1 /*
2 Copyright (c) 2003-2011, 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 1.9.4
68 
69 #define uthash_fatal(msg) exit(-1)        /* fatal error (out of memory,etc) */
70 #define uthash_malloc(sz) malloc(sz)      /* malloc fcn                      */
71 #define uthash_free(ptr,sz) free(ptr)     /* free fcn                        */
72 
73 #define uthash_noexpand_fyi(tbl)          /* can be defined to log noexpand  */
74 #define uthash_expand_fyi(tbl)            /* can be defined to log expands   */
75 
76 /* initial number of buckets */
77 #define HASH_INITIAL_NUM_BUCKETS 32      /* initial number of buckets        */
78 #define HASH_INITIAL_NUM_BUCKETS_LOG2 5  /* lg2 of initial number of buckets */
79 #define HASH_BKT_CAPACITY_THRESH 10      /* expand when bucket count reaches */
80 
81 /* calculate the element whose hash handle address is hhe */
82 #define ELMT_FROM_HH(tbl,hhp) ((void*)(((char*)(hhp)) - ((tbl)->hho)))
83 
84 #define HASH_FIND(hh,head,keyptr,keylen,out)                                     \
85 do {                                                                             \
86   unsigned _hf_bkt,_hf_hashv;                                                    \
87   out=NULL;                                                                      \
88   if (head) {                                                                    \
89      HASH_FCN(keyptr,keylen, (head)->hh.tbl->num_buckets, _hf_hashv, _hf_bkt);   \
90      if (HASH_BLOOM_TEST((head)->hh.tbl, _hf_hashv)) {                           \
91        HASH_FIND_IN_BKT((head)->hh.tbl, hh, (head)->hh.tbl->buckets[ _hf_bkt ],  \
92                         keyptr,keylen,out);                                      \
93      }                                                                           \
94   }                                                                              \
95 } while (0)
96 
97 #ifdef HASH_BLOOM
98 #define HASH_BLOOM_BITLEN (1ULL << HASH_BLOOM)
99 #define HASH_BLOOM_BYTELEN (HASH_BLOOM_BITLEN/8) + ((HASH_BLOOM_BITLEN%8) ? 1:0)
100 #define HASH_BLOOM_MAKE(tbl)                                                     \
101 do {                                                                             \
102   (tbl)->bloom_nbits = HASH_BLOOM;                                               \
103   (tbl)->bloom_bv = (uint8_t*)uthash_malloc(HASH_BLOOM_BYTELEN);                 \
104   if (!((tbl)->bloom_bv))  { uthash_fatal( "out of memory"); }                   \
105   memset((tbl)->bloom_bv, 0, HASH_BLOOM_BYTELEN);                                \
106   (tbl)->bloom_sig = HASH_BLOOM_SIGNATURE;                                       \
107 } while (0);
108 
109 #define HASH_BLOOM_FREE(tbl)                                                     \
110 do {                                                                             \
111   uthash_free((tbl)->bloom_bv, HASH_BLOOM_BYTELEN);                              \
112 } while (0);
113 
114 #define HASH_BLOOM_BITSET(bv,idx) (bv[(idx)/8] |= (1U << ((idx)%8)))
115 #define HASH_BLOOM_BITTEST(bv,idx) (bv[(idx)/8] & (1U << ((idx)%8)))
116 
117 #define HASH_BLOOM_ADD(tbl,hashv)                                                \
118   HASH_BLOOM_BITSET((tbl)->bloom_bv, (hashv & (uint32_t)((1ULL << (tbl)->bloom_nbits) - 1)))
119 
120 #define HASH_BLOOM_TEST(tbl,hashv)                                               \
121   HASH_BLOOM_BITTEST((tbl)->bloom_bv, (hashv & (uint32_t)((1ULL << (tbl)->bloom_nbits) - 1)))
122 
123 #else
124 #define HASH_BLOOM_MAKE(tbl)
125 #define HASH_BLOOM_FREE(tbl)
126 #define HASH_BLOOM_ADD(tbl,hashv)
127 #define HASH_BLOOM_TEST(tbl,hashv) (1)
128 #endif
129 
130 #define HASH_MAKE_TABLE(hh,head)                                                 \
131 do {                                                                             \
132   (head)->hh.tbl = (UT_hash_table*)uthash_malloc(                                \
133                   sizeof(UT_hash_table));                                        \
134   if (!((head)->hh.tbl))  { uthash_fatal( "out of memory"); }                    \
135   memset((head)->hh.tbl, 0, sizeof(UT_hash_table));                              \
136   (head)->hh.tbl->tail = &((head)->hh);                                          \
137   (head)->hh.tbl->num_buckets = HASH_INITIAL_NUM_BUCKETS;                        \
138   (head)->hh.tbl->log2_num_buckets = HASH_INITIAL_NUM_BUCKETS_LOG2;              \
139   (head)->hh.tbl->hho = (char*)(&(head)->hh) - (char*)(head);                    \
140   (head)->hh.tbl->buckets = (UT_hash_bucket*)uthash_malloc(                      \
141           HASH_INITIAL_NUM_BUCKETS*sizeof(struct UT_hash_bucket));               \
142   if (! (head)->hh.tbl->buckets) { uthash_fatal( "out of memory"); }             \
143   memset((head)->hh.tbl->buckets, 0,                                             \
144           HASH_INITIAL_NUM_BUCKETS*sizeof(struct UT_hash_bucket));               \
145   HASH_BLOOM_MAKE((head)->hh.tbl);                                               \
146   (head)->hh.tbl->signature = HASH_SIGNATURE;                                    \
147 } while(0)
148 
149 #define HASH_ADD(hh,head,fieldname,keylen_in,add)                                \
150         HASH_ADD_KEYPTR(hh,head,&add->fieldname,keylen_in,add)
151 
152 #define HASH_ADD_KEYPTR(hh,head,keyptr,keylen_in,add)                            \
153 do {                                                                             \
154  unsigned _ha_bkt;                                                               \
155  (add)->hh.next = NULL;                                                          \
156  (add)->hh.key = (char*)keyptr;                                                  \
157  (add)->hh.keylen = keylen_in;                                                   \
158  if (!(head)) {                                                                  \
159     head = (add);                                                                \
160     (head)->hh.prev = NULL;                                                      \
161     HASH_MAKE_TABLE(hh,head);                                                    \
162  } else {                                                                        \
163     (head)->hh.tbl->tail->next = (add);                                          \
164     (add)->hh.prev = ELMT_FROM_HH((head)->hh.tbl, (head)->hh.tbl->tail);         \
165     (head)->hh.tbl->tail = &((add)->hh);                                         \
166  }                                                                               \
167  (head)->hh.tbl->num_items++;                                                    \
168  (add)->hh.tbl = (head)->hh.tbl;                                                 \
169  HASH_FCN(keyptr,keylen_in, (head)->hh.tbl->num_buckets,                         \
170          (add)->hh.hashv, _ha_bkt);                                              \
171  HASH_ADD_TO_BKT((head)->hh.tbl->buckets[_ha_bkt],&(add)->hh);                   \
172  HASH_BLOOM_ADD((head)->hh.tbl,(add)->hh.hashv);                                 \
173  HASH_EMIT_KEY(hh,head,keyptr,keylen_in);                                        \
174  HASH_FSCK(hh,head);                                                             \
175 } while(0)
176 
177 #define HASH_TO_BKT( hashv, num_bkts, bkt )                                      \
178 do {                                                                             \
179   bkt = ((hashv) & ((num_bkts) - 1));                                            \
180 } while(0)
181 
182 /* delete "delptr" from the hash table.
