Thank Zilong Tan for the suggestion. Reference:
70 
71 	   - http://code.google.com/p/ulib/
72 	   - http://nothings.org/computer/judy/
73 
74 	* Allow to optionally use linear probing which usually has better
75 	  performance for random input. Double hashing is still the default as it
76 	  is more robust to certain non-random input.
77 
78 	* Added Wang's integer hash function (not used by default). This hash
79 	  function is more robust to certain non-random input.
80 
81   2011-02-14 (0.2.5):
82 
83     * Allow to declare global functions.
84 
85   2009-09-26 (0.2.4):
86 
87     * Improve portability
88 
89   2008-09-19 (0.2.3):
90 
91 	* Corrected the example
92 	* Improved interfaces
93 
94   2008-09-11 (0.2.2):
95 
96 	* Improved speed a little in kh_put()
97 
98   2008-09-10 (0.2.1):
99 
100 	* Added kh_clear()
101 	* Fixed a compiling error
102 
103   2008-09-02 (0.2.0):
104 
105 	* Changed to token concatenation which increases flexibility.
106 
107   2008-08-31 (0.1.2):
108 
109 	* Fixed a bug in kh_get(), which has not been tested previously.
110 
111   2008-08-31 (0.1.1):
112 
113 	* Added destructor
114 */
115 
116 
117 #ifndef __AC_KHASH_H
118 #define __AC_KHASH_H
119 
120 /*!
121   @header
122 
123   Generic hash table library.
124  */
125 
126 #define AC_VERSION_KHASH_H "0.2.8"
127 
128 #include <stdlib.h>
129 #include <string.h>
130 #include <limits.h>
131 
132 /* compiler specific configuration */
133 
134 #if UINT_MAX == 0xffffffffu
135 typedef unsigned int khint32_t;
136 #elif ULONG_MAX == 0xffffffffu
137 typedef unsigned long khint32_t;
138 #endif
139 
140 #if ULONG_MAX == ULLONG_MAX
141 typedef unsigned long khint64_t;
142 #else
143 typedef unsigned long long khint64_t;
144 #endif
145 
146 #ifndef kh_inline
147 #ifdef _MSC_VER
148 #define kh_inline __inline
149 #else
150 #define kh_inline inline
151 #endif
152 #endif /* kh_inline */
153 
154 #ifndef kh_unused
155 # ifdef __GNUC__
156 #   define kh_unused(x) __attribute__((__unused__)) x
157 # else
158 #   define kh_unused(x) x
159 # endif
160 #endif
161 
162 typedef khint32_t khint_t;
163 typedef khint_t khiter_t;
164 
165 #define __ac_isempty(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&2)
166 #define __ac_isdel(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&1)
167 #define __ac_iseither(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&3)
168 #define __ac_set_isdel_false(flag, i) (flag[i>>4]&=~(1ul<<((i&0xfU)<<1)))
169 #define __ac_set_isempty_false(flag, i) (flag[i>>4]&=~(2ul<<((i&0xfU)<<1)))
170 #define __ac_set_isboth_false(flag, i) (flag[i>>4]&=~(3ul<<((i&0xfU)<<1)))
171 #define __ac_set_isdel_true(flag, i) (flag[i>>4]|=1ul<<((i&0xfU)<<1))
172 
173 #define __ac_fsize(m) ((m) < 16? 1 : (m)>>4)
174 
175 #ifndef kroundup32
176 #define kroundup32(x) (--(x), (x)|=(x)>>1, (x)|=(x)>>2, (x)|=(x)>>4, (x)|=(x)>>8, (x)|=(x)>>16, ++(x))
177 #endif
178 
179 #ifndef kcalloc
180 #define kcalloc(N,Z) calloc(N,Z)
181 #endif
182 #ifndef kmalloc
183 #define kmalloc(Z) malloc(Z)
184 #endif
185 #ifndef krealloc
186 #define krealloc(P,Z) realloc(P,Z)
187 #endif
188 #ifndef kfree
189 #define kfree(P) free(P)
190 #endif
191 
192 static const double __ac_HASH_UPPER = 0.77;
193 
194 #define __KHASH_TYPE(name, khkey_t, khval_t) \
195 	typedef struct kh_##name##_s { \
196 		khint_t n_buckets, size, n_occupied, upper_bound; \
197 		khint32_t *flags; \
198 		khkey_t *keys; \
199 		khval_t *vals; \
200 	} kh_##name##_t;
201 
