reactos/lib/3rdparty/icu4ros/icu/source/common/uhash.h

   1 /*
   2 ******************************************************************************
   3 *   Copyright (C) 1997-2006, 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  * A key comparison function.
 122  * @param val1 A key stored in a hashtable
 123  * @param val2 A key stored in a hashtable
 124  * @return TRUE if the two keys are equal.
 125  */
 126 typedef UBool U_CALLCONV UValueComparator(const UHashTok val1,
 127                                           const UHashTok val2);
 128 /**
 129  * A function called by <TT>uhash_remove</TT>,
 130  * <TT>uhash_close</TT>, or <TT>uhash_put</TT> to delete
 131  * an existing key or value.
 132  * @param obj A key or value stored in a hashtable
 133  */
 134 typedef void U_CALLCONV UObjectDeleter(void* obj);
 135
 136 /**
 137  * This specifies whether or not, and how, the hastable resizes itself.
 138  * See uhash_setResizePolicy().
 139  */
 140 enum UHashResizePolicy {
 141     U_GROW,            /* Grow on demand, do not shrink */
 142     U_GROW_AND_SHRINK, /* Grow and shrink on demand */
 143     U_FIXED            /* Never change size */
 144 };
 145
 146 /**
 147  * The UHashtable struct.  Clients should treat this as an opaque data
 148  * type and manipulate it only through the uhash_... API.
 149  */
 150 struct UHashtable {
 151
 152     /* Main key-value pair storage array */
 153
 154     UHashElement *elements;
 155
 156     /* Function pointers */
 157
 158     UHashFunction *keyHasher;      /* Computes hash from key.
 159                                    * Never null. */
 160     UKeyComparator *keyComparator; /* Compares keys for equality.
 161                                    * Never null. */
 162     UValueComparator *valueComparator; /* Compares the values for equality */
 163
 164     UObjectDeleter *keyDeleter;    /* Deletes keys when required.
 165                                    * If NULL won't do anything */
 166     UObjectDeleter *valueDeleter;  /* Deletes values when required.
 167                                    * If NULL won't do anything */
 168
 169     /* Size parameters */
 170
 171     int32_t     count;      /* The number of key-value pairs in this table.
 172                              * 0 <= count <= length.  In practice we
 173                              * never let count == length (see code). */
 174     int32_t     length;     /* The physical size of the arrays hashes, keys
 175                              * and values.  Must be prime. */
 176     int32_t     primeIndex;     /* Index into our prime table for length.
 177                                  * length == PRIMES[primeIndex] */
 178
 179     /* Rehashing thresholds */
 180
 181     int32_t     highWaterMark;  /* If count > highWaterMark, rehash */
 182     int32_t     lowWaterMark;   /* If count < lowWaterMark, rehash */
 183     float       highWaterRatio; /* 0..1; high water as a fraction of length */
 184     float       lowWaterRatio;  /* 0..1; low water as a fraction of length */
 185
 186     UBool       allocated; /* Was this UHashtable allocated? */
 187 };
 188 typedef struct UHashtable UHashtable;
 189
 190 U_CDECL_END
 191
 192 /********************************************************************
 193  * API
 194  ********************************************************************/
 195
 196 /**
 197  * Initialize a new UHashtable.
 198  * @param keyHash A pointer to the key hashing function.  Must not be
 199  * NULL.
 200  * @param keyComp A pointer to the function that compares keys.  Must
 201  * not be NULL.
 202  * @param status A pointer to an UErrorCode to receive any errors.
 203  * @return A pointer to a UHashtable, or 0 if an error occurred.
 204  * @see uhash_openSize
 205  */
 206 U_CAPI UHashtable* U_EXPORT2
 207 uhash_open(UHashFunction *keyHash,
 208            UKeyComparator *keyComp,
 209            UValueComparator *valueComp,
 210            UErrorCode *status);
 211
 212 /**
 213  * Initialize a new UHashtable with a given initial size.
 214  * @param keyHash A pointer to the key hashing function.  Must not be
 215  * NULL.
