tor: container.h Source File

00001 /* Copyright (c) 2003-2004, Roger Dingledine
00002  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
00003  * Copyright (c) 2007-2010, The Tor Project, Inc. */
00004 /* See LICENSE for licensing information */
00005 
00006 #ifndef _TOR_CONTAINER_H
00007 #define _TOR_CONTAINER_H
00008 
00009 #include "util.h"
00010 
00017 typedef struct smartlist_t {
00022   void **list;
00023   int num_used;
00024   int capacity;
00025 } smartlist_t;
00026 
00027 smartlist_t *smartlist_create(void);
00028 void smartlist_free(smartlist_t *sl);
00029 void smartlist_clear(smartlist_t *sl);
00030 void smartlist_add(smartlist_t *sl, void *element);
00031 void smartlist_add_all(smartlist_t *sl, const smartlist_t *s2);
00032 void smartlist_remove(smartlist_t *sl, const void *element);
00033 void *smartlist_pop_last(smartlist_t *sl);
00034 void smartlist_reverse(smartlist_t *sl);
00035 void smartlist_string_remove(smartlist_t *sl, const char *element);
00036 int smartlist_isin(const smartlist_t *sl, const void *element) ATTR_PURE;
00037 int smartlist_string_isin(const smartlist_t *sl, const char *element)
00038   ATTR_PURE;
00039 int smartlist_string_pos(const smartlist_t *, const char *elt) ATTR_PURE;
00040 int smartlist_string_isin_case(const smartlist_t *sl, const char *element)
00041   ATTR_PURE;
00042 int smartlist_string_num_isin(const smartlist_t *sl, int num) ATTR_PURE;
00043 int smartlist_digest_isin(const smartlist_t *sl, const char *element)
00044   ATTR_PURE;
00045 int smartlist_overlap(const smartlist_t *sl1, const smartlist_t *sl2)
00046   ATTR_PURE;
00047 void smartlist_intersect(smartlist_t *sl1, const smartlist_t *sl2);
00048 void smartlist_subtract(smartlist_t *sl1, const smartlist_t *sl2);
00049 
00050 /* smartlist_choose() is defined in crypto.[ch] */
00051 #ifdef DEBUG_SMARTLIST
00052 
00054 static INLINE int smartlist_len(const smartlist_t *sl) ATTR_PURE;
00055 static INLINE int smartlist_len(const smartlist_t *sl) {
00056   tor_assert(sl);
00057   return (sl)->num_used;
00058 }
00061 static INLINE void *smartlist_get(const smartlist_t *sl, int idx) ATTR_PURE;
00062 static INLINE void *smartlist_get(const smartlist_t *sl, int idx) {
00063   tor_assert(sl);
00064   tor_assert(idx>=0);
00065   tor_assert(sl->num_used > idx);
00066   return sl->list[idx];
00067 }
00068 static INLINE void smartlist_set(smartlist_t *sl, int idx, void *val) {
00069   tor_assert(sl);
00070   tor_assert(idx>=0);
00071   tor_assert(sl->num_used > idx);
00072   sl->list[idx] = val;
00073 }
00074 #else
00075 #define smartlist_len(sl) ((sl)->num_used)
00076 #define smartlist_get(sl, idx) ((sl)->list[idx])
00077 #define smartlist_set(sl, idx, val) ((sl)->list[idx] = (val))
00078 #endif
00079 
00082 static INLINE void smartlist_swap(smartlist_t *sl, int idx1, int idx2)
00083 {
00084   if (idx1 != idx2) {
00085     void *elt = smartlist_get(sl, idx1);
00086     smartlist_set(sl, idx1, smartlist_get(sl, idx2));
00087     smartlist_set(sl, idx2, elt);
00088   }
00089 }
00090 
00091 void smartlist_del(smartlist_t *sl, int idx);
00092 void smartlist_del_keeporder(smartlist_t *sl, int idx);
00093 void smartlist_insert(smartlist_t *sl, int idx, void *val);
00094 void smartlist_sort(smartlist_t *sl,
00095                     int (*compare)(const void **a, const void **b));
00096 void *smartlist_get_most_frequent(const smartlist_t *sl,
00097                     int (*compare)(const void **a, const void **b));
00098 void smartlist_uniq(smartlist_t *sl,
00099                     int (*compare)(const void **a, const void **b),
00100                     void (*free_fn)(void *elt));
00101 
00102 void smartlist_sort_strings(smartlist_t *sl);
00103 void smartlist_sort_digests(smartlist_t *sl);
00104 void smartlist_sort_digests256(smartlist_t *sl);
00105 
00106 char *smartlist_get_most_frequent_string(smartlist_t *sl);
00107 char *smartlist_get_most_frequent_digest256(smartlist_t *sl);
00108 
00109 void smartlist_uniq_strings(smartlist_t *sl);
00110 void smartlist_uniq_digests(smartlist_t *sl);
00111 void smartlist_uniq_digests256(smartlist_t *sl);
