1 /*
2 Copyright (c) 2003-2013, Troy D. Hanson     http://uthash.sourceforge.net
3 All rights reserved.
4 
5 Redistribution and use in source and binary forms, with or without
6 modification, are permitted provided that the following conditions are met:
7 
8     * Redistributions of source code must retain the above copyright
9       notice, this list of conditions and the following disclaimer.
10 
11 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
12 IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
13 TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
14 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
15 OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
16 EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
17 PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
18 PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
19 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
20 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
21 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
22 */
23 
24 #ifndef UTHASH_H
25 #define UTHASH_H
26 
27 #include <string.h>   /* memcmp,strlen */
28 #include <stddef.h>   /* ptrdiff_t */
29 #include <stdlib.h>   /* exit() */
30 
31 /* These macros use decltype or the earlier __typeof GNU extension.
32    As decltype is only available in newer compilers (VS2010 or gcc 4.3+
33    when compiling c++ source) this code uses whatever method is needed
34    or, for VS2008 where neither is available, uses casting workarounds. */
35 #ifdef _MSC_VER         /* MS compiler */
36 #if _MSC_VER >= 1600 && defined(__cplusplus)  /* VS2010 or newer in C++ mode */
37 #define DECLTYPE(x) (decltype(x))
38 #else                   /* VS2008 or older (or VS2010 in C mode) */
39 #define NO_DECLTYPE
40 #define DECLTYPE(x)
41 #endif
42 #else                   /* GNU, Sun and other compilers */
43 #define DECLTYPE(x) (__typeof(x))
44 #endif
45 
46 #ifdef NO_DECLTYPE
47 #define DECLTYPE_ASSIGN(dst,src)                                                 \
48 do {                                                                             \
49   char **_da_dst = (char**)(&(dst));                                             \
50   *_da_dst = (char*)(src);                                                       \
51 } while(0)
52 #else
53 #define DECLTYPE_ASSIGN(dst,src)                                                 \
54 do {                                                                             \
55   (dst) = DECLTYPE(dst)(src);                                                    \
56 } while(0)
57 #endif
58 
59 /* a number of the hash function use uint32_t which isn't defined on win32 */
60 #ifdef _MSC_VER
61 typedef unsigned int uint32_t;
62 typedef unsigned char uint8_t;
63 #else
64 #include <inttypes.h>   /* uint32_t */
65 #endif
66 
67 #define UTHASH_VERSION 1.9.7
68 
69 #ifndef uthash_fatal
70 #define uthash_fatal(msg) exit(-1)        /* fatal error (out of memory,etc) */
71 #endif
72 #ifndef uthash_malloc
73 #define uthash_malloc(sz) malloc(sz)      /* malloc fcn                      */
74 #endif
75 #ifndef uthash_free
76 #define uthash_free(ptr,sz) free(ptr)     /* free fcn                        */
77 #endif
78 
79 #ifndef uthash_noexpand_fyi
80 #define uthash_noexpand_fyi(tbl)          /* can be defined to log noexpand  */
81 #endif
82 #ifndef uthash_expand_fyi
83 #define uthash_expand_fyi(tbl)            /* can be defined to log expands   */
84 #endif
85 
86 /* initial number of buckets */
87 #define HASH_INITIAL_NUM_BUCKETS 32      /* initial number of buckets        */
88 #define HASH_INITIAL_NUM_BUCKETS_LOG2 5  /* lg2 of initial number of buckets */
89 #define HASH_BKT_CAPACITY_THRESH 10      /* expand when bucket count reaches */
90 
91 /* calculate the element whose hash handle address is hhe */
92 #define ELMT_FROM_HH(tbl,hhp) ((void*)(((char*)(hhp)) - ((tbl)->hho)))
93 
94 #define HASH_FIND(hh,head,keyptr,keylen,out)                                     \
95 do {                                                                             \
96   unsigned _hf_bkt,_hf_hashv;                                                    \
97   out=NULL;                                                                      \
98   if (head) {                                                                    \
99      HASH_FCN(keyptr,keylen, (head)->hh.tbl->num_buckets, _hf_hashv, _hf_bkt);   \
100      if (HASH_BLOOM_TEST((head)->hh.tbl, _hf_hashv)) {                           \
101        HASH_FIND_IN_BKT((head)->hh.tbl, hh, (head)->hh.tbl->buckets[ _hf_bkt ],  \
102                         keyptr,keylen,out);                                      \
103      }                                                                           \
104   }                                                                              \
105 } while (0)
106 
107 #ifdef HASH_BLOOM
108 #define HASH_BLOOM_BITLEN (1ULL << HASH_BLOOM)
109 #define HASH_BLOOM_BYTELEN (HASH_BLOOM_BITLEN/8) + ((HASH_BLOOM_BITLEN%8) ? 1:0)
110 #define HASH_BLOOM_MAKE(tbl)                                                     \
111 do {                                                                             \
112   (tbl)->bloom_nbits = HASH_BLOOM;                                               \
113   (tbl)->bloom_bv = (uint8_t*)uthash_malloc(HASH_BLOOM_BYTELEN);                 \
114   if (!((tbl)->bloom_bv))  { uthash_fatal( "out of memory"); }                   \
115   memset((tbl)->bloom_bv, 0, HASH_BLOOM_BYTELEN);                                \
116   (tbl)->bloom_sig = HASH_BLOOM_SIGNATURE;                                       \
117 } while (0)
118 
119 #define HASH_BLOOM_FREE(tbl)                                                     \
120 do {                                                                             \
121   uthash_free((tbl)->bloom_bv, HASH_BLOOM_BYTELEN);                              \
122 } while (0)
123 
124 #define HASH_BLOOM_BITSET(bv,idx) (bv[(idx)/8] |= (1U << ((idx)%8)))
125 #define HASH_BLOOM_BITTEST(bv,idx) (bv[(idx)/8] & (1U << ((idx)%8)))
126 
127 #define HASH_BLOOM_ADD(tbl,hashv)                                                \
128   HASH_BLOOM_BITSET((tbl)->bloom_bv, (hashv & (uint32_t)((1ULL << (tbl)->bloom_nbits) - 1)))
129 
130 #define HASH_BLOOM_TEST(tbl,hashv)                                               \
131   HASH_BLOOM_BITTEST((tbl)->bloom_bv, (hashv & (uint32_t)((1ULL << (tbl)->bloom_nbits) - 1)))
132 
133 #else
134 #define HASH_BLOOM_MAKE(tbl)
135 #define HASH_BLOOM_FREE(tbl)
136 #define HASH_BLOOM_ADD(tbl,hashv)
137 #define HASH_BLOOM_TEST(tbl,hashv) (1)
138 #endif
139 
140 #define HASH_MAKE_TABLE(hh,head)                                                 \
141 do {                                                                             \
142   (head)->hh.tbl = (UT_hash_table*)uthash_malloc(                                \
143                   sizeof(UT_hash_table));                                        \
144   if (!((head)->hh.tbl))  { uthash_fatal( "out of memory"); }                    \
145   memset((head)->hh.tbl, 0, sizeof(UT_hash_table));                              \
146   (head)->hh.tbl->tail = &((head)->hh);                                          \
147   (head)->hh.tbl->num_buckets = HASH_INITIAL_NUM_BUCKETS;                        \
148   (head)->hh.tbl->log2_num_buckets = HASH_INITIAL_NUM_BUCKETS_LOG2;              \
149   (head)->hh.tbl->hho = (char*)(&(head)->hh) - (char*)(head);                    \
150   (head)->hh.tbl->buckets = (UT_hash_bucket*)uthash_malloc(                      \
151           HASH_INITIAL_NUM_BUCKETS*sizeof(struct UT_hash_bucket));               \
