src/common/container.h

   1 /* Copyright (c) 2003-2004, Roger Dingledine
   2  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
   3  * Copyright (c) 2007-2013, The Tor Project, Inc. */
   4 /* See LICENSE for licensing information */
   5
   6 #ifndef TOR_CONTAINER_H
   7 #define TOR_CONTAINER_H
   8
   9 #include "util.h"
  10
  11 /** A resizeable list of pointers, with associated helpful functionality.
  12  *
  13  * The members of this struct are exposed only so that macros and inlines can
  14  * use them; all access to smartlist internals should go through the functions
  15  * and macros defined here.
  16  **/
  17 typedef struct smartlist_t {
  18   /** @{ */
  19   /** <b>list</b> has enough capacity to store exactly <b>capacity</b> elements
  20    * before it needs to be resized.  Only the first <b>num_used</b> (\<=
  21    * capacity) elements point to valid data.
  22    */
  23   void **list;
  24   int num_used;
  25   int capacity;
  26   /** @} */
  27 } smartlist_t;
  28
  29 smartlist_t *smartlist_new(void);
  30 void smartlist_free(smartlist_t *sl);
  31 void smartlist_clear(smartlist_t *sl);
  32 void smartlist_add(smartlist_t *sl, void *element);
  33 void smartlist_add_all(smartlist_t *sl, const smartlist_t *s2);
  34 void smartlist_remove(smartlist_t *sl, const void *element);
  35 void *smartlist_pop_last(smartlist_t *sl);
  36 void smartlist_reverse(smartlist_t *sl);
  37 void smartlist_string_remove(smartlist_t *sl, const char *element);
  38 int smartlist_contains(const smartlist_t *sl, const void *element);
  39 int smartlist_contains_string(const smartlist_t *sl, const char *element);
  40 int smartlist_string_pos(const smartlist_t *, const char *elt);
  41 int smartlist_contains_string_case(const smartlist_t *sl, const char *element);
  42 int smartlist_contains_int_as_string(const smartlist_t *sl, int num);
  43 int smartlist_strings_eq(const smartlist_t *sl1, const smartlist_t *sl2);
  44 int smartlist_contains_digest(const smartlist_t *sl, const char *element);
  45 int smartlist_overlap(const smartlist_t *sl1, const smartlist_t *sl2);
  46 void smartlist_intersect(smartlist_t *sl1, const smartlist_t *sl2);
  47 void smartlist_subtract(smartlist_t *sl1, const smartlist_t *sl2);
  48
  49 /* smartlist_choose() is defined in crypto.[ch] */
  50 #ifdef DEBUG_SMARTLIST
  51 /** Return the number of items in sl.
  52  */
  53 static INLINE int smartlist_len(const smartlist_t *sl);
  54 static INLINE int smartlist_len(const smartlist_t *sl) {
  55   tor_assert(sl);
  56   return (sl)->num_used;
  57 }
  58 /** Return the <b>idx</b>th element of sl.
  59  */
  60 static INLINE void *smartlist_get(const smartlist_t *sl, int idx);
  61 static INLINE void *smartlist_get(const smartlist_t *sl, int idx) {
  62   tor_assert(sl);
  63   tor_assert(idx>=0);
  64   tor_assert(sl->num_used > idx);
  65   return sl->list[idx];
  66 }
  67 static INLINE void smartlist_set(smartlist_t *sl, int idx, void *val) {
  68   tor_assert(sl);
  69   tor_assert(idx>=0);
  70   tor_assert(sl->num_used > idx);
  71   sl->list[idx] = val;
  72 }
  73 #else
  74 #define smartlist_len(sl) ((sl)->num_used)
  75 #define smartlist_get(sl, idx) ((sl)->list[idx])
  76 #define smartlist_set(sl, idx, val) ((sl)->list[idx] = (val))
  77 #endif
  78
  79 /** Exchange the elements at indices <b>idx1</b> and <b>idx2</b> of the
  80  * smartlist <b>sl</b>. */
  81 static INLINE void smartlist_swap(smartlist_t *sl, int idx1, int idx2)
  82 {
  83   if (idx1 != idx2) {
  84     void *elt = smartlist_get(sl, idx1);
  85     smartlist_set(sl, idx1, smartlist_get(sl, idx2));
  86     smartlist_set(sl, idx2, elt);
  87   }
  88 }
  89
  90 void smartlist_del(smartlist_t *sl, int idx);
  91 void smartlist_del_keeporder(smartlist_t *sl, int idx);
  92 void smartlist_insert(smartlist_t *sl, int idx, void *val);
  93 void smartlist_sort(smartlist_t *sl,
