icuSources/common/uhash.h

   1 /*
   2 ******************************************************************************
   3 *   Copyright (C) 1997-2004, International Business Machines
   4 *   Corporation and others.  All Rights Reserved.
   5 ******************************************************************************
   6 *   Date        Name        Description
   7 *   03/22/00    aliu        Adapted from original C++ ICU Hashtable.
   8 *   07/06/01    aliu        Modified to support int32_t keys on
   9 *                           platforms with sizeof(void*) < 32.
  10 ******************************************************************************
  11 */
  12
  13 #ifndef UHASH_H
  14 #define UHASH_H
  15
  16 #include "unicode/utypes.h"
  17
  18 /**
  19  * UHashtable stores key-value pairs and does moderately fast lookup
  20  * based on keys.  It provides a good tradeoff between access time and
  21  * storage space.  As elements are added to it, it grows to accomodate
  22  * them.  By default, the table never shrinks, even if all elements
  23  * are removed from it.
  24  *
  25  * Keys and values are stored as void* pointers.  These void* pointers
  26  * may be actual pointers to strings, objects, or any other structure
  27  * in memory, or they may simply be integral values cast to void*.
  28  * UHashtable doesn't care and manipulates them via user-supplied
  29  * functions.  These functions hash keys, compare keys, delete keys,
  30  * and delete values.  Some function pointers are optional (may be
  31  * NULL); others must be supplied.  Several prebuilt functions exist
  32  * to handle common key types.
  33  *
  34  * UHashtable ownership of keys and values is flexible, and controlled
  35  * by whether or not the key deleter and value deleter functions are
  36  * set.  If a void* key is actually a pointer to a deletable object,
  37  * then UHashtable can be made to delete that object by setting the
  38  * key deleter function pointer to a non-NULL value.  If this is done,
  39  * then keys passed to uhash_put() are owned by the hashtable and will
  40  * be deleted by it at some point, either as keys are replaced, or
  41  * when uhash_close() is finally called.  The same is true of values
  42  * and the value deleter function pointer.  Keys passed to methods
  43  * other than uhash_put() are never owned by the hashtable.
  44  *
  45  * NULL values are not allowed.  uhash_get() returns NULL to indicate
  46  * a key that is not in the table, and having a NULL value in the
  47  * table would generate an ambiguous result.  If a key and a NULL
  48  * value is passed to uhash_put(), this has the effect of doing a
  49  * uhash_remove() on that key.  This keeps uhash_get(), uhash_count(),
  50  * and uhash_nextElement() consistent with one another.
  51  *
  52  * To see everything in a hashtable, use uhash_nextElement() to
  53  * iterate through its contents.  Each call to this function returns a
  54  * UHashElement pointer.  A hash element contains a key, value, and
  55  * hashcode.  During iteration an element may be deleted by calling
  56  * uhash_removeElement(); iteration may safely continue thereafter.
  57  * The uhash_remove() function may also be safely called in
  58  * mid-iteration.  However, if uhash_put() is called during iteration
  59  * then the iteration will be out of sync.  Under no circumstances
  60  * should the UHashElement returned by uhash_nextElement be modified
  61  * directly.
  62  *
  63  * By default, the hashtable grows when necessary, but never shrinks,
  64  * even if all items are removed.  For most applications this is
  65  * optimal.  However, in a highly dynamic usage where memory is at a
  66  * premium, the table can be set to both grow and shrink by calling
  67  * uhash_setResizePolicy() with the policy U_GROW_AND_SHRINK.  In a
  68  * situation where memory is critical and the client wants a table
  69  * that does not grow at all, the constant U_FIXED can be used.
  70  */
  71
  72 /********************************************************************
  73  * Data Structures
  74  ********************************************************************/
  75
  76 U_CDECL_BEGIN
  77
  78 /**
  79  * A key or value within the hashtable.  It may be either a 32-bit
  80  * integral value or an opaque void* pointer.  The void* pointer may
  81  * be smaller than 32 bits (e.g. 24 bits) or may be larger (e.g. 64
  82  * bits).  The hashing and comparison functions take a pointer to a
  83  * UHashTok, but the deleter receives the void* pointer within it.