152   if (! (head)->hh.tbl->buckets) { uthash_fatal( "out of memory"); }             \
153   memset((head)->hh.tbl->buckets, 0,                                             \
154           HASH_INITIAL_NUM_BUCKETS*sizeof(struct UT_hash_bucket));               \
155   HASH_BLOOM_MAKE((head)->hh.tbl);                                               \
156   (head)->hh.tbl->signature = HASH_SIGNATURE;                                    \
157 } while(0)
158 
159 #define HASH_ADD(hh,head,fieldname,keylen_in,add)                                \
160         HASH_ADD_KEYPTR(hh,head,&((add)->fieldname),keylen_in,add)
161 
162 #define HASH_ADD_KEYPTR(hh,head,keyptr,keylen_in,add)                            \
163 do {                                                                             \
164  unsigned _ha_bkt;                                                               \
165  (add)->hh.next = NULL;                                                          \
166  (add)->hh.key = (char*)keyptr;                                                  \
167  (add)->hh.keylen = (unsigned)keylen_in;                                                   \
168  if (!(head)) {                                                                  \
169     head = (add);                                                                \
170     (head)->hh.prev = NULL;                                                      \
171     HASH_MAKE_TABLE(hh,head);                                                    \
172  } else {                                                                        \
173     (head)->hh.tbl->tail->next = (add);                                          \
174     (add)->hh.prev = ELMT_FROM_HH((head)->hh.tbl, (head)->hh.tbl->tail);         \
175     (head)->hh.tbl->tail = &((add)->hh);                                         \
176  }                                                                               \
177  (head)->hh.tbl->num_items++;                                                    \
178  (add)->hh.tbl = (head)->hh.tbl;                                                 \
179  HASH_FCN(keyptr,keylen_in, (head)->hh.tbl->num_buckets,                         \
180          (add)->hh.hashv, _ha_bkt);                                              \
181  HASH_ADD_TO_BKT((head)->hh.tbl->buckets[_ha_bkt],&(add)->hh);                   \
182  HASH_BLOOM_ADD((head)->hh.tbl,(add)->hh.hashv);                                 \
183  HASH_EMIT_KEY(hh,head,keyptr,keylen_in);                                        \
184  HASH_FSCK(hh,head);                                                             \
185 } while(0)
186 
187 #define HASH_TO_BKT( hashv, num_bkts, bkt )                                      \
188 do {                                                                             \
189   bkt = ((hashv) & ((num_bkts) - 1));                                            \
190 } while(0)
191 
192 /* delete "delptr" from the hash table.
193  * "the usual" patch-up process for the app-order doubly-linked-list.
194  * The use of _hd_hh_del below deserves special explanation.
195  * These used to be expressed using (delptr) but that led to a bug
196  * if someone used the same symbol for the head and deletee, like
197  *  HASH_DELETE(hh,users,users);
198  * We want that to work, but by changing the head (users) below
199  * we were forfeiting our ability to further refer to the deletee (users)
200  * in the patch-up process. Solution: use scratch space to
201  * copy the deletee pointer, then the latter references are via that
202  * scratch pointer rather than through the repointed (users) symbol.
203  */
204 #define HASH_DELETE(hh,head,delptr)                                              \
205 do {                                                                             \
206     unsigned _hd_bkt;                                                            \
207     struct UT_hash_handle *_hd_hh_del;                                           \
208     if ( ((delptr)->hh.prev == NULL) && ((delptr)->hh.next == NULL) )  {         \
209         uthash_free((head)->hh.tbl->buckets,                                     \
210                     (head)->hh.tbl->num_buckets*sizeof(struct UT_hash_bucket) ); \
211         HASH_BLOOM_FREE((head)->hh.tbl);                                         \
212         uthash_free((head)->hh.tbl, sizeof(UT_hash_table));                      \
213         head = NULL;                                                             \
214     } else {                                                                     \
215         _hd_hh_del = &((delptr)->hh);                                            \
216         if ((delptr) == ELMT_FROM_HH((head)->hh.tbl,(head)->hh.tbl->tail)) {     \
217             (head)->hh.tbl->tail =                                               \
218                 (UT_hash_handle*)((ptrdiff_t)((delptr)->hh.prev) +               \
219                 (head)->hh.tbl->hho);                                            \
220         }                                                                        \
221         if ((delptr)->hh.prev) {                                                 \
222             ((UT_hash_handle*)((ptrdiff_t)((delptr)->hh.prev) +                  \
223                     (head)->hh.tbl->hho))->next = (delptr)->hh.next;             \
224         } else {                                                                 \
225             DECLTYPE_ASSIGN(head,(delptr)->hh.next);                             \
226         }                                                                        \
227         if (_hd_hh_del->next) {                                                  \
228             ((UT_hash_handle*)((ptrdiff_t)_hd_hh_del->next +                     \
229                     (head)->hh.tbl->hho))->prev =                                \
230                     _hd_hh_del->prev;                                            \
231         }                                                                        \
232         HASH_TO_BKT( _hd_hh_del->hashv, (head)->hh.tbl->num_buckets, _hd_bkt);   \
233         HASH_DEL_IN_BKT(hh,(head)->hh.tbl->buckets[_hd_bkt], _hd_hh_del);        \
234         (head)->hh.tbl->num_items--;                                             \
235     }                                                                            \
236     HASH_FSCK(hh,head);                                                          \
237 } while (0)
238 
239 
240 /* convenience forms of HASH_FIND/HASH_ADD/HASH_DEL */
241 #define HASH_FIND_STR(head,findstr,out)                                          \
242     HASH_FIND(hh,head,findstr,strlen(findstr),out)
243 #define HASH_ADD_STR(head,strfield,add)                                          \
244     HASH_ADD(hh,head,strfield,strlen(add->strfield),add)
245 #define HASH_FIND_INT(head,findint,out)                                          \
246     HASH_FIND(hh,head,findint,sizeof(int),out)
247 #define HASH_ADD_INT(head,intfield,add)                                          \
248     HASH_ADD(hh,head,intfield,sizeof(int),add)
249 #define HASH_FIND_PTR(head,findptr,out)                                          \
250     HASH_FIND(hh,head,findptr,sizeof(void *),out)
251 #define HASH_ADD_PTR(head,ptrfield,add)                                          \
252     HASH_ADD(hh,head,ptrfield,sizeof(void *),add)
253 #define HASH_DEL(head,delptr)                                                    \
254     HASH_DELETE(hh,head,delptr)
255 
256 /* HASH_FSCK checks hash integrity on every add/delete when HASH_DEBUG is defined.
