michael@0: /*
michael@0:  * Copyright 2010 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #ifndef SkGlyphCache_Globals_DEFINED
michael@0: #define SkGlyphCache_Globals_DEFINED
michael@0: 
michael@0: #include "SkGlyphCache.h"
michael@0: #include "SkTLS.h"
michael@0: 
michael@0: #ifndef SK_DEFAULT_FONT_CACHE_COUNT_LIMIT
michael@0:     #define SK_DEFAULT_FONT_CACHE_COUNT_LIMIT   2048
michael@0: #endif
michael@0: 
michael@0: #ifndef SK_DEFAULT_FONT_CACHE_LIMIT
michael@0:     #define SK_DEFAULT_FONT_CACHE_LIMIT     (2 * 1024 * 1024)
michael@0: #endif
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: class SkMutex;
michael@0: 
michael@0: class SkGlyphCache_Globals {
michael@0: public:
michael@0:     enum UseMutex {
michael@0:         kNo_UseMutex,  // thread-local cache
michael@0:         kYes_UseMutex  // shared cache
michael@0:     };
michael@0: 
michael@0:     SkGlyphCache_Globals(UseMutex um) {
michael@0:         fHead = NULL;
michael@0:         fTotalMemoryUsed = 0;
michael@0:         fCacheSizeLimit = SK_DEFAULT_FONT_CACHE_LIMIT;
michael@0:         fCacheCount = 0;
michael@0:         fCacheCountLimit = SK_DEFAULT_FONT_CACHE_COUNT_LIMIT;
michael@0: 
michael@0:         fMutex = (kYes_UseMutex == um) ? SkNEW(SkMutex) : NULL;
michael@0:     }
michael@0: 
michael@0:     ~SkGlyphCache_Globals() {
michael@0:         SkGlyphCache* cache = fHead;
michael@0:         while (cache) {
michael@0:             SkGlyphCache* next = cache->fNext;
michael@0:             SkDELETE(cache);
michael@0:             cache = next;
michael@0:         }
michael@0: 
michael@0:         SkDELETE(fMutex);
michael@0:     }
michael@0: 
michael@0:     SkMutex*        fMutex;
michael@0: 
michael@0:     SkGlyphCache* internalGetHead() const { return fHead; }
michael@0:     SkGlyphCache* internalGetTail() const;
michael@0: 
michael@0:     size_t getTotalMemoryUsed() const { return fTotalMemoryUsed; }
michael@0:     int getCacheCountUsed() const { return fCacheCount; }
michael@0: 
michael@0: #ifdef SK_DEBUG
michael@0:     void validate() const;
michael@0: #else
michael@0:     void validate() const {}
michael@0: #endif
michael@0: 
michael@0:     int getCacheCountLimit() const { return fCacheCountLimit; }
michael@0:     int setCacheCountLimit(int limit);
michael@0: 
michael@0:     size_t  getCacheSizeLimit() const { return fCacheSizeLimit; }
michael@0:     size_t  setCacheSizeLimit(size_t limit);
michael@0: 
michael@0:     // returns true if this cache is over-budget either due to size limit
michael@0:     // or count limit.
michael@0:     bool isOverBudget() const {
michael@0:         return fCacheCount > fCacheCountLimit ||
michael@0:                fTotalMemoryUsed > fCacheSizeLimit;
michael@0:     }
michael@0: 
michael@0:     void purgeAll(); // does not change budget
michael@0: 
michael@0:     // call when a glyphcache is available for caching (i.e. not in use)
michael@0:     void attachCacheToHead(SkGlyphCache*);
michael@0: 
michael@0:     // can only be called when the mutex is already held
michael@0:     void internalDetachCache(SkGlyphCache*);
michael@0:     void internalAttachCacheToHead(SkGlyphCache*);
michael@0: 
michael@0:     // can return NULL
michael@0:     static SkGlyphCache_Globals* FindTLS() {
michael@0:         return (SkGlyphCache_Globals*)SkTLS::Find(CreateTLS);
michael@0:     }
michael@0: 
michael@0:     static SkGlyphCache_Globals& GetTLS() {
michael@0:         return *(SkGlyphCache_Globals*)SkTLS::Get(CreateTLS, DeleteTLS);
michael@0:     }
michael@0: 
michael@0:     static void DeleteTLS() { SkTLS::Delete(CreateTLS); }
michael@0: 
michael@0: private:
michael@0:     SkGlyphCache* fHead;
michael@0:     size_t  fTotalMemoryUsed;
michael@0:     size_t  fCacheSizeLimit;
michael@0:     int32_t fCacheCountLimit;
michael@0:     int32_t fCacheCount;
michael@0: 
michael@0:     // Checkout budgets, modulated by the specified min-bytes-needed-to-purge,
michael@0:     // and attempt to purge caches to match.
michael@0:     // Returns number of bytes freed.
michael@0:     size_t internalPurge(size_t minBytesNeeded = 0);
michael@0: 
michael@0:     static void* CreateTLS() {
michael@0:         return SkNEW_ARGS(SkGlyphCache_Globals, (kNo_UseMutex));
michael@0:     }
michael@0: 
michael@0:     static void DeleteTLS(void* ptr) {
michael@0:         SkDELETE((SkGlyphCache_Globals*)ptr);
michael@0:     }
michael@0: };
michael@0: 
michael@0: #endif