  84  *
  85  * Because a UHashTok is the size of a native pointer or a 32-bit
  86  * integer, we pass it around by value.
  87  */
  88 union UHashTok {
  89     void*   pointer;
  90     int32_t integer;
  91 };
  92 typedef union UHashTok UHashTok;
  93
  94 /**
  95  * This is a single hash element.
  96  */
  97 struct UHashElement {
  98     /* Reorder these elements to pack nicely if necessary */
  99     int32_t  hashcode;
 100     UHashTok value;
 101     UHashTok key;
 102 };
 103 typedef struct UHashElement UHashElement;
 104
 105 /**
 106  * A hashing function.
 107  * @param key A key stored in a hashtable
 108  * @return A NON-NEGATIVE hash code for parm.
 109  */
 110 typedef int32_t U_CALLCONV UHashFunction(const UHashTok key);
 111
 112 /**
 113  * A key comparison function.
 114  * @param key1 A key stored in a hashtable
 115  * @param key2 A key stored in a hashtable
 116  * @return TRUE if the two keys are equal.
 117  */
 118 typedef UBool U_CALLCONV UKeyComparator(const UHashTok key1,
 119                                         const UHashTok key2);
 120
 121 /**
 122  * A function called by <TT>uhash_remove</TT>,
 123  * <TT>uhash_close</TT>, or <TT>uhash_put</TT> to delete
 124  * an existing key or value.
 125  * @param obj A key or value stored in a hashtable
 126  */
 127 typedef void U_CALLCONV UObjectDeleter(void* obj);
 128
 129 /**
 130  * This specifies whether or not, and how, the hastable resizes itself.
 131  * See uhash_setResizePolicy().
 132  */
 133 enum UHashResizePolicy {
 134     U_GROW,            /* Grow on demand, do not shrink */
 135     U_GROW_AND_SHRINK, /* Grow and shrink on demand */
 136     U_FIXED            /* Never change size */
 137 };
 138
 139 /**
 140  * The UHashtable struct.  Clients should treat this as an opaque data
 141  * type and manipulate it only through the uhash_... API.
 142  */
 143 struct UHashtable {
 144
 145     /* Main key-value pair storage array */
 146
 147     UHashElement *elements;
 148
 149     /* Size parameters */
 150
 151     int32_t     count;      /* The number of key-value pairs in this table.
 152                              * 0 <= count <= length.  In practice we
 153                              * never let count == length (see code). */
 154     int32_t     length;     /* The physical size of the arrays hashes, keys
 155                              * and values.  Must be prime. */
 156     int32_t     primeIndex;     /* Index into our prime table for length.
 157                                  * length == PRIMES[primeIndex] */
 158
 159     /* Rehashing thresholds */
 160
 161     int32_t     highWaterMark;  /* If count > highWaterMark, rehash */
 162     int32_t     lowWaterMark;   /* If count < lowWaterMark, rehash */
 163     float       highWaterRatio; /* 0..1; high water as a fraction of length */
 164     float       lowWaterRatio;  /* 0..1; low water as a fraction of length */
 165
 166     /* Function pointers */
 167
 168     UHashFunction *keyHasher;      /* Computes hash from key.
 169                                    * Never null. */
 170     UKeyComparator *keyComparator; /* Compares keys for equality.
 171                                    * Never null. */
 172     UObjectDeleter *keyDeleter;    /* Deletes keys when required.
 173                                    * If NULL won't do anything */
 174     UObjectDeleter *valueDeleter;  /* Deletes values when required.
 175                                    * If NULL won't do anything */
 176 };
 177 typedef struct UHashtable UHashtable;
 178
 179 U_CDECL_END
 180
 181 /********************************************************************
 182  * API
 183  ********************************************************************/
 184
 185 /**
 186  * Initialize a new UHashtable.