257  * This is for uthash developer only; it compiles away if HASH_DEBUG isn't defined.
258  */
259 #ifdef HASH_DEBUG
260 #define HASH_OOPS(...) do { fprintf(stderr,__VA_ARGS__); exit(-1); } while (0)
261 #define HASH_FSCK(hh,head)                                                       \
262 do {                                                                             \
263     unsigned _bkt_i;                                                             \
264     unsigned _count, _bkt_count;                                                 \
265     char *_prev;                                                                 \
266     struct UT_hash_handle *_thh;                                                 \
267     if (head) {                                                                  \
268         _count = 0;                                                              \
269         for( _bkt_i = 0; _bkt_i < (head)->hh.tbl->num_buckets; _bkt_i++) {       \
270             _bkt_count = 0;                                                      \
271             _thh = (head)->hh.tbl->buckets[_bkt_i].hh_head;                      \
272             _prev = NULL;                                                        \
273             while (_thh) {                                                       \
274                if (_prev != (char*)(_thh->hh_prev)) {                            \
275                    HASH_OOPS("invalid hh_prev %p, actual %p\n",                  \
276                     _thh->hh_prev, _prev );                                      \
277                }                                                                 \
278                _bkt_count++;                                                     \
279                _prev = (char*)(_thh);                                            \
280                _thh = _thh->hh_next;                                             \
281             }                                                                    \
282             _count += _bkt_count;                                                \
283             if ((head)->hh.tbl->buckets[_bkt_i].count !=  _bkt_count) {          \
284                HASH_OOPS("invalid bucket count %d, actual %d\n",                 \
285                 (head)->hh.tbl->buckets[_bkt_i].count, _bkt_count);              \
286             }                                                                    \
287         }                                                                        \
288         if (_count != (head)->hh.tbl->num_items) {                               \
289             HASH_OOPS("invalid hh item count %d, actual %d\n",                   \
290                 (head)->hh.tbl->num_items, _count );                             \
291         }                                                                        \
292         /* traverse hh in app order; check next/prev integrity, count */         \
293         _count = 0;                                                              \
294         _prev = NULL;                                                            \
295         _thh =  &(head)->hh;                                                     \
296         while (_thh) {                                                           \
297            _count++;                                                             \
298            if (_prev !=(char*)(_thh->prev)) {                                    \
299               HASH_OOPS("invalid prev %p, actual %p\n",                          \
300                     _thh->prev, _prev );                                         \
301            }                                                                     \
302            _prev = (char*)ELMT_FROM_HH((head)->hh.tbl, _thh);                    \
303            _thh = ( _thh->next ?  (UT_hash_handle*)((char*)(_thh->next) +        \
304                                   (head)->hh.tbl->hho) : NULL );                 \
305         }                                                                        \
306         if (_count != (head)->hh.tbl->num_items) {                               \
307             HASH_OOPS("invalid app item count %d, actual %d\n",                  \
308                 (head)->hh.tbl->num_items, _count );                             \
309         }                                                                        \
310     }                                                                            \
311 } while (0)
312 #else
313 #define HASH_FSCK(hh,head)
314 #endif
315 
316 /* When compiled with -DHASH_EMIT_KEYS, length-prefixed keys are emitted to
317  * the descriptor to which this macro is defined for tuning the hash function.
318  * The app can #include <unistd.h> to get the prototype for write(2). */
319 #ifdef HASH_EMIT_KEYS
320 #define HASH_EMIT_KEY(hh,head,keyptr,fieldlen)                                   \
321 do {                                                                             \
322     unsigned _klen = fieldlen;                                                   \
323     write(HASH_EMIT_KEYS, &_klen, sizeof(_klen));                                \
324     write(HASH_EMIT_KEYS, keyptr, fieldlen);                                     \
325 } while (0)
326 #else
327 #define HASH_EMIT_KEY(hh,head,keyptr,fieldlen)
328 #endif
329 
330 /* default to Jenkin's hash unless overridden e.g. DHASH_FUNCTION=HASH_SAX */
331 #ifdef HASH_FUNCTION
332 #define HASH_FCN HASH_FUNCTION
333 #else
334 #define HASH_FCN HASH_JEN
335 #endif
336 
337 /* The Bernstein hash function, used in Perl prior to v5.6 */
338 #define HASH_BER(key,keylen,num_bkts,hashv,bkt)                                  \
339 do {                                                                             \
340   unsigned _hb_keylen=keylen;                                                    \
341   char *_hb_key=(char*)(key);                                                    \
342   (hashv) = 0;                                                                   \
343   while (_hb_keylen--)  { (hashv) = ((hashv) * 33) + *_hb_key++; }               \
344   bkt = (hashv) & (num_bkts-1);                                                  \
345 } while (0)
346 
347 
348 /* SAX/FNV/OAT/JEN hash functions are macro variants of those listed at
349  * http://eternallyconfuzzled.com/tuts/algorithms/jsw_tut_hashing.aspx */
350 #define HASH_SAX(key,keylen,num_bkts,hashv,bkt)                                  \
351 do {                                                                             \
352   unsigned _sx_i;                                                                \
353   char *_hs_key=(char*)(key);                                                    \
354   hashv = 0;                                                                     \
355   for(_sx_i=0; _sx_i < keylen; _sx_i++)                                          \
356       hashv ^= (hashv << 5) + (hashv >> 2) + _hs_key[_sx_i];                     \
357   bkt = hashv & (num_bkts-1);                                                    \
358 } while (0)
359 
360 #define HASH_FNV(key,keylen,num_bkts,hashv,bkt)                                  \
361 do {                                                                             \
362   unsigned _fn_i;                                                                \
363   char *_hf_key=(char*)(key);                                                    \
364   hashv = 2166136261UL;                                                          \
365   for(_fn_i=0; _fn_i < keylen; _fn_i++)                                          \
366       hashv = (hashv * 16777619) ^ _hf_key[_fn_i];                               \
367   bkt = hashv & (num_bkts-1);                                                    \
368 } while(0)
369 
370 #define HASH_OAT(key,keylen,num_bkts,hashv,bkt)                                  \
371 do {                                                                             \
372   unsigned _ho_i;                                                                \
373   char *_ho_key=(char*)(key);                                                    \
374   hashv = 0;                                                                     \
375   for(_ho_i=0; _ho_i < keylen; _ho_i++) {                                        \
376       hashv += _ho_key[_ho_i];                                                   \
377       hashv += (hashv << 10);                                                    \
378       hashv ^= (hashv >> 6);                                                     \
379   }                                                                              \
380   hashv += (hashv << 3);                                                         \
381   hashv ^= (hashv >> 11);                                                        \