00112 void *smartlist_bsearch(smartlist_t *sl, const void *key,
00113                         int (*compare)(const void *key, const void **member))
00114   ATTR_PURE;
00115 int smartlist_bsearch_idx(const smartlist_t *sl, const void *key,
00116                           int (*compare)(const void *key, const void **member),
00117                           int *found_out);
00118 
00119 void smartlist_pqueue_add(smartlist_t *sl,
00120                           int (*compare)(const void *a, const void *b),
00121                           int idx_field_offset,
00122                           void *item);
00123 void *smartlist_pqueue_pop(smartlist_t *sl,
00124                            int (*compare)(const void *a, const void *b),
00125                            int idx_field_offset);
00126 void smartlist_pqueue_remove(smartlist_t *sl,
00127                              int (*compare)(const void *a, const void *b),
00128                              int idx_field_offset,
00129                              void *item);
00130 void smartlist_pqueue_assert_ok(smartlist_t *sl,
00131                                 int (*compare)(const void *a, const void *b),
00132                                 int idx_field_offset);
00133 
00134 #define SPLIT_SKIP_SPACE   0x01
00135 #define SPLIT_IGNORE_BLANK 0x02
00136 #define SPLIT_STRIP_SPACE  0x04
00137 int smartlist_split_string(smartlist_t *sl, const char *str, const char *sep,
00138                            int flags, int max);
00139 char *smartlist_join_strings(smartlist_t *sl, const char *join, int terminate,
00140                              size_t *len_out) ATTR_MALLOC;
00141 char *smartlist_join_strings2(smartlist_t *sl, const char *join,
00142                               size_t join_len, int terminate, size_t *len_out)
00143   ATTR_MALLOC;
00144 
00177 /* Note: these macros use token pasting, and reach into smartlist internals.
00178  * This can make them a little daunting. Here's the approximate unpacking of
00179  * the above examples, for entertainment value:
00180  *
00181  * <pre>
00182  * smartlist_t *list = smartlist_split("A:B:C", ":", 0, 0);
00183  * {
00184  *   int cp_sl_idx, cp_sl_len = smartlist_len(list);
00185  *   char *cp;
00186  *   for (cp_sl_idx = 0; cp_sl_idx < cp_sl_len; ++cp_sl_idx) {
00187  *     cp = smartlist_get(list, cp_sl_idx);
00188  *     printf("%d: %s\n", cp_sl_idx, cp);
00189  *     tor_free(cp);
00190  *   }
00191  * }
00192  * smartlist_free(list);
00193  * </pre>
00194  *
00195  * <pre>
00196  * {
00197  *   int cp_sl_idx, cp_sl_len = smartlist_len(list);
00198  *   char *cp;
00199  *   for (cp_sl_idx = 0; cp_sl_idx < cp_sl_len; ++cp_sl_idx) {
00200  *     cp = smartlist_get(list, cp_sl_idx);
00201  *     if (!strcmp(cp, "junk")) {
00202  *       tor_free(cp);
00203  *       smartlist_del(list, cp_sl_idx);
00204  *       --cp_sl_idx;
00205  *       --cp_sl_len;
00206  *     }
00207  *   }
00208  * }
00209  * </pre>
00210  */
00211 #define SMARTLIST_FOREACH_BEGIN(sl, type, var)  \
00212   STMT_BEGIN                                                    \
00213     int var ## _sl_idx, var ## _sl_len=(sl)->num_used;          \
00214     type var;                                                   \
00215     for (var ## _sl_idx = 0; var ## _sl_idx < var ## _sl_len;   \
00216          ++var ## _sl_idx) {                                    \
00217       var = (sl)->list[var ## _sl_idx];
00218 
00219 #define SMARTLIST_FOREACH_END(var)              \
00220     var = NULL;                                 \
00221   } STMT_END
00222 
00223 #define SMARTLIST_FOREACH(sl, type, var, cmd)                   \
00224   SMARTLIST_FOREACH_BEGIN(sl,type,var) {                        \
00225     cmd;                                                        \
00226   } SMARTLIST_FOREACH_END(var)
00227 
00231 #define SMARTLIST_DEL_CURRENT(sl, var)          \
00232   STMT_BEGIN                                    \
00233     smartlist_del(sl, var ## _sl_idx);          \
00234     --var ## _sl_idx;                           \
