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 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> >
  63 class Hashtable {
  64 public:
  65         /**
  66          * @brief Hash table constructor
  67          * @param initialcapacity Sets the initial capacity of the hash table.
  68          * Default size 1024.
  69          * @param factor Sets the percentage full before the hashtable is
  70          * resized. Default ratio 0.5.
  71          */
  72         Hashtable(unsigned int initialcapacity = 1024, double factor = 0.5) {
  73                 // Allocate space for the hash table
  74                 table = (struct Hashlistnode<_Key, _Val> *)ourcalloc(initialcapacity, sizeof(struct Hashlistnode<_Key, _Val>));
  75                 zero = NULL;
  76                 loadfactor = factor;
  77                 capacity = initialcapacity;
  78                 capacitymask = initialcapacity - 1;
  79
  80                 threshold = (unsigned int)(initialcapacity * loadfactor);
  81                 Size = 0;                                                       // Initial number of elements in the hash
  82                 tail = list = NULL;
  83         }
  84
  85         /** @brief Hash table destructor */
  86         ~Hashtable() {
  87                 ourfree(table);
  88                 if (zero)
  89                         ourfree(zero);
  90         }
  91
  92         /** Override: new operator */
  93         void *operator new(size_t size) {
  94                 return ourmalloc(size);
  95         }
  96
  97         /** Override: delete operator */
  98         void operator delete(void *p, size_t size) {
  99                 ourfree(p);
 100         }
 101
 102         /** Override: new[] operator */
 103         void *operator new[](size_t size) {
 104                 return ourmalloc(size);
 105         }
 106
 107         /** Override: delete[] operator */
 108         void operator delete[](void *p, size_t size) {
 109                 ourfree(p);
 110         }
 111
 112         /** @brief Reset the table to its initial state. */
 113         void clear() {
 114                 memset(table, 0, capacity * sizeof(struct Hashlistnode<_Key, _Val>));
 115                 if (zero) {
 116                         ourfree(zero);
 117                         zero = NULL;
 118                 }
 119                 Size = 0;
 120                 tail = list = NULL;
 121         }
 122
 123         /** Doesn't work with zero value */
 124         _Val getRandomValue() {
 125                 while (true) {
 126                         unsigned int index = random() & capacitymask;
 127                         struct Hashlistnode<_Key, _Val> *bin = &table[index];
 128                         if (bin->key != NULL && bin->val != NULL) {
 129                                 return bin->val;
 130                         }
 131                 }
 132         }
 133
 134         void resetAndDeleteKeys() {
 135                 for (unsigned int i = 0; i < capacity; i++) {
 136                         struct Hashlistnode<_Key, _Val> *bin = &table[i];
 137                         if (bin->key != NULL) {
 138                                 delete bin->key;
 139                                 bin->key = NULL;
 140                                 if (bin->val != NULL) {
 141                                         bin->val = NULL;
 142                                 }
 143                         }
 144                 }
 145                 if (zero) {
 146                         ourfree(zero);
 147                         zero = NULL;
 148                 }
 149                 Size = 0;
 150                 tail = list = NULL;
 151         }
 152
 153         void resetAndDeleteVals() {
 154                 for (unsigned int i = 0; i < capacity; i++) {
 155                         struct Hashlistnode<_Key, _Val> *bin = &table[i];
 156                         if (bin->key != NULL) {
 157                                 bin->key = NULL;
 158                                 if (bin->val != NULL) {
 159                                         delete bin->val;
 160                                         bin->val = NULL;
 161                                 }
 162                         }
 163                 }
 164                 if (zero) {
 165                         if (zero->val != NULL)
 166                                 delete zero->val;
 167                         ourfree(zero);
 168                         zero = NULL;
 169                 }
 170                 Size = 0;
 171                 tail = list = NULL;
 172         }
 173
 174         void resetAndFreeVals() {
 175                 for (unsigned int i = 0; i < capacity; i++) {
 176                         struct Hashlistnode<_Key, _Val> *bin = &table[i];
 177                         if (bin->key != NULL) {
 178                                 bin->key = NULL;
 179                                 if (bin->val != NULL) {
 180                                         ourfree(bin->val);
 181                                         bin->val = NULL;
 182                                 }
 183                         }
 184                 }
 185                 if (zero) {
 186                         if (zero->val != NULL)
 187                                 ourfree(zero->val);
 188                         ourfree(zero);
 189                         zero = NULL;
 190                 }
 191                 Size = 0;
 192                 tail = list = NULL;
 193         }
 194
 195         /**
 196          * @brief Put a key/value pair into the table
 197          * @param key The key for the new value; must not be 0 or NULL
 198          * @param val The value to store in the table
 199          */
 200         _Val put(_Key key, _Val val) {
