uthash.h revision 1.2
1/*	$NetBSD: uthash.h,v 1.2 2014/03/09 16:58:03 christos Exp $	*/
2
3/*
4Copyright (c) 2003-2013, Troy D. Hanson     http://uthash.sourceforge.net
5All rights reserved.
6
7Redistribution and use in source and binary forms, with or without
8modification, are permitted provided that the following conditions are met:
9
10    * Redistributions of source code must retain the above copyright
11      notice, this list of conditions and the following disclaimer.
12
13THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
14IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
15TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
16PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
17OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
21LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
22NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
23SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24*/
25
26/* Id: uthash.h 2682 2012-11-23 22:04:22Z kaiwang27  */
27
28#ifndef UTHASH_H
29#define UTHASH_H
30
31#include <string.h>   /* memcmp,strlen */
32#include <stddef.h>   /* ptrdiff_t */
33#include <stdlib.h>   /* exit() */
34
35/* These macros use decltype or the earlier __typeof GNU extension.
36   As decltype is only available in newer compilers (VS2010 or gcc 4.3+
37   when compiling c++ source) this code uses whatever method is needed
38   or, for VS2008 where neither is available, uses casting workarounds. */
39#ifdef _MSC_VER         /* MS compiler */
40#if _MSC_VER >= 1600 && defined(__cplusplus)  /* VS2010 or newer in C++ mode */
41#define DECLTYPE(x) (decltype(x))
42#else                   /* VS2008 or older (or VS2010 in C mode) */
43#define NO_DECLTYPE
44#define DECLTYPE(x)
45#endif
46#else                   /* GNU, Sun and other compilers */
47#define DECLTYPE(x) (__typeof(x))
48#endif
49
50#ifdef NO_DECLTYPE
51#define DECLTYPE_ASSIGN(dst,src)                                                 \
52do {                                                                             \
53  char **_da_dst = (char**)(&(dst));                                             \
54  *_da_dst = (char*)(src);                                                       \
55} while(0)
56#else
57#define DECLTYPE_ASSIGN(dst,src)                                                 \
58do {                                                                             \
59  (dst) = DECLTYPE(dst)(src);                                                    \
60} while(0)
61#endif
62
63/* a number of the hash function use uint32_t which isn't defined on win32 */
64#ifdef _MSC_VER
65typedef unsigned int uint32_t;
66typedef unsigned char uint8_t;
67#else
68#include <inttypes.h>   /* uint32_t */
69#endif
70
71#define UTHASH_VERSION 1.9.7
72
73#ifndef uthash_fatal
74#define uthash_fatal(msg) exit(-1)        /* fatal error (out of memory,etc) */
75#endif
76#ifndef uthash_malloc
77#define uthash_malloc(sz) malloc(sz)      /* malloc fcn                      */
78#endif
79#ifndef uthash_free
80#define uthash_free(ptr,sz) free(ptr)     /* free fcn                        */
81#endif
82
83#ifndef uthash_noexpand_fyi
84#define uthash_noexpand_fyi(tbl)          /* can be defined to log noexpand  */
85#endif
86#ifndef uthash_expand_fyi
87#define uthash_expand_fyi(tbl)            /* can be defined to log expands   */
88#endif
89
90/* initial number of buckets */
91#define HASH_INITIAL_NUM_BUCKETS 32      /* initial number of buckets        */
92#define HASH_INITIAL_NUM_BUCKETS_LOG2 5  /* lg2 of initial number of buckets */
93#define HASH_BKT_CAPACITY_THRESH 10      /* expand when bucket count reaches */
94
95/* calculate the element whose hash handle address is hhe */
96#define ELMT_FROM_HH(tbl,hhp) ((void*)(((char*)(hhp)) - ((tbl)->hho)))
97
98#define HASH_FIND(hh,head,keyptr,keylen,out)                                     \
99do {                                                                             \
100  unsigned _hf_bkt,_hf_hashv;                                                    \
101  out=NULL;                                                                      \
102  if (head) {                                                                    \
103     HASH_FCN(keyptr,keylen, (head)->hh.tbl->num_buckets, _hf_hashv, _hf_bkt);   \
104     if (HASH_BLOOM_TEST((head)->hh.tbl, _hf_hashv)) {                           \
105       HASH_FIND_IN_BKT((head)->hh.tbl, hh, (head)->hh.tbl->buckets[ _hf_bkt ],  \
106                        keyptr,keylen,out);                                      \
107     }                                                                           \
108  }                                                                              \
109} while (0)
110
111#ifdef HASH_BLOOM
112#define HASH_BLOOM_BITLEN (1ULL << HASH_BLOOM)
113#define HASH_BLOOM_BYTELEN (HASH_BLOOM_BITLEN/8) + ((HASH_BLOOM_BITLEN%8) ? 1:0)
114#define HASH_BLOOM_MAKE(tbl)                                                     \
115do {                                                                             \
116  (tbl)->bloom_nbits = HASH_BLOOM;                                               \
117  (tbl)->bloom_bv = (uint8_t*)uthash_malloc(HASH_BLOOM_BYTELEN);                 \
118  if (!((tbl)->bloom_bv))  { uthash_fatal( "out of memory"); }                   \
119  memset((tbl)->bloom_bv, 0, HASH_BLOOM_BYTELEN);                                \
120  (tbl)->bloom_sig = HASH_BLOOM_SIGNATURE;                                       \
121} while (0)
122
123#define HASH_BLOOM_FREE(tbl)                                                     \
124do {                                                                             \
125  uthash_free((tbl)->bloom_bv, HASH_BLOOM_BYTELEN);                              \
126} while (0)
127
128#define HASH_BLOOM_BITSET(bv,idx) (bv[(idx)/8] |= (1U << ((idx)%8)))
129#define HASH_BLOOM_BITTEST(bv,idx) (bv[(idx)/8] & (1U << ((idx)%8)))
130
131#define HASH_BLOOM_ADD(tbl,hashv)                                                \
132  HASH_BLOOM_BITSET((tbl)->bloom_bv, (hashv & (uint32_t)((1ULL << (tbl)->bloom_nbits) - 1)))
133
134#define HASH_BLOOM_TEST(tbl,hashv)                                               \
135  HASH_BLOOM_BITTEST((tbl)->bloom_bv, (hashv & (uint32_t)((1ULL << (tbl)->bloom_nbits) - 1)))
136
137#else
138#define HASH_BLOOM_MAKE(tbl)
139#define HASH_BLOOM_FREE(tbl)
140#define HASH_BLOOM_ADD(tbl,hashv)
141#define HASH_BLOOM_TEST(tbl,hashv) (1)
142#endif
143
144#define HASH_MAKE_TABLE(hh,head)                                                 \
145do {                                                                             \
146  (head)->hh.tbl = (UT_hash_table*)uthash_malloc(                                \
147                  sizeof(UT_hash_table));                                        \
148  if (!((head)->hh.tbl))  { uthash_fatal( "out of memory"); }                    \
149  memset((head)->hh.tbl, 0, sizeof(UT_hash_table));                              \
150  (head)->hh.tbl->tail = &((head)->hh);                                          \
151  (head)->hh.tbl->num_buckets = HASH_INITIAL_NUM_BUCKETS;                        \
152  (head)->hh.tbl->log2_num_buckets = HASH_INITIAL_NUM_BUCKETS_LOG2;              \
153  (head)->hh.tbl->hho = (char*)(&(head)->hh) - (char*)(head);                    \
154  (head)->hh.tbl->buckets = (UT_hash_bucket*)uthash_malloc(                      \
155          HASH_INITIAL_NUM_BUCKETS*sizeof(struct UT_hash_bucket));               \