 216  * @param keyComp A pointer to the function that compares keys.  Must
 217  * not be NULL.
 218  * @param size The initial capacity of this hash table.
 219  * @param status A pointer to an UErrorCode to receive any errors.
 220  * @return A pointer to a UHashtable, or 0 if an error occurred.
 221  * @see uhash_open
 222  */
 223 U_CAPI UHashtable* U_EXPORT2
 224 uhash_openSize(UHashFunction *keyHash,
 225                UKeyComparator *keyComp,
 226                UValueComparator *valueComp,
 227                int32_t size,
 228                UErrorCode *status);
 229
 230 /**
 231  * Initialize an existing UHashtable.
 232  * @param keyHash A pointer to the key hashing function.  Must not be
 233  * NULL.
 234  * @param keyComp A pointer to the function that compares keys.  Must
 235  * not be NULL.
 236  * @param status A pointer to an UErrorCode to receive any errors.
 237  * @return A pointer to a UHashtable, or 0 if an error occurred.
 238  * @see uhash_openSize
 239  */
 240 U_CAPI UHashtable* U_EXPORT2
 241 uhash_init(UHashtable *hash,
 242            UHashFunction *keyHash,
 243            UKeyComparator *keyComp,
 244            UValueComparator *valueComp,
 245            UErrorCode *status);
 246
 247 /**
 248  * Close a UHashtable, releasing the memory used.
 249  * @param hash The UHashtable to close.
 250  */
 251 U_CAPI void U_EXPORT2
 252 uhash_close(UHashtable *hash);
 253
 254
 255
 256 /**
 257  * Set the function used to hash keys.
 258  * @param hash The UHashtable to set
 259  * @param fn the function to be used hash keys; must not be NULL
 260  * @return the previous key hasher; non-NULL
 261  */
 262 U_CAPI UHashFunction *U_EXPORT2
 263 uhash_setKeyHasher(UHashtable *hash, UHashFunction *fn);
 264
 265 /**
 266  * Set the function used to compare keys.  The default comparison is a
 267  * void* pointer comparison.
 268  * @param hash The UHashtable to set
 269  * @param fn the function to be used compare keys; must not be NULL
 270  * @return the previous key comparator; non-NULL
 271  */
 272 U_CAPI UKeyComparator *U_EXPORT2
 273 uhash_setKeyComparator(UHashtable *hash, UKeyComparator *fn);
 274
 275 /**
 276  * Set the function used to compare values.  The default comparison is a
 277  * void* pointer comparison.
 278  * @param hash The UHashtable to set
 279  * @param fn the function to be used compare keys; must not be NULL
 280  * @return the previous key comparator; non-NULL
 281  */
 282 U_CAPI UValueComparator *U_EXPORT2
 283 uhash_setValueComparator(UHashtable *hash, UValueComparator *fn);
 284
 285 /**
 286  * Set the function used to delete keys.  If this function pointer is
 287  * NULL, this hashtable does not delete keys.  If it is non-NULL, this
 288  * hashtable does delete keys.  This function should be set once
 289  * before any elements are added to the hashtable and should not be
 290  * changed thereafter.
 291  * @param hash The UHashtable to set
 292  * @param fn the function to be used delete keys, or NULL
 293  * @return the previous key deleter; may be NULL
 294  */
 295 U_CAPI UObjectDeleter *U_EXPORT2
 296 uhash_setKeyDeleter(UHashtable *hash, UObjectDeleter *fn);
 297
 298 /**
 299  * Set the function used to delete values.  If this function pointer
 300  * is NULL, this hashtable does not delete values.  If it is non-NULL,
 301  * this hashtable does delete values.  This function should be set
 302  * once before any elements are added to the hashtable and should not
 303  * be changed thereafter.
 304  * @param hash The UHashtable to set
 305  * @param fn the function to be used delete values, or NULL
 306  * @return the previous value deleter; may be NULL
 307  */
 308 U_CAPI UObjectDeleter *U_EXPORT2
 309 uhash_setValueDeleter(UHashtable *hash, UObjectDeleter *fn);
 310
 311 /**
 312  * Specify whether or not, and how, the hastable resizes itself.