  94                     int (*compare)(const void **a, const void **b));
  95 void *smartlist_get_most_frequent(const smartlist_t *sl,
  96                     int (*compare)(const void **a, const void **b));
  97 void smartlist_uniq(smartlist_t *sl,
  98                     int (*compare)(const void **a, const void **b),
  99                     void (*free_fn)(void *elt));
 100
 101 void smartlist_sort_strings(smartlist_t *sl);
 102 void smartlist_sort_digests(smartlist_t *sl);
 103 void smartlist_sort_digests256(smartlist_t *sl);
 104
 105 char *smartlist_get_most_frequent_string(smartlist_t *sl);
 106 char *smartlist_get_most_frequent_digest256(smartlist_t *sl);
 107
 108 void smartlist_uniq_strings(smartlist_t *sl);
 109 void smartlist_uniq_digests(smartlist_t *sl);
 110 void smartlist_uniq_digests256(smartlist_t *sl);
 111 void *smartlist_bsearch(smartlist_t *sl, const void *key,
 112                         int (*compare)(const void *key, const void **member));
 113 int smartlist_bsearch_idx(const smartlist_t *sl, const void *key,
 114                           int (*compare)(const void *key, const void **member),
 115                           int *found_out);
 116
 117 void smartlist_pqueue_add(smartlist_t *sl,
 118                           int (*compare)(const void *a, const void *b),
 119                           int idx_field_offset,
 120                           void *item);
 121 void *smartlist_pqueue_pop(smartlist_t *sl,
 122                            int (*compare)(const void *a, const void *b),
 123                            int idx_field_offset);
 124 void smartlist_pqueue_remove(smartlist_t *sl,
 125                              int (*compare)(const void *a, const void *b),
 126                              int idx_field_offset,
 127                              void *item);
 128 void smartlist_pqueue_assert_ok(smartlist_t *sl,
 129                                 int (*compare)(const void *a, const void *b),
 130                                 int idx_field_offset);
 131
 132 #define SPLIT_SKIP_SPACE   0x01
 133 #define SPLIT_IGNORE_BLANK 0x02
 134 #define SPLIT_STRIP_SPACE  0x04
 135 int smartlist_split_string(smartlist_t *sl, const char *str, const char *sep,
 136                            int flags, int max);
 137 char *smartlist_join_strings(smartlist_t *sl, const char *join, int terminate,
 138                              size_t *len_out) ATTR_MALLOC;
 139 char *smartlist_join_strings2(smartlist_t *sl, const char *join,
 140                               size_t join_len, int terminate, size_t *len_out)
 141   ATTR_MALLOC;
 142
 143 /** Iterate over the items in a smartlist <b>sl</b>, in order.  For each item,
 144  * assign it to a new local variable of type <b>type</b> named <b>var</b>, and
 145  * execute the statements inside the loop body.  Inside the loop, the loop
 146  * index can be accessed as <b>var</b>_sl_idx and the length of the list can
 147  * be accessed as <b>var</b>_sl_len.
 148  *
 149  * NOTE: Do not change the length of the list while the loop is in progress,
 150  * unless you adjust the _sl_len variable correspondingly.  See second example
 151  * below.
 152  *
 153  * Example use:
 154  * <pre>
 155  *   smartlist_t *list = smartlist_split("A:B:C", ":", 0, 0);
 156  *   SMARTLIST_FOREACH_BEGIN(list, char *, cp) {
 157  *     printf("%d: %s\n", cp_sl_idx, cp);
 158  *     tor_free(cp);
 159  *   } SMARTLIST_FOREACH_END(cp);
 160  *   smartlist_free(list);
 161  * </pre>
 162  *
 163  * Example use (advanced):
 164  * <pre>
 165  *   SMARTLIST_FOREACH_BEGIN(list, char *, cp) {
 166  *     if (!strcmp(cp, "junk")) {
 167  *       tor_free(cp);
 168  *       SMARTLIST_DEL_CURRENT(list, cp);
 169  *     }
 170  *   } SMARTLIST_FOREACH_END(cp);
 171  * </pre>
 172  */
 173 /* Note: these macros use token pasting, and reach into smartlist internals.