156  if (! (head)->hh.tbl->buckets) { uthash_fatal( "out of memory"); }             \
157  memset((head)->hh.tbl->buckets, 0,                                             \
158          HASH_INITIAL_NUM_BUCKETS*sizeof(struct UT_hash_bucket));               \
159  HASH_BLOOM_MAKE((head)->hh.tbl);                                               \
160  (head)->hh.tbl->signature = HASH_SIGNATURE;                                    \
161} while(0)
162
163#define HASH_ADD(hh,head,fieldname,keylen_in,add)                                \
164        HASH_ADD_KEYPTR(hh,head,&((add)->fieldname),keylen_in,add)
165
166#define HASH_ADD_KEYPTR(hh,head,keyptr,keylen_in,add)                            \
167do {                                                                             \
168 unsigned _ha_bkt;                                                               \
169 (add)->hh.next = NULL;                                                          \
170 (add)->hh.key = (char*)keyptr;                                                  \
171 (add)->hh.keylen = (unsigned)keylen_in;                                                   \
172 if (!(head)) {                                                                  \
173    head = (add);                                                                \
174    (head)->hh.prev = NULL;                                                      \
175    HASH_MAKE_TABLE(hh,head);                                                    \
176 } else {                                                                        \
177    (head)->hh.tbl->tail->next = (add);                                          \
178    (add)->hh.prev = ELMT_FROM_HH((head)->hh.tbl, (head)->hh.tbl->tail);         \
179    (head)->hh.tbl->tail = &((add)->hh);                                         \
180 }                                                                               \
181 (head)->hh.tbl->num_items++;                                                    \
182 (add)->hh.tbl = (head)->hh.tbl;                                                 \
183 HASH_FCN(keyptr,keylen_in, (head)->hh.tbl->num_buckets,                         \
184         (add)->hh.hashv, _ha_bkt);                                              \
185 HASH_ADD_TO_BKT((head)->hh.tbl->buckets[_ha_bkt],&(add)->hh);                   \
186 HASH_BLOOM_ADD((head)->hh.tbl,(add)->hh.hashv);                                 \
187 HASH_EMIT_KEY(hh,head,keyptr,keylen_in);                                        \
188 HASH_FSCK(hh,head);                                                             \
189} while(0)
190
191#define HASH_TO_BKT( hashv, num_bkts, bkt )                                      \
192do {                                                                             \
193  bkt = ((hashv) & ((num_bkts) - 1));                                            \
194} while(0)
195
196/* delete "delptr" from the hash table.
197 * "the usual" patch-up process for the app-order doubly-linked-list.
198 * The use of _hd_hh_del below deserves special explanation.
199 * These used to be expressed using (delptr) but that led to a bug
200 * if someone used the same symbol for the head and deletee, like
201 *  HASH_DELETE(hh,users,users);
202 * We want that to work, but by changing the head (users) below
203 * we were forfeiting our ability to further refer to the deletee (users)
204 * in the patch-up process. Solution: use scratch space to
205 * copy the deletee pointer, then the latter references are via that
206 * scratch pointer rather than through the repointed (users) symbol.
207 */
208#define HASH_DELETE(hh,head,delptr)                                              \
209do {                                                                             \
210    unsigned _hd_bkt;                                                            \
211    struct UT_hash_handle *_hd_hh_del;                                           \
212    if ( ((delptr)->hh.prev == NULL) && ((delptr)->hh.next == NULL) )  {         \
213        uthash_free((head)->hh.tbl->buckets,                                     \
214                    (head)->hh.tbl->num_buckets*sizeof(struct UT_hash_bucket) ); \
215        HASH_BLOOM_FREE((head)->hh.tbl);                                         \
216        uthash_free((head)->hh.tbl, sizeof(UT_hash_table));                      \
217        head = NULL;                                                             \
218    } else {                                                                     \
219        _hd_hh_del = &((delptr)->hh);                                            \
220        if ((delptr) == ELMT_FROM_HH((head)->hh.tbl,(head)->hh.tbl->tail)) {     \
221            (head)->hh.tbl->tail =                                               \
222                (UT_hash_handle*)((ptrdiff_t)((delptr)->hh.prev) +               \
223                (head)->hh.tbl->hho);                                            \
224        }                                                                        \
225        if ((delptr)->hh.prev) {                                                 \
226            ((UT_hash_handle*)((ptrdiff_t)((delptr)->hh.prev) +                  \
227                    (head)->hh.tbl->hho))->next = (delptr)->hh.next;             \
228        } else {                                                                 \
229            DECLTYPE_ASSIGN(head,(delptr)->hh.next);                             \
230        }                                                                        \
231        if (_hd_hh_del->next) {                                                  \
232            ((UT_hash_handle*)((ptrdiff_t)_hd_hh_del->next +                     \
233                    (head)->hh.tbl->hho))->prev =                                \
234                    _hd_hh_del->prev;                                            \
235        }                                                                        \
236        HASH_TO_BKT( _hd_hh_del->hashv, (head)->hh.tbl->num_buckets, _hd_bkt);   \
237        HASH_DEL_IN_BKT(hh,(head)->hh.tbl->buckets[_hd_bkt], _hd_hh_del);        \
238        (head)->hh.tbl->num_items--;                                             \
239    }                                                                            \
240    HASH_FSCK(hh,head);                                                          \
241} while (0)
242
243
244/* convenience forms of HASH_FIND/HASH_ADD/HASH_DEL */
245#define HASH_FIND_STR(head,findstr,out)                                          \
246    HASH_FIND(hh,head,findstr,strlen(findstr),out)
247#define HASH_ADD_STR(head,strfield,add)                                          \
248    HASH_ADD(hh,head,strfield,strlen(add->strfield),add)
249#define HASH_FIND_INT(head,findint,out)                                          \
250    HASH_FIND(hh,head,findint,sizeof(int),out)
251#define HASH_ADD_INT(head,intfield,add)                                          \
252    HASH_ADD(hh,head,intfield,sizeof(int),add)
253#define HASH_FIND_PTR(head,findptr,out)                                          \
254    HASH_FIND(hh,head,findptr,sizeof(void *),out)
255#define HASH_ADD_PTR(head,ptrfield,add)                                          \
256    HASH_ADD(hh,head,ptrfield,sizeof(void *),add)
257#define HASH_DEL(head,delptr)                                                    \
258    HASH_DELETE(hh,head,delptr)
259
260/* HASH_FSCK checks hash integrity on every add/delete when HASH_DEBUG is defined.