202 #define __KHASH_PROTOTYPES(name, khkey_t, khval_t)	 						\
203 	extern kh_##name##_t * kh_init_##name(void);							\
204 	extern void kh_destroy_##name(kh_##name##_t *h);						\
205 	extern void kh_clear_##name(kh_##name##_t *h);							\
206 	extern khint_t kh_get_##name(const kh_##name##_t *h, khkey_t key); 		\
207 	extern int kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets); 	\
208 	extern khint_t kh_put_##name(kh_##name##_t *h, khkey_t key, int *ret); 	\
209 	extern void kh_del_##name(kh_##name##_t *h, khint_t x);
210 
211 #define __KHASH_IMPL(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \
212 	SCOPE kh_##name##_t *kh_init_##name(void) {							\
213 		return (kh_##name##_t*)kcalloc(1, sizeof(kh_##name##_t));		\
214 	}																	\
215 	SCOPE void kh_destroy_##name(kh_##name##_t *h)						\
216 	{																	\
217 		if (h) {														\
218 			kfree((void *)h->keys); kfree(h->flags);					\
219 			kfree((void *)h->vals);										\
220 			kfree(h);													\
221 		}																\
222 	}																	\
223 	SCOPE void kh_unused(kh_clear_##name)(kh_##name##_t *h)				\
224 	{																	\
225 		if (h && h->flags) {											\
226 			memset(h->flags, 0xaa, __ac_fsize(h->n_buckets) * sizeof(khint32_t)); \
227 			h->size = h->n_occupied = 0;								\
228 		}																\
229 	}																	\
230 	SCOPE khint_t kh_get_##name(const kh_##name##_t *h, khkey_t key) 	\
231 	{																	\
232 		if (h->n_buckets) {												\
233 			khint_t k, i, last, mask, step = 0; \
234 			mask = h->n_buckets - 1;									\
235 			k = __hash_func(key); i = k & mask;							\
236 			last = i; \
237 			while (!__ac_isempty(h->flags, i) && (__ac_isdel(h->flags, i) || !__hash_equal(h->keys[i], key))) { \
238 				i = (i + (++step)) & mask; \
239 				if (i == last) return h->n_buckets;						\
240 			}															\
241 			return __ac_iseither(h->flags, i)? h->n_buckets : i;		\
242 		} else return 0;												\
243 	}																	\
244 	SCOPE int kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets) \
245 	{ /* This function uses 0.25*n_buckets bytes of working space instead of [sizeof(key_t+val_t)+.25]*n_buckets. */ \
246 		khint32_t *new_flags = 0;										\
247 		khint_t j = 1;													\
248 		{																\
249 			kroundup32(new_n_buckets); 									\
250 			if (new_n_buckets < 4) new_n_buckets = 4;					\
251 			if (h->size >= (khint_t)(new_n_buckets * __ac_HASH_UPPER + 0.5)) j = 0;	/* requested size is too small */ \
252 			else { /* hash table size to be changed (shrink or expand); rehash */ \
253 				new_flags = (khint32_t*)kmalloc(__ac_fsize(new_n_buckets) * sizeof(khint32_t));	\
254 				if (!new_flags) return -1;								\
255 				memset(new_flags, 0xaa, __ac_fsize(new_n_buckets) * sizeof(khint32_t)); \
256 				if (h->n_buckets < new_n_buckets) {	/* expand */		\
257 					khkey_t *new_keys = (khkey_t*)krealloc((void *)h->keys, new_n_buckets * sizeof(khkey_t)); \
258 					if (!new_keys) { kfree(new_flags); return -1; }		\
259 					h->keys = new_keys;									\
260 					if (kh_is_map) {									\
261 						khval_t *new_vals = (khval_t*)krealloc((void *)h->vals, new_n_buckets * sizeof(khval_t)); \
262 						if (!new_vals) { kfree(new_flags); return -1; }	\
263 						h->vals = new_vals;								\
264 					}													\
265 				} /* otherwise shrink */								\
266 			}															\
267 		}																\
268 		if (j) { /* rehashing is needed */								\