 313  * By default, tables grow but do not shrink (policy U_GROW).
 314  * See enum UHashResizePolicy.
 315  * @param hash The UHashtable to set
 316  * @param policy The way the hashtable resizes itself, {U_GROW, U_GROW_AND_SHRINK, U_FIXED}
 317  */
 318 U_CAPI void U_EXPORT2
 319 uhash_setResizePolicy(UHashtable *hash, enum UHashResizePolicy policy);
 320
 321 /**
 322  * Get the number of key-value pairs stored in a UHashtable.
 323  * @param hash The UHashtable to query.
 324  * @return The number of key-value pairs stored in hash.
 325  */
 326 U_CAPI int32_t U_EXPORT2
 327 uhash_count(const UHashtable *hash);
 328
 329 /**
 330  * Put a (key=pointer, value=pointer) item in a UHashtable.  If the
 331  * keyDeleter is non-NULL, then the hashtable owns 'key' after this
 332  * call.  If the valueDeleter is non-NULL, then the hashtable owns
 333  * 'value' after this call.  Storing a NULL value is the same as
 334  * calling uhash_remove().
 335  * @param hash The target UHashtable.
 336  * @param key The key to store.
 337  * @param value The value to store, may be NULL (see above).
 338  * @param status A pointer to an UErrorCode to receive any errors.
 339  * @return The previous value, or NULL if none.
 340  * @see uhash_get
 341  */
 342 U_CAPI void* U_EXPORT2
 343 uhash_put(UHashtable *hash,
 344           void *key,
 345           void *value,
 346           UErrorCode *status);
 347
 348 /**
 349  * Put a (key=integer, value=pointer) item in a UHashtable.
 350  * keyDeleter must be NULL.  If the valueDeleter is non-NULL, then the
 351  * hashtable owns 'value' after this call.  Storing a NULL value is
 352  * the same as calling uhash_remove().
 353  * @param hash The target UHashtable.
 354  * @param key The integer key to store.
 355  * @param value The value to store, may be NULL (see above).
 356  * @param status A pointer to an UErrorCode to receive any errors.
 357  * @return The previous value, or NULL if none.
 358  * @see uhash_get
 359  */
 360 U_CAPI void* U_EXPORT2
 361 uhash_iput(UHashtable *hash,
 362            int32_t key,
 363            void* value,
 364            UErrorCode *status);
 365
 366 /**
 367  * Put a (key=pointer, value=integer) item in a UHashtable.  If the
 368  * keyDeleter is non-NULL, then the hashtable owns 'key' after this
 369  * call.  valueDeleter must be NULL.  Storing a 0 value is the same as
 370  * calling uhash_remove().
 371  * @param hash The target UHashtable.
 372  * @param key The key to store.
 373  * @param value The integer value to store.
 374  * @param status A pointer to an UErrorCode to receive any errors.
 375  * @return The previous value, or 0 if none.
 376  * @see uhash_get
 377  */
 378 U_CAPI int32_t U_EXPORT2
 379 uhash_puti(UHashtable *hash,
 380            void* key,
 381            int32_t value,
 382            UErrorCode *status);
 383
 384 /**
 385  * Put a (key=integer, value=integer) item in a UHashtable.  If the
 386  * keyDeleter is non-NULL, then the hashtable owns 'key' after this
 387  * call.  valueDeleter must be NULL.  Storing a 0 value is the same as
 388  * calling uhash_remove().
 389  * @param hash The target UHashtable.
 390  * @param key The key to store.
 391  * @param value The integer value to store.
 392  * @param status A pointer to an UErrorCode to receive any errors.
 393  * @return The previous value, or 0 if none.
 394  * @see uhash_get
 395  */
 396 U_CAPI int32_t U_EXPORT2
 397 uhash_iputi(UHashtable *hash,
 398            int32_t key,
 399            int32_t value,
 400            UErrorCode *status);
 401
 402 /**
 403  * Retrieve a pointer value from a UHashtable using a pointer key,
 404  * as previously stored by uhash_put().