261 * This is for uthash developer only; it compiles away if HASH_DEBUG isn't defined.
262 */
263#ifdef HASH_DEBUG
264#define HASH_OOPS(...) do { fprintf(stderr,__VA_ARGS__); exit(-1); } while (0)
265#define HASH_FSCK(hh,head)                                                       \
266do {                                                                             \
267    unsigned _bkt_i;                                                             \
268    unsigned _count, _bkt_count;                                                 \
269    char *_prev;                                                                 \
270    struct UT_hash_handle *_thh;                                                 \
271    if (head) {                                                                  \
272        _count = 0;                                                              \
273        for( _bkt_i = 0; _bkt_i < (head)->hh.tbl->num_buckets; _bkt_i++) {       \
274            _bkt_count = 0;                                                      \
275            _thh = (head)->hh.tbl->buckets[_bkt_i].hh_head;                      \
276            _prev = NULL;                                                        \
277            while (_thh) {                                                       \
278               if (_prev != (char*)(_thh->hh_prev)) {                            \
279                   HASH_OOPS("invalid hh_prev %p, actual %p\n",                  \
280                    _thh->hh_prev, _prev );                                      \
281               }                                                                 \
282               _bkt_count++;                                                     \
283               _prev = (char*)(_thh);                                            \
284               _thh = _thh->hh_next;                                             \
285            }                                                                    \
286            _count += _bkt_count;                                                \
287            if ((head)->hh.tbl->buckets[_bkt_i].count !=  _bkt_count) {          \
288               HASH_OOPS("invalid bucket count %d, actual %d\n",                 \
289                (head)->hh.tbl->buckets[_bkt_i].count, _bkt_count);              \
290            }                                                                    \
291        }                                                                        \
292        if (_count != (head)->hh.tbl->num_items) {                               \
293            HASH_OOPS("invalid hh item count %d, actual %d\n",                   \
294                (head)->hh.tbl->num_items, _count );                             \
295        }                                                                        \
296        /* traverse hh in app order; check next/prev integrity, count */         \
297        _count = 0;                                                              \
298        _prev = NULL;                                                            \
299        _thh =  &(head)->hh;                                                     \
300        while (_thh) {                                                           \
301           _count++;                                                             \
302           if (_prev !=(char*)(_thh->prev)) {                                    \
303              HASH_OOPS("invalid prev %p, actual %p\n",                          \
304                    _thh->prev, _prev );                                         \
305           }                                                                     \
306           _prev = (char*)ELMT_FROM_HH((head)->hh.tbl, _thh);                    \
307           _thh = ( _thh->next ?  (UT_hash_handle*)((char*)(_thh->next) +        \
308                                  (head)->hh.tbl->hho) : NULL );                 \
309        }                                                                        \
310        if (_count != (head)->hh.tbl->num_items) {                               \
311            HASH_OOPS("invalid app item count %d, actual %d\n",                  \
312                (head)->hh.tbl->num_items, _count );                             \
313        }                                                                        \
314    }                                                                            \
315} while (0)
316#else
317#define HASH_FSCK(hh,head)
318#endif
319
320/* When compiled with -DHASH_EMIT_KEYS, length-prefixed keys are emitted to
321 * the descriptor to which this macro is defined for tuning the hash function.
322 * The app can #include <unistd.h> to get the prototype for write(2). */
323#ifdef HASH_EMIT_KEYS
324#define HASH_EMIT_KEY(hh,head,keyptr,fieldlen)                                   \
325do {                                                                             \
326    unsigned _klen = fieldlen;                                                   \
327    write(HASH_EMIT_KEYS, &_klen, sizeof(_klen));                                \
328    write(HASH_EMIT_KEYS, keyptr, fieldlen);                                     \
329} while (0)
330#else
331#define HASH_EMIT_KEY(hh,head,keyptr,fieldlen)
332#endif
333
334/* default to Jenkin's hash unless overridden e.g. DHASH_FUNCTION=HASH_SAX */
335#ifdef HASH_FUNCTION
336#define HASH_FCN HASH_FUNCTION
337#else
338#define HASH_FCN HASH_JEN
339#endif
340
341/* The Bernstein hash function, used in Perl prior to v5.6 */
342#define HASH_BER(key,keylen,num_bkts,hashv,bkt)                                  \
343do {                                                                             \
344  unsigned _hb_keylen=keylen;                                                    \
345  char *_hb_key=(char*)(key);                                                    \
346  (hashv) = 0;                                                                   \
347  while (_hb_keylen--)  { (hashv) = ((hashv) * 33) + *_hb_key++; }               \
348  bkt = (hashv) & (num_bkts-1);                                                  \
349} while (0)
350
351
352/* SAX/FNV/OAT/JEN hash functions are macro variants of those listed at
353 * http://eternallyconfuzzled.com/tuts/algorithms/jsw_tut_hashing.aspx */
354#define HASH_SAX(key,keylen,num_bkts,hashv,bkt)                                  \
355do {                                                                             \
356  unsigned _sx_i;                                                                \
357  char *_hs_key=(char*)(key);                                                    \
358  hashv = 0;                                                                     \
359  for(_sx_i=0; _sx_i < keylen; _sx_i++)                                          \
360      hashv ^= (hashv << 5) + (hashv >> 2) + _hs_key[_sx_i];                     \
361  bkt = hashv & (num_bkts-1);                                                    \
362} while (0)
363
364#define HASH_FNV(key,keylen,num_bkts,hashv,bkt)                                  \
365do {                                                                             \
366  unsigned _fn_i;                                                                \
367  char *_hf_key=(char*)(key);                                                    \
368  hashv = 2166136261UL;                                                          \
369  for(_fn_i=0; _fn_i < keylen; _fn_i++)                                          \
370      hashv = (hashv * 16777619) ^ _hf_key[_fn_i];                               \
371  bkt = hashv & (num_bkts-1);                                                    \
372} while(0)
373
374#define HASH_OAT(key,keylen,num_bkts,hashv,bkt)                                  \
375do {                                                                             \
376  unsigned _ho_i;                                                                \
377  char *_ho_key=(char*)(key);                                                    \
378  hashv = 0;                                                                     \
379  for(_ho_i=0; _ho_i < keylen; _ho_i++) {                                        \
380      hashv += _ho_key[_ho_i];                                                   \
381      hashv += (hashv << 10);                                                    \
382      hashv ^= (hashv >> 6);                                                     \
383  }                                                                              \
384  hashv += (hashv << 3);                                                         \
385  hashv ^= (hashv >> 11);                                                        \