269 			for (j = 0; j != h->n_buckets; ++j) {						\
270 				if (__ac_iseither(h->flags, j) == 0) {					\
271 					khkey_t key = h->keys[j];							\
272 					khval_t val;										\
273 					khint_t new_mask;									\
274 					new_mask = new_n_buckets - 1; 						\
275 					if (kh_is_map) val = h->vals[j];					\
276 					__ac_set_isdel_true(h->flags, j);					\
277 					while (1) { /* kick-out process; sort of like in Cuckoo hashing */ \
278 						khint_t k, i, step = 0; \
279 						k = __hash_func(key);							\
280 						i = k & new_mask;								\
281 						while (!__ac_isempty(new_flags, i)) i = (i + (++step)) & new_mask; \
282 						__ac_set_isempty_false(new_flags, i);			\
283 						if (i < h->n_buckets && __ac_iseither(h->flags, i) == 0) { /* kick out the existing element */ \
284 							{ khkey_t tmp = h->keys[i]; h->keys[i] = key; key = tmp; } \
285 							if (kh_is_map) { khval_t tmp = h->vals[i]; h->vals[i] = val; val = tmp; } \
286 							__ac_set_isdel_true(h->flags, i); /* mark it as deleted in the old hash table */ \
287 						} else { /* write the element and jump out of the loop */ \
288 							h->keys[i] = key;							\
289 							if (kh_is_map) h->vals[i] = val;			\
290 							break;										\
291 						}												\
292 					}													\
293 				}														\
294 			}															\
295 			if (h->n_buckets > new_n_buckets) { /* shrink the hash table */ \
296 				h->keys = (khkey_t*)krealloc((void *)h->keys, new_n_buckets * sizeof(khkey_t)); \
297 				if (kh_is_map) h->vals = (khval_t*)krealloc((void *)h->vals, new_n_buckets * sizeof(khval_t)); \
298 			}															\
299 			kfree(h->flags); /* free the working space */				\
300 			h->flags = new_flags;										\
301 			h->n_buckets = new_n_buckets;								\
302 			h->n_occupied = h->size;									\
303 			h->upper_bound = (khint_t)(h->n_buckets * __ac_HASH_UPPER + 0.5); \
304 		}																\
305 		return 0;														\
306 	}																	\
307 	SCOPE khint_t kh_put_##name(kh_##name##_t *h, khkey_t key, int *ret) \
308 	{																	\
309 		khint_t x;														\
310 		if (h->n_occupied >= h->upper_bound) { /* update the hash table */ \
311 			if (h->n_buckets > (h->size<<1)) {							\
312 				if (kh_resize_##name(h, h->n_buckets - 1) < 0) { /* clear "deleted" elements */ \
313 					*ret = -1; return h->n_buckets;						\
314 				}														\
315 			} else if (kh_resize_##name(h, h->n_buckets + 1) < 0) { /* expand the hash table */ \
316 				*ret = -1; return h->n_buckets;							\
317 			}															\
318 		} /* TODO: to implement automatically shrinking; resize() already support shrinking */ \
319 		{																\
320 			khint_t k, i, site, last, mask = h->n_buckets - 1, step = 0; \
321 			x = site = h->n_buckets; k = __hash_func(key); i = k & mask; \
322 			if (__ac_isempty(h->flags, i)) x = i; /* for speed up */	\
323 			else {														\
324 				last = i; \
325 				while (!__ac_isempty(h->flags, i) && (__ac_isdel(h->flags, i) || !__hash_equal(h->keys[i], key))) { \
326 					if (__ac_isdel(h->flags, i)) site = i;				\
327 					i = (i + (++step)) & mask; \
328 					if (i == last) { x = site; break; }					\
329 				}														\
330 				if (x == h->n_buckets) {								\
331 					if (__ac_isempty(h->flags, i) && site != h->n_buckets) x = site; \
332 					else x = i;											\
333 				}														\
334 			}															\
335 		}																\
336 		if (__ac_isempty(h->flags, x)) { /* not present at all */		\
