icuSources/common/serv.cpp

   1 /**
   2 *******************************************************************************
   3 * Copyright (C) 2001-2014, International Business Machines Corporation.
   4 * All Rights Reserved.
   5 *******************************************************************************
   6 */
   7
   8 #include "unicode/utypes.h"
   9
  10 #if !UCONFIG_NO_SERVICE
  11
  12 #include "serv.h"
  13 #include "umutex.h"
  14
  15 #undef SERVICE_REFCOUNT
  16
  17 // in case we use the refcount stuff
  18
  19 U_NAMESPACE_BEGIN
  20
  21 /*
  22 ******************************************************************
  23 */
  24
  25 const UChar ICUServiceKey::PREFIX_DELIMITER = 0x002F;   /* '/' */
  26
  27 ICUServiceKey::ICUServiceKey(const UnicodeString& id)
  28 : _id(id) {
  29 }
  30
  31 ICUServiceKey::~ICUServiceKey()
  32 {
  33 }
  34
  35 const UnicodeString&
  36 ICUServiceKey::getID() const
  37 {
  38     return _id;
  39 }
  40
  41 UnicodeString&
  42 ICUServiceKey::canonicalID(UnicodeString& result) const
  43 {
  44     return result.append(_id);
  45 }
  46
  47 UnicodeString&
  48 ICUServiceKey::currentID(UnicodeString& result) const
  49 {
  50     return canonicalID(result);
  51 }
  52
  53 UnicodeString&
  54 ICUServiceKey::currentDescriptor(UnicodeString& result) const
  55 {
  56     prefix(result);
  57     result.append(PREFIX_DELIMITER);
  58     return currentID(result);
  59 }
  60
  61 UBool
  62 ICUServiceKey::fallback()
  63 {
  64     return FALSE;
  65 }
  66
  67 UBool
  68 ICUServiceKey::isFallbackOf(const UnicodeString& id) const
  69 {
  70     return id == _id;
  71 }
  72
  73 UnicodeString&
  74 ICUServiceKey::prefix(UnicodeString& result) const
  75 {
  76     return result;
  77 }
  78
  79 UnicodeString&
  80 ICUServiceKey::parsePrefix(UnicodeString& result)
  81 {
  82     int32_t n = result.indexOf(PREFIX_DELIMITER);
  83     if (n < 0) {
  84         n = 0;
  85     }
  86     result.remove(n);
  87     return result;
  88 }
  89
  90 UnicodeString&
  91 ICUServiceKey::parseSuffix(UnicodeString& result)
  92 {
  93     int32_t n = result.indexOf(PREFIX_DELIMITER);
  94     if (n >= 0) {
  95         result.remove(0, n+1);
  96     }
  97     return result;
  98 }
  99
 100 #ifdef SERVICE_DEBUG
 101 UnicodeString&
 102 ICUServiceKey::debug(UnicodeString& result) const
 103 {
 104     debugClass(result);
 105     result.append((UnicodeString)" id: ");
 106     result.append(_id);
 107     return result;
 108 }
 109
 110 UnicodeString&
 111 ICUServiceKey::debugClass(UnicodeString& result) const
 112 {
 113     return result.append((UnicodeString)"ICUServiceKey");
 114 }
 115 #endif
 116
 117 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(ICUServiceKey)
 118
 119 /*
 120 ******************************************************************
 121 */
 122
 123 ICUServiceFactory::~ICUServiceFactory() {}
 124
 125 SimpleFactory::SimpleFactory(UObject* instanceToAdopt, const UnicodeString& id, UBool visible)
 126 : _instance(instanceToAdopt), _id(id), _visible(visible)
 127 {
 128 }
 129
 130 SimpleFactory::~SimpleFactory()
 131 {
 132     delete _instance;
 133 }
 134
 135 UObject*
 136 SimpleFactory::create(const ICUServiceKey& key, const ICUService* service, UErrorCode& status) const
 137 {
 138     if (U_SUCCESS(status)) {
 139         UnicodeString temp;
 140         if (_id == key.currentID(temp)) {