386  hashv += (hashv << 15);                                                        \
387  bkt = hashv & (num_bkts-1);                                                    \
388} while(0)
389
390#define HASH_JEN_MIX(a,b,c)                                                      \
391do {                                                                             \
392  a -= b; a -= c; a ^= ( c >> 13 );                                              \
393  b -= c; b -= a; b ^= ( a << 8 );                                               \
394  c -= a; c -= b; c ^= ( b >> 13 );                                              \
395  a -= b; a -= c; a ^= ( c >> 12 );                                              \
396  b -= c; b -= a; b ^= ( a << 16 );                                              \
397  c -= a; c -= b; c ^= ( b >> 5 );                                               \
398  a -= b; a -= c; a ^= ( c >> 3 );                                               \
399  b -= c; b -= a; b ^= ( a << 10 );                                              \
400  c -= a; c -= b; c ^= ( b >> 15 );                                              \
401} while (0)
402
403#define HASH_JEN(key,keylen,num_bkts,hashv,bkt)                                  \
404do {                                                                             \
405  unsigned _hj_i,_hj_j,_hj_k;                                                    \
406  char *_hj_key=(char*)(key);                                                    \
407  hashv = 0xfeedbeef;                                                            \
408  _hj_i = _hj_j = 0x9e3779b9;                                                    \
409  _hj_k = (unsigned)keylen;                                                                \
410  while (_hj_k >= 12) {                                                          \
411    _hj_i +=    (_hj_key[0] + ( (unsigned)_hj_key[1] << 8 )                      \
412        + ( (unsigned)_hj_key[2] << 16 )                                         \
413        + ( (unsigned)_hj_key[3] << 24 ) );                                      \
414    _hj_j +=    (_hj_key[4] + ( (unsigned)_hj_key[5] << 8 )                      \
415        + ( (unsigned)_hj_key[6] << 16 )                                         \
416        + ( (unsigned)_hj_key[7] << 24 ) );                                      \
417    hashv += (_hj_key[8] + ( (unsigned)_hj_key[9] << 8 )                         \
418        + ( (unsigned)_hj_key[10] << 16 )                                        \
419        + ( (unsigned)_hj_key[11] << 24 ) );                                     \
420                                                                                 \
421     HASH_JEN_MIX(_hj_i, _hj_j, hashv);                                          \
422                                                                                 \
423     _hj_key += 12;                                                              \
424     _hj_k -= 12;                                                                \
425  }                                                                              \
426  hashv += keylen;                                                               \
427  switch ( _hj_k ) {                                                             \
428     case 11: hashv += ( (unsigned)_hj_key[10] << 24 );                          \
429     case 10: hashv += ( (unsigned)_hj_key[9] << 16 );                           \
430     case 9:  hashv += ( (unsigned)_hj_key[8] << 8 );                            \
431     case 8:  _hj_j += ( (unsigned)_hj_key[7] << 24 );                           \
432     case 7:  _hj_j += ( (unsigned)_hj_key[6] << 16 );                           \
433     case 6:  _hj_j += ( (unsigned)_hj_key[5] << 8 );                            \
434     case 5:  _hj_j += _hj_key[4];                                               \
435     case 4:  _hj_i += ( (unsigned)_hj_key[3] << 24 );                           \
436     case 3:  _hj_i += ( (unsigned)_hj_key[2] << 16 );                           \
437     case 2:  _hj_i += ( (unsigned)_hj_key[1] << 8 );                            \
438     case 1:  _hj_i += _hj_key[0];                                               \
439  }                                                                              \
440  HASH_JEN_MIX(_hj_i, _hj_j, hashv);                                             \
441  bkt = hashv & (num_bkts-1);                                                    \
442} while(0)
443
444/* The Paul Hsieh hash function */
445#undef get16bits
446#if (defined(__GNUC__) && defined(__i386__)) || defined(__WATCOMC__)             \
447  || defined(_MSC_VER) || defined (__BORLANDC__) || defined (__TURBOC__)
448#define get16bits(d) (*((const uint16_t *) (d)))
449#endif
450
451#if !defined (get16bits)
452#define get16bits(d) ((((uint32_t)(((const uint8_t *)(d))[1])) << 8)             \
453                       +(uint32_t)(((const uint8_t *)(d))[0]) )
454#endif
455#define HASH_SFH(key,keylen,num_bkts,hashv,bkt)                                  \
456do {                                                                             \
457  char *_sfh_key=(char*)(key);                                                   \
458  uint32_t _sfh_tmp, _sfh_len = keylen;                                          \
459                                                                                 \
460  int _sfh_rem = _sfh_len & 3;                                                   \
461  _sfh_len >>= 2;                                                                \
462  hashv = 0xcafebabe;                                                            \
463                                                                                 \
464  /* Main loop */                                                                \
465  for (;_sfh_len > 0; _sfh_len--) {                                              \
466    hashv    += get16bits (_sfh_key);                                            \
467    _sfh_tmp       = (get16bits (_sfh_key+2) << 11) ^ hashv;                     \
468    hashv     = (hashv << 16) ^ _sfh_tmp;                                        \
469    _sfh_key += 2*sizeof (uint16_t);                                             \
470    hashv    += hashv >> 11;                                                     \
471  }                                                                              \
472                                                                                 \
473  /* Handle end cases */                                                         \
474  switch (_sfh_rem) {                                                            \
475    case 3: hashv += get16bits (_sfh_key);                                       \
476            hashv ^= hashv << 16;                                                \
477            hashv ^= _sfh_key[sizeof (uint16_t)] << 18;                          \
478            hashv += hashv >> 11;                                                \
479            break;                                                               \
480    case 2: hashv += get16bits (_sfh_key);                                       \
481            hashv ^= hashv << 11;                                                \
482            hashv += hashv >> 17;                                                \
483            break;                                                               \
484    case 1: hashv += *_sfh_key;                                                  \
485            hashv ^= hashv << 10;                                                \
486            hashv += hashv >> 1;                                                 \
487  }                                                                              \
488                                                                                 \
489    /* Force "avalanching" of final 127 bits */                                  \
490    hashv ^= hashv << 3;                                                         \
491    hashv += hashv >> 5;                                                         \
492    hashv ^= hashv << 4;                                                         \
493    hashv += hashv >> 17;                                                        \
494    hashv ^= hashv << 25;                                                        \
495    hashv += hashv >> 6;                                                         \
496    bkt = hashv & (num_bkts-1);                                                  \
497} while(0)
498
499#ifdef HASH_USING_NO_STRICT_ALIASING
500/* The MurmurHash exploits some CPU's (x86,x86_64) tolerance for unaligned reads.