 201                 /* Hashtable cannot handle 0 as a key */
 202                 if (!key) {
 203                         _Val oldval;
 204                         if (!zero) {
 205                                 zero = (struct Hashlistnode<_Key, _Val> *)ourmalloc(sizeof(struct Hashlistnode<_Key, _Val>));
 206                                 zero->next = list;
 207                                 if (list != NULL)
 208                                         list->prev = zero;
 209                                 else
 210                                         tail = zero;
 211                                 list = zero;
 212                                 Size++;
 213                                 oldval = (_Val) 0;
 214                         } else
 215                                 oldval = zero->val;
 216                         zero->key = key;
 217                         zero->val = val;
 218                         return oldval;
 219                 }
 220
 221                 if (Size > threshold)
 222                         resize(capacity << 1);
 223
 224                 struct Hashlistnode<_Key, _Val> *search;
 225
 226                 unsigned int hashcode = hash_function(key);
 227                 unsigned int index = hashcode;
 228                 do {
 229                         index &= capacitymask;
 230                         search = &table[index];
 231                         if (!search->key) {
 232                                 //key is null, probably done
 233                                 break;
 234                         }
 235                         if (search->hashcode == hashcode)
 236                                 if (equals(search->key, key)) {
 237                                         _Val oldval = search->val;
 238                                         search->val = val;
 239                                         return oldval;
 240                                 }
 241                         index++;
 242                 } while (true);
 243
 244                 search->key = key;
 245                 search->val = val;
 246                 search->hashcode = hashcode;
 247                 search->next = list;
 248                 if (list == NULL)
 249                         tail = search;
 250                 else
 251                         list->prev = search;
 252                 Size++;
 253                 return (_Val) 0;
 254         }
 255
 256         /**
 257          * @brief Lookup the corresponding value for the given key
 258          * @param key The key for finding the value; must not be 0 or NULL
 259          * @return The value in the table, if the key is found; otherwise 0
 260          */
 261         _Val get(_Key key) const {
 262                 struct Hashlistnode<_Key, _Val> *search;
 263
 264                 /* Hashtable cannot handle 0 as a key */
 265                 if (!key) {
 266                         if (zero)
 267                                 return zero->val;
 268                         else
 269                                 return (_Val) 0;
 270                 }
 271
 272                 unsigned int hashcode = hash_function(key);
 273                 unsigned int oindex = hashcode & capacitymask;
 274                 unsigned int index = oindex;
 275                 do {
 276                         search = &table[index];
 277                         if (!search->key) {
 278                                 if (!search->val)
 279                                         break;
 280                         } else
 281                         if (hashcode == search->hashcode)
 282                                 if (equals(search->key, key))
 283                                         return search->val;
 284                         index++;
 285                         index &= capacitymask;
 286                         if (index == oindex)
 287                                 break;
 288                 } while (true);
 289                 return (_Val)0;
 290         }
 291
 292         /**
 293          * @brief Remove the given key and return the corresponding value
 294          * @param key The key for finding the value; must not be 0 or NULL
 295          * @return The value in the table, if the key is found; otherwise 0
 296          */
 297         _Val remove(_Key key) {
 298                 struct Hashlistnode<_Key, _Val> *search;
 299
 300                 if (!key) {
 301                         if (!zero) {
 302                                 return (_Val)0;
 303                         } else {
 304                                 _Val v = zero->val;
 305                                 if (zero -> next != NULL)
 306                                         zero -> next -> prev = zero ->prev;
 307                                 else
 308                                         tail = zero -> prev;
 309
 310                                 if (zero -> prev != NULL)
 311                                         zero -> prev -> next = zero -> next;
 312                                 else
 313                                         list = zero->next;
 314
 315                                 ourfree(zero);
 316                                 zero = NULL;
 317                                 Size--;
 318                                 return v;
 319                         }
 320                 }
 321
 322
 323                 unsigned int hashcode = hash_function(key);
 324                 unsigned int index = hashcode;
 325                 do {
 326                         index &= capacitymask;
 327                         search = &table[index];
 328                         if (!search->key) {
 329                                 if (!search->val)
 330                                         break;