 141             return service->cloneInstance(_instance);
 142         }
 143     }
 144     return NULL;
 145 }
 146
 147 void
 148 SimpleFactory::updateVisibleIDs(Hashtable& result, UErrorCode& status) const
 149 {
 150     if (_visible) {
 151         result.put(_id, (void*)this, status); // cast away const
 152     } else {
 153         result.remove(_id);
 154     }
 155 }
 156
 157 UnicodeString&
 158 SimpleFactory::getDisplayName(const UnicodeString& id, const Locale& /* locale */, UnicodeString& result) const
 159 {
 160     if (_visible && _id == id) {
 161         result = _id;
 162     } else {
 163         result.setToBogus();
 164     }
 165     return result;
 166 }
 167
 168 #ifdef SERVICE_DEBUG
 169 UnicodeString&
 170 SimpleFactory::debug(UnicodeString& toAppendTo) const
 171 {
 172     debugClass(toAppendTo);
 173     toAppendTo.append((UnicodeString)" id: ");
 174     toAppendTo.append(_id);
 175     toAppendTo.append((UnicodeString)", visible: ");
 176     toAppendTo.append(_visible ? (UnicodeString)"T" : (UnicodeString)"F");
 177     return toAppendTo;
 178 }
 179
 180 UnicodeString&
 181 SimpleFactory::debugClass(UnicodeString& toAppendTo) const
 182 {
 183     return toAppendTo.append((UnicodeString)"SimpleFactory");
 184 }
 185 #endif
 186
 187 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(SimpleFactory)
 188
 189 /*
 190 ******************************************************************
 191 */
 192
 193 ServiceListener::~ServiceListener() {}
 194
 195 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(ServiceListener)
 196
 197 /*
 198 ******************************************************************
 199 */
 200
 201 // Record the actual id for this service in the cache, so we can return it
 202 // even if we succeed later with a different id.
 203 class CacheEntry : public UMemory {
 204 private:
 205     int32_t refcount;
 206
 207 public:
 208     UnicodeString actualDescriptor;
 209     UObject* service;
 210
 211     /**
 212     * Releases a reference to the shared resource.
 213     */
 214     ~CacheEntry() {
 215         delete service;
 216     }
 217
 218     CacheEntry(const UnicodeString& _actualDescriptor, UObject* _service)
 219         : refcount(1), actualDescriptor(_actualDescriptor), service(_service) {
 220     }
 221
 222     /**
 223     * Instantiation creates an initial reference, so don't call this
 224     * unless you're creating a new pointer to this.  Management of
 225     * that pointer will have to know how to deal with refcounts.
 226     * Return true if the resource has not already been released.
 227     */
 228     CacheEntry* ref() {
 229         ++refcount;
 230         return this;
 231     }
 232
 233     /**
 234     * Destructions removes a reference, so don't call this unless
 235     * you're removing pointer to this somewhere.  Management of that
 236     * pointer will have to know how to deal with refcounts.  Once
 237     * the refcount drops to zero, the resource is released.  Return
 238     * false if the resouce has been released.
 239     */
 240     CacheEntry* unref() {
 241         if ((--refcount) == 0) {
 242             delete this;
 243             return NULL;
 244         }
 245         return this;
 246     }
 247
 248     /**
 249     * Return TRUE if there is at least one reference to this and the
 250     * resource has not been released.
