| /* |
| * Copyright 2013 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef SkScaledImageCache_DEFINED |
| #define SkScaledImageCache_DEFINED |
| |
| #include "SkBitmap.h" |
| |
| class SkMipMap; |
| |
| /** |
| * Cache object for bitmaps (with possible scale in X Y as part of the key). |
| * |
| * Multiple caches can be instantiated, but each instance is not implicitly |
| * thread-safe, so if a given instance is to be shared across threads, the |
| * caller must manage the access itself (e.g. via a mutex). |
| * |
| * As a convenience, a global instance is also defined, which can be safely |
| * access across threads via the static methods (e.g. FindAndLock, etc.). |
| */ |
| class SkScaledImageCache { |
| public: |
| struct ID; |
| |
| /* |
| * The following static methods are thread-safe wrappers around a global |
| * instance of this cache. |
| */ |
| |
| static ID* FindAndLock(const SkBitmap& original, SkScalar scaleX, |
| SkScalar scaleY, SkBitmap* scaled); |
| static ID* FindAndLockMip(const SkBitmap& original, SkMipMap const**); |
| |
| static ID* AddAndLock(const SkBitmap& original, SkScalar scaleX, |
| SkScalar scaleY, const SkBitmap& scaled); |
| static ID* AddAndLockMip(const SkBitmap& original, const SkMipMap*); |
| |
| static void Unlock(ID*); |
| |
| static size_t GetBytesUsed(); |
| static size_t GetByteLimit(); |
| static size_t SetByteLimit(size_t newLimit); |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| SkScaledImageCache(size_t byteLimit); |
| ~SkScaledImageCache(); |
| |
| /** |
| * Search the cache for a scaled version of original. If found, return it |
| * in scaled, and return its ID pointer. Use the returned ptr to unlock |
| * the cache when you are done using scaled. |
| * |
| * If a match is not found, scaled will be unmodifed, and NULL will be |
| * returned. |
| */ |
| ID* findAndLock(const SkBitmap& original, SkScalar scaleX, |
| SkScalar scaleY, SkBitmap* scaled); |
| ID* findAndLockMip(const SkBitmap& original, SkMipMap const**); |
| |
| /** |
| * To add a new (scaled) bitmap to the cache, call AddAndLock. Use the |
| * returned ptr to unlock the cache when you are done using scaled. |
| */ |
| ID* addAndLock(const SkBitmap& original, SkScalar scaleX, |
| SkScalar scaleY, const SkBitmap& scaled); |
| ID* addAndLockMip(const SkBitmap& original, const SkMipMap*); |
| |
| /** |
| * Given a non-null ID ptr returned by either findAndLock or addAndLock, |
| * this releases the associated resources to be available to be purged |
| * if needed. After this, the cached bitmap should no longer be |
| * referenced by the caller. |
| */ |
| void unlock(ID*); |
| |
| size_t getBytesUsed() const { return fBytesUsed; } |
| size_t getByteLimit() const { return fByteLimit; } |
| |
| /** |
| * Set the maximum number of bytes available to this cache. If the current |
| * cache exceeds this new value, it will be purged to try to fit within |
| * this new limit. |
| */ |
| size_t setByteLimit(size_t newLimit); |
| |
| public: |
| struct Rec; |
| private: |
| Rec* fHead; |
| Rec* fTail; |
| |
| class Hash; |
| Hash* fHash; |
| |
| size_t fBytesUsed; |
| size_t fByteLimit; |
| int fCount; |
| |
| Rec* findAndLock(const SkBitmap& original, SkScalar sx, SkScalar sy); |
| |
| void purgeAsNeeded(); |
| |
| // linklist management |
| void moveToHead(Rec*); |
| void addToHead(Rec*); |
| void detach(Rec*); |
| #ifdef SK_DEBUG |
| void validate() const; |
| #else |
| void validate() const {} |
| #endif |
| }; |
| |
| #endif |