 187  * @param keyHash A pointer to the key hashing function.  Must not be
 188  * NULL.
 189  * @param keyComp A pointer to the function that compares keys.  Must
 190  * not be NULL.
 191  * @param status A pointer to an UErrorCode to receive any errors.
 192  * @return A pointer to a UHashtable, or 0 if an error occurred.
 193  * @see uhash_openSize
 194  */
 195 U_CAPI UHashtable* U_EXPORT2
 196 uhash_open(UHashFunction *keyHash,
 197            UKeyComparator *keyComp,
 198            UErrorCode *status);
 199
 200 /**
 201  * Initialize a new UHashtable with a given initial size.
 202  * @param keyHash A pointer to the key hashing function.  Must not be
 203  * NULL.
 204  * @param keyComp A pointer to the function that compares keys.  Must
 205  * not be NULL.
 206  * @param size The initial capacity of this hash table.
 207  * @param status A pointer to an UErrorCode to receive any errors.
 208  * @return A pointer to a UHashtable, or 0 if an error occurred.
 209  * @see uhash_open
 210  */
 211 U_CAPI UHashtable* U_EXPORT2
 212 uhash_openSize(UHashFunction *keyHash,
 213                UKeyComparator *keyComp,
 214                int32_t size,
 215                UErrorCode *status);
 216
 217 /**
 218  * Close a UHashtable, releasing the memory used.
 219  * @param hash The UHashtable to close.
 220  */
 221 U_CAPI void U_EXPORT2
 222 uhash_close(UHashtable *hash);
 223
 224
 225
 226 /**
 227  * Set the function used to hash keys.
 228  * @param hash The UHashtable to set
 229  * @param fn the function to be used hash keys; must not be NULL
 230  * @return the previous key hasher; non-NULL
 231  */
 232 U_CAPI UHashFunction *U_EXPORT2
 233 uhash_setKeyHasher(UHashtable *hash, UHashFunction *fn);
 234
 235 /**
 236  * Set the function used to compare keys.  The default comparison is a
 237  * void* pointer comparison.
 238  * @param hash The UHashtable to set
 239  * @param fn the function to be used compare keys; must not be NULL
 240  * @return the previous key comparator; non-NULL
 241  */
 242 U_CAPI UKeyComparator *U_EXPORT2
 243 uhash_setKeyComparator(UHashtable *hash, UKeyComparator *fn);
 244
 245 /**
 246  * Set the function used to delete keys.  If this function pointer is
 247  * NULL, this hashtable does not delete keys.  If it is non-NULL, this
 248  * hashtable does delete keys.  This function should be set once
 249  * before any elements are added to the hashtable and should not be
 250  * changed thereafter.
 251  * @param hash The UHashtable to set
 252  * @param fn the function to be used delete keys, or NULL
 253  * @return the previous key deleter; may be NULL
 254  */
 255 U_CAPI UObjectDeleter *U_EXPORT2
 256 uhash_setKeyDeleter(UHashtable *hash, UObjectDeleter *fn);
 257
 258 /**
 259  * Set the function used to delete values.  If this function pointer
 260  * is NULL, this hashtable does not delete values.  If it is non-NULL,
 261  * this hashtable does delete values.  This function should be set
 262  * once before any elements are added to the hashtable and should not
 263  * be changed thereafter.
 264  * @param hash The UHashtable to set
 265  * @param fn the function to be used delete values, or NULL
 266  * @return the previous value deleter; may be NULL
 267  */
 268 U_CAPI UObjectDeleter *U_EXPORT2
 269 uhash_setValueDeleter(UHashtable *hash, UObjectDeleter *fn);
 270
 271 /**
 272  * Specify whether or not, and how, the hastable resizes itself.
 273  * By default, tables grow but do not shrink (policy U_GROW).
 274  * See enum UHashResizePolicy.