 251     */
 252     UBool isShared() const {
 253         return refcount > 1;
 254     }
 255 };
 256
 257 // UObjectDeleter for serviceCache
 258 U_CDECL_BEGIN
 259 static void U_CALLCONV
 260 cacheDeleter(void* obj) {
 261     U_NAMESPACE_USE ((CacheEntry*)obj)->unref();
 262 }
 263
 264 /**
 265 * Deleter for UObjects
 266 */
 267 static void U_CALLCONV
 268 deleteUObject(void *obj) {
 269     U_NAMESPACE_USE delete (UObject*) obj;
 270 }
 271 U_CDECL_END
 272
 273 /*
 274 ******************************************************************
 275 */
 276
 277 class DNCache : public UMemory {
 278 public:
 279     Hashtable cache;
 280     const Locale locale;
 281
 282     DNCache(const Locale& _locale)
 283         : cache(), locale(_locale)
 284     {
 285         // cache.setKeyDeleter(uprv_deleteUObject);
 286     }
 287 };
 288
 289
 290 /*
 291 ******************************************************************
 292 */
 293
 294 StringPair*
 295 StringPair::create(const UnicodeString& displayName,
 296                    const UnicodeString& id,
 297                    UErrorCode& status)
 298 {
 299     if (U_SUCCESS(status)) {
 300         StringPair* sp = new StringPair(displayName, id);
 301         if (sp == NULL || sp->isBogus()) {
 302             status = U_MEMORY_ALLOCATION_ERROR;
 303             delete sp;
 304             return NULL;
 305         }
 306         return sp;
 307     }
 308     return NULL;
 309 }
 310
 311 UBool
 312 StringPair::isBogus() const {
 313     return displayName.isBogus() || id.isBogus();
 314 }
 315
 316 StringPair::StringPair(const UnicodeString& _displayName,
 317                        const UnicodeString& _id)
 318 : displayName(_displayName)
 319 , id(_id)
 320 {
 321 }
 322
 323 U_CDECL_BEGIN
 324 static void U_CALLCONV
 325 userv_deleteStringPair(void *obj) {
 326     U_NAMESPACE_USE delete (StringPair*) obj;
 327 }
 328 U_CDECL_END
 329
 330 /*
 331 ******************************************************************
 332 */
 333
 334 static UMutex lock = U_MUTEX_INITIALIZER;
 335
 336 ICUService::ICUService()
 337 : name()
 338 , timestamp(0)
 339 , factories(NULL)
 340 , serviceCache(NULL)
 341 , idCache(NULL)
 342 , dnCache(NULL)
 343 {
 344 }
 345
 346 ICUService::ICUService(const UnicodeString& newName)
 347 : name(newName)
 348 , timestamp(0)
 349 , factories(NULL)
 350 , serviceCache(NULL)
 351 , idCache(NULL)
 352 , dnCache(NULL)
 353 {
 354 }
 355
 356 ICUService::~ICUService()
 357 {
 358     {
 359         Mutex mutex(&lock);
 360         clearCaches();
 361         delete factories;
 362         factories = NULL;
 363     }
 364 }
 365
 366 UObject*
 367 ICUService::get(const UnicodeString& descriptor, UErrorCode& status) const
 368 {
 369     return get(descriptor, NULL, status);
 370 }
 371
 372 UObject*
 373 ICUService::get(const UnicodeString& descriptor, UnicodeString* actualReturn, UErrorCode& status) const
 374 {
 375     UObject* result = NULL;
 376     ICUServiceKey* key = createKey(&descriptor, status);
 377     if (key) {
 378         result = getKey(*key, actualReturn, status);
 379         delete key;
 380     }
 381     return result;
 382 }
 383
 384 UObject*
 385 ICUService::getKey(ICUServiceKey& key, UErrorCode& status) const
 386 {
 387     return getKey(key, NULL, status);
 388 }
 389
 390 // this is a vector that subclasses of ICUService can override to further customize the result object
 391 // before returning it.  All other public get functions should call this one.
 392
 393 UObject*
 394 ICUService::getKey(ICUServiceKey& key, UnicodeString* actualReturn, UErrorCode& status) const
 395 {
 396     return getKey(key, actualReturn, NULL, status);
 397 }
 398
 399 // make it possible to call reentrantly on systems that don't have reentrant mutexes.
 400 // we can use this simple approach since we know the situation where we're calling
 401 // reentrantly even without knowing the thread.