 405  * @param hash The target UHashtable.
 406  * @param key A pointer key stored in a hashtable
 407  * @return The requested item, or NULL if not found.
 408  */
 409 U_CAPI void* U_EXPORT2
 410 uhash_get(const UHashtable *hash,
 411           const void *key);
 412
 413 /**
 414  * Retrieve a pointer value from a UHashtable using a integer key,
 415  * as previously stored by uhash_iput().
 416  * @param hash The target UHashtable.
 417  * @param key An integer key stored in a hashtable
 418  * @return The requested item, or NULL if not found.
 419  */
 420 U_CAPI void* U_EXPORT2
 421 uhash_iget(const UHashtable *hash,
 422            int32_t key);
 423
 424 /**
 425  * Retrieve an integer value from a UHashtable using a pointer key,
 426  * as previously stored by uhash_puti().
 427  * @param hash The target UHashtable.
 428  * @param key A pointer key stored in a hashtable
 429  * @return The requested item, or 0 if not found.
 430  */
 431 U_CAPI int32_t U_EXPORT2
 432 uhash_geti(const UHashtable *hash,
 433            const void* key);
 434 /**
 435  * Retrieve an integer value from a UHashtable using an integer key,
 436  * as previously stored by uhash_iputi().
 437  * @param hash The target UHashtable.
 438  * @param key An integer key stored in a hashtable
 439  * @return The requested item, or 0 if not found.
 440  */
 441 U_CAPI int32_t U_EXPORT2
 442 uhash_igeti(const UHashtable *hash,
 443            int32_t key);
 444
 445 /**
 446  * Remove an item from a UHashtable stored by uhash_put().
 447  * @param hash The target UHashtable.
 448  * @param key A key stored in a hashtable
 449  * @return The item removed, or NULL if not found.
 450  */
 451 U_CAPI void* U_EXPORT2
 452 uhash_remove(UHashtable *hash,
 453              const void *key);
 454
 455 /**
 456  * Remove an item from a UHashtable stored by uhash_iput().
 457  * @param hash The target UHashtable.
 458  * @param key An integer key stored in a hashtable
 459  * @return The item removed, or NULL if not found.
 460  */
 461 U_CAPI void* U_EXPORT2
 462 uhash_iremove(UHashtable *hash,
 463               int32_t key);
 464
 465 /**
 466  * Remove an item from a UHashtable stored by uhash_puti().
 467  * @param hash The target UHashtable.
 468  * @param key An key stored in a hashtable
 469  * @return The item removed, or 0 if not found.
 470  */
 471 U_CAPI int32_t U_EXPORT2
 472 uhash_removei(UHashtable *hash,
 473               const void* key);
 474
 475 /**
 476  * Remove an item from a UHashtable stored by uhash_iputi().
 477  * @param hash The target UHashtable.
 478  * @param key An integer key stored in a hashtable
 479  * @return The item removed, or 0 if not found.
 480  */
 481 U_CAPI int32_t U_EXPORT2
 482 uhash_iremovei(UHashtable *hash,
 483                int32_t key);
 484
 485 /**
 486  * Remove all items from a UHashtable.
 487  * @param hash The target UHashtable.
 488  */
 489 U_CAPI void U_EXPORT2
 490 uhash_removeAll(UHashtable *hash);
 491
 492 /**
 493  * Locate an element of a UHashtable.  The caller must not modify the
 494  * returned object.  The primary use of this function is to obtain the
 495  * stored key when it may not be identical to the search key.  For
 496  * example, if the compare function is a case-insensitive string
 497  * compare, then the hash key may be desired in order to obtain the
 498  * canonical case corresponding to a search key.
 499  * @param hash The target UHashtable.
 500  * @param key A key stored in a hashtable
 501  * @return a hash element, or NULL if the key is not found.
 502  */
 503 U_CAPI const UHashElement* U_EXPORT2
 504 uhash_find(const UHashtable *hash, const void* key);
 505
 506 /**
 507  * Iterate through the elements of a UHashtable.  The caller must not
 508  * modify the returned object.  However, uhash_removeElement() may be
 509  * called during iteration to remove an element from the table.