 174  * This can make them a little daunting. Here's the approximate unpacking of
 175  * the above examples, for entertainment value:
 176  *
 177  * <pre>
 178  * smartlist_t *list = smartlist_split("A:B:C", ":", 0, 0);
 179  * {
 180  *   int cp_sl_idx, cp_sl_len = smartlist_len(list);
 181  *   char *cp;
 182  *   for (cp_sl_idx = 0; cp_sl_idx < cp_sl_len; ++cp_sl_idx) {
 183  *     cp = smartlist_get(list, cp_sl_idx);
 184  *     printf("%d: %s\n", cp_sl_idx, cp);
 185  *     tor_free(cp);
 186  *   }
 187  * }
 188  * smartlist_free(list);
 189  * </pre>
 190  *
 191  * <pre>
 192  * {
 193  *   int cp_sl_idx, cp_sl_len = smartlist_len(list);
 194  *   char *cp;
 195  *   for (cp_sl_idx = 0; cp_sl_idx < cp_sl_len; ++cp_sl_idx) {
 196  *     cp = smartlist_get(list, cp_sl_idx);
 197  *     if (!strcmp(cp, "junk")) {
 198  *       tor_free(cp);
 199  *       smartlist_del(list, cp_sl_idx);
 200  *       --cp_sl_idx;
 201  *       --cp_sl_len;
 202  *     }
 203  *   }
 204  * }
 205  * </pre>
 206  */
 207 #define SMARTLIST_FOREACH_BEGIN(sl, type, var)  \
 208   STMT_BEGIN                                                    \
 209     int var ## _sl_idx, var ## _sl_len=(sl)->num_used;          \
 210     type var;                                                   \
 211     for (var ## _sl_idx = 0; var ## _sl_idx < var ## _sl_len;   \
 212          ++var ## _sl_idx) {                                    \
 213       var = (sl)->list[var ## _sl_idx];
 214
 215 #define SMARTLIST_FOREACH_END(var)              \
 216     var = NULL;                                 \
 217   } STMT_END
 218
 219 /**
 220  * An alias for SMARTLIST_FOREACH_BEGIN and SMARTLIST_FOREACH_END, using
 221  * <b>cmd</b> as the loop body.  This wrapper is here for convenience with
 222  * very short loops.
 223  *
 224  * By convention, we do not use this for loops which nest, or for loops over
 225  * 10 lines or so.  Use SMARTLIST_FOREACH_{BEGIN,END} for those.
 226  */
 227 #define SMARTLIST_FOREACH(sl, type, var, cmd)                   \
 228   SMARTLIST_FOREACH_BEGIN(sl,type,var) {                        \
 229     cmd;                                                        \
 230   } SMARTLIST_FOREACH_END(var)
 231
 232 /** Helper: While in a SMARTLIST_FOREACH loop over the list <b>sl</b> indexed
 233  * with the variable <b>var</b>, remove the current element in a way that
 234  * won't confuse the loop. */
 235 #define SMARTLIST_DEL_CURRENT(sl, var)          \
 236   STMT_BEGIN                                    \
 237     smartlist_del(sl, var ## _sl_idx);          \
 238     --var ## _sl_idx;                           \
 239     --var ## _sl_len;                           \
 240   STMT_END
 241
 242 /** Helper: While in a SMARTLIST_FOREACH loop over the list <b>sl</b> indexed
 243  * with the variable <b>var</b>, replace the current element with <b>val</b>.
 244  * Does not deallocate the current value of <b>var</b>.
 245  */
 246 #define SMARTLIST_REPLACE_CURRENT(sl, var, val) \
 247   STMT_BEGIN                                    \
 248     smartlist_set(sl, var ## _sl_idx, val);     \
 249   STMT_END
 250
 251 /* Helper: Given two lists of items, possibly of different types, such that
 252  * both lists are sorted on some common field (as determined by a comparison
 253  * expression <b>cmpexpr</b>), and such that one list (<b>sl1</b>) has no
 254  * duplicates on the common field, loop through the lists in lockstep, and
 255  * execute <b>unmatched_var2</b> on items in var2 that do not appear in
 256  * var1.
 257  *
 258  * WARNING: It isn't safe to add remove elements from either list while the
 259  * loop is in progress.