 402 class XMutex : public UMemory {
 403 public:
 404     inline XMutex(UMutex *mutex, UBool reentering)
 405         : fMutex(mutex)
 406         , fActive(!reentering)
 407     {
 408         if (fActive) umtx_lock(fMutex);
 409     }
 410     inline ~XMutex() {
 411         if (fActive) umtx_unlock(fMutex);
 412     }
 413
 414 private:
 415     UMutex  *fMutex;
 416     UBool fActive;
 417 };
 418
 419 struct UVectorDeleter {
 420     UVector* _obj;
 421     UVectorDeleter() : _obj(NULL) {}
 422     ~UVectorDeleter() { delete _obj; }
 423 };
 424
 425 // called only by factories, treat as private
 426 UObject*
 427 ICUService::getKey(ICUServiceKey& key, UnicodeString* actualReturn, const ICUServiceFactory* factory, UErrorCode& status) const
 428 {
 429     if (U_FAILURE(status)) {
 430         return NULL;
 431     }
 432
 433     if (isDefault()) {
 434         return handleDefault(key, actualReturn, status);
 435     }
 436
 437     ICUService* ncthis = (ICUService*)this; // cast away semantic const
 438
 439     CacheEntry* result = NULL;
 440     {
 441         // The factory list can't be modified until we're done,
 442         // otherwise we might update the cache with an invalid result.
 443         // The cache has to stay in synch with the factory list.
 444         // ICU doesn't have monitors so we can't use rw locks, so
 445         // we single-thread everything using this service, for now.
 446
 447         // if factory is not null, we're calling from within the mutex,
 448         // and since some unix machines don't have reentrant mutexes we
 449         // need to make sure not to try to lock it again.
 450         XMutex mutex(&lock, factory != NULL);
 451
 452         if (serviceCache == NULL) {
 453             ncthis->serviceCache = new Hashtable(status);
 454             if (ncthis->serviceCache == NULL) {
 455                 return NULL;
 456             }
 457             if (U_FAILURE(status)) {
 458                 delete serviceCache;
 459                 return NULL;
 460             }
 461             serviceCache->setValueDeleter(cacheDeleter);
 462         }
 463
 464         UnicodeString currentDescriptor;
 465         UVectorDeleter cacheDescriptorList;
 466         UBool putInCache = FALSE;
 467
 468         int32_t startIndex = 0;
 469         int32_t limit = factories->size();
 470         UBool cacheResult = TRUE;
 471
 472         if (factory != NULL) {
 473             for (int32_t i = 0; i < limit; ++i) {
 474                 if (factory == (const ICUServiceFactory*)factories->elementAt(i)) {
 475                     startIndex = i + 1;
 476                     break;
 477                 }
 478             }
 479             if (startIndex == 0) {
 480                 // throw new InternalError("Factory " + factory + "not registered with service: " + this);
 481                 status = U_ILLEGAL_ARGUMENT_ERROR;
 482                 return NULL;
 483             }
 484             cacheResult = FALSE;
 485         }
 486
 487         do {
 488             currentDescriptor.remove();
 489             key.currentDescriptor(currentDescriptor);
 490             result = (CacheEntry*)serviceCache->get(currentDescriptor);
 491             if (result != NULL) {
 492                 break;
 493             }
 494
 495             // first test of cache failed, so we'll have to update
 496             // the cache if we eventually succeed-- that is, if we're
 497             // going to update the cache at all.
 498             putInCache = TRUE;
 499
 500             int32_t index = startIndex;
 501             while (index < limit) {
 502                 ICUServiceFactory* f = (ICUServiceFactory*)factories->elementAt(index++);
 503                 UObject* service = f->create(key, this, status);
 504                 if (U_FAILURE(status)) {
 505                     delete service;
 506                     return NULL;
 507                 }
 508                 if (service != NULL) {
 509                     result = new CacheEntry(currentDescriptor, service);
 510                     if (result == NULL) {
 511                         delete service;
 512                         status = U_MEMORY_ALLOCATION_ERROR;
 513                         return NULL;
 514                     }
 515
 516                     goto outerEnd;
 517                 }
 518             }
 519
 520             // prepare to load the cache with all additional ids that
 521             // will resolve to result, assuming we'll succeed.  We
 522             // don't want to keep querying on an id that's going to
 523             // fallback to the one that succeeded, we want to hit the
 524             // cache the first time next goaround.