 510  * Iteration may safely be resumed afterwards.  If uhash_put() is
 511  * called during iteration the iteration will then be out of sync and
 512  * should be restarted.
 513  * @param hash The target UHashtable.
 514  * @param pos This should be set to -1 initially, and left untouched
 515  * thereafter.
 516  * @return a hash element, or NULL if no further key-value pairs
 517  * exist in the table.
 518  */
 519 U_CAPI const UHashElement* U_EXPORT2
 520 uhash_nextElement(const UHashtable *hash,
 521                   int32_t *pos);
 522
 523 /**
 524  * Remove an element, returned by uhash_nextElement(), from the table.
 525  * Iteration may be safely continued afterwards.
 526  * @param hash The hashtable
 527  * @param e The element, returned by uhash_nextElement(), to remove.
 528  * Must not be NULL.  Must not be an empty or deleted element (as long
 529  * as this was returned by uhash_nextElement() it will not be empty or
 530  * deleted).  Note: Although this parameter is const, it will be
 531  * modified.
 532  * @return the value that was removed.
 533  */
 534 U_CAPI void* U_EXPORT2
 535 uhash_removeElement(UHashtable *hash, const UHashElement* e);
 536
 537 /********************************************************************
 538  * UHashTok convenience
 539  ********************************************************************/
 540
 541 /**
 542  * Return a UHashTok for an integer.
 543  * @param i The given integer
 544  * @return a UHashTok for an integer.
 545  */
 546 /*U_CAPI UHashTok U_EXPORT2
 547 uhash_toki(int32_t i);*/
 548
 549 /**
 550  * Return a UHashTok for a pointer.
 551  * @param p The given pointer
 552  * @return a UHashTok for a pointer.
 553  */
 554 /*U_CAPI UHashTok U_EXPORT2
 555 uhash_tokp(void* p);*/
 556
 557 /********************************************************************
 558  * UChar* and char* Support Functions
 559  ********************************************************************/
 560
 561 /**
 562  * Generate a hash code for a null-terminated UChar* string.  If the
 563  * string is not null-terminated do not use this function.  Use
 564  * together with uhash_compareUChars.
 565  * @param key The string (const UChar*) to hash.
 566  * @return A hash code for the key.
 567  */
 568 U_CAPI int32_t U_EXPORT2
 569 uhash_hashUChars(const UHashTok key);
 570
 571 /**
 572  * Generate a hash code for a null-terminated char* string.  If the
 573  * string is not null-terminated do not use this function.  Use
 574  * together with uhash_compareChars.
 575  * @param key The string (const char*) to hash.
 576  * @return A hash code for the key.
 577  */
 578 U_CAPI int32_t U_EXPORT2
 579 uhash_hashChars(const UHashTok key);
 580
 581 /* Used by UnicodeString to compute its hashcode - Not public API. */
 582 U_CAPI int32_t U_EXPORT2
 583 uhash_hashUCharsN(const UChar *key, int32_t length);
 584
 585 /**
 586  * Generate a case-insensitive hash code for a null-terminated char*
 587  * string.  If the string is not null-terminated do not use this
 588  * function.  Use together with uhash_compareIChars.
 589  * @param key The string (const char*) to hash.
 590  * @return A hash code for the key.
 591  */
 592 U_CAPI int32_t U_EXPORT2
 593 uhash_hashIChars(const UHashTok key);
 594
 595 /**
 596  * Comparator for null-terminated UChar* strings.  Use together with
 597  * uhash_hashUChars.
 598  * @param key1 The string for comparison
 599  * @param key2 The string for comparison
 600  * @return true if key1 and key2 are equal, return false otherwise.
 601  */
 602 U_CAPI UBool U_EXPORT2
 603 uhash_compareUChars(const UHashTok key1, const UHashTok key2);
 604
 605 /**
 606  * Comparator for null-terminated char* strings.  Use together with
 607  * uhash_hashChars.