382   hashv += (hashv << 15);                                                        \
383   bkt = hashv & (num_bkts-1);                                                    \
384 } while(0)
385 
386 #define HASH_JEN_MIX(a,b,c)                                                      \
387 do {                                                                             \
388   a -= b; a -= c; a ^= ( c >> 13 );                                              \
389   b -= c; b -= a; b ^= ( a << 8 );                                               \
390   c -= a; c -= b; c ^= ( b >> 13 );                                              \
391   a -= b; a -= c; a ^= ( c >> 12 );                                              \
392   b -= c; b -= a; b ^= ( a << 16 );                                              \
393   c -= a; c -= b; c ^= ( b >> 5 );                                               \
394   a -= b; a -= c; a ^= ( c >> 3 );                                               \
395   b -= c; b -= a; b ^= ( a << 10 );                                              \
396   c -= a; c -= b; c ^= ( b >> 15 );                                              \
397 } while (0)
398 
399 #define HASH_JEN(key,keylen,num_bkts,hashv,bkt)                                  \
400 do {                                                                             \
401   unsigned _hj_i,_hj_j,_hj_k;                                                    \
402   char *_hj_key=(char*)(key);                                                    \
403   hashv = 0xfeedbeef;                                                            \
404   _hj_i = _hj_j = 0x9e3779b9;                                                    \
405   _hj_k = (unsigned)keylen;                                                                \
406   while (_hj_k >= 12) {                                                          \
407     _hj_i +=    (_hj_key[0] + ( (unsigned)_hj_key[1] << 8 )                      \
408         + ( (unsigned)_hj_key[2] << 16 )                                         \
409         + ( (unsigned)_hj_key[3] << 24 ) );                                      \
410     _hj_j +=    (_hj_key[4] + ( (unsigned)_hj_key[5] << 8 )                      \
411         + ( (unsigned)_hj_key[6] << 16 )                                         \
412         + ( (unsigned)_hj_key[7] << 24 ) );                                      \
413     hashv += (_hj_key[8] + ( (unsigned)_hj_key[9] << 8 )                         \
414         + ( (unsigned)_hj_key[10] << 16 )                                        \
415         + ( (unsigned)_hj_key[11] << 24 ) );                                     \
416                                                                                  \
417      HASH_JEN_MIX(_hj_i, _hj_j, hashv);                                          \
418                                                                                  \
419      _hj_key += 12;                                                              \
420      _hj_k -= 12;                                                                \
421   }                                                                              \
422   hashv += keylen;                                                               \
423   switch ( _hj_k ) {                                                             \
424      case 11: hashv += ( (unsigned)_hj_key[10] << 24 );                          \
425      case 10: hashv += ( (unsigned)_hj_key[9] << 16 );                           \
426      case 9:  hashv += ( (unsigned)_hj_key[8] << 8 );                            \
427      case 8:  _hj_j += ( (unsigned)_hj_key[7] << 24 );                           \
428      case 7:  _hj_j += ( (unsigned)_hj_key[6] << 16 );                           \
429      case 6:  _hj_j += ( (unsigned)_hj_key[5] << 8 );                            \
430      case 5:  _hj_j += _hj_key[4];                                               \
431      case 4:  _hj_i += ( (unsigned)_hj_key[3] << 24 );                           \
432      case 3:  _hj_i += ( (unsigned)_hj_key[2] << 16 );                           \
433      case 2:  _hj_i += ( (unsigned)_hj_key[1] << 8 );                            \
434      case 1:  _hj_i += _hj_key[0];                                               \
435   }                                                                              \
436   HASH_JEN_MIX(_hj_i, _hj_j, hashv);                                             \
437   bkt = hashv & (num_bkts-1);                                                    \
438 } while(0)
439 
440 /* The Paul Hsieh hash function */
441 #undef get16bits
442 #if (defined(__GNUC__) && defined(__i386__)) || defined(__WATCOMC__)             \
443   || defined(_MSC_VER) || defined (__BORLANDC__) || defined (__TURBOC__)
444 #define get16bits(d) (*((const uint16_t *) (d)))
445 #endif
446 
447 #if !defined (get16bits)
448 #define get16bits(d) ((((uint32_t)(((const uint8_t *)(d))[1])) << 8)             \
449                        +(uint32_t)(((const uint8_t *)(d))[0]) )
450 #endif
451 #define HASH_SFH(key,keylen,num_bkts,hashv,bkt)                                  \
452 do {                                                                             \
453   char *_sfh_key=(char*)(key);                                                   \
454   uint32_t _sfh_tmp, _sfh_len = keylen;                                          \
455                                                                                  \
456   int _sfh_rem = _sfh_len & 3;                                                   \
457   _sfh_len >>= 2;                                                                \
458   hashv = 0xcafebabe;                                                            \
459                                                                                  \
460   /* Main loop */                                                                \
461   for (;_sfh_len > 0; _sfh_len--) {                                              \
462     hashv    += get16bits (_sfh_key);                                            \
463     _sfh_tmp       = (get16bits (_sfh_key+2) << 11) ^ hashv;                     \
464     hashv     = (hashv << 16) ^ _sfh_tmp;                                        \
465     _sfh_key += 2*sizeof (uint16_t);                                             \
466     hashv    += hashv >> 11;                                                     \
467   }                                                                              \
468                                                                                  \
469   /* Handle end cases */                                                         \
470   switch (_sfh_rem) {                                                            \
471     case 3: hashv += get16bits (_sfh_key);                                       \
472             hashv ^= hashv << 16;                                                \
473             hashv ^= _sfh_key[sizeof (uint16_t)] << 18;                          \
474             hashv += hashv >> 11;                                                \
475             break;                                                               \
476     case 2: hashv += get16bits (_sfh_key);                                       \
477             hashv ^= hashv << 11;                                                \
478             hashv += hashv >> 17;                                                \
479             break;                                                               \
480     case 1: hashv += *_sfh_key;                                                  \
481             hashv ^= hashv << 10;                                                \
482             hashv += hashv >> 1;                                                 \
483   }                                                                              \
484                                                                                  \
485     /* Force "avalanching" of final 127 bits */                                  \
486     hashv ^= hashv << 3;                                                         \
487     hashv += hashv >> 5;                                                         \
488     hashv ^= hashv << 4;                                                         \
489     hashv += hashv >> 17;                                                        \
490     hashv ^= hashv << 25;                                                        \
491     hashv += hashv >> 6;                                                         \
492     bkt = hashv & (num_bkts-1);                                                  \
493 } while(0)
494 
495 #ifdef HASH_USING_NO_STRICT_ALIASING
496 /* The MurmurHash exploits some CPU's (x86,x86_64) tolerance for unaligned reads.