 275  * @param hash The UHashtable to set
 276  * @param policy The way the hashtable resizes itself, {U_GROW, U_GROW_AND_SHRINK, U_FIXED}
 277  */
 278 U_CAPI void U_EXPORT2
 279 uhash_setResizePolicy(UHashtable *hash, enum UHashResizePolicy policy);
 280
 281 /**
 282  * Get the number of key-value pairs stored in a UHashtable.
 283  * @param hash The UHashtable to query.
 284  * @return The number of key-value pairs stored in hash.
 285  */
 286 U_CAPI int32_t U_EXPORT2
 287 uhash_count(const UHashtable *hash);
 288
 289 /**
 290  * Put a (key=pointer, value=pointer) item in a UHashtable.  If the
 291  * keyDeleter is non-NULL, then the hashtable owns 'key' after this
 292  * call.  If the valueDeleter is non-NULL, then the hashtable owns
 293  * 'value' after this call.  Storing a NULL value is the same as
 294  * calling uhash_remove().
 295  * @param hash The target UHashtable.
 296  * @param key The key to store.
 297  * @param value The value to store, may be NULL (see above).
 298  * @param status A pointer to an UErrorCode to receive any errors.
 299  * @return The previous value, or NULL if none.
 300  * @see uhash_get
 301  */
 302 U_CAPI void* U_EXPORT2
 303 uhash_put(UHashtable *hash,
 304           void *key,
 305           void *value,
 306           UErrorCode *status);
 307
 308 /**
 309  * Put a (key=integer, value=pointer) item in a UHashtable.
 310  * keyDeleter must be NULL.  If the valueDeleter is non-NULL, then the
 311  * hashtable owns 'value' after this call.  Storing a NULL value is
 312  * the same as calling uhash_remove().
 313  * @param hash The target UHashtable.
 314  * @param key The integer key to store.
 315  * @param value The value to store, may be NULL (see above).
 316  * @param status A pointer to an UErrorCode to receive any errors.
 317  * @return The previous value, or NULL if none.
 318  * @see uhash_get
 319  */
 320 U_CAPI void* U_EXPORT2
 321 uhash_iput(UHashtable *hash,
 322            int32_t key,
 323            void* value,
 324            UErrorCode *status);
 325
 326 /**
 327  * Put a (key=pointer, value=integer) item in a UHashtable.  If the
 328  * keyDeleter is non-NULL, then the hashtable owns 'key' after this
 329  * call.  valueDeleter must be NULL.  Storing a 0 value is the same as
 330  * calling uhash_remove().
 331  * @param hash The target UHashtable.
 332  * @param key The key to store.
 333  * @param value The integer value to store.
 334  * @param status A pointer to an UErrorCode to receive any errors.
 335  * @return The previous value, or 0 if none.
 336  * @see uhash_get
 337  */
 338 U_CAPI int32_t U_EXPORT2
 339 uhash_puti(UHashtable *hash,
 340            void* key,
 341            int32_t value,
 342            UErrorCode *status);
 343
 344 /**
 345  * Put a (key=integer, value=integer) item in a UHashtable.  If the
 346  * keyDeleter is non-NULL, then the hashtable owns 'key' after this
 347  * call.  valueDeleter must be NULL.  Storing a 0 value is the same as
 348  * calling uhash_remove().
 349  * @param hash The target UHashtable.
 350  * @param key The key to store.
 351  * @param value The integer value to store.
 352  * @param status A pointer to an UErrorCode to receive any errors.
 353  * @return The previous value, or 0 if none.
 354  * @see uhash_get
 355  */
 356 U_CAPI int32_t U_EXPORT2
 357 uhash_iputi(UHashtable *hash,
 358            int32_t key,
 359            int32_t value,
 360            UErrorCode *status);
 361
 362 /**
 363  * Retrieve a pointer value from a UHashtable using a pointer key,
 364  * as previously stored by uhash_put().
 365  * @param hash The target UHashtable.
 366  * @param key A pointer key stored in a hashtable
 367  * @return The requested item, or NULL if not found.
