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