00235     --var ## _sl_len;                           \
00236   STMT_END
00237 
00242 #define SMARTLIST_REPLACE_CURRENT(sl, var, val) \
00243   STMT_BEGIN                                    \
00244     smartlist_set(sl, var ## _sl_idx, val);     \
00245   STMT_END
00246 
00247 /* Helper: Given two lists of items, possibly of different types, such that
00248  * both lists are sorted on some common field (as determined by a comparison
00249  * expression <b>cmpexpr</b>), and such that one list (<b>sl1</b>) has no
00250  * duplicates on the common field, loop through the lists in lockstep, and
00251  * execute <b>unmatched_var2</b> on items in var2 that do not appear in
00252  * var1.
00253  *
00254  * WARNING: It isn't safe to add remove elements from either list while the
00255  * loop is in progress.
00256  *
00257  * Example use:
00258  *  SMARTLIST_FOREACH_JOIN(routerstatus_list, routerstatus_t *, rs,
00259  *                     routerinfo_list, routerinfo_t *, ri,
00260  *                     memcmp(rs->identity_digest, ri->identity_digest, 20),
00261  *                     log_info(LD_GENERAL,"No match for %s", ri->nickname)) {
00262  *    log_info(LD_GENERAL, "%s matches routerstatus %p", ri->nickname, rs);
00263  * } SMARTLIST_FOREACH_JOIN_END(rs, ri);
00264  **/
00265 /* The example above unpacks (approximately) to:
00266  *  int rs_sl_idx = 0, rs_sl_len = smartlist_len(routerstatus_list);
00267  *  int ri_sl_idx, ri_sl_len = smartlist_len(routerinfo_list);
00268  *  int rs_ri_cmp;
00269  *  routerstatus_t *rs;
00270  *  routerinfo_t *ri;
00271  *  for (; ri_sl_idx < ri_sl_len; ++ri_sl_idx) {
00272  *    ri = smartlist_get(routerinfo_list, ri_sl_idx);
00273  *    while (rs_sl_idx < rs_sl_len) {
00274  *      rs = smartlist_get(routerstatus_list, rs_sl_idx);
00275  *      rs_ri_cmp = memcmp(rs->identity_digest, ri->identity_digest, 20);
00276  *      if (rs_ri_cmp > 0) {
00277  *        break;
00278  *      } else if (rs_ri_cmp == 0) {
00279  *        goto matched_ri;
00280  *      } else {
00281  *        ++rs_sl_idx;
00282  *      }
00283  *    }
00284  *    log_info(LD_GENERAL,"No match for %s", ri->nickname);
00285  *    continue;
00286  *   matched_ri: {
00287  *    log_info(LD_GENERAL,"%s matches with routerstatus %p",ri->nickname,rs);
00288  *    }
00289  *  }
00290  */
00291 #define SMARTLIST_FOREACH_JOIN(sl1, type1, var1, sl2, type2, var2,      \
00292                                 cmpexpr, unmatched_var2)                \
00293   STMT_BEGIN                                                            \
00294   int var1 ## _sl_idx = 0, var1 ## _sl_len=(sl1)->num_used;             \
00295   int var2 ## _sl_idx = 0, var2 ## _sl_len=(sl2)->num_used;             \
00296   int var1 ## _ ## var2 ## _cmp;                                        \
00297   type1 var1;                                                           \
00298   type2 var2;                                                           \
00299   for (; var2##_sl_idx < var2##_sl_len; ++var2##_sl_idx) {              \
00300     var2 = (sl2)->list[var2##_sl_idx];                                  \
00301     while (var1##_sl_idx < var1##_sl_len) {                             \
00302       var1 = (sl1)->list[var1##_sl_idx];                                \
00303       var1##_##var2##_cmp = (cmpexpr);                                  \
00304       if (var1##_##var2##_cmp > 0) {                                    \
00305         break;                                                          \
00306       } else if (var1##_##var2##_cmp == 0) {                            \
00307         goto matched_##var2;                                            \
00308       } else {                                                          \
00309         ++var1##_sl_idx;                                                \
00310       }                                                                 \
00311     }                                                                   \
00312     /* Ran out of v1, or no match for var2. */                          \
