scuffed-code/icu4c/source/common/lrucache.h
2014-01-17 23:11:22 +00:00

96 lines
2.8 KiB
C++

/*
******************************************************************************
* Copyright (C) 2014, International Business Machines Corporation and
* others. All Rights Reserved.
******************************************************************************
*
* File LRUCACHE.H
******************************************************************************
*/
#ifndef __LRU_CACHE_H__
#define __LRU_CACHE_H__
#include "unicode/uobject.h"
#include "sharedobject.h"
struct UHashtable;
U_NAMESPACE_BEGIN
/**
* LRUCache keyed by locale ID.
*/
class U_COMMON_API LRUCache : public UObject {
public:
template<typename T>
void get(const char *localeId, const T *&ptr, UErrorCode &status) {
const T *value = (const T *) _get(localeId, status);
if (U_FAILURE(status)) {
return;
}
SharedObject::copyPtr(value, ptr);
}
UBool contains(const char *localeId) const;
virtual ~LRUCache();
protected:
virtual SharedObject *create(const char *localeId, UErrorCode &status)=0;
LRUCache(int32_t maxSize, UErrorCode &status);
private:
class CacheEntry : public UMemory {
public:
CacheEntry *moreRecent;
CacheEntry *lessRecent;
char *localeId;
const SharedObject *cachedData;
UErrorCode status; // This is the error if any from creating
// cachedData.
CacheEntry();
~CacheEntry();
void unlink();
void reset();
void init(
char *adoptedLocId, SharedObject *dataToAdopt, UErrorCode err);
private:
CacheEntry(const CacheEntry& other);
CacheEntry &operator=(const CacheEntry& other);
};
LRUCache();
LRUCache(const LRUCache &other);
LRUCache &operator=(const LRUCache &other);
// TODO (Travis Keep): Consider replacing both of these end nodes with a
// single sentinel.
CacheEntry *mostRecentlyUsedMarker;
CacheEntry *leastRecentlyUsedMarker;
UHashtable *localeIdToEntries;
int32_t maxSize;
void moveToMostRecent(CacheEntry *cacheEntry);
void init(char *localeId, CacheEntry *cacheEntry);
const SharedObject *_get(const char *localeId, UErrorCode &status);
};
typedef SharedObject *CreateFunc(const char *localeId, UErrorCode &status);
class U_COMMON_API SimpleLRUCache : public LRUCache {
public:
SimpleLRUCache(
int32_t maxSize,
CreateFunc cf,
UErrorCode &status) :
LRUCache(maxSize, status), createFunc(cf) {
}
virtual ~SimpleLRUCache();
protected:
virtual SharedObject *create(const char *localeId, UErrorCode &status);
private:
CreateFunc *createFunc;
};
U_NAMESPACE_END
#endif