501 * For other types of CPU's (e.g. Sparc) an unaligned read causes a bus error.
502 * MurmurHash uses the faster approach only on CPU's where we know it's safe.
503 *
504 * Note the preprocessor built-in defines can be emitted using:
505 *
506 *   gcc -m64 -dM -E - < /dev/null                  (on gcc)
507 *   cc -## a.c (where a.c is a simple test file)   (Sun Studio)
508 */
509#if (defined(__i386__) || defined(__x86_64__)  || defined(_M_IX86))
510#define MUR_GETBLOCK(p,i) p[i]
511#else /* non intel */
512#define MUR_PLUS0_ALIGNED(p) (((unsigned long)p & 0x3) == 0)
513#define MUR_PLUS1_ALIGNED(p) (((unsigned long)p & 0x3) == 1)
514#define MUR_PLUS2_ALIGNED(p) (((unsigned long)p & 0x3) == 2)
515#define MUR_PLUS3_ALIGNED(p) (((unsigned long)p & 0x3) == 3)
516#define WP(p) ((uint32_t*)((unsigned long)(p) & ~3UL))
517#if (defined(__BIG_ENDIAN__) || defined(SPARC) || defined(__ppc__) || defined(__ppc64__))
518#define MUR_THREE_ONE(p) ((((*WP(p))&0x00ffffff) << 8) | (((*(WP(p)+1))&0xff000000) >> 24))
519#define MUR_TWO_TWO(p)   ((((*WP(p))&0x0000ffff) <<16) | (((*(WP(p)+1))&0xffff0000) >> 16))
520#define MUR_ONE_THREE(p) ((((*WP(p))&0x000000ff) <<24) | (((*(WP(p)+1))&0xffffff00) >>  8))
521#else /* assume little endian non-intel */
522#define MUR_THREE_ONE(p) ((((*WP(p))&0xffffff00) >> 8) | (((*(WP(p)+1))&0x000000ff) << 24))
523#define MUR_TWO_TWO(p)   ((((*WP(p))&0xffff0000) >>16) | (((*(WP(p)+1))&0x0000ffff) << 16))
524#define MUR_ONE_THREE(p) ((((*WP(p))&0xff000000) >>24) | (((*(WP(p)+1))&0x00ffffff) <<  8))
525#endif
526#define MUR_GETBLOCK(p,i) (MUR_PLUS0_ALIGNED(p) ? ((p)[i]) :           \
527                            (MUR_PLUS1_ALIGNED(p) ? MUR_THREE_ONE(p) : \
528                             (MUR_PLUS2_ALIGNED(p) ? MUR_TWO_TWO(p) :  \
529                                                      MUR_ONE_THREE(p))))
530#endif
531#define MUR_ROTL32(x,r) (((x) << (r)) | ((x) >> (32 - (r))))
532#define MUR_FMIX(_h) \
533do {                 \
534  _h ^= _h >> 16;    \
535  _h *= 0x85ebca6b;  \
536  _h ^= _h >> 13;    \
537  _h *= 0xc2b2ae35l; \
538  _h ^= _h >> 16;    \
539} while(0)
540
541#define HASH_MUR(key,keylen,num_bkts,hashv,bkt)                        \
542do {                                                                   \
543  const uint8_t *_mur_data = (const uint8_t*)(key);                    \
544  const int _mur_nblocks = (keylen) / 4;                               \
545  uint32_t _mur_h1 = 0xf88D5353;                                       \
546  uint32_t _mur_c1 = 0xcc9e2d51;                                       \
547  uint32_t _mur_c2 = 0x1b873593;                                       \
548  uint32_t _mur_k1 = 0;                                                \
549  const uint8_t *_mur_tail;                                            \
550  const uint32_t *_mur_blocks = (const uint32_t*)(_mur_data+_mur_nblocks*4); \
551  int _mur_i;                                                          \
552  for(_mur_i = -_mur_nblocks; _mur_i; _mur_i++) {                      \
553    _mur_k1 = MUR_GETBLOCK(_mur_blocks,_mur_i);                        \
554    _mur_k1 *= _mur_c1;                                                \
555    _mur_k1 = MUR_ROTL32(_mur_k1,15);                                  \
556    _mur_k1 *= _mur_c2;                                                \
557                                                                       \
558    _mur_h1 ^= _mur_k1;                                                \
559    _mur_h1 = MUR_ROTL32(_mur_h1,13);                                  \
560    _mur_h1 = _mur_h1*5+0xe6546b64;                                    \
561  }                                                                    \
562  _mur_tail = (const uint8_t*)(_mur_data + _mur_nblocks*4);            \
563  _mur_k1=0;                                                           \
564  switch((keylen) & 3) {                                               \
565    case 3: _mur_k1 ^= _mur_tail[2] << 16;                             \
566    case 2: _mur_k1 ^= _mur_tail[1] << 8;                              \
567    case 1: _mur_k1 ^= _mur_tail[0];                                   \
568    _mur_k1 *= _mur_c1;                                                \
569    _mur_k1 = MUR_ROTL32(_mur_k1,15);                                  \
570    _mur_k1 *= _mur_c2;                                                \
571    _mur_h1 ^= _mur_k1;                                                \
572  }                                                                    \
573  _mur_h1 ^= (keylen);                                                 \
574  MUR_FMIX(_mur_h1);                                                   \
575  hashv = _mur_h1;                                                     \
576  bkt = hashv & (num_bkts-1);                                          \
577} while(0)
578#endif  /* HASH_USING_NO_STRICT_ALIASING */
579
580/* key comparison function; return 0 if keys equal */
581#define HASH_KEYCMP(a,b,len) memcmp(a,b,len)
582
583/* iterate over items in a known bucket to find desired item */
584#define HASH_FIND_IN_BKT(tbl,hh,head,keyptr,keylen_in,out)                       \
585do {                                                                             \
586 if (head.hh_head) DECLTYPE_ASSIGN(out,ELMT_FROM_HH(tbl,head.hh_head));          \
587 else out=NULL;                                                                  \
588 while (out) {                                                                   \
589    if ((out)->hh.keylen == keylen_in) {                                           \
590        if ((HASH_KEYCMP((out)->hh.key,keyptr,keylen_in)) == 0) break;             \
591    }                                                                            \
592    if ((out)->hh.hh_next) DECLTYPE_ASSIGN(out,ELMT_FROM_HH(tbl,(out)->hh.hh_next)); \
593    else out = NULL;                                                             \
594 }                                                                               \
595} while(0)
596
597/* add an item to a bucket  */
598#define HASH_ADD_TO_BKT(head,addhh)                                              \
599do {                                                                             \
600 head.count++;                                                                   \
601 (addhh)->hh_next = head.hh_head;                                                \
602 (addhh)->hh_prev = NULL;                                                        \
603 if (head.hh_head) { (head).hh_head->hh_prev = (addhh); }                        \
604 (head).hh_head=addhh;                                                           \
605 if (head.count >= ((head.expand_mult+1) * HASH_BKT_CAPACITY_THRESH)             \