 260  *
 261  * Example use:
 262  *  SMARTLIST_FOREACH_JOIN(routerstatus_list, routerstatus_t *, rs,
 263  *                     routerinfo_list, routerinfo_t *, ri,
 264  *                    tor_memcmp(rs->identity_digest, ri->identity_digest, 20),
 265  *                     log_info(LD_GENERAL,"No match for %s", ri->nickname)) {
 266  *    log_info(LD_GENERAL, "%s matches routerstatus %p", ri->nickname, rs);
 267  * } SMARTLIST_FOREACH_JOIN_END(rs, ri);
 268  **/
 269 /* The example above unpacks (approximately) to:
 270  *  int rs_sl_idx = 0, rs_sl_len = smartlist_len(routerstatus_list);
 271  *  int ri_sl_idx, ri_sl_len = smartlist_len(routerinfo_list);
 272  *  int rs_ri_cmp;
 273  *  routerstatus_t *rs;
 274  *  routerinfo_t *ri;
 275  *  for (; ri_sl_idx < ri_sl_len; ++ri_sl_idx) {
 276  *    ri = smartlist_get(routerinfo_list, ri_sl_idx);
 277  *    while (rs_sl_idx < rs_sl_len) {
 278  *      rs = smartlist_get(routerstatus_list, rs_sl_idx);
 279  *      rs_ri_cmp = tor_memcmp(rs->identity_digest, ri->identity_digest, 20);
 280  *      if (rs_ri_cmp > 0) {
 281  *        break;
 282  *      } else if (rs_ri_cmp == 0) {
 283  *        goto matched_ri;
 284  *      } else {
 285  *        ++rs_sl_idx;
 286  *      }
 287  *    }
 288  *    log_info(LD_GENERAL,"No match for %s", ri->nickname);
 289  *    continue;
 290  *   matched_ri: {
 291  *    log_info(LD_GENERAL,"%s matches with routerstatus %p",ri->nickname,rs);
 292  *    }
 293  *  }
 294  */
 295 #define SMARTLIST_FOREACH_JOIN(sl1, type1, var1, sl2, type2, var2,      \
 296                                 cmpexpr, unmatched_var2)                \
 297   STMT_BEGIN                                                            \
 298   int var1 ## _sl_idx = 0, var1 ## _sl_len=(sl1)->num_used;             \
 299   int var2 ## _sl_idx = 0, var2 ## _sl_len=(sl2)->num_used;             \
 300   int var1 ## _ ## var2 ## _cmp;                                        \
 301   type1 var1;                                                           \
 302   type2 var2;                                                           \
 303   for (; var2##_sl_idx < var2##_sl_len; ++var2##_sl_idx) {              \
 304     var2 = (sl2)->list[var2##_sl_idx];                                  \
 305     while (var1##_sl_idx < var1##_sl_len) {                             \
 306       var1 = (sl1)->list[var1##_sl_idx];                                \
 307       var1##_##var2##_cmp = (cmpexpr);                                  \
 308       if (var1##_##var2##_cmp > 0) {                                    \
 309         break;                                                          \
 310       } else if (var1##_##var2##_cmp == 0) {                            \
 311         goto matched_##var2;                                            \
 312       } else {                                                          \
 313         ++var1##_sl_idx;                                                \
 314       }                                                                 \
 315     }                                                                   \
 316     /* Ran out of v1, or no match for var2. */                          \
 317     unmatched_var2;                                                     \
 318     continue;                                                           \
 319     matched_##var2: ;                                                   \
 320
 321 #define SMARTLIST_FOREACH_JOIN_END(var1, var2)  \
 322   }                                             \
 323   STMT_END
 324
 325 #define DECLARE_MAP_FNS(maptype, keytype, prefix)                       \
 326   typedef struct maptype maptype;                                       \
 327   typedef struct prefix##entry_t *prefix##iter_t;                       \
 328   maptype* prefix##new(void);                                           \
 329   void* prefix##set(maptype *map, keytype key, void *val);              \
 330   void* prefix##get(const maptype *map, keytype key);                   \
 331   void* prefix##remove(maptype *map, keytype key);                      \
 332   void prefix##free(maptype *map, void (*free_val)(void*));             \
 333   int prefix##isempty(const maptype *map);                              \
 334   int prefix##size(const maptype *map);                                 \
 335   prefix##iter_t *prefix##iter_init(maptype *map);                      \
 336   prefix##iter_t *prefix##iter_next(maptype *map, prefix##iter_t *iter); \
 337   prefix##iter_t *prefix##iter_next_rmv(maptype *map, prefix##iter_t *iter); \
 338   void prefix##iter_get(prefix##iter_t *iter, keytype *keyp, void **valp); \
 339   int prefix##iter_done(prefix##iter_t *iter);                          \
 340   void prefix##assert_ok(const maptype *map)
 341
 342 /* Map from const char * to void *. Implemented with a hash table. */
 343 DECLARE_MAP_FNS(strmap_t, const char *, strmap_);
 344 /* Map from const char[DIGEST_LEN] to void *. Implemented with a hash table. */
 345 DECLARE_MAP_FNS(digestmap_t, const char *, digestmap_);
 346
 347 #undef DECLARE_MAP_FNS
 348
 349 /** Iterates over the key-value pairs in a map <b>map</b> in order.