00313     unmatched_var2;                                                     \
00314     continue;                                                           \
00315     matched_##var2: ;                                                   \
00316 
00317 #define SMARTLIST_FOREACH_JOIN_END(var1, var2)  \
00318   }                                             \
00319   STMT_END
00320 
00321 #define DECLARE_MAP_FNS(maptype, keytype, prefix)                       \
00322   typedef struct maptype maptype;                                       \
00323   typedef struct prefix##entry_t *prefix##iter_t;                       \
00324   maptype* prefix##new(void);                                           \
00325   void* prefix##set(maptype *map, keytype key, void *val);              \
00326   void* prefix##get(const maptype *map, keytype key);                   \
00327   void* prefix##remove(maptype *map, keytype key);                      \
00328   void prefix##free(maptype *map, void (*free_val)(void*));             \
00329   int prefix##isempty(const maptype *map);                              \
00330   int prefix##size(const maptype *map);                                 \
00331   prefix##iter_t *prefix##iter_init(maptype *map);                      \
00332   prefix##iter_t *prefix##iter_next(maptype *map, prefix##iter_t *iter); \
00333   prefix##iter_t *prefix##iter_next_rmv(maptype *map, prefix##iter_t *iter); \
00334   void prefix##iter_get(prefix##iter_t *iter, keytype *keyp, void **valp); \
00335   int prefix##iter_done(prefix##iter_t *iter);                          \
00336   void prefix##assert_ok(const maptype *map)
00337 
00338 /* Map from const char * to void *. Implemented with a hash table. */
00339 DECLARE_MAP_FNS(strmap_t, const char *, strmap_);
00340 /* Map from const char[DIGEST_LEN] to void *. Implemented with a hash table. */
00341 DECLARE_MAP_FNS(digestmap_t, const char *, digestmap_);
00342 
00343 #undef DECLARE_MAP_FNS
00344 
00355 /* Unpacks to, approximately:
00356  * {
00357  *   digestmap_iter_t *k_iter;
00358  *   for (k_iter = digestmap_iter_init(m); !digestmap_iter_done(k_iter);
00359  *        k_iter = digestmap_iter_next(m, k_iter)) {
00360  *     const char *k;
00361  *     void *r_voidp;
00362  *     routerinfo_t *r;
00363  *     digestmap_iter_get(k_iter, &k, &r_voidp);
00364  *     r = r_voidp;
00365  *     // use k and r
00366  *   }
00367  * }
00368  */
00369 #define MAP_FOREACH(prefix, map, keytype, keyvar, valtype, valvar)      \
00370   STMT_BEGIN                                                            \
00371     prefix##iter_t *keyvar##_iter;                                      \
00372     for (keyvar##_iter = prefix##iter_init(map);                        \
00373          !prefix##iter_done(keyvar##_iter);                             \
00374          keyvar##_iter = prefix##iter_next(map, keyvar##_iter)) {       \
00375       keytype keyvar;                                                   \
00376       void *valvar##_voidp;                                             \
00377       valtype valvar;                                                   \
00378       prefix##iter_get(keyvar##_iter, &keyvar, &valvar##_voidp);        \
00379       valvar = valvar##_voidp;
00380 
00390 /* Unpacks to, approximately:
00391  * {
00392  *   digestmap_iter_t *k_iter;
00393  *   int k_del=0;
00394  *   for (k_iter = digestmap_iter_init(m); !digestmap_iter_done(k_iter);
00395  *        k_iter = k_del ? digestmap_iter_next(m, k_iter)
00396  *                       : digestmap_iter_next_rmv(m, k_iter)) {
00397  *     const char *k;
00398  *     void *r_voidp;
00399  *     routerinfo_t *r;
00400  *     k_del=0;
00401  *     digestmap_iter_get(k_iter, &k, &r_voidp);
00402  *     r = r_voidp;
00403  *     if (is_very_old(r)) {
00404  *       k_del = 1;
00405  *     }
00406  *   }
00407  * }
00408  */
00409 #define MAP_FOREACH_MODIFY(prefix, map, keytype, keyvar, valtype, valvar) \
00410   STMT_BEGIN                                                            \
00411     prefix##iter_t *keyvar##_iter;                                      \