606     && (addhh)->tbl->noexpand != 1) {                                           \
607       HASH_EXPAND_BUCKETS((addhh)->tbl);                                        \
608 }                                                                               \
609} while(0)
610
611/* remove an item from a given bucket */
612#define HASH_DEL_IN_BKT(hh,head,hh_del)                                          \
613    (head).count--;                                                              \
614    if ((head).hh_head == hh_del) {                                              \
615      (head).hh_head = hh_del->hh_next;                                          \
616    }                                                                            \
617    if (hh_del->hh_prev) {                                                       \
618        hh_del->hh_prev->hh_next = hh_del->hh_next;                              \
619    }                                                                            \
620    if (hh_del->hh_next) {                                                       \
621        hh_del->hh_next->hh_prev = hh_del->hh_prev;                              \
622    }
623
624/* Bucket expansion has the effect of doubling the number of buckets
625 * and redistributing the items into the new buckets. Ideally the
626 * items will distribute more or less evenly into the new buckets
627 * (the extent to which this is true is a measure of the quality of
628 * the hash function as it applies to the key domain).
629 *
630 * With the items distributed into more buckets, the chain length
631 * (item count) in each bucket is reduced. Thus by expanding buckets
632 * the hash keeps a bound on the chain length. This bounded chain
633 * length is the essence of how a hash provides constant time lookup.
634 *
635 * The calculation of tbl->ideal_chain_maxlen below deserves some
636 * explanation. First, keep in mind that we're calculating the ideal
637 * maximum chain length based on the *new* (doubled) bucket count.
638 * In fractions this is just n/b (n=number of items,b=new num buckets).
639 * Since the ideal chain length is an integer, we want to calculate
640 * ceil(n/b). We don't depend on floating point arithmetic in this
641 * hash, so to calculate ceil(n/b) with integers we could write
642 *
643 *      ceil(n/b) = (n/b) + ((n%b)?1:0)
644 *
645 * and in fact a previous version of this hash did just that.
646 * But now we have improved things a bit by recognizing that b is
647 * always a power of two. We keep its base 2 log handy (call it lb),
648 * so now we can write this with a bit shift and logical AND:
649 *
650 *      ceil(n/b) = (n>>lb) + ( (n & (b-1)) ? 1:0)
651 *
652 */
653#define HASH_EXPAND_BUCKETS(tbl)                                                 \
654do {                                                                             \
655    unsigned _he_bkt;                                                            \
656    unsigned _he_bkt_i;                                                          \
657    struct UT_hash_handle *_he_thh, *_he_hh_nxt;                                 \
658    UT_hash_bucket *_he_new_buckets, *_he_newbkt;                                \
659    _he_new_buckets = (UT_hash_bucket*)uthash_malloc(                            \
660             2 * tbl->num_buckets * sizeof(struct UT_hash_bucket));              \
661    if (!_he_new_buckets) { uthash_fatal( "out of memory"); }                    \
662    memset(_he_new_buckets, 0,                                                   \
663            2 * tbl->num_buckets * sizeof(struct UT_hash_bucket));               \
664    tbl->ideal_chain_maxlen =                                                    \
665       (tbl->num_items >> (tbl->log2_num_buckets+1)) +                           \
666       ((tbl->num_items & ((tbl->num_buckets*2)-1)) ? 1 : 0);                    \
667    tbl->nonideal_items = 0;                                                     \
668    for(_he_bkt_i = 0; _he_bkt_i < tbl->num_buckets; _he_bkt_i++)                \
669    {                                                                            \
670        _he_thh = tbl->buckets[ _he_bkt_i ].hh_head;                             \
671        while (_he_thh) {                                                        \
672           _he_hh_nxt = _he_thh->hh_next;                                        \
673           HASH_TO_BKT( _he_thh->hashv, tbl->num_buckets*2, _he_bkt);            \
674           _he_newbkt = &(_he_new_buckets[ _he_bkt ]);                           \
675           if (++(_he_newbkt->count) > tbl->ideal_chain_maxlen) {                \
676             tbl->nonideal_items++;                                              \
677             _he_newbkt->expand_mult = _he_newbkt->count /                       \
678                                        tbl->ideal_chain_maxlen;                 \
679           }                                                                     \
680           _he_thh->hh_prev = NULL;                                              \
681           _he_thh->hh_next = _he_newbkt->hh_head;                               \
682           if (_he_newbkt->hh_head) _he_newbkt->hh_head->hh_prev =               \
683                _he_thh;                                                         \
684           _he_newbkt->hh_head = _he_thh;                                        \
685           _he_thh = _he_hh_nxt;                                                 \
686        }                                                                        \
687    }                                                                            \
688    uthash_free( tbl->buckets, tbl->num_buckets*sizeof(struct UT_hash_bucket) ); \
689    tbl->num_buckets *= 2;                                                       \
690    tbl->log2_num_buckets++;                                                     \
691    tbl->buckets = _he_new_buckets;                                              \
692    tbl->ineff_expands = (tbl->nonideal_items > (tbl->num_items >> 1)) ?         \
693        (tbl->ineff_expands+1) : 0;                                              \
694    if (tbl->ineff_expands > 1) {                                                \
695        tbl->noexpand=1;                                                         \
696        uthash_noexpand_fyi(tbl);                                                \
697    }                                                                            \
698    uthash_expand_fyi(tbl);                                                      \
699} while(0)
700
701
702/* This is an adaptation of Simon Tatham's O(n log(n)) mergesort */
703/* Note that HASH_SORT assumes the hash handle name to be hh.