183  * "the usual" patch-up process for the app-order doubly-linked-list.
184  * The use of _hd_hh_del below deserves special explanation.
185  * These used to be expressed using (delptr) but that led to a bug
186  * if someone used the same symbol for the head and deletee, like
187  *  HASH_DELETE(hh,users,users);
188  * We want that to work, but by changing the head (users) below
189  * we were forfeiting our ability to further refer to the deletee (users)
190  * in the patch-up process. Solution: use scratch space to
191  * copy the deletee pointer, then the latter references are via that
192  * scratch pointer rather than through the repointed (users) symbol.
193  */
194 #define HASH_DELETE(hh,head,delptr)                                              \
195 do {                                                                             \
196     unsigned _hd_bkt;                                                            \
197     struct UT_hash_handle *_hd_hh_del;                                           \
198     if ( ((delptr)->hh.prev == NULL) && ((delptr)->hh.next == NULL) )  {         \
199         uthash_free((head)->hh.tbl->buckets,                                     \
200                     (head)->hh.tbl->num_buckets*sizeof(struct UT_hash_bucket) ); \
201         HASH_BLOOM_FREE((head)->hh.tbl);                                         \
202         uthash_free((head)->hh.tbl, sizeof(UT_hash_table));                      \
203         head = NULL;                                                             \
204     } else {                                                                     \
205         _hd_hh_del = &((delptr)->hh);                                            \
206         if ((delptr) == ELMT_FROM_HH((head)->hh.tbl,(head)->hh.tbl->tail)) {     \
207             (head)->hh.tbl->tail =                                               \
208                 (UT_hash_handle*)((char*)((delptr)->hh.prev) +                   \
209                 (head)->hh.tbl->hho);                                            \
210         }                                                                        \
211         if ((delptr)->hh.prev) {                                                 \
212             ((UT_hash_handle*)((char*)((delptr)->hh.prev) +                      \
213                     (head)->hh.tbl->hho))->next = (delptr)->hh.next;             \
214         } else {                                                                 \
215             DECLTYPE_ASSIGN(head,(delptr)->hh.next);                             \
216         }                                                                        \
217         if (_hd_hh_del->next) {                                                  \
218             ((UT_hash_handle*)((char*)_hd_hh_del->next +                         \
219                     (head)->hh.tbl->hho))->prev =                                \
220                     _hd_hh_del->prev;                                            \
221         }                                                                        \
222         HASH_TO_BKT( _hd_hh_del->hashv, (head)->hh.tbl->num_buckets, _hd_bkt);   \
223         HASH_DEL_IN_BKT(hh,(head)->hh.tbl->buckets[_hd_bkt], _hd_hh_del);        \
224         (head)->hh.tbl->num_items--;                                             \
225     }                                                                            \
226     HASH_FSCK(hh,head);                                                          \
227 } while (0)
228 
229 
230 /* convenience forms of HASH_FIND/HASH_ADD/HASH_DEL */
231 #define HASH_FIND_STR(head,findstr,out)                                          \
232     HASH_FIND(hh,head,findstr,strlen(findstr),out)
233 #define HASH_ADD_STR(head,strfield,add)                                          \
234     HASH_ADD(hh,head,strfield,strlen(add->strfield),add)
235 #define HASH_FIND_INT(head,findint,out)                                          \
236     HASH_FIND(hh,head,findint,sizeof(int),out)
237 #define HASH_ADD_INT(head,intfield,add)                                          \
238     HASH_ADD(hh,head,intfield,sizeof(int),add)
239 #define HASH_FIND_PTR(head,findptr,out)                                          \
240     HASH_FIND(hh,head,findptr,sizeof(void *),out)
241 #define HASH_ADD_PTR(head,ptrfield,add)                                          \
242     HASH_ADD(hh,head,ptrfield,sizeof(void *),add)
243 #define HASH_DEL(head,delptr)                                                    \
244     HASH_DELETE(hh,head,delptr)
245 
246 /* HASH_FSCK checks hash integrity on every add/delete when HASH_DEBUG is defined.
247  * This is for uthash developer only; it compiles away if HASH_DEBUG isn't defined.
