version2/src/C/hashtable.h

   1 /*      Copyright (c) 2015 Regents of the University of California
   2  *
   3  *      Author: Brian Demsky <bdemsky@uci.edu>
   4  *
   5  *      This program is free software; you can redistribute it and/or
   6  *      modify it under the terms of the GNU General Public License
   7  *      version 2 as published by the Free Software Foundation.
   8  */
   9
  10 /** @file hashtable.h
  11  *  @brief Hashtable.  Standard chained bucket variety.
  12  */
  13
  14 #ifndef HASHTABLE_H__
  15 #define HASHTABLE_H__
  16
  17 #include <stdlib.h>
  18 #include <stdio.h>
  19 #include <string.h>
  20 #include "common.h"
  21 #include "mymemory.h"
  22
  23 /**
  24  * @brief Hashtable node
  25  *
  26  * @tparam _Key    Type name for the key
  27  * @tparam _Val    Type name for the values to be stored
  28  */
  29 template<typename _Key, typename _Val>
  30 struct Hashlistnode {
  31         _Key key;
  32         _Val val;
  33         uint hashcode;
  34         struct Hashlistnode<_Key, _Val> *next;
  35         struct Hashlistnode<_Key, _Val> *prev;
  36 };
  37
  38 template<typename _Key, int _Shift, typename _KeyInt>
  39 inline unsigned int defaultHashFunction(_Key hash) {
  40         return (unsigned int)(((_KeyInt)hash) >> _Shift);
  41 }
  42
  43 template<typename _Key>
  44 inline bool defaultEquals(_Key key1, _Key key2) {
  45         return key1 == key2;
  46 }
  47
  48 /**
  49  * @brief A simple, custom hash table
  50  *
  51  * By default it is snapshotting, but you can pass in your own allocation
  52  * functions. Note that this table does not support the value 0 (NULL) used as
  53  * a key and is designed primarily with pointer-based keys in mind. Other
  54  * primitive key types are supported only for non-zero values.
  55  *
  56  * @tparam _Key    Type name for the key
  57  * @tparam _Val    Type name for the values to be stored
  58  * @tparam _KeyInt int32_t type that is at least as large as _Key. Used for key
  59  *                 manipulation and storage.
  60  * @tparam _Shift  Logical shift to apply to all keys. Default 0.
  61  */
  62
  63 template<typename _Key, typename _Val, typename _KeyInt = uintptr_t, int _Shift = 0, unsigned int (*hash_function)(_Key) = defaultHashFunction<_Key, _Shift, _KeyInt>, bool (*equals)(_Key, _Key) = defaultEquals<_Key> >
  64 class Hashtable {
  65 public:
  66         /**
  67          * @brief Hash table constructor
  68          * @param initialcapacity Sets the initial capacity of the hash table.
  69          * Default size 1024.
  70          * @param factor Sets the percentage full before the hashtable is
  71          * resized. Default ratio 0.5.