 368  */
 369 U_CAPI void* U_EXPORT2
 370 uhash_get(const UHashtable *hash,
 371           const void *key);
 372
 373 /**
 374  * Retrieve a pointer value from a UHashtable using a integer key,
 375  * as previously stored by uhash_iput().
 376  * @param hash The target UHashtable.
 377  * @param key An integer key stored in a hashtable
 378  * @return The requested item, or NULL if not found.
 379  */
 380 U_CAPI void* U_EXPORT2
 381 uhash_iget(const UHashtable *hash,
 382            int32_t key);
 383
 384 /**
 385  * Retrieve an integer value from a UHashtable using a pointer key,
 386  * as previously stored by uhash_puti().
 387  * @param hash The target UHashtable.
 388  * @param key A pointer key stored in a hashtable
 389  * @return The requested item, or 0 if not found.
 390  */
 391 U_CAPI int32_t U_EXPORT2
 392 uhash_geti(const UHashtable *hash,
 393            const void* key);
 394 /**
 395  * Retrieve an integer value from a UHashtable using an integer key,
 396  * as previously stored by uhash_iputi().
 397  * @param hash The target UHashtable.
 398  * @param key An integer key stored in a hashtable
 399  * @return The requested item, or 0 if not found.
 400  */
 401 U_CAPI int32_t U_EXPORT2
 402 uhash_igeti(const UHashtable *hash,
 403            int32_t key);
 404
 405 /**
 406  * Remove an item from a UHashtable stored by uhash_put().
 407  * @param hash The target UHashtable.
 408  * @param key A key stored in a hashtable
 409  * @return The item removed, or NULL if not found.
 410  */
 411 U_CAPI void* U_EXPORT2
 412 uhash_remove(UHashtable *hash,
 413              const void *key);
 414
 415 /**
 416  * Remove an item from a UHashtable stored by uhash_iput().
 417  * @param hash The target UHashtable.
 418  * @param key An integer key stored in a hashtable
 419  * @return The item removed, or NULL if not found.
 420  */
 421 U_CAPI void* U_EXPORT2
 422 uhash_iremove(UHashtable *hash,
 423               int32_t key);
 424
 425 /**
 426  * Remove an item from a UHashtable stored by uhash_puti().
 427  * @param hash The target UHashtable.
 428  * @param key An key stored in a hashtable
 429  * @return The item removed, or 0 if not found.
 430  */
 431 U_CAPI int32_t U_EXPORT2
 432 uhash_removei(UHashtable *hash,
 433               const void* key);
 434
 435 /**
 436  * Remove an item from a UHashtable stored by uhash_iputi().
 437  * @param hash The target UHashtable.
 438  * @param key An integer key stored in a hashtable
 439  * @return The item removed, or 0 if not found.
 440  */
 441 U_CAPI int32_t U_EXPORT2
 442 uhash_iremovei(UHashtable *hash,
 443                int32_t key);
 444
 445 /**
 446  * Remove all items from a UHashtable.
 447  * @param hash The target UHashtable.
 448  */
 449 U_CAPI void U_EXPORT2
 450 uhash_removeAll(UHashtable *hash);
 451
 452 /**
 453  * Locate an element of a UHashtable.  The caller must not modify the
 454  * returned object.  The primary use of this function is to obtain the
 455  * stored key when it may not be identical to the search key.  For
 456  * example, if the compare function is a case-insensitive string
 457  * compare, then the hash key may be desired in order to obtain the
 458  * canonical case corresponding to a search key.
 459  * @param hash The target UHashtable.
 460  * @param key A key stored in a hashtable
 461  * @return a hash element, or NULL if the key is not found.
 462  */
 463 U_CAPI const UHashElement* U_EXPORT2
 464 uhash_find(const UHashtable *hash, const void* key);
 465
 466 /**
 467  * Iterate through the elements of a UHashtable.  The caller must not
 468  * modify the returned object.  However, uhash_removeElement() may be
 469  * called during iteration to remove an element from the table.
 470  * Iteration may safely be resumed afterwards.  If uhash_put() is
 471  * called during iteration the iteration will then be out of sync and
 472  * should be restarted.