248  */
249 #ifdef HASH_DEBUG
250 #define HASH_OOPS(...) do { fprintf(stderr,__VA_ARGS__); exit(-1); } while (0)
251 #define HASH_FSCK(hh,head)                                                       \
252 do {                                                                             \
253     unsigned _bkt_i;                                                             \
254     unsigned _count, _bkt_count;                                                 \
255     char *_prev;                                                                 \
256     struct UT_hash_handle *_thh;                                                 \
257     if (head) {                                                                  \
258         _count = 0;                                                              \
259         for( _bkt_i = 0; _bkt_i < (head)->hh.tbl->num_buckets; _bkt_i++) {       \
260             _bkt_count = 0;                                                      \
261             _thh = (head)->hh.tbl->buckets[_bkt_i].hh_head;                      \
262             _prev = NULL;                                                        \
263             while (_thh) {                                                       \
264                if (_prev != (char*)(_thh->hh_prev)) {                            \
265                    HASH_OOPS("invalid hh_prev %p, actual %p\n",                  \
266                     _thh->hh_prev, _prev );                                      \
267                }                                                                 \
268                _bkt_count++;                                                     \
269                _prev = (char*)(_thh);                                            \
270                _thh = _thh->hh_next;                                             \
271             }                                                                    \
272             _count += _bkt_count;                                                \
273             if ((head)->hh.tbl->buckets[_bkt_i].count !=  _bkt_count) {          \
274                HASH_OOPS("invalid bucket count %d, actual %d\n",                 \
275                 (head)->hh.tbl->buckets[_bkt_i].count, _bkt_count);              \
276             }                                                                    \
277         }                                                                        \
278         if (_count != (head)->hh.tbl->num_items) {                               \
279             HASH_OOPS("invalid hh item count %d, actual %d\n",                   \
280                 (head)->hh.tbl->num_items, _count );                             \
281         }                                                                        \
282         /* traverse hh in app order; check next/prev integrity, count */         \
283         _count = 0;                                                              \
284         _prev = NULL;                                                            \
285         _thh =  &(head)->hh;                                                     \
286         while (_thh) {                                                           \
287            _count++;                                                             \
288            if (_prev !=(char*)(_thh->prev)) {                                    \
289               HASH_OOPS("invalid prev %p, actual %p\n",                          \
290                     _thh->prev, _prev );                                         \
291            }                                                                     \
292            _prev = (char*)ELMT_FROM_HH((head)->hh.tbl, _thh);                    \
293            _thh = ( _thh->next ?  (UT_hash_handle*)((char*)(_thh->next) +        \
294                                   (head)->hh.tbl->hho) : NULL );                 \
295         }                                                                        \
296         if (_count != (head)->hh.tbl->num_items) {                               \
297             HASH_OOPS("invalid app item count %d, actual %d\n",                  \
298                 (head)->hh.tbl->num_items, _count );                             \
299         }                                                                        \
300     }                                                                            \
301 } while (0)
302 #else
303 #define HASH_FSCK(hh,head)
304 #endif
305 
306 /* When compiled with -DHASH_EMIT_KEYS, length-prefixed keys are emitted to
307  * the descriptor to which this macro is defined for tuning the hash function.
308  * The app can #include <unistd.h> to get the prototype for write(2). */
309 #ifdef HASH_EMIT_KEYS
310 #define HASH_EMIT_KEY(hh,head,keyptr,fieldlen)                                   \
311 do {                                                                             \
312     unsigned _klen = fieldlen;                                                   \
313     write(HASH_EMIT_KEYS, &_klen, sizeof(_klen));                                \
314     write(HASH_EMIT_KEYS, keyptr, fieldlen);                                     \
315 } while (0)
316 #else
317 #define HASH_EMIT_KEY(hh,head,keyptr,fieldlen)
318 #endif
319 
320 /* default to Jenkin's hash unless overridden e.g. DHASH_FUNCTION=HASH_SAX */
321 #ifdef HASH_FUNCTION
322 #define HASH_FCN HASH_FUNCTION
323 #else
324 #define HASH_FCN HASH_JEN
325 #endif
326 
327 /* The Bernstein hash function, used in Perl prior to v5.6 */
328 #define HASH_BER(key,keylen,num_bkts,hashv,bkt)                                  \
329 do {                                                                             \
330   unsigned _hb_keylen=keylen;                                                    \
331   char *_hb_key=(char*)(key);                                                    \
332   (hashv) = 0;                                                                   \
333   while (_hb_keylen--)  { (hashv) = ((hashv) * 33) + *_hb_key++; }               \
334   bkt = (hashv) & (num_bkts-1);                                                  \
335 } while (0)
336 
337 
338 /* SAX/FNV/OAT/JEN hash functions are macro variants of those listed at
339  * http://eternallyconfuzzled.com/tuts/algorithms/jsw_tut_hashing.aspx */
340 #define HASH_SAX(key,keylen,num_bkts,hashv,bkt)                                  \
341 do {                                                                             \
342   unsigned _sx_i;                                                                \
343   char *_hs_key=(char*)(key);                                                    \
344   hashv = 0;                                                                     \
345   for(_sx_i=0; _sx_i < keylen; _sx_i++)                                          \
346       hashv ^= (hashv << 5) + (hashv >> 2) + _hs_key[_sx_i];                     \
347   bkt = hashv & (num_bkts-1);                                                    \
348 } while (0)
349 
350 #define HASH_FNV(key,keylen,num_bkts,hashv,bkt)                                  \
351 do {                                                                             \
352   unsigned _fn_i;                                                                \
353   char *_hf_key=(char*)(key);                                                    \
354   hashv = 2166136261UL;                                                          \
355   for(_fn_i=0; _fn_i < keylen; _fn_i++)                                          \
356       hashv = (hashv * 16777619) ^ _hf_key[_fn_i];                               \
357   bkt = hashv & (num_bkts-1);                                                    \
358 } while(0);
359 
360 #define HASH_OAT(key,keylen,num_bkts,hashv,bkt)                                  \
361 do {                                                                             \
362   unsigned _ho_i;                                                                \
363   char *_ho_key=(char*)(key);                                                    \
364   hashv = 0;                                                                     \
365   for(_ho_i=0; _ho_i < keylen; _ho_i++) {                                        \
366       hashv += _ho_key[_ho_i];                                                   \
367       hashv += (hashv << 10);                                                    \
368       hashv ^= (hashv >> 6);                                                     \
369   }                                                                              \
370   hashv += (hashv << 3);                                                         \
371   hashv ^= (hashv >> 11);                                                        \