337 			h->keys[x] = key;											\
338 			__ac_set_isboth_false(h->flags, x);							\
339 			++h->size; ++h->n_occupied;									\
340 			*ret = 1;													\
341 		} else if (__ac_isdel(h->flags, x)) { /* deleted */				\
342 			h->keys[x] = key;											\
343 			__ac_set_isboth_false(h->flags, x);							\
344 			++h->size;													\
345 			*ret = 2;													\
346 		} else *ret = 0; /* Don't touch h->keys[x] if present and not deleted */ \
347 		return x;														\
348 	}																	\
349 	SCOPE void kh_del_##name(kh_##name##_t *h, khint_t x)				\
350 	{																	\
351 		if (x != h->n_buckets && !__ac_iseither(h->flags, x)) {			\
352 			__ac_set_isdel_true(h->flags, x);							\
353 			--h->size;													\
354 		}																\
355 	}
356 
357 #define KHASH_DECLARE(name, khkey_t, khval_t)		 					\
358 	__KHASH_TYPE(name, khkey_t, khval_t) 								\
359 	__KHASH_PROTOTYPES(name, khkey_t, khval_t)
360 
361 #define KHASH_INIT2(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \
362 	__KHASH_TYPE(name, khkey_t, khval_t) 								\
363 	__KHASH_IMPL(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal)
364 
365 #define KHASH_INIT(name, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \
366 	KHASH_INIT2(name, static kh_inline, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal)
367 
368 /* --- BEGIN OF HASH FUNCTIONS --- */
369 
370 /*! @function
371   @abstract     Integer hash function
372   @param  key   The integer [khint32_t]
373   @return       The hash value [khint_t]
374  */
375 #define kh_int_hash_func(key) (khint32_t)(key)
376 /*! @function
377   @abstract     Integer comparison function
378  */
379 #define kh_int_hash_equal(a, b) ((a) == (b))
380 /*! @function
381   @abstract     64-bit integer hash function
382   @param  key   The integer [khint64_t]
383   @return       The hash value [khint_t]
384  */
385 #define kh_int64_hash_func(key) (khint32_t)((key)>>33^(key)^(key)<<11)
386 /*! @function
387   @abstract     64-bit integer comparison function
388  */
389 #define kh_int64_hash_equal(a, b) ((a) == (b))
390 /*! @function
391   @abstract     const char* hash function
392   @param  s     Pointer to a null terminated string
393   @return       The hash value
394  */
395 static kh_inline khint_t __ac_X31_hash_string(const char *s)
396 {
397 	khint_t h = (khint_t)*s;
398 	if (h) for (++s ; *s; ++s) h = (h << 5) - h + (khint_t)*s;
399 	return h;
400 }
401 /*! @function
402   @abstract     Another interface to const char* hash function
403   @param  key   Pointer to a null terminated string [const char*]
404   @return       The hash value [khint_t]
405  */
406 #define kh_str_hash_func(key) __ac_X31_hash_string(key)
407 /*! @function
408   @abstract     Const char* comparison function
409  */
410 #define kh_str_hash_equal(a, b) (strcmp(a, b) == 0)
411 
412 static kh_inline khint_t __ac_Wang_hash(khint_t key)
413 {
414     key += ~(key << 15);
415     key ^=  (key >> 10);
416     key +=  (key << 3);
417     key ^=  (key >> 6);
418     key += ~(key << 11);
419     key ^=  (key >> 16);
420     return key;
421 }
422 #define kh_int_hash_func2(k) __ac_Wang_hash((khint_t)key)
423 
424 /* --- END OF HASH FUNCTIONS --- */
425 
426 /* Other convenient macros... */
427 
428 /*!
429   @abstract Type of the hash table.
430   @param  name  Name of the hash table [symbol]
431  */
432 #define khash_t(name) kh_##name##_t
433 
434 /*! @function
435   @abstract     Initiate a hash table.