 473  * @param hash The target UHashtable.
 474  * @param pos This should be set to -1 initially, and left untouched
 475  * thereafter.
 476  * @return a hash element, or NULL if no further key-value pairs
 477  * exist in the table.
 478  */
 479 U_CAPI const UHashElement* U_EXPORT2
 480 uhash_nextElement(const UHashtable *hash,
 481                   int32_t *pos);
 482
 483 /**
 484  * Remove an element, returned by uhash_nextElement(), from the table.
 485  * Iteration may be safely continued afterwards.
 486  * @param hash The hashtable
 487  * @param e The element, returned by uhash_nextElement(), to remove.
 488  * Must not be NULL.  Must not be an empty or deleted element (as long
 489  * as this was returned by uhash_nextElement() it will not be empty or
 490  * deleted).  Note: Although this parameter is const, it will be
 491  * modified.
 492  * @return the value that was removed.
 493  */
 494 U_CAPI void* U_EXPORT2
 495 uhash_removeElement(UHashtable *hash, const UHashElement* e);
 496
 497 /********************************************************************
 498  * UHashTok convenience
 499  ********************************************************************/
 500
 501 /**
 502  * Return a UHashTok for an integer.
 503  * @param i The given integer
 504  * @return a UHashTok for an integer.
 505  */
 506 U_CAPI UHashTok U_EXPORT2
 507 uhash_toki(int32_t i);
 508
 509 /**
 510  * Return a UHashTok for a pointer.
 511  * @param p The given pointer
 512  * @return a UHashTok for a pointer.
 513  */
 514 U_CAPI UHashTok U_EXPORT2
 515 uhash_tokp(void* p);
 516
 517 /********************************************************************
 518  * UChar* and char* Support Functions
 519  ********************************************************************/
 520
 521 /**
 522  * Generate a hash code for a null-terminated UChar* string.  If the
 523  * string is not null-terminated do not use this function.  Use
 524  * together with uhash_compareUChars.
 525  * @param key The string (const UChar*) to hash.
 526  * @return A hash code for the key.
 527  */
 528 U_CAPI int32_t U_EXPORT2
 529 uhash_hashUChars(const UHashTok key);
 530
 531 /**
 532  * Generate a hash code for a null-terminated char* string.  If the
 533  * string is not null-terminated do not use this function.  Use
 534  * together with uhash_compareChars.
 535  * @param key The string (const char*) to hash.
 536  * @return A hash code for the key.
 537  */
 538 U_CAPI int32_t U_EXPORT2
 539 uhash_hashChars(const UHashTok key);
 540
 541 /* Used by UnicodeString to compute its hashcode - Not public API. */
 542 U_CAPI int32_t U_EXPORT2
 543 uhash_hashUCharsN(const UChar *key, int32_t length);
 544
 545 /**
 546  * Generate a case-insensitive hash code for a null-terminated char*
 547  * string.  If the string is not null-terminated do not use this
 548  * function.  Use together with uhash_compareIChars.
 549  * @param key The string (const char*) to hash.
 550  * @return A hash code for the key.
 551  */
 552 U_CAPI int32_t U_EXPORT2
 553 uhash_hashIChars(const UHashTok key);
 554
 555 /**
 556  * Comparator for null-terminated UChar* strings.  Use together with
 557  * uhash_hashUChars.
 558  * @param key1 The string for comparison
 559  * @param key2 The string for comparison
 560  * @return true if key1 and key2 are equal, return false otherwise.
 561  */
 562 U_CAPI UBool U_EXPORT2
 563 uhash_compareUChars(const UHashTok key1, const UHashTok key2);
 564
 565 /**
 566  * Comparator for null-terminated char* strings.  Use together with
 567  * uhash_hashChars.
 568  * @param key1 The string for comparison
 569  * @param key2 The string for comparison
 570  * @return true if key1 and key2 are equal, return false otherwise.