497  * For other types of CPU's (e.g. Sparc) an unaligned read causes a bus error.
498  * MurmurHash uses the faster approach only on CPU's where we know it's safe.
499  *
500  * Note the preprocessor built-in defines can be emitted using:
501  *
502  *   gcc -m64 -dM -E - < /dev/null                  (on gcc)
503  *   cc -## a.c (where a.c is a simple test file)   (Sun Studio)
504  */
505 #if (defined(__i386__) || defined(__x86_64__)  || defined(_M_IX86))
506 #define MUR_GETBLOCK(p,i) p[i]
507 #else /* non intel */
508 #define MUR_PLUS0_ALIGNED(p) (((unsigned long)p & 0x3) == 0)
509 #define MUR_PLUS1_ALIGNED(p) (((unsigned long)p & 0x3) == 1)
510 #define MUR_PLUS2_ALIGNED(p) (((unsigned long)p & 0x3) == 2)
511 #define MUR_PLUS3_ALIGNED(p) (((unsigned long)p & 0x3) == 3)
512 #define WP(p) ((uint32_t*)((unsigned long)(p) & ~3UL))
513 #if (defined(__BIG_ENDIAN__) || defined(SPARC) || defined(__ppc__) || defined(__ppc64__))
514 #define MUR_THREE_ONE(p) ((((*WP(p))&0x00ffffff) << 8) | (((*(WP(p)+1))&0xff000000) >> 24))
515 #define MUR_TWO_TWO(p)   ((((*WP(p))&0x0000ffff) <<16) | (((*(WP(p)+1))&0xffff0000) >> 16))
516 #define MUR_ONE_THREE(p) ((((*WP(p))&0x000000ff) <<24) | (((*(WP(p)+1))&0xffffff00) >>  8))
517 #else /* assume little endian non-intel */
518 #define MUR_THREE_ONE(p) ((((*WP(p))&0xffffff00) >> 8) | (((*(WP(p)+1))&0x000000ff) << 24))
519 #define MUR_TWO_TWO(p)   ((((*WP(p))&0xffff0000) >>16) | (((*(WP(p)+1))&0x0000ffff) << 16))
520 #define MUR_ONE_THREE(p) ((((*WP(p))&0xff000000) >>24) | (((*(WP(p)+1))&0x00ffffff) <<  8))
521 #endif
522 #define MUR_GETBLOCK(p,i) (MUR_PLUS0_ALIGNED(p) ? ((p)[i]) :           \
523                             (MUR_PLUS1_ALIGNED(p) ? MUR_THREE_ONE(p) : \
524                              (MUR_PLUS2_ALIGNED(p) ? MUR_TWO_TWO(p) :  \
525                                                       MUR_ONE_THREE(p))))
526 #endif
527 #define MUR_ROTL32(x,r) (((x) << (r)) | ((x) >> (32 - (r))))
528 #define MUR_FMIX(_h) \
529 do {                 \
530   _h ^= _h >> 16;    \
531   _h *= 0x85ebca6b;  \
532   _h ^= _h >> 13;    \
533   _h *= 0xc2b2ae35l; \
534   _h ^= _h >> 16;    \
535 } while(0)
536 
537 #define HASH_MUR(key,keylen,num_bkts,hashv,bkt)                        \
538 do {                                                                   \
539   const uint8_t *_mur_data = (const uint8_t*)(key);                    \
540   const int _mur_nblocks = (keylen) / 4;                               \
541   uint32_t _mur_h1 = 0xf88D5353;                                       \
542   uint32_t _mur_c1 = 0xcc9e2d51;                                       \
543   uint32_t _mur_c2 = 0x1b873593;                                       \
544   uint32_t _mur_k1 = 0;                                                \
545   const uint8_t *_mur_tail;                                            \
546   const uint32_t *_mur_blocks = (const uint32_t*)(_mur_data+_mur_nblocks*4); \
547   int _mur_i;                                                          \
548   for(_mur_i = -_mur_nblocks; _mur_i; _mur_i++) {                      \
549     _mur_k1 = MUR_GETBLOCK(_mur_blocks,_mur_i);                        \
550     _mur_k1 *= _mur_c1;                                                \
551     _mur_k1 = MUR_ROTL32(_mur_k1,15);                                  \
552     _mur_k1 *= _mur_c2;                                                \
553                                                                        \
554     _mur_h1 ^= _mur_k1;                                                \
555     _mur_h1 = MUR_ROTL32(_mur_h1,13);                                  \
556     _mur_h1 = _mur_h1*5+0xe6546b64;                                    \
557   }                                                                    \
558   _mur_tail = (const uint8_t*)(_mur_data + _mur_nblocks*4);            \
559   _mur_k1=0;                                                           \
560   switch((keylen) & 3) {                                               \
561     case 3: _mur_k1 ^= _mur_tail[2] << 16;                             \
562     case 2: _mur_k1 ^= _mur_tail[1] << 8;                              \
563     case 1: _mur_k1 ^= _mur_tail[0];                                   \
564     _mur_k1 *= _mur_c1;                                                \
565     _mur_k1 = MUR_ROTL32(_mur_k1,15);                                  \
566     _mur_k1 *= _mur_c2;                                                \
567     _mur_h1 ^= _mur_k1;                                                \
568   }                                                                    \
569   _mur_h1 ^= (keylen);                                                 \
570   MUR_FMIX(_mur_h1);                                                   \
571   hashv = _mur_h1;                                                     \
572   bkt = hashv & (num_bkts-1);                                          \
573 } while(0)
574 #endif  /* HASH_USING_NO_STRICT_ALIASING */
575 
576 /* key comparison function; return 0 if keys equal */
577 #define HASH_KEYCMP(a,b,len) memcmp(a,b,len)
578 
579 /* iterate over items in a known bucket to find desired item */
580 #define HASH_FIND_IN_BKT(tbl,hh,head,keyptr,keylen_in,out)                       \
581 do {                                                                             \
582  if (head.hh_head) DECLTYPE_ASSIGN(out,ELMT_FROM_HH(tbl,head.hh_head));          \
583  else out=NULL;                                                                  \
584  while (out) {                                                                   \
585     if ((out)->hh.keylen == keylen_in) {                                           \
586         if ((HASH_KEYCMP((out)->hh.key,keyptr,keylen_in)) == 0) break;             \
587     }                                                                            \
588     if ((out)->hh.hh_next) DECLTYPE_ASSIGN(out,ELMT_FROM_HH(tbl,(out)->hh.hh_next)); \
589     else out = NULL;                                                             \
590  }                                                                               \
591 } while(0)
592 
593 /* add an item to a bucket  */
594 #define HASH_ADD_TO_BKT(head,addhh)                                              \
595 do {                                                                             \
596  head.count++;                                                                   \
597  (addhh)->hh_next = head.hh_head;                                                \
598  (addhh)->hh_prev = NULL;                                                        \
599  if (head.hh_head) { (head).hh_head->hh_prev = (addhh); }                        \
600  (head).hh_head=addhh;                                                           \
601  if (head.count >= ((head.expand_mult+1) * HASH_BKT_CAPACITY_THRESH)             \