00412     int keyvar##_del=0;                                                 \
00413     for (keyvar##_iter = prefix##iter_init(map);                        \
00414          !prefix##iter_done(keyvar##_iter);                             \
00415          keyvar##_iter = keyvar##_del ?                                 \
00416            prefix##iter_next_rmv(map, keyvar##_iter) :                  \
00417            prefix##iter_next(map, keyvar##_iter)) {                     \
00418       keytype keyvar;                                                   \
00419       void *valvar##_voidp;                                             \
00420       valtype valvar;                                                   \
00421       keyvar##_del=0;                                                   \
00422       prefix##iter_get(keyvar##_iter, &keyvar, &valvar##_voidp);        \
00423       valvar = valvar##_voidp;
00424 
00427 #define MAP_DEL_CURRENT(keyvar)                   \
00428   STMT_BEGIN                                      \
00429     keyvar##_del = 1;                             \
00430   STMT_END
00431 
00433 #define MAP_FOREACH_END } STMT_END ;
00434 
00441 #define DIGESTMAP_FOREACH(map, keyvar, valtype, valvar)                 \
00442   MAP_FOREACH(digestmap_, map, const char *, keyvar, valtype, valvar)
00443 
00452 #define DIGESTMAP_FOREACH_MODIFY(map, keyvar, valtype, valvar)          \
00453   MAP_FOREACH_MODIFY(digestmap_, map, const char *, keyvar, valtype, valvar)
00454 
00455 #define DIGESTMAP_FOREACH_END MAP_FOREACH_END
00456 
00457 #define STRMAP_FOREACH(map, keyvar, valtype, valvar)                 \
00458   MAP_FOREACH(strmap_, map, const char *, keyvar, valtype, valvar)
00459 #define STRMAP_FOREACH_MODIFY(map, keyvar, valtype, valvar)          \
00460   MAP_FOREACH_MODIFY(strmap_, map, const char *, keyvar, valtype, valvar)
00461 #define STRMAP_FOREACH_END MAP_FOREACH_END
00462 
00463 void* strmap_set_lc(strmap_t *map, const char *key, void *val);
00464 void* strmap_get_lc(const strmap_t *map, const char *key);
00465 void* strmap_remove_lc(strmap_t *map, const char *key);
00466 
00467 #define DECLARE_TYPED_DIGESTMAP_FNS(prefix, maptype, valtype)           \
00468   typedef struct maptype maptype;                                       \
00469   typedef struct prefix##iter_t prefix##iter_t;                         \
00470   static INLINE maptype* prefix##new(void)                              \
00471   {                                                                     \
00472     return (maptype*)digestmap_new();                                   \
00473   }                                                                     \
00474   static INLINE digestmap_t* prefix##to_digestmap(maptype *map)         \
00475   {                                                                     \
00476     return (digestmap_t*)map;                                           \
00477   }                                                                     \
00478   static INLINE valtype* prefix##get(maptype *map, const char *key)     \
00479   {                                                                     \
00480     return (valtype*)digestmap_get((digestmap_t*)map, key);             \
00481   }                                                                     \
00482   static INLINE valtype* prefix##set(maptype *map, const char *key,     \
00483                                      valtype *val)                      \
00484   {                                                                     \
00485     return (valtype*)digestmap_set((digestmap_t*)map, key, val);        \
00486   }                                                                     \
00487   static INLINE valtype* prefix##remove(maptype *map, const char *key)  \
00488   {                                                                     \
00489     return (valtype*)digestmap_remove((digestmap_t*)map, key);          \
00490   }                                                                     \