704 * HASH_SRT was added to allow the hash handle name to be passed in. */
705#define HASH_SORT(head,cmpfcn) HASH_SRT(hh,head,cmpfcn)
706#define HASH_SRT(hh,head,cmpfcn)                                                 \
707do {                                                                             \
708  unsigned _hs_i;                                                                \
709  unsigned _hs_looping,_hs_nmerges,_hs_insize,_hs_psize,_hs_qsize;               \
710  struct UT_hash_handle *_hs_p, *_hs_q, *_hs_e, *_hs_list, *_hs_tail;            \
711  if (head) {                                                                    \
712      _hs_insize = 1;                                                            \
713      _hs_looping = 1;                                                           \
714      _hs_list = &((head)->hh);                                                  \
715      while (_hs_looping) {                                                      \
716          _hs_p = _hs_list;                                                      \
717          _hs_list = NULL;                                                       \
718          _hs_tail = NULL;                                                       \
719          _hs_nmerges = 0;                                                       \
720          while (_hs_p) {                                                        \
721              _hs_nmerges++;                                                     \
722              _hs_q = _hs_p;                                                     \
723              _hs_psize = 0;                                                     \
724              for ( _hs_i = 0; _hs_i  < _hs_insize; _hs_i++ ) {                  \
725                  _hs_psize++;                                                   \
726                  _hs_q = (UT_hash_handle*)((_hs_q->next) ?                      \
727                          ((void*)((char*)(_hs_q->next) +                        \
728                          (head)->hh.tbl->hho)) : NULL);                         \
729                  if (! (_hs_q) ) break;                                         \
730              }                                                                  \
731              _hs_qsize = _hs_insize;                                            \
732              while ((_hs_psize > 0) || ((_hs_qsize > 0) && _hs_q )) {           \
733                  if (_hs_psize == 0) {                                          \
734                      _hs_e = _hs_q;                                             \
735                      _hs_q = (UT_hash_handle*)((_hs_q->next) ?                  \
736                              ((void*)((char*)(_hs_q->next) +                    \
737                              (head)->hh.tbl->hho)) : NULL);                     \
738                      _hs_qsize--;                                               \
739                  } else if ( (_hs_qsize == 0) || !(_hs_q) ) {                   \
740                      _hs_e = _hs_p;                                             \
741                      _hs_p = (UT_hash_handle*)((_hs_p->next) ?                  \
742                              ((void*)((char*)(_hs_p->next) +                    \
743                              (head)->hh.tbl->hho)) : NULL);                     \
744                      _hs_psize--;                                               \
745                  } else if ((                                                   \
746                      cmpfcn(DECLTYPE(head)(ELMT_FROM_HH((head)->hh.tbl,_hs_p)), \
747                             DECLTYPE(head)(ELMT_FROM_HH((head)->hh.tbl,_hs_q))) \
748                             ) <= 0) {                                           \
749                      _hs_e = _hs_p;                                             \
750                      _hs_p = (UT_hash_handle*)((_hs_p->next) ?                  \
751                              ((void*)((char*)(_hs_p->next) +                    \
752                              (head)->hh.tbl->hho)) : NULL);                     \
753                      _hs_psize--;                                               \
754                  } else {                                                       \
755                      _hs_e = _hs_q;                                             \
756                      _hs_q = (UT_hash_handle*)((_hs_q->next) ?                  \
757                              ((void*)((char*)(_hs_q->next) +                    \
758                              (head)->hh.tbl->hho)) : NULL);                     \
759                      _hs_qsize--;                                               \
760                  }                                                              \
761                  if ( _hs_tail ) {                                              \
762                      _hs_tail->next = ((_hs_e) ?                                \
763                            ELMT_FROM_HH((head)->hh.tbl,_hs_e) : NULL);          \
764                  } else {                                                       \
765                      _hs_list = _hs_e;                                          \
766                  }                                                              \
767                  _hs_e->prev = ((_hs_tail) ?                                    \
768                     ELMT_FROM_HH((head)->hh.tbl,_hs_tail) : NULL);              \
769                  _hs_tail = _hs_e;                                              \
770              }                                                                  \
771              _hs_p = _hs_q;                                                     \
772          }                                                                      \
773          _hs_tail->next = NULL;                                                 \
774          if ( _hs_nmerges <= 1 ) {                                              \
775              _hs_looping=0;                                                     \
776              (head)->hh.tbl->tail = _hs_tail;                                   \
777              DECLTYPE_ASSIGN(head,ELMT_FROM_HH((head)->hh.tbl, _hs_list));      \
778          }                                                                      \
779          _hs_insize *= 2;                                                       \
780      }                                                                          \
781      HASH_FSCK(hh,head);                                                        \
782 }                                                                               \
783} while (0)
784
785/* This function selects items from one hash into another hash.