602      && (addhh)->tbl->noexpand != 1) {                                           \
603        HASH_EXPAND_BUCKETS((addhh)->tbl);                                        \
604  }                                                                               \
605 } while(0)
606 
607 /* remove an item from a given bucket */
608 #define HASH_DEL_IN_BKT(hh,head,hh_del)                                          \
609     (head).count--;                                                              \
610     if ((head).hh_head == hh_del) {                                              \
611       (head).hh_head = hh_del->hh_next;                                          \
612     }                                                                            \
613     if (hh_del->hh_prev) {                                                       \
614         hh_del->hh_prev->hh_next = hh_del->hh_next;                              \
615     }                                                                            \
616     if (hh_del->hh_next) {                                                       \
617         hh_del->hh_next->hh_prev = hh_del->hh_prev;                              \
618     }
619 
620 /* Bucket expansion has the effect of doubling the number of buckets
621  * and redistributing the items into the new buckets. Ideally the
622  * items will distribute more or less evenly into the new buckets
623  * (the extent to which this is true is a measure of the quality of
624  * the hash function as it applies to the key domain).
625  *
626  * With the items distributed into more buckets, the chain length
627  * (item count) in each bucket is reduced. Thus by expanding buckets
628  * the hash keeps a bound on the chain length. This bounded chain
629  * length is the essence of how a hash provides constant time lookup.
630  *
631  * The calculation of tbl->ideal_chain_maxlen below deserves some
632  * explanation. First, keep in mind that we're calculating the ideal
633  * maximum chain length based on the *new* (doubled) bucket count.
634  * In fractions this is just n/b (n=number of items,b=new num buckets).
635  * Since the ideal chain length is an integer, we want to calculate
636  * ceil(n/b). We don't depend on floating point arithmetic in this
637  * hash, so to calculate ceil(n/b) with integers we could write
638  *
639  *      ceil(n/b) = (n/b) + ((n%b)?1:0)
640  *
641  * and in fact a previous version of this hash did just that.
642  * But now we have improved things a bit by recognizing that b is
643  * always a power of two. We keep its base 2 log handy (call it lb),
644  * so now we can write this with a bit shift and logical AND:
645  *
646  *      ceil(n/b) = (n>>lb) + ( (n & (b-1)) ? 1:0)
647  *
648  */
649 #define HASH_EXPAND_BUCKETS(tbl)                                                 \
650 do {                                                                             \
651     unsigned _he_bkt;                                                            \
652     unsigned _he_bkt_i;                                                          \
653     struct UT_hash_handle *_he_thh, *_he_hh_nxt;                                 \
654     UT_hash_bucket *_he_new_buckets, *_he_newbkt;                                \
655     _he_new_buckets = (UT_hash_bucket*)uthash_malloc(                            \
656              2 * tbl->num_buckets * sizeof(struct UT_hash_bucket));              \
657     if (!_he_new_buckets) { uthash_fatal( "out of memory"); }                    \
658     memset(_he_new_buckets, 0,                                                   \
659             2 * tbl->num_buckets * sizeof(struct UT_hash_bucket));               \
660     tbl->ideal_chain_maxlen =                                                    \
661        (tbl->num_items >> (tbl->log2_num_buckets+1)) +                           \
662        ((tbl->num_items & ((tbl->num_buckets*2)-1)) ? 1 : 0);                    \
663     tbl->nonideal_items = 0;                                                     \
664     for(_he_bkt_i = 0; _he_bkt_i < tbl->num_buckets; _he_bkt_i++)                \
665     {                                                                            \
666         _he_thh = tbl->buckets[ _he_bkt_i ].hh_head;                             \
667         while (_he_thh) {                                                        \
668            _he_hh_nxt = _he_thh->hh_next;                                        \
669            HASH_TO_BKT( _he_thh->hashv, tbl->num_buckets*2, _he_bkt);            \
670            _he_newbkt = &(_he_new_buckets[ _he_bkt ]);                           \
671            if (++(_he_newbkt->count) > tbl->ideal_chain_maxlen) {                \
672              tbl->nonideal_items++;                                              \
673              _he_newbkt->expand_mult = _he_newbkt->count /                       \
674                                         tbl->ideal_chain_maxlen;                 \
675            }                                                                     \
676            _he_thh->hh_prev = NULL;                                              \
677            _he_thh->hh_next = _he_newbkt->hh_head;                               \
678            if (_he_newbkt->hh_head) _he_newbkt->hh_head->hh_prev =               \
679                 _he_thh;                                                         \
680            _he_newbkt->hh_head = _he_thh;                                        \
681            _he_thh = _he_hh_nxt;                                                 \
682         }                                                                        \
683     }                                                                            \
684     uthash_free( tbl->buckets, tbl->num_buckets*sizeof(struct UT_hash_bucket) ); \
685     tbl->num_buckets *= 2;                                                       \
686     tbl->log2_num_buckets++;                                                     \
687     tbl->buckets = _he_new_buckets;                                              \
688     tbl->ineff_expands = (tbl->nonideal_items > (tbl->num_items >> 1)) ?         \
689         (tbl->ineff_expands+1) : 0;                                              \
690     if (tbl->ineff_expands > 1) {                                                \
691         tbl->noexpand=1;                                                         \
692         uthash_noexpand_fyi(tbl);                                                \
693     }                                                                            \
694     uthash_expand_fyi(tbl);                                                      \
695 } while(0)
696 
697 
698 /* This is an adaptation of Simon Tatham's O(n log(n)) mergesort */
699 /* Note that HASH_SORT assumes the hash handle name to be hh.
