1 /* 2 ****************************************************************************** 3 * Copyright (C) 2014, International Business Machines Corporation and 4 * others. All Rights Reserved. 5 ****************************************************************************** 6 * 7 * File LRUCACHE.H 8 ****************************************************************************** 9 */ 10 11 #ifndef __LRU_CACHE_H__ 12 #define __LRU_CACHE_H__ 13 14 #include "unicode/uobject.h" 15 #include "sharedobject.h" 16 17 struct UHashtable; 18 19 U_NAMESPACE_BEGIN 20 21 /** 22 * LRUCache keyed by locale ID. 23 */ 24 25 class U_COMMON_API LRUCache : public UObject { 26 public: 27 template<typename T> 28 void get(const char *localeId, const T *&ptr, UErrorCode &status) { 29 const T *value = (const T *) _get(localeId, status); 30 if (U_FAILURE(status)) { 31 return; 32 } 33 SharedObject::copyPtr(value, ptr); 34 } 35 UBool contains(const char *localeId) const; 36 virtual ~LRUCache(); 37 protected: 38 virtual SharedObject *create(const char *localeId, UErrorCode &status)=0; 39 LRUCache(int32_t maxSize, UErrorCode &status); 40 private: 41 class CacheEntry : public UMemory { 42 public: 43 CacheEntry *moreRecent; 44 CacheEntry *lessRecent; 45 char *localeId; 46 const SharedObject *cachedData; 47 UErrorCode status; // This is the error if any from creating 48 // cachedData. 49 CacheEntry(); 50 ~CacheEntry(); 51 52 void unlink(); 53 void reset(); 54 void init( 55 char *adoptedLocId, SharedObject *dataToAdopt, UErrorCode err); 56 private: 57 CacheEntry(const CacheEntry& other); 58 CacheEntry &operator=(const CacheEntry& other); 59 }; 60 LRUCache(); 61 LRUCache(const LRUCache &other); 62 LRUCache &operator=(const LRUCache &other); 63 64 // TODO (Travis Keep): Consider replacing both of these end nodes with a 65 // single sentinel. 66 CacheEntry *mostRecentlyUsedMarker; 67 CacheEntry *leastRecentlyUsedMarker; 68 UHashtable *localeIdToEntries; 69 int32_t maxSize; 70 71 void moveToMostRecent(CacheEntry *cacheEntry); 72 void init(char *localeId, CacheEntry *cacheEntry); 73 const SharedObject *_get(const char *localeId, UErrorCode &status); 74 }; 75 76 typedef SharedObject *CreateFunc(const char *localeId, UErrorCode &status); 77 78 class U_COMMON_API SimpleLRUCache : public LRUCache { 79 public: 80 SimpleLRUCache( 81 int32_t maxSize, 82 CreateFunc cf, 83 UErrorCode &status) : 84 LRUCache(maxSize, status), createFunc(cf) { 85 } 86 virtual ~SimpleLRUCache(); 87 protected: 88 virtual SharedObject *create(const char *localeId, UErrorCode &status); 89 private: 90 CreateFunc *createFunc; 91 }; 92 93 U_NAMESPACE_END 94 95 #endif 96