 350  * <b>prefix</b> is as for DECLARE_MAP_FNS (i.e., strmap_ or digestmap_).
 351  * The map's keys and values are of type keytype and valtype respectively;
 352  * each iteration assigns them to keyvar and valvar.
 353  *
 354  * Example use:
 355  *   MAP_FOREACH(digestmap_, m, const char *, k, routerinfo_t *, r) {
 356  *     // use k and r
 357  *   } MAP_FOREACH_END.
 358  */
 359 /* Unpacks to, approximately:
 360  * {
 361  *   digestmap_iter_t *k_iter;
 362  *   for (k_iter = digestmap_iter_init(m); !digestmap_iter_done(k_iter);
 363  *        k_iter = digestmap_iter_next(m, k_iter)) {
 364  *     const char *k;
 365  *     void *r_voidp;
 366  *     routerinfo_t *r;
 367  *     digestmap_iter_get(k_iter, &k, &r_voidp);
 368  *     r = r_voidp;
 369  *     // use k and r
 370  *   }
 371  * }
 372  */
 373 #define MAP_FOREACH(prefix, map, keytype, keyvar, valtype, valvar)      \
 374   STMT_BEGIN                                                            \
 375     prefix##iter_t *keyvar##_iter;                                      \
 376     for (keyvar##_iter = prefix##iter_init(map);                        \
 377          !prefix##iter_done(keyvar##_iter);                             \
 378          keyvar##_iter = prefix##iter_next(map, keyvar##_iter)) {       \
 379       keytype keyvar;                                                   \
 380       void *valvar##_voidp;                                             \
 381       valtype valvar;                                                   \
 382       prefix##iter_get(keyvar##_iter, &keyvar, &valvar##_voidp);        \
 383       valvar = valvar##_voidp;
 384
 385 /** As MAP_FOREACH, except allows members to be removed from the map
 386  * during the iteration via MAP_DEL_CURRENT.  Example use:
 387  *
 388  * Example use:
 389  *   MAP_FOREACH(digestmap_, m, const char *, k, routerinfo_t *, r) {
 390  *      if (is_very_old(r))
 391  *       MAP_DEL_CURRENT(k);
 392  *   } MAP_FOREACH_END.
 393  **/
 394 /* Unpacks to, approximately:
 395  * {
 396  *   digestmap_iter_t *k_iter;
 397  *   int k_del=0;
 398  *   for (k_iter = digestmap_iter_init(m); !digestmap_iter_done(k_iter);
 399  *        k_iter = k_del ? digestmap_iter_next(m, k_iter)
 400  *                       : digestmap_iter_next_rmv(m, k_iter)) {
 401  *     const char *k;
 402  *     void *r_voidp;
 403  *     routerinfo_t *r;
 404  *     k_del=0;
 405  *     digestmap_iter_get(k_iter, &k, &r_voidp);
 406  *     r = r_voidp;
 407  *     if (is_very_old(r)) {
 408  *       k_del = 1;
 409  *     }
 410  *   }
 411  * }
 412  */
 413 #define MAP_FOREACH_MODIFY(prefix, map, keytype, keyvar, valtype, valvar) \
 414   STMT_BEGIN                                                            \
 415     prefix##iter_t *keyvar##_iter;                                      \
 416     int keyvar##_del=0;                                                 \
 417     for (keyvar##_iter = prefix##iter_init(map);                        \
 418          !prefix##iter_done(keyvar##_iter);                             \
 419          keyvar##_iter = keyvar##_del ?                                 \
 420            prefix##iter_next_rmv(map, keyvar##_iter) :                  \
 421            prefix##iter_next(map, keyvar##_iter)) {                     \
 422       keytype keyvar;                                                   \
 423       void *valvar##_voidp;                                             \
 424       valtype valvar;                                                   \
 425       keyvar##_del=0;                                                   \
 426       prefix##iter_get(keyvar##_iter, &keyvar, &valvar##_voidp);        \
 427       valvar = valvar##_voidp;
 428
 429 /** Used with MAP_FOREACH_MODIFY to remove the currently-iterated-upon
 430  * member of the map.  */
 431 #define MAP_DEL_CURRENT(keyvar)                   \
 432   STMT_BEGIN                                      \
 433     keyvar##_del = 1;                             \
 434   STMT_END
 435
 436 /** Used to end a MAP_FOREACH() block. */
 437 #define MAP_FOREACH_END } STMT_END ;
 438
 439 /** As MAP_FOREACH, but does not require declaration of prefix or keytype.