  72          */
  73         Hashtable(unsigned int initialcapacity = 1024, double factor = 0.5) {
  74                 // Allocate space for the hash table
  75                 table = (struct Hashlistnode<_Key, _Val> *)ourcalloc(initialcapacity, sizeof(struct Hashlistnode<_Key, _Val>));
  76                 zero = NULL;
  77                 loadfactor = factor;
  78                 capacity = initialcapacity;
  79                 capacitymask = initialcapacity - 1;
  80
  81                 threshold = (unsigned int)(initialcapacity * loadfactor);
  82                 Size = 0;                                                       // Initial number of elements in the hash
  83                 tail = list = NULL;
  84         }
  85
  86 Hashtable<_Key, _Val, _KeyInt, _Shift, hash_function, equals> * clone() {
  87         Hashtable<_Key, _Val, _KeyInt, _Shift, hash_function, equals> * ctable = new Hashtable<_Key, _Val, _KeyInt, _Shift, hash_function, equals> (capacity, loadfactor);
  88         struct Hashlistnode<_Key, _Val> * ptr = list;
  89         while (ptr != NULL) {
  90                 ctable->put(ptr->key, ptr->val);
  91                 ptr = ptr->next;
  92         }
  93         return ctable;
  94 }
  95
  96
  97         /** @brief Hash table destructor */
  98         ~Hashtable() {
  99                 ourfree(table);
 100                 if (zero)
 101                         ourfree(zero);
 102         }
 103
 104         /** Override: new operator */
 105         void *operator new(size_t size) {
 106                 return ourmalloc(size);
 107         }
 108
 109         /** Override: delete operator */
 110         void operator delete(void *p, size_t size) {
 111                 ourfree(p);
 112         }
 113
 114         /** Override: new[] operator */
 115         void *operator new[](size_t size) {
 116                 return ourmalloc(size);
 117         }
 118
 119         /** Override: delete[] operator */
 120         void operator delete[](void *p, size_t size) {
 121                 ourfree(p);
 122         }
 123
 124         /** @brief Reset the table to its initial state. */
 125         void clear() {
 126                 memset(table, 0, capacity * sizeof(struct Hashlistnode<_Key, _Val>));
 127                 if (zero) {
 128                         ourfree(zero);
 129                         zero = NULL;
 130                 }
 131                 Size = 0;
 132                 tail = list = NULL;
 133         }
 134
 135         /** Doesn't work with zero value */
 136         _Val getRandomValue() {
 137                 while (true) {
 138                         unsigned int index = random() & capacitymask;
 139                         struct Hashlistnode<_Key, _Val> *bin = &table[index];
 140                         if (bin->key != NULL && bin->val != NULL) {
 141                                 return bin->val;
 142                         }
 143                 }
 144         }
 145
 146         void resetAndDeleteKeys() {
 147                 for (unsigned int i = 0; i < capacity; i++) {
 148                         struct Hashlistnode<_Key, _Val> *bin = &table[i];
 149                         if (bin->key != NULL) {
 150                                 delete bin->key;
 151                                 bin->key = NULL;
 152                                 if (bin->val != NULL) {
 153                                         bin->val = NULL;
 154                                 }
 155                         }
 156                 }
 157                 if (zero) {
 158                         ourfree(zero);
 159                         zero = NULL;
 160                 }
 161                 Size = 0;
 162                 tail = list = NULL;
 163         }
 164
 165         void resetAndDeleteVals() {
 166                 for (unsigned int i = 0; i < capacity; i++) {
 167                         struct Hashlistnode<_Key, _Val> *bin = &table[i];
 168                         if (bin->key != NULL) {
 169                                 bin->key = NULL;
 170                                 if (bin->val != NULL) {
 171                                         delete bin->val;
 172                                         bin->val = NULL;
 173                                 }
 174                         }
 175                 }
 176                 if (zero) {
 177                         if (zero->val != NULL)
 178                                 delete zero->val;
 179                         ourfree(zero);
 180                         zero = NULL;
 181                 }
 182                 Size = 0;
 183                 tail = list = NULL;
 184         }
 185
 186         void resetAndFreeVals() {
 187                 for (unsigned int i = 0; i < capacity; i++) {
 188                         struct Hashlistnode<_Key, _Val> *bin = &table[i];
 189                         if (bin->key != NULL) {
 190                                 bin->key = NULL;
 191                                 if (bin->val != NULL) {
 192                                         ourfree(bin->val);
 193                                         bin->val = NULL;
 194                                 }
 195                         }
 196                 }
 197                 if (zero) {
 198                         if (zero->val != NULL)
 199                                 ourfree(zero->val);
 200                         ourfree(zero);
 201                         zero = NULL;
 202                 }
 203                 Size = 0;
 204                 tail = list = NULL;
 205         }
 206
 207         /**
 208          * @brief Put a key/value pair into the table
 209          * @param key The key for the new value; must not be 0 or NULL
 210          * @param val The value to store in the table
 211          */