372   hashv += (hashv << 15);                                                        \
373   bkt = hashv & (num_bkts-1);                                                    \
374 } while(0)
375 
376 #define HASH_JEN_MIX(a,b,c)                                                      \
377 do {                                                                             \
378   a -= b; a -= c; a ^= ( c >> 13 );                                              \
379   b -= c; b -= a; b ^= ( a << 8 );                                               \
380   c -= a; c -= b; c ^= ( b >> 13 );                                              \
381   a -= b; a -= c; a ^= ( c >> 12 );                                              \
382   b -= c; b -= a; b ^= ( a << 16 );                                              \
383   c -= a; c -= b; c ^= ( b >> 5 );                                               \
384   a -= b; a -= c; a ^= ( c >> 3 );                                               \
385   b -= c; b -= a; b ^= ( a << 10 );                                              \
386   c -= a; c -= b; c ^= ( b >> 15 );                                              \
387 } while (0)
388 
389 #define HASH_JEN(key,keylen,num_bkts,hashv,bkt)                                  \
390 do {                                                                             \
391   unsigned _hj_i,_hj_j,_hj_k;                                                    \
392   char *_hj_key=(char*)(key);                                                    \
393   hashv = 0xfeedbeef;                                                            \
394   _hj_i = _hj_j = 0x9e3779b9;                                                    \
395   _hj_k = keylen;                                                                \
396   while (_hj_k >= 12) {                                                          \
397     _hj_i +=    (_hj_key[0] + ( (unsigned)_hj_key[1] << 8 )                      \
398         + ( (unsigned)_hj_key[2] << 16 )                                         \
399         + ( (unsigned)_hj_key[3] << 24 ) );                                      \
400     _hj_j +=    (_hj_key[4] + ( (unsigned)_hj_key[5] << 8 )                      \
401         + ( (unsigned)_hj_key[6] << 16 )                                         \
402         + ( (unsigned)_hj_key[7] << 24 ) );                                      \
403     hashv += (_hj_key[8] + ( (unsigned)_hj_key[9] << 8 )                         \
404         + ( (unsigned)_hj_key[10] << 16 )                                        \
405         + ( (unsigned)_hj_key[11] << 24 ) );                                     \
406                                                                                  \
407      HASH_JEN_MIX(_hj_i, _hj_j, hashv);                                          \
408                                                                                  \
409      _hj_key += 12;                                                              \
410      _hj_k -= 12;                                                                \
411   }                                                                              \
412   hashv += keylen;                                                               \
413   switch ( _hj_k ) {                                                             \
414      case 11: hashv += ( (unsigned)_hj_key[10] << 24 );                          \
415      case 10: hashv += ( (unsigned)_hj_key[9] << 16 );                           \
416      case 9:  hashv += ( (unsigned)_hj_key[8] << 8 );                            \
417      case 8:  _hj_j += ( (unsigned)_hj_key[7] << 24 );                           \
418      case 7:  _hj_j += ( (unsigned)_hj_key[6] << 16 );                           \
419      case 6:  _hj_j += ( (unsigned)_hj_key[5] << 8 );                            \
420      case 5:  _hj_j += _hj_key[4];                                               \
421      case 4:  _hj_i += ( (unsigned)_hj_key[3] << 24 );                           \
422      case 3:  _hj_i += ( (unsigned)_hj_key[2] << 16 );                           \
423      case 2:  _hj_i += ( (unsigned)_hj_key[1] << 8 );                            \
424      case 1:  _hj_i += _hj_key[0];                                               \
425   }                                                                              \
426   HASH_JEN_MIX(_hj_i, _hj_j, hashv);                                             \
427   bkt = hashv & (num_bkts-1);                                                    \
428 } while(0)
429 
430 /* The Paul Hsieh hash function */
431 #undef get16bits
432 #if (defined(__GNUC__) && defined(__i386__)) || defined(__WATCOMC__)             \
433   || defined(_MSC_VER) || defined (__BORLANDC__) || defined (__TURBOC__)
434 #define get16bits(d) (*((const uint16_t *) (d)))
435 #endif
436 
437 #if !defined (get16bits)
438 #define get16bits(d) ((((uint32_t)(((const uint8_t *)(d))[1])) << 8)             \
439                        +(uint32_t)(((const uint8_t *)(d))[0]) )
440 #endif
441 #define HASH_SFH(key,keylen,num_bkts,hashv,bkt)                                  \
442 do {                                                                             \
443   char *_sfh_key=(char*)(key);                                                   \
444   uint32_t _sfh_tmp, _sfh_len = keylen;                                          \
445                                                                                  \
446   int _sfh_rem = _sfh_len & 3;                                                   \
447   _sfh_len >>= 2;                                                                \
448   hashv = 0xcafebabe;                                                            \
449                                                                                  \
450   /* Main loop */                                                                \
451   for (;_sfh_len > 0; _sfh_len--) {                                              \
452     hashv    += get16bits (_sfh_key);                                            \
453     _sfh_tmp       = (get16bits (_sfh_key+2) << 11) ^ hashv;                     \
454     hashv     = (hashv << 16) ^ _sfh_tmp;                                        \
455     _sfh_key += 2*sizeof (uint16_t);                                             \
456     hashv    += hashv >> 11;                                                     \
457   }                                                                              \
458                                                                                  \
459   /* Handle end cases */                                                         \
460   switch (_sfh_rem) {                                                            \
461     case 3: hashv += get16bits (_sfh_key);                                       \
462             hashv ^= hashv << 16;                                                \
463             hashv ^= _sfh_key[sizeof (uint16_t)] << 18;                          \
464             hashv += hashv >> 11;                                                \
465             break;                                                               \
466     case 2: hashv += get16bits (_sfh_key);                                       \
467             hashv ^= hashv << 11;                                                \
468             hashv += hashv >> 17;                                                \
469             break;                                                               \
470     case 1: hashv += *_sfh_key;                                                  \
471             hashv ^= hashv << 10;                                                \
472             hashv += hashv >> 1;                                                 \
473   }                                                                              \
474                                                                                  \
475     /* Force "avalanching" of final 127 bits */                                  \
476     hashv ^= hashv << 3;                                                         \
477     hashv += hashv >> 5;                                                         \
478     hashv ^= hashv << 4;                                                         \
479     hashv += hashv >> 17;                                                        \
480     hashv ^= hashv << 25;                                                        \
481     hashv += hashv >> 6;                                                         \
482     bkt = hashv & (num_bkts-1);                                                  \
483 } while(0);
484 
485 #ifdef HASH_USING_NO_STRICT_ALIASING
486 /* The MurmurHash exploits some CPU's (x86,x86_64) tolerance for unaligned reads.