 440  * Example use:
 441  *   DIGESTMAP_FOREACH(m, k, routerinfo_t *, r) {
 442  *     // use k and r
 443  *   } DIGESTMAP_FOREACH_END.
 444  */
 445 #define DIGESTMAP_FOREACH(map, keyvar, valtype, valvar)                 \
 446   MAP_FOREACH(digestmap_, map, const char *, keyvar, valtype, valvar)
 447
 448 /** As MAP_FOREACH_MODIFY, but does not require declaration of prefix or
 449  * keytype.
 450  * Example use:
 451  *   DIGESTMAP_FOREACH_MODIFY(m, k, routerinfo_t *, r) {
 452  *      if (is_very_old(r))
 453  *       MAP_DEL_CURRENT(k);
 454  *   } DIGESTMAP_FOREACH_END.
 455  */
 456 #define DIGESTMAP_FOREACH_MODIFY(map, keyvar, valtype, valvar)          \
 457   MAP_FOREACH_MODIFY(digestmap_, map, const char *, keyvar, valtype, valvar)
 458 /** Used to end a DIGESTMAP_FOREACH() block. */
 459 #define DIGESTMAP_FOREACH_END MAP_FOREACH_END
 460
 461 #define STRMAP_FOREACH(map, keyvar, valtype, valvar)                 \
 462   MAP_FOREACH(strmap_, map, const char *, keyvar, valtype, valvar)
 463 #define STRMAP_FOREACH_MODIFY(map, keyvar, valtype, valvar)          \
 464   MAP_FOREACH_MODIFY(strmap_, map, const char *, keyvar, valtype, valvar)
 465 #define STRMAP_FOREACH_END MAP_FOREACH_END
 466
 467 void* strmap_set_lc(strmap_t *map, const char *key, void *val);
 468 void* strmap_get_lc(const strmap_t *map, const char *key);
 469 void* strmap_remove_lc(strmap_t *map, const char *key);
 470
 471 #define DECLARE_TYPED_DIGESTMAP_FNS(prefix, maptype, valtype)           \
 472   typedef struct maptype maptype;                                       \
 473   typedef struct prefix##iter_t prefix##iter_t;                         \
 474   static INLINE maptype* prefix##new(void)                              \
 475   {                                                                     \
 476     return (maptype*)digestmap_new();                                   \
 477   }                                                                     \
 478   static INLINE digestmap_t* prefix##to_digestmap(maptype *map)         \
 479   {                                                                     \
 480     return (digestmap_t*)map;                                           \
 481   }                                                                     \
 482   static INLINE valtype* prefix##get(maptype *map, const char *key)     \
 483   {                                                                     \
 484     return (valtype*)digestmap_get((digestmap_t*)map, key);             \
 485   }                                                                     \
 486   static INLINE valtype* prefix##set(maptype *map, const char *key,     \
 487                                      valtype *val)                      \
 488   {                                                                     \
 489     return (valtype*)digestmap_set((digestmap_t*)map, key, val);        \
 490   }                                                                     \
 491   static INLINE valtype* prefix##remove(maptype *map, const char *key)  \
 492   {                                                                     \
 493     return (valtype*)digestmap_remove((digestmap_t*)map, key);          \
 494   }                                                                     \
 495   static INLINE void prefix##free(maptype *map, void (*free_val)(void*)) \
 496   {                                                                     \
 497     digestmap_free((digestmap_t*)map, free_val);                        \
 498   }                                                                     \
 499   static INLINE int prefix##isempty(maptype *map)                       \
 500   {                                                                     \
 501     return digestmap_isempty((digestmap_t*)map);                        \
 502   }                                                                     \
 503   static INLINE int prefix##size(maptype *map)                          \