786 * The end result is that the selected items have dual presence
787 * in both hashes. There is no copy of the items made; rather
788 * they are added into the new hash through a secondary hash
789 * hash handle that must be present in the structure. */
790#define HASH_SELECT(hh_dst, dst, hh_src, src, cond)                              \
791do {                                                                             \
792  unsigned _src_bkt, _dst_bkt;                                                   \
793  void *_last_elt=NULL, *_elt;                                                   \
794  UT_hash_handle *_src_hh, *_dst_hh, *_last_elt_hh=NULL;                         \
795  ptrdiff_t _dst_hho = ((char*)(&(dst)->hh_dst) - (char*)(dst));                 \
796  if (src) {                                                                     \
797    for(_src_bkt=0; _src_bkt < (src)->hh_src.tbl->num_buckets; _src_bkt++) {     \
798      for(_src_hh = (src)->hh_src.tbl->buckets[_src_bkt].hh_head;                \
799          _src_hh;                                                               \
800          _src_hh = _src_hh->hh_next) {                                          \
801          _elt = ELMT_FROM_HH((src)->hh_src.tbl, _src_hh);                       \
802          if (cond(_elt)) {                                                      \
803            _dst_hh = (UT_hash_handle*)(((char*)_elt) + _dst_hho);               \
804            _dst_hh->key = _src_hh->key;                                         \
805            _dst_hh->keylen = _src_hh->keylen;                                   \
806            _dst_hh->hashv = _src_hh->hashv;                                     \
807            _dst_hh->prev = _last_elt;                                           \
808            _dst_hh->next = NULL;                                                \
809            if (_last_elt_hh) { _last_elt_hh->next = _elt; }                     \
810            if (!dst) {                                                          \
811              DECLTYPE_ASSIGN(dst,_elt);                                         \
812              HASH_MAKE_TABLE(hh_dst,dst);                                       \
813            } else {                                                             \
814              _dst_hh->tbl = (dst)->hh_dst.tbl;                                  \
815            }                                                                    \
816            HASH_TO_BKT(_dst_hh->hashv, _dst_hh->tbl->num_buckets, _dst_bkt);    \
817            HASH_ADD_TO_BKT(_dst_hh->tbl->buckets[_dst_bkt],_dst_hh);            \
818            (dst)->hh_dst.tbl->num_items++;                                      \
819            _last_elt = _elt;                                                    \
820            _last_elt_hh = _dst_hh;                                              \
821          }                                                                      \
822      }                                                                          \
823    }                                                                            \
824  }                                                                              \
825  HASH_FSCK(hh_dst,dst);                                                         \
826} while (0)
827
828#define HASH_CLEAR(hh,head)                                                      \
829do {                                                                             \
830  if (head) {                                                                    \
831    uthash_free((head)->hh.tbl->buckets,                                         \
832                (head)->hh.tbl->num_buckets*sizeof(struct UT_hash_bucket));      \
833    HASH_BLOOM_FREE((head)->hh.tbl);                                             \
834    uthash_free((head)->hh.tbl, sizeof(UT_hash_table));                          \
835    (head)=NULL;                                                                 \
836  }                                                                              \
837} while(0)
838
839#ifdef NO_DECLTYPE
840#define HASH_ITER(hh,head,el,tmp)                                                \
841for((el)=(head), (*(char**)(&(tmp)))=(char*)((head)?(head)->hh.next:NULL);       \
842  el; (el)=(tmp),(*(char**)(&(tmp)))=(char*)((tmp)?(tmp)->hh.next:NULL))
843#else
844#define HASH_ITER(hh,head,el,tmp)                                                \
845for((el)=(head),(tmp)=DECLTYPE(el)((head)?(head)->hh.next:NULL);                 \
846  el; (el)=(tmp),(tmp)=DECLTYPE(el)((tmp)?(tmp)->hh.next:NULL))
847#endif
848
849/* obtain a count of items in the hash */
850#define HASH_COUNT(head) HASH_CNT(hh,head)
851#define HASH_CNT(hh,head) ((head)?((head)->hh.tbl->num_items):0)
852
853typedef struct UT_hash_bucket {
854   struct UT_hash_handle *hh_head;
855   unsigned count;
856
857   /* expand_mult is normally set to 0. In this situation, the max chain length
858    * threshold is enforced at its default value, HASH_BKT_CAPACITY_THRESH. (If
859    * the bucket's chain exceeds this length, bucket expansion is triggered).
860    * However, setting expand_mult to a non-zero value delays bucket expansion
861    * (that would be triggered by additions to this particular bucket)
862    * until its chain length reaches a *multiple* of HASH_BKT_CAPACITY_THRESH.
863    * (The multiplier is simply expand_mult+1). The whole idea of this
864    * multiplier is to reduce bucket expansions, since they are expensive, in
865    * situations where we know that a particular bucket tends to be overused.
866    * It is better to let its chain length grow to a longer yet-still-bounded
867    * value, than to do an O(n) bucket expansion too often.
868    */
869   unsigned expand_mult;
870
871} UT_hash_bucket;
872
873/* random signature used only to find hash tables in external analysis */
874#define HASH_SIGNATURE 0xa0111fe1
875#define HASH_BLOOM_SIGNATURE 0xb12220f2
876
877typedef struct UT_hash_table {
878   UT_hash_bucket *buckets;
879   unsigned num_buckets, log2_num_buckets;
880   unsigned num_items;
881   struct UT_hash_handle *tail; /* tail hh in app order, for fast append    */
882   ptrdiff_t hho; /* hash handle offset (byte pos of hash handle in element */
883
884   /* in an ideal situation (all buckets used equally), no bucket would have
885    * more than ceil(#items/#buckets) items. that's the ideal chain length. */
886   unsigned ideal_chain_maxlen;
887
888   /* nonideal_items is the number of items in the hash whose chain position
889    * exceeds the ideal chain maxlen. these items pay the penalty for an uneven
890    * hash distribution; reaching them in a chain traversal takes >ideal steps */
891   unsigned nonideal_items;
892
893   /* ineffective expands occur when a bucket doubling was performed, but
894    * afterward, more than half the items in the hash had nonideal chain
895    * positions. If this happens on two consecutive expansions we inhibit any
896    * further expansion, as it's not helping; this happens when the hash
897    * function isn't a good fit for the key domain. When expansion is inhibited
898    * the hash will still work, albeit no longer in constant time. */
899   unsigned ineff_expands, noexpand;
900
901   uint32_t signature; /* used only to find hash tables in external analysis */
902#ifdef HASH_BLOOM
903   uint32_t bloom_sig; /* used only to test bloom exists in external analysis */
904   uint8_t *bloom_bv;
905   char bloom_nbits;
906#endif
907
908} UT_hash_table;
909
910typedef struct UT_hash_handle {
911   struct UT_hash_table *tbl;
912   void *prev;                       /* prev element in app order      */
913   void *next;                       /* next element in app order      */
914   struct UT_hash_handle *hh_prev;   /* previous hh in bucket order    */
915   struct UT_hash_handle *hh_next;   /* next hh in bucket order        */
916   void *key;                        /* ptr to enclosing struct's key  */
917   unsigned keylen;                  /* enclosing struct's key len     */
918   unsigned hashv;                   /* result of hash-fcn(key)        */
919} UT_hash_handle;
920
921#endif /* UTHASH_H */
922