 571  */
 572 U_CAPI UBool U_EXPORT2
 573 uhash_compareChars(const UHashTok key1, const UHashTok key2);
 574
 575 /**
 576  * Case-insensitive comparator for null-terminated char* strings.  Use
 577  * together with uhash_hashIChars.
 578  * @param key1 The string for comparison
 579  * @param key2 The string for comparison
 580  * @return true if key1 and key2 are equal, return false otherwise.
 581  */
 582 U_CAPI UBool U_EXPORT2
 583 uhash_compareIChars(const UHashTok key1, const UHashTok key2);
 584
 585 /********************************************************************
 586  * UnicodeString Support Functions
 587  ********************************************************************/
 588
 589 /**
 590  * Hash function for UnicodeString* keys.
 591  * @param key The string (const char*) to hash.
 592  * @return A hash code for the key.
 593  */
 594 U_CAPI int32_t U_EXPORT2
 595 uhash_hashUnicodeString(const UHashTok key);
 596
 597 /**
 598  * Hash function for UnicodeString* keys (case insensitive).
 599  * Make sure to use together with uhash_compareCaselessUnicodeString.
 600  * @param key The string (const char*) to hash.
 601  * @return A hash code for the key.
 602  */
 603 U_CAPI int32_t U_EXPORT2
 604 uhash_hashCaselessUnicodeString(const UHashTok key);
 605
 606 /**
 607  * Comparator function for UnicodeString* keys.
 608  * @param key1 The string for comparison
 609  * @param key2 The string for comparison
 610  * @return true if key1 and key2 are equal, return false otherwise.
 611  */
 612 U_CAPI UBool U_EXPORT2
 613 uhash_compareUnicodeString(const UHashTok key1, const UHashTok key2);
 614
 615 /**
 616  * Comparator function for UnicodeString* keys (case insensitive).
 617  * Make sure to use together with uhash_hashCaselessUnicodeString.
 618  * @param key1 The string for comparison
 619  * @param key2 The string for comparison
 620  * @return true if key1 and key2 are equal, return false otherwise.
 621  */
 622 U_CAPI UBool U_EXPORT2
 623 uhash_compareCaselessUnicodeString(const UHashTok key1, const UHashTok key2);
 624
 625 /**
 626  * Deleter function for UnicodeString* keys or values.
 627  * @param obj The object to be deleted
 628  */
 629 U_CAPI void U_EXPORT2
 630 uhash_deleteUnicodeString(void *obj);
 631
 632 /********************************************************************
 633  * int32_t Support Functions
 634  ********************************************************************/
 635
 636 /**
 637  * Hash function for 32-bit integer keys.
 638  * @param key The string (const char*) to hash.
 639  * @return A hash code for the key.
 640  */
 641 U_CAPI int32_t U_EXPORT2
 642 uhash_hashLong(const UHashTok key);
 643
 644 /**
 645  * Comparator function for 32-bit integer keys.
 646  * @param key1 The integer for comparison
 647  * @param Key2 The integer for comparison
 648  * @return true if key1 and key2 are equal, return false otherwise
 649  */
 650 U_CAPI UBool U_EXPORT2
 651 uhash_compareLong(const UHashTok key1, const UHashTok key2);
 652
 653 /********************************************************************
 654  * Other Support Functions
 655  ********************************************************************/
 656
 657 /**
 658  * Deleter for Hashtable objects.
 659  * @param obj The object to be deleted
 660  */
 661 U_CAPI void U_EXPORT2
 662 uhash_deleteHashtable(void *obj);
 663
 664 /**
 665  * Deleter for UVector objects.
 666  * @param obj The object to be deleted
 667  */
 668 U_CAPI void U_EXPORT2
 669 uhash_deleteUVector(void *obj);
 670
 671 /**
 672  * Deleter for any key or value allocated using uprv_malloc.  Calls
 673  * uprv_free.
 674  * @param obj The object to be deleted
 675  */
 676 U_CAPI void U_EXPORT2
 677 uhash_freeBlock(void *obj);
 678
 679 #endif