700  * HASH_SRT was added to allow the hash handle name to be passed in. */
701 #define HASH_SORT(head,cmpfcn) HASH_SRT(hh,head,cmpfcn)
702 #define HASH_SRT(hh,head,cmpfcn)                                                 \
703 do {                                                                             \
704   unsigned _hs_i;                                                                \
705   unsigned _hs_looping,_hs_nmerges,_hs_insize,_hs_psize,_hs_qsize;               \
706   struct UT_hash_handle *_hs_p, *_hs_q, *_hs_e, *_hs_list, *_hs_tail;            \
707   if (head) {                                                                    \
708       _hs_insize = 1;                                                            \
709       _hs_looping = 1;                                                           \
710       _hs_list = &((head)->hh);                                                  \
711       while (_hs_looping) {                                                      \
712           _hs_p = _hs_list;                                                      \
713           _hs_list = NULL;                                                       \
714           _hs_tail = NULL;                                                       \
715           _hs_nmerges = 0;                                                       \
716           while (_hs_p) {                                                        \
717               _hs_nmerges++;                                                     \
718               _hs_q = _hs_p;                                                     \
719               _hs_psize = 0;                                                     \
720               for ( _hs_i = 0; _hs_i  < _hs_insize; _hs_i++ ) {                  \
721                   _hs_psize++;                                                   \
722                   _hs_q = (UT_hash_handle*)((_hs_q->next) ?                      \
723                           ((void*)((char*)(_hs_q->next) +                        \
724                           (head)->hh.tbl->hho)) : NULL);                         \
725                   if (! (_hs_q) ) break;                                         \
726               }                                                                  \
727               _hs_qsize = _hs_insize;                                            \
728               while ((_hs_psize > 0) || ((_hs_qsize > 0) && _hs_q )) {           \
729                   if (_hs_psize == 0) {                                          \
730                       _hs_e = _hs_q;                                             \
731                       _hs_q = (UT_hash_handle*)((_hs_q->next) ?                  \
732                               ((void*)((char*)(_hs_q->next) +                    \
733                               (head)->hh.tbl->hho)) : NULL);                     \
734                       _hs_qsize--;                                               \
735                   } else if ( (_hs_qsize == 0) || !(_hs_q) ) {                   \
736                       _hs_e = _hs_p;                                             \
737                       _hs_p = (UT_hash_handle*)((_hs_p->next) ?                  \
738                               ((void*)((char*)(_hs_p->next) +                    \
739                               (head)->hh.tbl->hho)) : NULL);                     \
740                       _hs_psize--;                                               \
741                   } else if ((                                                   \
742                       cmpfcn(DECLTYPE(head)(ELMT_FROM_HH((head)->hh.tbl,_hs_p)), \
743                              DECLTYPE(head)(ELMT_FROM_HH((head)->hh.tbl,_hs_q))) \
744                              ) <= 0) {                                           \
745                       _hs_e = _hs_p;                                             \
746                       _hs_p = (UT_hash_handle*)((_hs_p->next) ?                  \
747                               ((void*)((char*)(_hs_p->next) +                    \
748                               (head)->hh.tbl->hho)) : NULL);                     \
749                       _hs_psize--;                                               \
750                   } else {                                                       \
751                       _hs_e = _hs_q;                                             \
752                       _hs_q = (UT_hash_handle*)((_hs_q->next) ?                  \
753                               ((void*)((char*)(_hs_q->next) +                    \
754                               (head)->hh.tbl->hho)) : NULL);                     \
755                       _hs_qsize--;                                               \
756                   }                                                              \
757                   if ( _hs_tail ) {                                              \
758                       _hs_tail->next = ((_hs_e) ?                                \
759                             ELMT_FROM_HH((head)->hh.tbl,_hs_e) : NULL);          \
760                   } else {                                                       \
761                       _hs_list = _hs_e;                                          \
762                   }                                                              \
763                   _hs_e->prev = ((_hs_tail) ?                                    \
764                      ELMT_FROM_HH((head)->hh.tbl,_hs_tail) : NULL);              \
765                   _hs_tail = _hs_e;                                              \
766               }                                                                  \
767               _hs_p = _hs_q;                                                     \
768           }                                                                      \
769           _hs_tail->next = NULL;                                                 \
770           if ( _hs_nmerges <= 1 ) {                                              \
771               _hs_looping=0;                                                     \
772               (head)->hh.tbl->tail = _hs_tail;                                   \
773               DECLTYPE_ASSIGN(head,ELMT_FROM_HH((head)->hh.tbl, _hs_list));      \
774           }                                                                      \
775           _hs_insize *= 2;                                                       \
776       }                                                                          \
777       HASH_FSCK(hh,head);                                                        \
778  }                                                                               \
779 } while (0)
780 
781 /* This function selects items from one hash into another hash.