 212         _Val put(_Key key, _Val val) {
 213                 /* Hashtable cannot handle 0 as a key */
 214                 if (!key) {
 215                         _Val oldval;
 216                         if (!zero) {
 217                                 zero = (struct Hashlistnode<_Key, _Val> *)ourmalloc(sizeof(struct Hashlistnode<_Key, _Val>));
 218                                 zero->next = list;
 219                                 if (list != NULL)
 220                                         list->prev = zero;
 221                                 else
 222                                         tail = zero;
 223                                 list = zero;
 224                                 Size++;
 225                                 oldval = (_Val) 0;
 226                         } else
 227                                 oldval = zero->val;
 228                         zero->key = key;
 229                         zero->val = val;
 230                         return oldval;
 231                 }
 232
 233                 if (Size > threshold)
 234                         resize(capacity << 1);
 235
 236                 struct Hashlistnode<_Key, _Val> *search;
 237
 238                 unsigned int hashcode = hash_function(key);
 239                 unsigned int index = hashcode;
 240                 do {
 241                         index &= capacitymask;
 242                         search = &table[index];
 243                         if (!search->key) {
 244                                 //key is null, probably done
 245                                 break;
 246                         }
 247                         if (search->hashcode == hashcode)
 248                                 if (equals(search->key, key)) {
 249                                         _Val oldval = search->val;
 250                                         search->val = val;
 251                                         return oldval;
 252                                 }
 253                         index++;
 254                 } while (true);
 255
 256                 search->key = key;
 257                 search->val = val;
 258                 search->hashcode = hashcode;
 259                 search->next = list;
 260                 if (list == NULL)
 261                         tail = search;
 262                 else
 263                         list->prev = search;
 264                 Size++;
 265                 return (_Val) 0;
 266         }
 267
 268         /**
 269          * @brief Lookup the corresponding value for the given key
 270          * @param key The key for finding the value; must not be 0 or NULL
 271          * @return The value in the table, if the key is found; otherwise 0
 272          */
 273         _Val get(_Key key) const {
 274                 struct Hashlistnode<_Key, _Val> *search;
 275
 276                 /* Hashtable cannot handle 0 as a key */
 277                 if (!key) {
 278                         if (zero)
 279                                 return zero->val;
 280                         else
 281                                 return (_Val) 0;
 282                 }
 283
 284                 unsigned int hashcode = hash_function(key);
 285                 unsigned int oindex = hashcode & capacitymask;
 286                 unsigned int index = oindex;
 287                 do {
 288                         search = &table[index];
 289                         if (!search->key) {
 290                                 if (!search->val)
 291                                         break;
 292                         } else
 293                         if (hashcode == search->hashcode)
 294                                 if (equals(search->key, key))
 295                                         return search->val;
 296                         index++;
 297                         index &= capacitymask;
 298                         if (index == oindex)
 299                                 break;
 300                 } while (true);
 301                 return (_Val)0;
 302         }
 303
 304         /**
 305          * @brief Remove the given key and return the corresponding value
 306          * @param key The key for finding the value; must not be 0 or NULL
 307          * @return The value in the table, if the key is found; otherwise 0
 308          */
 309         _Val remove(_Key key) {
 310                 struct Hashlistnode<_Key, _Val> *search;
 311
 312                 if (!key) {
 313                         if (!zero) {
 314                                 return (_Val)0;
 315                         } else {
 316                                 _Val v = zero->val;
 317                                 if (zero->next != NULL)
 318                                         zero->next->prev = zero->prev;
 319                                 else
 320                                         tail = zero->prev;
 321
 322                                 if (zero->prev != NULL)
 323                                         zero->prev->next = zero->next;
 324                                 else
 325                                         list = zero->next;
 326
 327                                 ourfree(zero);
 328                                 zero = NULL;
 329                                 Size--;
 330                                 return v;
 331                         }
 332                 }
 333
 334
 335                 unsigned int hashcode = hash_function(key);
 336                 unsigned int index = hashcode;
 337                 do {
 338                         index &= capacitymask;
 339                         search = &table[index];
 340                         if (!search->key) {
 341                                 if (!search->val)