00491   static INLINE void prefix##free(maptype *map, void (*free_val)(void*)) \
00492   {                                                                     \
00493     digestmap_free((digestmap_t*)map, free_val);                        \
00494   }                                                                     \
00495   static INLINE int prefix##isempty(maptype *map)                       \
00496   {                                                                     \
00497     return digestmap_isempty((digestmap_t*)map);                        \
00498   }                                                                     \
00499   static INLINE int prefix##size(maptype *map)                          \
00500   {                                                                     \
00501     return digestmap_size((digestmap_t*)map);                           \
00502   }                                                                     \
00503   static INLINE prefix##iter_t *prefix##iter_init(maptype *map)         \
00504   {                                                                     \
00505     return (prefix##iter_t*) digestmap_iter_init((digestmap_t*)map);    \
00506   }                                                                     \
00507   static INLINE prefix##iter_t *prefix##iter_next(maptype *map,         \
00508                                                   prefix##iter_t *iter) \
00509   {                                                                     \
00510     return (prefix##iter_t*) digestmap_iter_next(                       \
00511                        (digestmap_t*)map, (digestmap_iter_t*)iter);     \
00512   }                                                                     \
00513   static INLINE prefix##iter_t *prefix##iter_next_rmv(maptype *map,     \
00514                                                   prefix##iter_t *iter) \
00515   {                                                                     \
00516     return (prefix##iter_t*) digestmap_iter_next_rmv(                   \
00517                        (digestmap_t*)map, (digestmap_iter_t*)iter);     \
00518   }                                                                     \
00519   static INLINE void prefix##iter_get(prefix##iter_t *iter,             \
00520                                       const char **keyp,                \
00521                                       valtype **valp)                   \
00522   {                                                                     \
00523     void *v;                                                            \
00524     digestmap_iter_get((digestmap_iter_t*) iter, keyp, &v);             \
00525     *valp = v;                                                          \
00526   }                                                                     \
00527   static INLINE int prefix##iter_done(prefix##iter_t *iter)             \
00528   {                                                                     \
00529     return digestmap_iter_done((digestmap_iter_t*)iter);                \
00530   }
00531 
00532 #if SIZEOF_INT == 4
00533 #define BITARRAY_SHIFT 5
00534 #elif SIZEOF_INT == 8
00535 #define BITARRAY_SHIFT 6
00536 #else
00537 #error "int is neither 4 nor 8 bytes. I can't deal with that."
00538 #endif
00539 #define BITARRAY_MASK ((1u<<BITARRAY_SHIFT)-1)
00540 
00542 typedef unsigned int bitarray_t;
00544 static INLINE bitarray_t *
00545 bitarray_init_zero(unsigned int n_bits)
00546 {
00547   /* round up to the next int. */
00548   size_t sz = (n_bits+BITARRAY_MASK) >> BITARRAY_SHIFT;
00549   return tor_malloc_zero(sz*sizeof(unsigned int));
00550 }
00554 static INLINE bitarray_t *
00555 bitarray_expand(bitarray_t *ba,
00556                 unsigned int n_bits_old, unsigned int n_bits_new)
00557 {
00558   size_t sz_old = (n_bits_old+BITARRAY_MASK) >> BITARRAY_SHIFT;
00559   size_t sz_new = (n_bits_new+BITARRAY_MASK) >> BITARRAY_SHIFT;
00560   char *ptr;
00561   if (sz_new <= sz_old)
00562     return ba;
00563   ptr = tor_realloc(ba, sz_new*sizeof(unsigned int));