487  * For other types of CPU's (e.g. Sparc) an unaligned read causes a bus error.
488  * MurmurHash uses the faster approach only on CPU's where we know it's safe.
489  *
490  * Note the preprocessor built-in defines can be emitted using:
491  *
492  *   gcc -m64 -dM -E - < /dev/null                  (on gcc)
493  *   cc -## a.c (where a.c is a simple test file)   (Sun Studio)
494  */
495 #if (defined(__i386__) || defined(__x86_64__))
496 #define MUR_GETBLOCK(p,i) p[i]
497 #else /* non intel */
498 #define MUR_PLUS0_ALIGNED(p) (((unsigned long)p & 0x3) == 0)
499 #define MUR_PLUS1_ALIGNED(p) (((unsigned long)p & 0x3) == 1)
500 #define MUR_PLUS2_ALIGNED(p) (((unsigned long)p & 0x3) == 2)
501 #define MUR_PLUS3_ALIGNED(p) (((unsigned long)p & 0x3) == 3)
502 #define WP(p) ((uint32_t*)((unsigned long)(p) & ~3UL))
503 #if (defined(__BIG_ENDIAN__) || defined(SPARC) || defined(__ppc__) || defined(__ppc64__))
504 #define MUR_THREE_ONE(p) ((((*WP(p))&0x00ffffff) << 8) | (((*(WP(p)+1))&0xff000000) >> 24))
505 #define MUR_TWO_TWO(p)   ((((*WP(p))&0x0000ffff) <<16) | (((*(WP(p)+1))&0xffff0000) >> 16))
506 #define MUR_ONE_THREE(p) ((((*WP(p))&0x000000ff) <<24) | (((*(WP(p)+1))&0xffffff00) >>  8))
507 #else /* assume little endian non-intel */
508 #define MUR_THREE_ONE(p) ((((*WP(p))&0xffffff00) >> 8) | (((*(WP(p)+1))&0x000000ff) << 24))
509 #define MUR_TWO_TWO(p)   ((((*WP(p))&0xffff0000) >>16) | (((*(WP(p)+1))&0x0000ffff) << 16))
510 #define MUR_ONE_THREE(p) ((((*WP(p))&0xff000000) >>24) | (((*(WP(p)+1))&0x00ffffff) <<  8))
511 #endif
512 #define MUR_GETBLOCK(p,i) (MUR_PLUS0_ALIGNED(p) ? ((p)[i]) :           \
513                             (MUR_PLUS1_ALIGNED(p) ? MUR_THREE_ONE(p) : \
514                              (MUR_PLUS2_ALIGNED(p) ? MUR_TWO_TWO(p) :  \
515                                                       MUR_ONE_THREE(p))))
516 #endif
517 #define MUR_ROTL32(x,r) (((x) << (r)) | ((x) >> (32 - (r))))
518 #define MUR_FMIX(_h) \
519 do {                 \
520   _h ^= _h >> 16;    \
521   _h *= 0x85ebca6b;  \
522   _h ^= _h >> 13;    \
523   _h *= 0xc2b2ae35l; \
524   _h ^= _h >> 16;    \
525 } while(0)
526 
527 #define HASH_MUR(key,keylen,num_bkts,hashv,bkt)                        \
528 do {                                                                   \
529   const uint8_t *_mur_data = (const uint8_t*)(key);                    \
530   const int _mur_nblocks = (keylen) / 4;                               \
531   uint32_t _mur_h1 = 0xf88D5353;                                       \
532   uint32_t _mur_c1 = 0xcc9e2d51;                                       \
533   uint32_t _mur_c2 = 0x1b873593;                                       \
534   const uint32_t *_mur_blocks = (const uint32_t*)(_mur_data+_mur_nblocks*4); \
535   int _mur_i;                                                          \
536   for(_mur_i = -_mur_nblocks; _mur_i; _mur_i++) {                      \
537     uint32_t _mur_k1 = MUR_GETBLOCK(_mur_blocks,_mur_i);               \
538     _mur_k1 *= _mur_c1;                                                \
539     _mur_k1 = MUR_ROTL32(_mur_k1,15);                                  \
540     _mur_k1 *= _mur_c2;                                                \
541                                                                        \
542     _mur_h1 ^= _mur_k1;                                                \
543     _mur_h1 = MUR_ROTL32(_mur_h1,13);                                  \
544     _mur_h1 = _mur_h1*5+0xe6546b64;                                    \
545   }                                                                    \
546   const uint8_t *_mur_tail = (const uint8_t*)(_mur_data + _mur_nblocks*4); \
547   uint32_t _mur_k1=0;                                                  \
548   switch((keylen) & 3) {                                               \
549     case 3: _mur_k1 ^= _mur_tail[2] << 16;                             \
550     case 2: _mur_k1 ^= _mur_tail[1] << 8;                              \
551     case 1: _mur_k1 ^= _mur_tail[0];                                   \
552     _mur_k1 *= _mur_c1;                                                \
553     _mur_k1 = MUR_ROTL32(_mur_k1,15);                                  \
554     _mur_k1 *= _mur_c2;                                                \
555     _mur_h1 ^= _mur_k1;                                                \
556   }                                                                    \
557   _mur_h1 ^= (keylen);                                                 \
558   MUR_FMIX(_mur_h1);                                                   \
559   hashv = _mur_h1;                                                     \
560   bkt = hashv & (num_bkts-1);                                          \
561 } while(0)
562 #endif  /* HASH_USING_NO_STRICT_ALIASING */
563 
564 /* key comparison function; return 0 if keys equal */
565 #define HASH_KEYCMP(a,b,len) memcmp(a,b,len)
566 
567 /* iterate over items in a known bucket to find desired item */
568 #define HASH_FIND_IN_BKT(tbl,hh,head,keyptr,keylen_in,out)                       \
569 do {                                                                             \
570  if (head.hh_head) DECLTYPE_ASSIGN(out,ELMT_FROM_HH(tbl,head.hh_head));          \
571  else out=NULL;                                                                  \
572  while (out) {                                                                   \
573     if (out->hh.keylen == keylen_in) {                                           \
574         if ((HASH_KEYCMP(out->hh.key,keyptr,keylen_in)) == 0) break;             \
575     }                                                                            \
576     if (out->hh.hh_next) DECLTYPE_ASSIGN(out,ELMT_FROM_HH(tbl,out->hh.hh_next)); \
577     else out = NULL;                                                             \
578  }                                                                               \
579 } while(0)
580 
581 /* add an item to a bucket  */
582 #define HASH_ADD_TO_BKT(head,addhh)                                              \
583 do {                                                                             \
584  head.count++;                                                                   \
585  (addhh)->hh_next = head.hh_head;                                                \
586  (addhh)->hh_prev = NULL;                                                        \
587  if (head.hh_head) { (head).hh_head->hh_prev = (addhh); }                        \
588  (head).hh_head=addhh;                                                           \
589  if (head.count >= ((head.expand_mult+1) * HASH_BKT_CAPACITY_THRESH)             \
590      && (addhh)->tbl->noexpand != 1) {                                           \