 342                                         break;
 343                         } else
 344                         if (hashcode == search->hashcode)
 345                                 if (equals(search->key, key)) {
 346                                         _Val v = search->val;
 347                                         //empty out this bin
 348                                         search->val = (_Val) 1;
 349                                         search->key = 0;
 350
 351                                         if (search->next != NULL)
 352                                                 search->next->prev = search->prev;
 353                                         else
 354                                                 tail = search->prev;
 355
 356                                         if (search->prev != NULL)
 357                                                 search->prev->next = search->next;
 358                                         else
 359                                                 list = search->next;
 360
 361                                         Size--;
 362                                         return v;
 363                                 }
 364                         index++;
 365                 } while (true);
 366                 return (_Val)0;
 367         }
 368
 369         unsigned int size() const {
 370                 return Size;
 371         }
 372
 373
 374         /**
 375          * @brief Check whether the table contains a value for the given key
 376          * @param key The key for finding the value; must not be 0 or NULL
 377          * @return True, if the key is found; false otherwise
 378          */
 379         bool contains(_Key key) const {
 380                 struct Hashlistnode<_Key, _Val> *search;
 381
 382                 /* Hashtable cannot handle 0 as a key */
 383                 if (!key) {
 384                         return zero != NULL;
 385                 }
 386
 387                 unsigned int index = hash_function(key);
 388                 unsigned int hashcode = index;
 389                 do {
 390                         index &= capacitymask;
 391                         search = &table[index];
 392                         if (!search->key) {
 393                                 if (!search->val)
 394                                         break;
 395                         } else
 396                         if (hashcode == search->hashcode)
 397                                 if (equals(search->key, key))
 398                                         return true;
 399                         index++;
 400                 } while (true);
 401                 return false;
 402         }
 403
 404         /**
 405          * @brief Resize the table
 406          * @param newsize The new size of the table
 407          */
 408         void resize(unsigned int newsize) {
 409                 struct Hashlistnode<_Key, _Val> *oldtable = table;
 410                 struct Hashlistnode<_Key, _Val> *newtable;
 411                 unsigned int oldcapacity = capacity;
 412
 413                 if ((newtable = (struct Hashlistnode<_Key, _Val> *)ourcalloc(newsize, sizeof(struct Hashlistnode<_Key, _Val>))) == NULL) {
 414                         model_print("calloc error %s %d\n", __FILE__, __LINE__);
 415                         exit(EXIT_FAILURE);
 416                 }
 417
 418                 table = newtable;                                                                                       // Update the global hashtable upon resize()
 419                 capacity = newsize;
 420                 capacitymask = newsize - 1;
 421                 list = tail = NULL;
 422                 threshold = (unsigned int)(newsize * loadfactor);
 423
 424                 struct Hashlistnode<_Key, _Val> *bin = &oldtable[0];
 425                 struct Hashlistnode<_Key, _Val> *lastbin = &oldtable[oldcapacity];
 426                 for (; bin < lastbin; bin++) {
 427                         _Key key = bin->key;
 428
 429                         struct Hashlistnode<_Key, _Val> *search;
 430                         if (!key)
 431                                 continue;
 432
 433                         unsigned int hashcode = bin->hashcode;
 434                         unsigned int index = hashcode;
 435                         do {
 436                                 index &= capacitymask;
 437                                 search = &table[index];
 438                                 index++;
 439                         } while (search->key);
 440
 441                         if (tail == NULL)
 442                                 tail = search;
 443                         search->next = list;
 444                         if (list != NULL)
 445                                 list->prev = search;
 446                         list = search;
 447                         search->hashcode = hashcode;
 448                         search->key = key;
 449                         search->val = bin->val;
 450                 }
 451
 452                 ourfree(oldtable);                                                                                              // Free the memory of the old hash table
 453         }
 454         double getLoadFactor() {return loadfactor;}
 455         unsigned int getCapacity() {return capacity;}
 456         struct Hashlistnode<_Key, _Val> *table;
 457         struct Hashlistnode<_Key, _Val> *zero;
 458         struct Hashlistnode<_Key, _Val> *list;
 459         struct Hashlistnode<_Key, _Val> *tail;
 460         unsigned int capacity;
 461         unsigned int Size;
 462 private:
 463         unsigned int capacitymask;
 464         unsigned int threshold;
 465         double loadfactor;
 466 };
 467
 468 #endif/* __HASHTABLE_H__ */