00564   /* This memset does nothing to the older excess bytes.  But they were
00565    * already set to 0 by bitarry_init_zero. */
00566   memset(ptr+sz_old*sizeof(unsigned int), 0,
00567          (sz_new-sz_old)*sizeof(unsigned int));
00568   return (bitarray_t*) ptr;
00569 }
00571 static INLINE void
00572 bitarray_free(bitarray_t *ba)
00573 {
00574   tor_free(ba);
00575 }
00577 static INLINE void
00578 bitarray_set(bitarray_t *b, int bit)
00579 {
00580   b[bit >> BITARRAY_SHIFT] |= (1u << (bit & BITARRAY_MASK));
00581 }
00583 static INLINE void
00584 bitarray_clear(bitarray_t *b, int bit)
00585 {
00586   b[bit >> BITARRAY_SHIFT] &= ~ (1u << (bit & BITARRAY_MASK));
00587 }
00590 static INLINE unsigned int
00591 bitarray_is_set(bitarray_t *b, int bit)
00592 {
00593   return b[bit >> BITARRAY_SHIFT] & (1u << (bit & BITARRAY_MASK));
00594 }
00595 
00597 typedef struct {
00598   int mask; /* One less than the number of bits in <b>ba</b>; always one less
00599              * than a power of two. */
00600   bitarray_t *ba; /* A bit array to implement the Bloom filter. */
00601 } digestset_t;
00602 
00603 #define BIT(n) ((n) & set->mask)
00604 
00605 static INLINE void
00606 digestset_add(digestset_t *set, const char *digest)
00607 {
00608   const uint32_t *p = (const uint32_t *)digest;
00609   const uint32_t d1 = p[0] + (p[1]>>16);
00610   const uint32_t d2 = p[1] + (p[2]>>16);
00611   const uint32_t d3 = p[2] + (p[3]>>16);
00612   const uint32_t d4 = p[3] + (p[0]>>16);
00613   bitarray_set(set->ba, BIT(d1));
00614   bitarray_set(set->ba, BIT(d2));
00615   bitarray_set(set->ba, BIT(d3));
00616   bitarray_set(set->ba, BIT(d4));
00617 }
00618 
00621 static INLINE int
00622 digestset_isin(const digestset_t *set, const char *digest)
00623 {
00624   const uint32_t *p = (const uint32_t *)digest;
00625   const uint32_t d1 = p[0] + (p[1]>>16);
00626   const uint32_t d2 = p[1] + (p[2]>>16);
00627   const uint32_t d3 = p[2] + (p[3]>>16);
00628   const uint32_t d4 = p[3] + (p[0]>>16);
00629   return bitarray_is_set(set->ba, BIT(d1)) &&
00630          bitarray_is_set(set->ba, BIT(d2)) &&
00631          bitarray_is_set(set->ba, BIT(d3)) &&
00632          bitarray_is_set(set->ba, BIT(d4));
00633 }
00634 #undef BIT
00635 
00636 digestset_t *digestset_new(int max_elements);
00637 void digestset_free(digestset_t* set);
00638 
00639 /* These functions, given an <b>array</b> of <b>n_elements</b>, return the
00640  * <b>nth</b> lowest element. <b>nth</b>=0 gives the lowest element;
00641  * <b>n_elements</b>-1 gives the highest; and (<b>n_elements</b>-1) / 2 gives
00642  * the median.  As a side effect, the elements of <b>array</b> are sorted. */
00643 int find_nth_int(int *array, int n_elements, int nth);
00644 time_t find_nth_time(time_t *array, int n_elements, int nth);
00645 double find_nth_double(double *array, int n_elements, int nth);
00646 int32_t find_nth_int32(int32_t *array, int n_elements, int nth);
00647 uint32_t find_nth_uint32(uint32_t *array, int n_elements, int nth);
00648 long find_nth_long(long *array, int n_elements, int nth);
00649 static INLINE int
00650 median_int(int *array, int n_elements)
00651 {
00652   return find_nth_int(array, n_elements, (n_elements-1)/2);
00653 }
00654 static INLINE time_t
00655 median_time(time_t *array, int n_elements)
00656 {
00657   return find_nth_time(array, n_elements, (n_elements-1)/2);
00658 }
00659 static INLINE double
00660 median_double(double *array, int n_elements)
00661 {
00662   return find_nth_double(array, n_elements, (n_elements-1)/2);
00663 }
00664 static INLINE uint32_t
00665 median_uint32(uint32_t *array, int n_elements)
00666 {
00667   return find_nth_uint32(array, n_elements, (n_elements-1)/2);
00668 }
00669 static INLINE int32_t
00670 median_int32(int32_t *array, int n_elements)
00671 {
00672   return find_nth_int32(array, n_elements, (n_elements-1)/2);
00673 }
00674 static INLINE long
00675 median_long(long *array, int n_elements)
00676 {
00677   return find_nth_long(array, n_elements, (n_elements-1)/2);
00678 }
00679 
00680 #endif
00681