782  * The end result is that the selected items have dual presence
783  * in both hashes. There is no copy of the items made; rather
784  * they are added into the new hash through a secondary hash
785  * hash handle that must be present in the structure. */
786 #define HASH_SELECT(hh_dst, dst, hh_src, src, cond)                              \
787 do {                                                                             \
788   unsigned _src_bkt, _dst_bkt;                                                   \
789   void *_last_elt=NULL, *_elt;                                                   \
790   UT_hash_handle *_src_hh, *_dst_hh, *_last_elt_hh=NULL;                         \
791   ptrdiff_t _dst_hho = ((char*)(&(dst)->hh_dst) - (char*)(dst));                 \
792   if (src) {                                                                     \
793     for(_src_bkt=0; _src_bkt < (src)->hh_src.tbl->num_buckets; _src_bkt++) {     \
794       for(_src_hh = (src)->hh_src.tbl->buckets[_src_bkt].hh_head;                \
795           _src_hh;                                                               \
796           _src_hh = _src_hh->hh_next) {                                          \
797           _elt = ELMT_FROM_HH((src)->hh_src.tbl, _src_hh);                       \
798           if (cond(_elt)) {                                                      \
799             _dst_hh = (UT_hash_handle*)(((char*)_elt) + _dst_hho);               \
800             _dst_hh->key = _src_hh->key;                                         \
801             _dst_hh->keylen = _src_hh->keylen;                                   \
802             _dst_hh->hashv = _src_hh->hashv;                                     \
803             _dst_hh->prev = _last_elt;                                           \
804             _dst_hh->next = NULL;                                                \
805             if (_last_elt_hh) { _last_elt_hh->next = _elt; }                     \
806             if (!dst) {                                                          \
807               DECLTYPE_ASSIGN(dst,_elt);                                         \
808               HASH_MAKE_TABLE(hh_dst,dst);                                       \
809             } else {                                                             \
810               _dst_hh->tbl = (dst)->hh_dst.tbl;                                  \
811             }                                                                    \
812             HASH_TO_BKT(_dst_hh->hashv, _dst_hh->tbl->num_buckets, _dst_bkt);    \
813             HASH_ADD_TO_BKT(_dst_hh->tbl->buckets[_dst_bkt],_dst_hh);            \
814             (dst)->hh_dst.tbl->num_items++;                                      \
815             _last_elt = _elt;                                                    \
816             _last_elt_hh = _dst_hh;                                              \
817           }                                                                      \
818       }                                                                          \
819     }                                                                            \
820   }                                                                              \
821   HASH_FSCK(hh_dst,dst);                                                         \
822 } while (0)
823 
824 #define HASH_CLEAR(hh,head)                                                      \
825 do {                                                                             \
826   if (head) {                                                                    \
827     uthash_free((head)->hh.tbl->buckets,                                         \
828                 (head)->hh.tbl->num_buckets*sizeof(struct UT_hash_bucket));      \
829     HASH_BLOOM_FREE((head)->hh.tbl);                                             \
830     uthash_free((head)->hh.tbl, sizeof(UT_hash_table));                          \
831     (head)=NULL;                                                                 \
832   }                                                                              \
833 } while(0)
834 
835 #ifdef NO_DECLTYPE
836 #define HASH_ITER(hh,head,el,tmp)                                                \
837 for((el)=(head), (*(char**)(&(tmp)))=(char*)((head)?(head)->hh.next:NULL);       \
838   el; (el)=(tmp),(*(char**)(&(tmp)))=(char*)((tmp)?(tmp)->hh.next:NULL))
839 #else
840 #define HASH_ITER(hh,head,el,tmp)                                                \
841 for((el)=(head),(tmp)=DECLTYPE(el)((head)?(head)->hh.next:NULL);                 \
842   el; (el)=(tmp),(tmp)=DECLTYPE(el)((tmp)?(tmp)->hh.next:NULL))
843 #endif
844 
845 /* obtain a count of items in the hash */
846 #define HASH_COUNT(head) HASH_CNT(hh,head)
847 #define HASH_CNT(hh,head) ((head)?((head)->hh.tbl->num_items):0)
848 
849 typedef struct UT_hash_bucket {
850    struct UT_hash_handle *hh_head;
851    unsigned count;
852 
853    /* expand_mult is normally set to 0. In this situation, the max chain length
854     * threshold is enforced at its default value, HASH_BKT_CAPACITY_THRESH. (If
855     * the bucket's chain exceeds this length, bucket expansion is triggered).
856     * However, setting expand_mult to a non-zero value delays bucket expansion
857     * (that would be triggered by additions to this particular bucket)
858     * until its chain length reaches a *multiple* of HASH_BKT_CAPACITY_THRESH.
859     * (The multiplier is simply expand_mult+1). The whole idea of this
860     * multiplier is to reduce bucket expansions, since they are expensive, in
861     * situations where we know that a particular bucket tends to be overused.
862     * It is better to let its chain length grow to a longer yet-still-bounded
863     * value, than to do an O(n) bucket expansion too often.
864     */
865    unsigned expand_mult;
866 
867 } UT_hash_bucket;
868 
869 /* random signature used only to find hash tables in external analysis */
870 #define HASH_SIGNATURE 0xa0111fe1
871 #define HASH_BLOOM_SIGNATURE 0xb12220f2
872 
873 typedef struct UT_hash_table {
874    UT_hash_bucket *buckets;
875    unsigned num_buckets, log2_num_buckets;
876    unsigned num_items;
877    struct UT_hash_handle *tail; /* tail hh in app order, for fast append    */
878    ptrdiff_t hho; /* hash handle offset (byte pos of hash handle in element */
879 
880    /* in an ideal situation (all buckets used equally), no bucket would have
881     * more than ceil(#items/#buckets) items. that's the ideal chain length. */
882    unsigned ideal_chain_maxlen;
883 
884    /* nonideal_items is the number of items in the hash whose chain position
885     * exceeds the ideal chain maxlen. these items pay the penalty for an uneven
886     * hash distribution; reaching them in a chain traversal takes >ideal steps */
887    unsigned nonideal_items;
888 
889    /* ineffective expands occur when a bucket doubling was performed, but
890     * afterward, more than half the items in the hash had nonideal chain
891     * positions. If this happens on two consecutive expansions we inhibit any
892     * further expansion, as it's not helping; this happens when the hash
893     * function isn't a good fit for the key domain. When expansion is inhibited
894     * the hash will still work, albeit no longer in constant time. */
895    unsigned ineff_expands, noexpand;
896 
897    uint32_t signature; /* used only to find hash tables in external analysis */
898 #ifdef HASH_BLOOM
899    uint32_t bloom_sig; /* used only to test bloom exists in external analysis */
900    uint8_t *bloom_bv;
901    char bloom_nbits;
902 #endif
903 
904 } UT_hash_table;
905 
906 typedef struct UT_hash_handle {
907    struct UT_hash_table *tbl;
908    void *prev;                       /* prev element in app order      */
909    void *next;                       /* next element in app order      */
910    struct UT_hash_handle *hh_prev;   /* previous hh in bucket order    */
911    struct UT_hash_handle *hh_next;   /* next hh in bucket order        */
912    void *key;                        /* ptr to enclosing struct's key  */
913    unsigned keylen;                  /* enclosing struct's key len     */
914    unsigned hashv;                   /* result of hash-fcn(key)        */
915 } UT_hash_handle;
916 
917 #endif /* UTHASH_H */
918