 525             if (cacheDescriptorList._obj == NULL) {
 526                 cacheDescriptorList._obj = new UVector(uprv_deleteUObject, NULL, 5, status);
 527                 if (U_FAILURE(status)) {
 528                     return NULL;
 529                 }
 530             }
 531             UnicodeString* idToCache = new UnicodeString(currentDescriptor);
 532             if (idToCache == NULL || idToCache->isBogus()) {
 533                 status = U_MEMORY_ALLOCATION_ERROR;
 534                 return NULL;
 535             }
 536
 537             cacheDescriptorList._obj->addElement(idToCache, status);
 538             if (U_FAILURE(status)) {
 539                 return NULL;
 540             }
 541         } while (key.fallback());
 542 outerEnd:
 543
 544         if (result != NULL) {
 545             if (putInCache && cacheResult) {
 546                 serviceCache->put(result->actualDescriptor, result, status);
 547                 if (U_FAILURE(status)) {
 548                     delete result;
 549                     return NULL;
 550                 }
 551
 552                 if (cacheDescriptorList._obj != NULL) {
 553                     for (int32_t i = cacheDescriptorList._obj->size(); --i >= 0;) {
 554                         UnicodeString* desc = (UnicodeString*)cacheDescriptorList._obj->elementAt(i);
 555                         serviceCache->put(*desc, result, status);
 556                         if (U_FAILURE(status)) {
 557                             delete result;
 558                             return NULL;
 559                         }
 560
 561                         result->ref();
 562                         cacheDescriptorList._obj->removeElementAt(i);
 563                     }
 564                 }
 565             }
 566
 567             if (actualReturn != NULL) {
 568                 // strip null prefix
 569                 if (result->actualDescriptor.indexOf((UChar)0x2f) == 0) { // U+002f=slash (/)
 570                     actualReturn->remove();
 571                     actualReturn->append(result->actualDescriptor,
 572                         1,
 573                         result->actualDescriptor.length() - 1);
 574                 } else {
 575                     *actualReturn = result->actualDescriptor;
 576                 }
 577
 578                 if (actualReturn->isBogus()) {
 579                     status = U_MEMORY_ALLOCATION_ERROR;
 580                     delete result;
 581                     return NULL;
 582                 }
 583             }
 584
 585             UObject* service = cloneInstance(result->service);
 586             if (putInCache && !cacheResult) {
 587                 delete result;
 588             }
 589             return service;
 590         }
 591     }
 592
 593     return handleDefault(key, actualReturn, status);
 594 }
 595
 596 UObject*
 597 ICUService::handleDefault(const ICUServiceKey& /* key */, UnicodeString* /* actualIDReturn */, UErrorCode& /* status */) const
 598 {
 599     return NULL;
 600 }
 601
 602 UVector&
 603 ICUService::getVisibleIDs(UVector& result, UErrorCode& status) const {
 604     return getVisibleIDs(result, NULL, status);
 605 }
 606
 607 UVector&
 608 ICUService::getVisibleIDs(UVector& result, const UnicodeString* matchID, UErrorCode& status) const
 609 {
 610     result.removeAllElements();
 611
 612     if (U_FAILURE(status)) {
 613         return result;
 614     }
 615
 616     {
 617         Mutex mutex(&lock);
 618         const Hashtable* map = getVisibleIDMap(status);
 619         if (map != NULL) {
 620             ICUServiceKey* fallbackKey = createKey(matchID, status);
 621
 622             for (int32_t pos = UHASH_FIRST;;) {
 623                 const UHashElement* e = map->nextElement(pos);
 624                 if (e == NULL) {