 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_compareChars(const UHashTok key1, const UHashTok key2);
 614
 615 /**
 616  * Case-insensitive comparator for null-terminated char* strings.  Use
 617  * together with uhash_hashIChars.
 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_compareIChars(const UHashTok key1, const UHashTok key2);
 624
 625 /********************************************************************
 626  * UnicodeString Support Functions
 627  ********************************************************************/
 628
 629 /**
 630  * Hash function for UnicodeString* keys.
 631  * @param key The string (const char*) to hash.
 632  * @return A hash code for the key.
 633  */
 634 U_CAPI int32_t U_EXPORT2
 635 uhash_hashUnicodeString(const UHashTok key);
 636
 637 /**
 638  * Hash function for UnicodeString* keys (case insensitive).
 639  * Make sure to use together with uhash_compareCaselessUnicodeString.
 640  * @param key The string (const char*) to hash.
 641  * @return A hash code for the key.
 642  */
 643 U_CAPI int32_t U_EXPORT2
 644 uhash_hashCaselessUnicodeString(const UHashTok key);
 645
 646 /**
 647  * Comparator function for UnicodeString* keys.
 648  * @param key1 The string for comparison
 649  * @param key2 The string for comparison
 650  * @return true if key1 and key2 are equal, return false otherwise.
 651  */
 652 U_CAPI UBool U_EXPORT2
 653 uhash_compareUnicodeString(const UHashTok key1, const UHashTok key2);
 654
 655 /**
 656  * Comparator function for UnicodeString* keys (case insensitive).
 657  * Make sure to use together with uhash_hashCaselessUnicodeString.
 658  * @param key1 The string for comparison
 659  * @param key2 The string for comparison
 660  * @return true if key1 and key2 are equal, return false otherwise.
 661  */
 662 U_CAPI UBool U_EXPORT2
 663 uhash_compareCaselessUnicodeString(const UHashTok key1, const UHashTok key2);
 664
 665 /**
 666  * Deleter function for UnicodeString* keys or values.
 667  * @param obj The object to be deleted
 668  */
 669 U_CAPI void U_EXPORT2
 670 uhash_deleteUnicodeString(void *obj);
 671
 672 /********************************************************************
 673  * int32_t Support Functions
 674  ********************************************************************/
 675
 676 /**
 677  * Hash function for 32-bit integer keys.
 678  * @param key The string (const char*) to hash.
 679  * @return A hash code for the key.
 680  */
 681 U_CAPI int32_t U_EXPORT2
 682 uhash_hashLong(const UHashTok key);
 683
 684 /**
 685  * Comparator function for 32-bit integer keys.
 686  * @param key1 The integer for comparison
 687  * @param Key2 The integer for comparison
 688  * @return true if key1 and key2 are equal, return false otherwise
 689  */
 690 U_CAPI UBool U_EXPORT2
 691 uhash_compareLong(const UHashTok key1, const UHashTok key2);
 692
 693 /********************************************************************
 694  * Other Support Functions
 695  ********************************************************************/
 696
 697 /**
 698  * Deleter for Hashtable objects.
 699  * @param obj The object to be deleted
 700  */
 701 U_CAPI void U_EXPORT2
 702 uhash_deleteHashtable(void *obj);
 703
 704 /**
 705  * Deleter for UVector objects.
 706  * @param obj The object to be deleted
 707  */
 708 U_CAPI void U_EXPORT2
 709 uhash_deleteUVector(void *obj);
 710
 711 /**
 712  * Deleter for any key or value allocated using uprv_malloc.  Calls
 713  * uprv_free.
 714  * @param obj The object to be deleted
 715  */
 716 U_CAPI void U_EXPORT2
 717 uhash_freeBlock(void *obj);
 718
 719 /**
 720  * Checks if the given hash tables are equal or not.
 721  * @param hash1
 722  * @param hash2
 723  * @return true if the hashtables are equal and false if not.
 724  */
 725 U_CAPI UBool U_EXPORT2
 726 uhash_equals(const UHashtable* hash1, const UHashtable* hash2);
 727
 728 #endif