591        HASH_EXPAND_BUCKETS((addhh)->tbl);                                        \
592  }                                                                               \
593 } while(0)
594 
595 /* remove an item from a given bucket */
596 #define HASH_DEL_IN_BKT(hh,head,hh_del)                                          \
597     (head).count--;                                                              \
598     if ((head).hh_head == hh_del) {                                              \
599       (head).hh_head = hh_del->hh_next;                                          \
600     }                                                                            \
601     if (hh_del->hh_prev) {                                                       \
602         hh_del->hh_prev->hh_next = hh_del->hh_next;                              \
603     }                                                                            \
604     if (hh_del->hh_next) {                                                       \
605         hh_del->hh_next->hh_prev = hh_del->hh_prev;                              \
606     }
607 
608 /* Bucket expansion has the effect of doubling the number of buckets
609  * and redistributing the items into the new buckets. Ideally the
610  * items will distribute more or less evenly into the new buckets
611  * (the extent to which this is true is a measure of the quality of
612  * the hash function as it applies to the key domain).
613  *
614  * With the items distributed into more buckets, the chain length
615  * (item count) in each bucket is reduced. Thus by expanding buckets
616  * the hash keeps a bound on the chain length. This bounded chain
617  * length is the essence of how a hash provides constant time lookup.
618  *
619  * The calculation of tbl->ideal_chain_maxlen below deserves some
620  * explanation. First, keep in mind that we're calculating the ideal
621  * maximum chain length based on the *new* (doubled) bucket count.
622  * In fractions this is just n/b (n=number of items,b=new num buckets).
623  * Since the ideal chain length is an integer, we want to calculate
624  * ceil(n/b). We don't depend on floating point arithmetic in this
625  * hash, so to calculate ceil(n/b) with integers we could write
626  *
627  *      ceil(n/b) = (n/b) + ((n%b)?1:0)
628  *
629  * and in fact a previous version of this hash did just that.
630  * But now we have improved things a bit by recognizing that b is
631  * always a power of two. We keep its base 2 log handy (call it lb),
632  * so now we can write this with a bit shift and logical AND:
633  *
634  *      ceil(n/b) = (n>>lb) + ( (n & (b-1)) ? 1:0)
635  *
636  */
637 #define HASH_EXPAND_BUCKETS(tbl)                                                 \
638 do {                                                                             \
639     unsigned _he_bkt;                                                            \
640     unsigned _he_bkt_i;                                                          \
641     struct UT_hash_handle *_he_thh, *_he_hh_nxt;                                 \
642     UT_hash_bucket *_he_new_buckets, *_he_newbkt;                                \
643     _he_new_buckets = (UT_hash_bucket*)uthash_malloc(                            \
644              2 * tbl->num_buckets * sizeof(struct UT_hash_bucket));              \
645     if (!_he_new_buckets) { uthash_fatal( "out of memory"); }                    \
646     memset(_he_new_buckets, 0,                                                   \
647             2 * tbl->num_buckets * sizeof(struct UT_hash_bucket));               \
648     tbl->ideal_chain_maxlen =                                                    \
649        (tbl->num_items >> (tbl->log2_num_buckets+1)) +                           \
650        ((tbl->num_items & ((tbl->num_buckets*2)-1)) ? 1 : 0);                    \
651     tbl->nonideal_items = 0;                                                     \
652     for(_he_bkt_i = 0; _he_bkt_i < tbl->num_buckets; _he_bkt_i++)                \
653     {                                                                            \
654         _he_thh = tbl->buckets[ _he_bkt_i ].hh_head;                             \
655         while (_he_thh) {                                                        \
656            _he_hh_nxt = _he_thh->hh_next;                                        \
657            HASH_TO_BKT( _he_thh->hashv, tbl->num_buckets*2, _he_bkt);            \
658            _he_newbkt = &(_he_new_buckets[ _he_bkt ]);                           \
659            if (++(_he_newbkt->count) > tbl->ideal_chain_maxlen) {                \
660              tbl->nonideal_items++;                                              \
661              _he_newbkt->expand_mult = _he_newbkt->count /                       \
662                                         tbl->ideal_chain_maxlen;                 \
663            }                                                                     \
664            _he_thh->hh_prev = NULL;                                              \
665            _he_thh->hh_next = _he_newbkt->hh_head;                               \
666            if (_he_newbkt->hh_head) _he_newbkt->hh_head->hh_prev =               \
667                 _he_thh;                                                         \
668            _he_newbkt->hh_head = _he_thh;                                        \
669            _he_thh = _he_hh_nxt;                                                 \
670         }                                                                        \
671     }                                                                            \
672     uthash_free( tbl->buckets, tbl->num_buckets*sizeof(struct UT_hash_bucket) ); \
673     tbl->num_buckets *= 2;                                                       \
674     tbl->log2_num_buckets++;                                                     \
675     tbl->buckets = _he_new_buckets;                                              \
676     tbl->ineff_expands = (tbl->nonideal_items > (tbl->num_items >> 1)) ?         \
677         (tbl->ineff_expands+1) : 0;                                              \
678     if (tbl->ineff_expands > 1) {                                                \
679         tbl->noexpand=1;                                                         \
680         uthash_noexpand_fyi(tbl);                                                \
681     }                                                                            \
682     uthash_expand_fyi(tbl);                                                      \
683 } while(0)
684 
685 
686 /* This is an adaptation of Simon Tatham's O(n log(n)) mergesort */
687 /* Note that HASH_SORT assumes the hash handle name to be hh.