 625                     break;
 626                 }
 627
 628                 const UnicodeString* id = (const UnicodeString*)e->key.pointer;
 629                 if (fallbackKey != NULL) {
 630                     if (!fallbackKey->isFallbackOf(*id)) {
 631                         continue;
 632                     }
 633                 }
 634
 635                 UnicodeString* idClone = new UnicodeString(*id);
 636                 if (idClone == NULL || idClone->isBogus()) {
 637                     delete idClone;
 638                     status = U_MEMORY_ALLOCATION_ERROR;
 639                     break;
 640                 }
 641                 result.addElement(idClone, status);
 642                 if (U_FAILURE(status)) {
 643                     delete idClone;
 644                     break;
 645                 }
 646             }
 647             delete fallbackKey;
 648         }
 649     }
 650     if (U_FAILURE(status)) {
 651         result.removeAllElements();
 652     }
 653     return result;
 654 }
 655
 656 const Hashtable*
 657 ICUService::getVisibleIDMap(UErrorCode& status) const {
 658     if (U_FAILURE(status)) return NULL;
 659
 660     // must only be called when lock is already held
 661
 662     ICUService* ncthis = (ICUService*)this; // cast away semantic const
 663     if (idCache == NULL) {
 664         ncthis->idCache = new Hashtable(status);
 665         if (idCache == NULL) {
 666             status = U_MEMORY_ALLOCATION_ERROR;
 667         } else if (factories != NULL) {
 668             for (int32_t pos = factories->size(); --pos >= 0;) {
 669                 ICUServiceFactory* f = (ICUServiceFactory*)factories->elementAt(pos);
 670                 f->updateVisibleIDs(*idCache, status);
 671             }
 672             if (U_FAILURE(status)) {
 673                 delete idCache;
 674                 ncthis->idCache = NULL;
 675             }
 676         }
 677     }
 678
 679     return idCache;
 680 }
 681
 682
 683 UnicodeString&
 684 ICUService::getDisplayName(const UnicodeString& id, UnicodeString& result) const
 685 {
 686     return getDisplayName(id, result, Locale::getDefault());
 687 }
 688
 689 UnicodeString&
 690 ICUService::getDisplayName(const UnicodeString& id, UnicodeString& result, const Locale& locale) const
 691 {
 692     {
 693         UErrorCode status = U_ZERO_ERROR;
 694         Mutex mutex(&lock);
 695         const Hashtable* map = getVisibleIDMap(status);
 696         if (map != NULL) {
 697             ICUServiceFactory* f = (ICUServiceFactory*)map->get(id);
 698             if (f != NULL) {
 699                 f->getDisplayName(id, locale, result);
 700                 return result;
 701             }
 702
 703             // fallback
 704             UErrorCode status = U_ZERO_ERROR;
 705             ICUServiceKey* fallbackKey = createKey(&id, status);
 706             while (fallbackKey->fallback()) {
 707                 UnicodeString us;
 708                 fallbackKey->currentID(us);
 709                 f = (ICUServiceFactory*)map->get(us);
 710                 if (f != NULL) {
 711                     f->getDisplayName(id, locale, result);
 712                     delete fallbackKey;
 713                     return result;
 714                 }
 715             }
 716             delete fallbackKey;
 717         }
 718     }
 719     result.setToBogus();
 720     return result;
 721 }
 722
 723 UVector&
 724 ICUService::getDisplayNames(UVector& result, UErrorCode& status) const
 725 {
 726     return getDisplayNames(result, Locale::getDefault(), NULL, status);
 727 }
 728
 729
 730 UVector&
 731 ICUService::getDisplayNames(UVector& result, const Locale& locale, UErrorCode& status) const
 732 {
 733     return getDisplayNames(result, locale, NULL, status);