436   @param  name  Name of the hash table [symbol]
437   @return       Pointer to the hash table [khash_t(name)*]
438  */
439 #define kh_init(name) kh_init_##name()
440 
441 /*! @function
442   @abstract     Destroy a hash table.
443   @param  name  Name of the hash table [symbol]
444   @param  h     Pointer to the hash table [khash_t(name)*]
445  */
446 #define kh_destroy(name, h) kh_destroy_##name(h)
447 
448 /*! @function
449   @abstract     Reset a hash table without deallocating memory.
450   @param  name  Name of the hash table [symbol]
451   @param  h     Pointer to the hash table [khash_t(name)*]
452  */
453 #define kh_clear(name, h) kh_clear_##name(h)
454 
455 /*! @function
456   @abstract     Resize a hash table.
457   @param  name  Name of the hash table [symbol]
458   @param  h     Pointer to the hash table [khash_t(name)*]
459   @param  s     New size [khint_t]
460  */
461 #define kh_resize(name, h, s) kh_resize_##name(h, s)
462 
463 /*! @function
464   @abstract     Insert a key to the hash table.
465   @param  name  Name of the hash table [symbol]
466   @param  h     Pointer to the hash table [khash_t(name)*]
467   @param  k     Key [type of keys]
468   @param  r     Extra return code: -1 if the operation failed;
469                 0 if the key is present in the hash table;
470                 1 if the bucket is empty (never used); 2 if the element in
471 				the bucket has been deleted [int*]
472   @return       Iterator to the inserted element [khint_t]
473  */
474 #define kh_put(name, h, k, r) kh_put_##name(h, k, r)
475 
476 /*! @function
477   @abstract     Retrieve a key from the hash table.
478   @param  name  Name of the hash table [symbol]
479   @param  h     Pointer to the hash table [khash_t(name)*]
480   @param  k     Key [type of keys]
481   @return       Iterator to the found element, or kh_end(h) if the element is absent [khint_t]
482  */
483 #define kh_get(name, h, k) kh_get_##name(h, k)
484 
485 /*! @function
486   @abstract     Remove a key from the hash table.
487   @param  name  Name of the hash table [symbol]
488   @param  h     Pointer to the hash table [khash_t(name)*]
489   @param  k     Iterator to the element to be deleted [khint_t]
490  */
491 #define kh_del(name, h, k) kh_del_##name(h, k)
492 
493 /*! @function
494   @abstract     Test whether a bucket contains data.
495   @param  h     Pointer to the hash table [khash_t(name)*]
496   @param  x     Iterator to the bucket [khint_t]
497   @return       1 if containing data; 0 otherwise [int]
498  */
499 #define kh_exist(h, x) (!__ac_iseither((h)->flags, (x)))
500 
501 /*! @function
502   @abstract     Get key given an iterator
503   @param  h     Pointer to the hash table [khash_t(name)*]
504   @param  x     Iterator to the bucket [khint_t]
505   @return       Key [type of keys]
506  */
507 #define kh_key(h, x) ((h)->keys[x])
508 
509 /*! @function
510   @abstract     Get value given an iterator
511   @param  h     Pointer to the hash table [khash_t(name)*]
512   @param  x     Iterator to the bucket [khint_t]
513   @return       Value [type of values]
514   @discussion   For hash sets, calling this results in segfault.