 504   {                                                                     \
 505     return digestmap_size((digestmap_t*)map);                           \
 506   }                                                                     \
 507   static INLINE prefix##iter_t *prefix##iter_init(maptype *map)         \
 508   {                                                                     \
 509     return (prefix##iter_t*) digestmap_iter_init((digestmap_t*)map);    \
 510   }                                                                     \
 511   static INLINE prefix##iter_t *prefix##iter_next(maptype *map,         \
 512                                                   prefix##iter_t *iter) \
 513   {                                                                     \
 514     return (prefix##iter_t*) digestmap_iter_next(                       \
 515                        (digestmap_t*)map, (digestmap_iter_t*)iter);     \
 516   }                                                                     \
 517   static INLINE prefix##iter_t *prefix##iter_next_rmv(maptype *map,     \
 518                                                   prefix##iter_t *iter) \
 519   {                                                                     \
 520     return (prefix##iter_t*) digestmap_iter_next_rmv(                   \
 521                        (digestmap_t*)map, (digestmap_iter_t*)iter);     \
 522   }                                                                     \
 523   static INLINE void prefix##iter_get(prefix##iter_t *iter,             \
 524                                       const char **keyp,                \
 525                                       valtype **valp)                   \
 526   {                                                                     \
 527     void *v;                                                            \
 528     digestmap_iter_get((digestmap_iter_t*) iter, keyp, &v);             \
 529     *valp = v;                                                          \
 530   }                                                                     \
 531   static INLINE int prefix##iter_done(prefix##iter_t *iter)             \
 532   {                                                                     \
 533     return digestmap_iter_done((digestmap_iter_t*)iter);                \
 534   }
 535
 536 #if SIZEOF_INT == 4
 537 #define BITARRAY_SHIFT 5
 538 #elif SIZEOF_INT == 8
 539 #define BITARRAY_SHIFT 6
 540 #else
 541 #error "int is neither 4 nor 8 bytes. I can't deal with that."
 542 #endif
 543 #define BITARRAY_MASK ((1u<<BITARRAY_SHIFT)-1)
 544
 545 /** A random-access array of one-bit-wide elements. */
 546 typedef unsigned int bitarray_t;
 547 /** Create a new bit array that can hold <b>n_bits</b> bits. */
 548 static INLINE bitarray_t *
 549 bitarray_init_zero(unsigned int n_bits)
 550 {
 551   /* round up to the next int. */
 552   size_t sz = (n_bits+BITARRAY_MASK) >> BITARRAY_SHIFT;
 553   return tor_malloc_zero(sz*sizeof(unsigned int));
 554 }
 555 /** Expand <b>ba</b> from holding <b>n_bits_old</b> to <b>n_bits_new</b>,
 556  * clearing all new bits.  Returns a possibly changed pointer to the
 557  * bitarray. */
 558 static INLINE bitarray_t *
 559 bitarray_expand(bitarray_t *ba,
 560                 unsigned int n_bits_old, unsigned int n_bits_new)
 561 {
 562   size_t sz_old = (n_bits_old+BITARRAY_MASK) >> BITARRAY_SHIFT;
 563   size_t sz_new = (n_bits_new+BITARRAY_MASK) >> BITARRAY_SHIFT;
 564   char *ptr;
 565   if (sz_new <= sz_old)
 566     return ba;
 567   ptr = tor_realloc(ba, sz_new*sizeof(unsigned int));
 568   /* This memset does nothing to the older excess bytes.  But they were
 569    * already set to 0 by bitarry_init_zero. */
 570   memset(ptr+sz_old*sizeof(unsigned int), 0,
 571          (sz_new-sz_old)*sizeof(unsigned int));
 572   return (bitarray_t*) ptr;
 573 }
 574 /** Free the bit array <b>ba</b>. */