 734 }
 735
 736 UVector&
 737 ICUService::getDisplayNames(UVector& result,
 738                             const Locale& locale,
 739                             const UnicodeString* matchID,
 740                             UErrorCode& status) const
 741 {
 742     result.removeAllElements();
 743     result.setDeleter(userv_deleteStringPair);
 744     if (U_SUCCESS(status)) {
 745         ICUService* ncthis = (ICUService*)this; // cast away semantic const
 746         Mutex mutex(&lock);
 747
 748         if (dnCache != NULL && dnCache->locale != locale) {
 749             delete dnCache;
 750             ncthis->dnCache = NULL;
 751         }
 752
 753         if (dnCache == NULL) {
 754             const Hashtable* m = getVisibleIDMap(status);
 755             if (U_FAILURE(status)) {
 756                 return result;
 757             }
 758             ncthis->dnCache = new DNCache(locale);
 759             if (dnCache == NULL) {
 760                 status = U_MEMORY_ALLOCATION_ERROR;
 761                 return result;
 762             }
 763
 764             int32_t pos = UHASH_FIRST;
 765             const UHashElement* entry = NULL;
 766             while ((entry = m->nextElement(pos)) != NULL) {
 767                 const UnicodeString* id = (const UnicodeString*)entry->key.pointer;
 768                 ICUServiceFactory* f = (ICUServiceFactory*)entry->value.pointer;
 769                 UnicodeString dname;
 770                 f->getDisplayName(*id, locale, dname);
 771                 if (dname.isBogus()) {
 772                     status = U_MEMORY_ALLOCATION_ERROR;
 773                 } else {
 774                     dnCache->cache.put(dname, (void*)id, status); // share pointer with visibleIDMap
 775                     if (U_SUCCESS(status)) {
 776                         continue;
 777                     }
 778                 }
 779                 delete dnCache;
 780                 ncthis->dnCache = NULL;
 781                 return result;
 782             }
 783         }
 784     }
 785
 786     ICUServiceKey* matchKey = createKey(matchID, status);
 787     /* To ensure that all elements in the hashtable are iterated, set pos to -1.
 788      * nextElement(pos) will skip the position at pos and begin the iteration
 789      * at the next position, which in this case will be 0.
 790      */
 791     int32_t pos = UHASH_FIRST;
 792     const UHashElement *entry = NULL;
 793     while ((entry = dnCache->cache.nextElement(pos)) != NULL) {
 794         const UnicodeString* id = (const UnicodeString*)entry->value.pointer;
 795         if (matchKey != NULL && !matchKey->isFallbackOf(*id)) {
 796             continue;
 797         }
 798         const UnicodeString* dn = (const UnicodeString*)entry->key.pointer;
 799         StringPair* sp = StringPair::create(*id, *dn, status);
 800         result.addElement(sp, status);
 801         if (U_FAILURE(status)) {
 802             result.removeAllElements();
 803             break;
 804         }
 805     }
 806     delete matchKey;
 807
 808     return result;
 809 }
 810
 811 URegistryKey
 812 ICUService::registerInstance(UObject* objToAdopt, const UnicodeString& id, UErrorCode& status)
 813 {
 814     return registerInstance(objToAdopt, id, TRUE, status);
 815 }
 816
 817 URegistryKey
 818 ICUService::registerInstance(UObject* objToAdopt, const UnicodeString& id, UBool visible, UErrorCode& status)
 819 {
 820     ICUServiceKey* key = createKey(&id, status);
 821     if (key != NULL) {
 822         UnicodeString canonicalID;
 823         key->canonicalID(canonicalID);
 824         delete key;
 825
 826         ICUServiceFactory* f = createSimpleFactory(objToAdopt, canonicalID, visible, status);
 827         if (f != NULL) {
 828             return registerFactory(f, status);
 829         }