 331                         } else
 332                         if (hashcode == search->hashcode)
 333                                 if (equals(search->key, key)) {
 334                                         _Val v = search->val;
 335                                         //empty out this bin
 336                                         search->val = (_Val) 1;
 337                                         search->key = 0;
 338
 339                                         if (search -> next != NULL)
 340                                                 search -> next -> prev = search ->prev;
 341                                         else
 342                                                 tail = search -> prev;
 343
 344                                         if (search -> prev != NULL)
 345                                                 search -> prev -> next = search -> next;
 346                                         else
 347                                                 list = search->next;
 348
 349                                         Size--;
 350                                         return v;
 351                                 }
 352                         index++;
 353                 } while (true);
 354                 return (_Val)0;
 355         }
 356
 357         unsigned int size() const {
 358                 return Size;
 359         }
 360
 361
 362         /**
 363          * @brief Check whether the table contains a value for the given key
 364          * @param key The key for finding the value; must not be 0 or NULL
 365          * @return True, if the key is found; false otherwise
 366          */
 367         bool contains(_Key key) const {
 368                 struct Hashlistnode<_Key, _Val> *search;
 369
 370                 /* Hashtable cannot handle 0 as a key */
 371                 if (!key) {
 372                         return zero != NULL;
 373                 }
 374
 375                 unsigned int index = hash_function(key);
 376                 unsigned int hashcode = index;
 377                 do {
 378                         index &= capacitymask;
 379                         search = &table[index];
 380                         if (!search->key) {
 381                                 if (!search->val)
 382                                         break;
 383                         } else
 384                         if (hashcode == search->hashcode)
 385                                 if (equals(search->key, key))
 386                                         return true;
 387                         index++;
 388                 } while (true);
 389                 return false;
 390         }
 391
 392         /**
 393          * @brief Resize the table
 394          * @param newsize The new size of the table
 395          */
 396         void resize(unsigned int newsize) {
 397                 struct Hashlistnode<_Key, _Val> *oldtable = table;
 398                 struct Hashlistnode<_Key, _Val> *newtable;
 399                 unsigned int oldcapacity = capacity;
 400
 401                 if ((newtable = (struct Hashlistnode<_Key, _Val> *)ourcalloc(newsize, sizeof(struct Hashlistnode<_Key, _Val>))) == NULL) {
 402                         model_print("calloc error %s %d\n", __FILE__, __LINE__);
 403                         exit(EXIT_FAILURE);
 404                 }
 405
 406                 table = newtable;                                                                                       // Update the global hashtable upon resize()
 407                 capacity = newsize;
 408                 capacitymask = newsize - 1;
 409                 list = tail = NULL;
 410                 threshold = (unsigned int)(newsize * loadfactor);
 411
 412                 struct Hashlistnode<_Key, _Val> *bin = &oldtable[0];
 413                 struct Hashlistnode<_Key, _Val> *lastbin = &oldtable[oldcapacity];
 414                 for (; bin < lastbin; bin++) {
 415                         _Key key = bin->key;
 416
 417                         struct Hashlistnode<_Key, _Val> *search;
 418                         if (!key)
 419                                 continue;
 420
 421                         unsigned int hashcode = bin->hashcode;
 422                         unsigned int index = hashcode;
 423                         do {
 424                                 index &= capacitymask;
 425                                 search = &table[index];
 426                                 index++;
 427                         } while (search->key);
 428
 429                         if (tail == NULL)
 430                                 tail = search;
 431                         search -> next = list;
 432                         if (list != NULL)
 433                                 list -> prev = search;
 434                         list = search;
 435                         search->hashcode = hashcode;
 436                         search->key = key;
 437                         search->val = bin->val;
 438                 }
 439
 440                 ourfree(oldtable);                                                                                              // Free the memory of the old hash table
 441         }
 442         double getLoadFactor() {return loadfactor;}
 443         unsigned int getCapacity() {return capacity;}
 444         struct Hashlistnode<_Key, _Val> *table;
 445         struct Hashlistnode<_Key, _Val> *zero;
 446   struct Hashlistnode<_Key, _Val> * list;
 447   struct Hashlistnode<_Key, _Val> * tail;
 448   unsigned int capacity;
 449         unsigned int Size;
 450 private:
 451         unsigned int capacitymask;
 452         unsigned int threshold;
 453         double loadfactor;
 454 };
 455
 456 #endif/* __HASHTABLE_H__ */