 575 static INLINE void
 576 bitarray_free(bitarray_t *ba)
 577 {
 578   tor_free(ba);
 579 }
 580 /** Set the <b>bit</b>th bit in <b>b</b> to 1. */
 581 static INLINE void
 582 bitarray_set(bitarray_t *b, int bit)
 583 {
 584   b[bit >> BITARRAY_SHIFT] |= (1u << (bit & BITARRAY_MASK));
 585 }
 586 /** Set the <b>bit</b>th bit in <b>b</b> to 0. */
 587 static INLINE void
 588 bitarray_clear(bitarray_t *b, int bit)
 589 {
 590   b[bit >> BITARRAY_SHIFT] &= ~ (1u << (bit & BITARRAY_MASK));
 591 }
 592 /** Return true iff <b>bit</b>th bit in <b>b</b> is nonzero.  NOTE: does
 593  * not necessarily return 1 on true. */
 594 static INLINE unsigned int
 595 bitarray_is_set(bitarray_t *b, int bit)
 596 {
 597   return b[bit >> BITARRAY_SHIFT] & (1u << (bit & BITARRAY_MASK));
 598 }
 599
 600 /** A set of digests, implemented as a Bloom filter. */
 601 typedef struct {
 602   int mask; /**< One less than the number of bits in <b>ba</b>; always one less
 603              * than a power of two. */
 604   bitarray_t *ba; /**< A bit array to implement the Bloom filter. */
 605 } digestset_t;
 606
 607 #define BIT(n) ((n) & set->mask)
 608 /** Add the digest <b>digest</b> to <b>set</b>. */
 609 static INLINE void
 610 digestset_add(digestset_t *set, const char *digest)
 611 {
 612   const uint32_t *p = (const uint32_t *)digest;
 613   const uint32_t d1 = p[0] + (p[1]>>16);
 614   const uint32_t d2 = p[1] + (p[2]>>16);
 615   const uint32_t d3 = p[2] + (p[3]>>16);
 616   const uint32_t d4 = p[3] + (p[0]>>16);
 617   bitarray_set(set->ba, BIT(d1));
 618   bitarray_set(set->ba, BIT(d2));
 619   bitarray_set(set->ba, BIT(d3));
 620   bitarray_set(set->ba, BIT(d4));
 621 }
 622
 623 /** If <b>digest</b> is in <b>set</b>, return nonzero.  Otherwise,
 624  * <em>probably</em> return zero. */
 625 static INLINE int
 626 digestset_contains(const digestset_t *set, const char *digest)
 627 {
 628   const uint32_t *p = (const uint32_t *)digest;
 629   const uint32_t d1 = p[0] + (p[1]>>16);
 630   const uint32_t d2 = p[1] + (p[2]>>16);
 631   const uint32_t d3 = p[2] + (p[3]>>16);
 632   const uint32_t d4 = p[3] + (p[0]>>16);
 633   return bitarray_is_set(set->ba, BIT(d1)) &&
 634          bitarray_is_set(set->ba, BIT(d2)) &&
 635          bitarray_is_set(set->ba, BIT(d3)) &&
 636          bitarray_is_set(set->ba, BIT(d4));
 637 }
 638 #undef BIT
 639
 640 digestset_t *digestset_new(int max_elements);
 641 void digestset_free(digestset_t* set);
 642
 643 /* These functions, given an <b>array</b> of <b>n_elements</b>, return the
 644  * <b>nth</b> lowest element. <b>nth</b>=0 gives the lowest element;
 645  * <b>n_elements</b>-1 gives the highest; and (<b>n_elements</b>-1) / 2 gives
 646  * the median.  As a side effect, the elements of <b>array</b> are sorted. */
 647 int find_nth_int(int *array, int n_elements, int nth);
 648 time_t find_nth_time(time_t *array, int n_elements, int nth);
 649 double find_nth_double(double *array, int n_elements, int nth);
 650 int32_t find_nth_int32(int32_t *array, int n_elements, int nth);
 651 uint32_t find_nth_uint32(uint32_t *array, int n_elements, int nth);
 652 long find_nth_long(long *array, int n_elements, int nth);
 653 static INLINE int
 654 median_int(int *array, int n_elements)
 655 {
 656   return find_nth_int(array, n_elements, (n_elements-1)/2);
 657 }
 658 static INLINE time_t
 659 median_time(time_t *array, int n_elements)
 660 {
 661   return find_nth_time(array, n_elements, (n_elements-1)/2);
 662 }
 663 static INLINE double
 664 median_double(double *array, int n_elements)
 665 {
 666   return find_nth_double(array, n_elements, (n_elements-1)/2);
 667 }
 668 static INLINE uint32_t
 669 median_uint32(uint32_t *array, int n_elements)
 670 {
 671   return find_nth_uint32(array, n_elements, (n_elements-1)/2);
 672 }
 673 static INLINE int32_t
 674 median_int32(int32_t *array, int n_elements)
 675 {
 676   return find_nth_int32(array, n_elements, (n_elements-1)/2);
 677 }
 678
 679 #endif
 680