688  * HASH_SRT was added to allow the hash handle name to be passed in. */
689 #define HASH_SORT(head,cmpfcn) HASH_SRT(hh,head,cmpfcn)
690 #define HASH_SRT(hh,head,cmpfcn)                                                 \
691 do {                                                                             \
692   unsigned _hs_i;                                                                \
693   unsigned _hs_looping,_hs_nmerges,_hs_insize,_hs_psize,_hs_qsize;               \
694   struct UT_hash_handle *_hs_p, *_hs_q, *_hs_e, *_hs_list, *_hs_tail;            \
695   if (head) {                                                                    \
696       _hs_insize = 1;                                                            \
697       _hs_looping = 1;                                                           \
698       _hs_list = &((head)->hh);                                                  \
699       while (_hs_looping) {                                                      \
700           _hs_p = _hs_list;                                                      \
701           _hs_list = NULL;                                                       \
702           _hs_tail = NULL;                                                       \
703           _hs_nmerges = 0;                                                       \
704           while (_hs_p) {                                                        \
705               _hs_nmerges++;                                                     \
706               _hs_q = _hs_p;                                                     \
707               _hs_psize = 0;                                                     \
708               for ( _hs_i = 0; _hs_i  < _hs_insize; _hs_i++ ) {                  \
709                   _hs_psize++;                                                   \
710                   _hs_q = (UT_hash_handle*)((_hs_q->next) ?                      \
711                           ((void*)((char*)(_hs_q->next) +                        \
712                           (head)->hh.tbl->hho)) : NULL);                         \
713                   if (! (_hs_q) ) break;                                         \
714               }                                                                  \
715               _hs_qsize = _hs_insize;                                            \
716               while ((_hs_psize > 0) || ((_hs_qsize > 0) && _hs_q )) {           \
717                   if (_hs_psize == 0) {                                          \
718                       _hs_e = _hs_q;                                             \
719                       _hs_q = (UT_hash_handle*)((_hs_q->next) ?                  \
720                               ((void*)((char*)(_hs_q->next) +                    \
721                               (head)->hh.tbl->hho)) : NULL);                     \
722                       _hs_qsize--;                                               \
723                   } else if ( (_hs_qsize == 0) || !(_hs_q) ) {                   \
724                       _hs_e = _hs_p;                                             \
725                       _hs_p = (UT_hash_handle*)((_hs_p->next) ?                  \
726                               ((void*)((char*)(_hs_p->next) +                    \
727                               (head)->hh.tbl->hho)) : NULL);                     \
728                       _hs_psize--;                                               \
729                   } else if ((                                                   \
730                       cmpfcn(DECLTYPE(head)(ELMT_FROM_HH((head)->hh.tbl,_hs_p)), \
731                              DECLTYPE(head)(ELMT_FROM_HH((head)->hh.tbl,_hs_q))) \
732                              ) <= 0) {                                           \
733                       _hs_e = _hs_p;                                             \
734                       _hs_p = (UT_hash_handle*)((_hs_p->next) ?                  \
735                               ((void*)((char*)(_hs_p->next) +                    \
736                               (head)->hh.tbl->hho)) : NULL);                     \
737                       _hs_psize--;                                               \
738                   } else {                                                       \
739                       _hs_e = _hs_q;                                             \
740                       _hs_q = (UT_hash_handle*)((_hs_q->next) ?                  \
741                               ((void*)((char*)(_hs_q->next) +                    \
742                               (head)->hh.tbl->hho)) : NULL);                     \
743                       _hs_qsize--;                                               \
744                   }                                                              \
745                   if ( _hs_tail ) {                                              \
746                       _hs_tail->next = ((_hs_e) ?                                \
747                             ELMT_FROM_HH((head)->hh.tbl,_hs_e) : NULL);          \
748                   } else {                                                       \
749                       _hs_list = _hs_e;                                          \
750                   }                                                              \
751                   _hs_e->prev = ((_hs_tail) ?                                    \
752                      ELMT_FROM_HH((head)->hh.tbl,_hs_tail) : NULL);              \
753                   _hs_tail = _hs_e;                                              \
754               }                                                                  \
755               _hs_p = _hs_q;                                                     \
756           }                                                                      \
757           _hs_tail->next = NULL;                                                 \
758           if ( _hs_nmerges <= 1 ) {                                              \
759               _hs_looping=0;                                                     \
760               (head)->hh.tbl->tail = _hs_tail;                                   \
761               DECLTYPE_ASSIGN(head,ELMT_FROM_HH((head)->hh.tbl, _hs_list));      \
762           }                                                                      \
763           _hs_insize *= 2;                                                       \
764       }                                                                          \
765       HASH_FSCK(hh,head);                                                        \
766  }                                                                               \
767 } while (0)
768 
769 /* This function selects items from one hash into another hash.