515  */
516 #define kh_val(h, x) ((h)->vals[x])
517 
518 /*! @function
519   @abstract     Alias of kh_val()
520  */
521 #define kh_value(h, x) ((h)->vals[x])
522 
523 /*! @function
524   @abstract     Get the start iterator
525   @param  h     Pointer to the hash table [khash_t(name)*]
526   @return       The start iterator [khint_t]
527  */
528 #define kh_begin(h) (khint_t)(0)
529 
530 /*! @function
531   @abstract     Get the end iterator
532   @param  h     Pointer to the hash table [khash_t(name)*]
533   @return       The end iterator [khint_t]
534  */
535 #define kh_end(h) ((h)->n_buckets)
536 
537 /*! @function
538   @abstract     Get the number of elements in the hash table
539   @param  h     Pointer to the hash table [khash_t(name)*]
540   @return       Number of elements in the hash table [khint_t]
541  */
542 #define kh_size(h) ((h)->size)
543 
544 /*! @function
545   @abstract     Get the number of buckets in the hash table
546   @param  h     Pointer to the hash table [khash_t(name)*]
547   @return       Number of buckets in the hash table [khint_t]
548  */
549 #define kh_n_buckets(h) ((h)->n_buckets)
550 
551 /*! @function
552   @abstract     Iterate over the entries in the hash table
553   @param  h     Pointer to the hash table [khash_t(name)*]
554   @param  kvar  Variable to which key will be assigned
555   @param  vvar  Variable to which value will be assigned
556   @param  code  Block of code to execute
557  */
558 #define kh_foreach(h, kvar, vvar, code) { khint_t __i;		\
559 	for (__i = kh_begin(h); __i != kh_end(h); ++__i) {		\
560 		if (!kh_exist(h,__i)) continue;						\
561 		(kvar) = kh_key(h,__i);								\
562 		(vvar) = kh_val(h,__i);								\
563 		code;												\
564 	} }
565 
566 /*! @function
567   @abstract     Iterate over the values in the hash table
568   @param  h     Pointer to the hash table [khash_t(name)*]
569   @param  vvar  Variable to which value will be assigned
570   @param  code  Block of code to execute
571  */
572 #define kh_foreach_value(h, vvar, code) { khint_t __i;		\
573 	for (__i = kh_begin(h); __i != kh_end(h); ++__i) {		\
574 		if (!kh_exist(h,__i)) continue;						\
575 		(vvar) = kh_val(h,__i);								\
576 		code;												\
577 	} }
578 
579 /* More conenient interfaces */
580 
581 /*! @function
582   @abstract     Instantiate a hash set containing integer keys
583   @param  name  Name of the hash table [symbol]
584  */
585 #define KHASH_SET_INIT_INT(name)										\
586 	KHASH_INIT(name, khint32_t, char, 0, kh_int_hash_func, kh_int_hash_equal)
587 
588 /*! @function
589   @abstract     Instantiate a hash map containing integer keys
590   @param  name  Name of the hash table [symbol]
591   @param  khval_t  Type of values [type]
592  */
593 #define KHASH_MAP_INIT_INT(name, khval_t)								\
594 	KHASH_INIT(name, khint32_t, khval_t, 1, kh_int_hash_func, kh_int_hash_equal)
595 
596 /*! @function
597   @abstract     Instantiate a hash map containing 64-bit integer keys
598   @param  name  Name of the hash table [symbol]
599  */
600 #define KHASH_SET_INIT_INT64(name)										\
601 	KHASH_INIT(name, khint64_t, char, 0, kh_int64_hash_func, kh_int64_hash_equal)
602 
603 /*! @function
604   @abstract     Instantiate a hash map containing 64-bit integer keys
605   @param  name  Name of the hash table [symbol]
606   @param  khval_t  Type of values [type]
607  */
608 #define KHASH_MAP_INIT_INT64(name, khval_t)								\
609 	KHASH_INIT(name, khint64_t, khval_t, 1, kh_int64_hash_func, kh_int64_hash_equal)
610 
611 typedef const char *kh_cstr_t;
612 /*! @function
613   @abstract     Instantiate a hash map containing const char* keys
614   @param  name  Name of the hash table [symbol]
615  */
616 #define KHASH_SET_INIT_STR(name)										\
617 	KHASH_INIT(name, kh_cstr_t, char, 0, kh_str_hash_func, kh_str_hash_equal)
618 
619 /*! @function
620   @abstract     Instantiate a hash map containing const char* keys
621   @param  name  Name of the hash table [symbol]
622   @param  khval_t  Type of values [type]
623  */
624 #define KHASH_MAP_INIT_STR(name, khval_t)								\
625 	KHASH_INIT(name, kh_cstr_t, khval_t, 1, kh_str_hash_func, kh_str_hash_equal)
626 
627 #endif /* __AC_KHASH_H */
628