 830     }
 831     delete objToAdopt;
 832     return NULL;
 833 }
 834
 835 ICUServiceFactory*
 836 ICUService::createSimpleFactory(UObject* objToAdopt, const UnicodeString& id, UBool visible, UErrorCode& status)
 837 {
 838     if (U_SUCCESS(status)) {
 839         if ((objToAdopt != NULL) && (!id.isBogus())) {
 840             return new SimpleFactory(objToAdopt, id, visible);
 841         }
 842         status = U_ILLEGAL_ARGUMENT_ERROR;
 843     }
 844     return NULL;
 845 }
 846
 847 URegistryKey
 848 ICUService::registerFactory(ICUServiceFactory* factoryToAdopt, UErrorCode& status)
 849 {
 850     if (U_SUCCESS(status) && factoryToAdopt != NULL) {
 851         Mutex mutex(&lock);
 852
 853         if (factories == NULL) {
 854             factories = new UVector(deleteUObject, NULL, status);
 855             if (U_FAILURE(status)) {
 856                 delete factories;
 857                 return NULL;
 858             }
 859         }
 860         factories->insertElementAt(factoryToAdopt, 0, status);
 861         if (U_SUCCESS(status)) {
 862             clearCaches();
 863         } else {
 864             delete factoryToAdopt;
 865             factoryToAdopt = NULL;
 866         }
 867     }
 868
 869     if (factoryToAdopt != NULL) {
 870         notifyChanged();
 871     }
 872
 873     return (URegistryKey)factoryToAdopt;
 874 }
 875
 876 UBool
 877 ICUService::unregister(URegistryKey rkey, UErrorCode& status)
 878 {
 879     ICUServiceFactory *factory = (ICUServiceFactory*)rkey;
 880     UBool result = FALSE;
 881     if (factory != NULL && factories != NULL) {
 882         Mutex mutex(&lock);
 883
 884         if (factories->removeElement(factory)) {
 885             clearCaches();
 886             result = TRUE;
 887         } else {
 888             status = U_ILLEGAL_ARGUMENT_ERROR;
 889             delete factory;
 890         }
 891     }
 892     if (result) {
 893         notifyChanged();
 894     }
 895     return result;
 896 }
 897
 898 void
 899 ICUService::reset()
 900 {
 901     {
 902         Mutex mutex(&lock);
 903         reInitializeFactories();
 904         clearCaches();
 905     }
 906     notifyChanged();
 907 }
 908
 909 void
 910 ICUService::reInitializeFactories()
 911 {
 912     if (factories != NULL) {
 913         factories->removeAllElements();
 914     }
 915 }
 916
 917 UBool
 918 ICUService::isDefault() const
 919 {
 920     return countFactories() == 0;
 921 }
 922
 923 ICUServiceKey*
 924 ICUService::createKey(const UnicodeString* id, UErrorCode& status) const
 925 {
 926     return (U_FAILURE(status) || id == NULL) ? NULL : new ICUServiceKey(*id);
 927 }
 928
 929 void
 930 ICUService::clearCaches()
 931 {
 932     // callers synchronize before use
 933     ++timestamp;
 934     delete dnCache;
 935     dnCache = NULL;
 936     delete idCache;
 937     idCache = NULL;
 938     delete serviceCache; serviceCache = NULL;
 939 }
 940
 941 void
 942 ICUService::clearServiceCache()
 943 {
 944     // callers synchronize before use
 945     delete serviceCache; serviceCache = NULL;
 946 }
 947
 948 UBool
 949 ICUService::acceptsListener(const EventListener& l) const
 950 {
 951     return dynamic_cast<const ServiceListener*>(&l) != NULL;
 952 }
 953
 954 void
 955 ICUService::notifyListener(EventListener& l) const
 956 {
 957     ((ServiceListener&)l).serviceChanged(*this);
 958 }
 959
 960 UnicodeString&
 961 ICUService::getName(UnicodeString& result) const
 962 {
 963     return result.append(name);
 964 }
 965
 966 int32_t
 967 ICUService::countFactories() const
 968 {
 969     return factories == NULL ? 0 : factories->size();
 970 }
 971
 972 int32_t
 973 ICUService::getTimestamp() const
 974 {
 975     return timestamp;
 976 }
 977
 978 U_NAMESPACE_END
 979
 980 /* UCONFIG_NO_SERVICE */
 981 #endif