770  * The end result is that the selected items have dual presence
771  * in both hashes. There is no copy of the items made; rather
772  * they are added into the new hash through a secondary hash
773  * hash handle that must be present in the structure. */
774 #define HASH_SELECT(hh_dst, dst, hh_src, src, cond)                              \
775 do {                                                                             \
776   unsigned _src_bkt, _dst_bkt;                                                   \
777   void *_last_elt=NULL, *_elt;                                                   \
778   UT_hash_handle *_src_hh, *_dst_hh, *_last_elt_hh=NULL;                         \
779   ptrdiff_t _dst_hho = ((char*)(&(dst)->hh_dst) - (char*)(dst));                 \
780   if (src) {                                                                     \
781     for(_src_bkt=0; _src_bkt < (src)->hh_src.tbl->num_buckets; _src_bkt++) {     \
782       for(_src_hh = (src)->hh_src.tbl->buckets[_src_bkt].hh_head;                \
783           _src_hh;                                                               \
784           _src_hh = _src_hh->hh_next) {                                          \
785           _elt = ELMT_FROM_HH((src)->hh_src.tbl, _src_hh);                       \
786           if (cond(_elt)) {                                                      \
787             _dst_hh = (UT_hash_handle*)(((char*)_elt) + _dst_hho);               \
788             _dst_hh->key = _src_hh->key;                                         \
789             _dst_hh->keylen = _src_hh->keylen;                                   \
790             _dst_hh->hashv = _src_hh->hashv;                                     \
791             _dst_hh->prev = _last_elt;                                           \
792             _dst_hh->next = NULL;                                                \
793             if (_last_elt_hh) { _last_elt_hh->next = _elt; }                     \
794             if (!dst) {                                                          \
795               DECLTYPE_ASSIGN(dst,_elt);                                         \
796               HASH_MAKE_TABLE(hh_dst,dst);                                       \
797             } else {                                                             \
798               _dst_hh->tbl = (dst)->hh_dst.tbl;                                  \
799             }                                                                    \
800             HASH_TO_BKT(_dst_hh->hashv, _dst_hh->tbl->num_buckets, _dst_bkt);    \
801             HASH_ADD_TO_BKT(_dst_hh->tbl->buckets[_dst_bkt],_dst_hh);            \
802             (dst)->hh_dst.tbl->num_items++;                                      \
803             _last_elt = _elt;                                                    \
804             _last_elt_hh = _dst_hh;                                              \
805           }                                                                      \
806       }                                                                          \
807     }                                                                            \
808   }                                                                              \
809   HASH_FSCK(hh_dst,dst);                                                         \
810 } while (0)
811 
812 #define HASH_CLEAR(hh,head)                                                      \
813 do {                                                                             \
814   if (head) {                                                                    \
815     uthash_free((head)->hh.tbl->buckets,                                         \
816                 (head)->hh.tbl->num_buckets*sizeof(struct UT_hash_bucket));      \
817     uthash_free((head)->hh.tbl, sizeof(UT_hash_table));                          \
818     (head)=NULL;                                                                 \
819   }                                                                              \
820 } while(0)
821 
822 #ifdef NO_DECLTYPE
823 #define HASH_ITER(hh,head,el,tmp)                                                \
824 for((el)=(head), (*(char**)(&(tmp)))=(char*)((head)?(head)->hh.next:NULL);       \
825   el; (el)=(tmp),(*(char**)(&(tmp)))=(char*)((tmp)?(tmp)->hh.next:NULL))
826 #else
827 #define HASH_ITER(hh,head,el,tmp)                                                \
828 for((el)=(head),(tmp)=DECLTYPE(el)((head)?(head)->hh.next:NULL);                 \
829   el; (el)=(tmp),(tmp)=DECLTYPE(el)((tmp)?(tmp)->hh.next:NULL))
830 #endif
831 
832 /* obtain a count of items in the hash */
833 #define HASH_COUNT(head) HASH_CNT(hh,head)
834 #define HASH_CNT(hh,head) ((head)?((head)->hh.tbl->num_items):0)
835 
836 typedef struct UT_hash_bucket {
837    struct UT_hash_handle *hh_head;
838    unsigned count;
839 
840    /* expand_mult is normally set to 0. In this situation, the max chain length
841     * threshold is enforced at its default value, HASH_BKT_CAPACITY_THRESH. (If
842     * the bucket's chain exceeds this length, bucket expansion is triggered).
843     * However, setting expand_mult to a non-zero value delays bucket expansion
844     * (that would be triggered by additions to this particular bucket)
845     * until its chain length reaches a *multiple* of HASH_BKT_CAPACITY_THRESH.
846     * (The multiplier is simply expand_mult+1). The whole idea of this
847     * multiplier is to reduce bucket expansions, since they are expensive, in
848     * situations where we know that a particular bucket tends to be overused.
849     * It is better to let its chain length grow to a longer yet-still-bounded
850     * value, than to do an O(n) bucket expansion too often.
851     */
852    unsigned expand_mult;
853 
854 } UT_hash_bucket;
855 
856 /* random signature used only to find hash tables in external analysis */
857 #define HASH_SIGNATURE 0xa0111fe1
858 #define HASH_BLOOM_SIGNATURE 0xb12220f2
859 
860 typedef struct UT_hash_table {
861    UT_hash_bucket *buckets;
862    unsigned num_buckets, log2_num_buckets;
863    unsigned num_items;
864    struct UT_hash_handle *tail; /* tail hh in app order, for fast append    */
865    ptrdiff_t hho; /* hash handle offset (byte pos of hash handle in element */
866 
867    /* in an ideal situation (all buckets used equally), no bucket would have
868     * more than ceil(#items/#buckets) items. that's the ideal chain length. */
869    unsigned ideal_chain_maxlen;
870 
871    /* nonideal_items is the number of items in the hash whose chain position
872     * exceeds the ideal chain maxlen. these items pay the penalty for an uneven
873     * hash distribution; reaching them in a chain traversal takes >ideal steps */
874    unsigned nonideal_items;
875 
876    /* ineffective expands occur when a bucket doubling was performed, but
877     * afterward, more than half the items in the hash had nonideal chain
878     * positions. If this happens on two consecutive expansions we inhibit any
879     * further expansion, as it's not helping; this happens when the hash
880     * function isn't a good fit for the key domain. When expansion is inhibited
881     * the hash will still work, albeit no longer in constant time. */
882    unsigned ineff_expands, noexpand;
883 
884    uint32_t signature; /* used only to find hash tables in external analysis */
885 #ifdef HASH_BLOOM
886    uint32_t bloom_sig; /* used only to test bloom exists in external analysis */
887    uint8_t *bloom_bv;
888    char bloom_nbits;
889 #endif
890 
891 } UT_hash_table;
892 
893 typedef struct UT_hash_handle {
894    struct UT_hash_table *tbl;
895    void *prev;                       /* prev element in app order      */
896    void *next;                       /* next element in app order      */
897    struct UT_hash_handle *hh_prev;   /* previous hh in bucket order    */
898    struct UT_hash_handle *hh_next;   /* next hh in bucket order        */
899    void *key;                        /* ptr to enclosing struct's key  */
900    unsigned keylen;                  /* enclosing struct's key len     */
901    unsigned hashv;                   /* result of hash-fcn(key)        */
902 } UT_hash_handle;
903 
904 #endif /* UTHASH_H */
905