| /* |
| * 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 SkDiscardableMemory; |
| 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; |
| |
| struct Key { |
| // Call this to access your private contents. Must not use the address after calling init() |
| void* writableContents() { return this + 1; } |
| |
| // must call this after your private data has been written. |
| // length must be a multiple of 4 |
| void init(size_t length); |
| |
| // This is only valid after having called init(). |
| uint32_t hash() const { return fHash; } |
| |
| bool operator==(const Key& other) const { |
| const uint32_t* a = this->as32(); |
| const uint32_t* b = other.as32(); |
| for (int i = 0; i < fCount32; ++i) { |
| if (a[i] != b[i]) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| // delete using sk_free |
| Key* clone() const; |
| |
| private: |
| // store fCount32 first, so we don't consider it in operator< |
| int32_t fCount32; // 2 + user contents count32 |
| uint32_t fHash; |
| /* uint32_t fContents32[] */ |
| |
| const uint32_t* as32() const { return (const uint32_t*)this; } |
| const uint32_t* as32SkipCount() const { return this->as32() + 1; } |
| }; |
| |
| /** |
| * Returns a locked/pinned SkDiscardableMemory instance for the specified |
| * number of bytes, or NULL on failure. |
| */ |
| typedef SkDiscardableMemory* (*DiscardableFactory)(size_t bytes); |
| |
| /* |
| * The following static methods are thread-safe wrappers around a global |
| * instance of this cache. |
| */ |
| |
| static ID* FindAndLock(const Key&, SkBitmap* result); |
| static ID* AddAndLock(const Key&, const SkBitmap& result); |
| |
| static ID* FindAndLock(const Key&, const SkMipMap** result); |
| static ID* AddAndLock(const Key&, const SkMipMap* result); |
| |
| static void Unlock(ID*); |
| |
| static size_t GetTotalBytesUsed(); |
| static size_t GetTotalByteLimit(); |
| static size_t SetTotalByteLimit(size_t newLimit); |
| |
| static size_t SetSingleAllocationByteLimit(size_t); |
| static size_t GetSingleAllocationByteLimit(); |
| |
| static SkBitmap::Allocator* GetAllocator(); |
| |
| /** |
| * Call SkDebugf() with diagnostic information about the state of the cache |
| */ |
| static void Dump(); |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| /** |
| * Construct the cache to call DiscardableFactory when it |
| * allocates memory for the pixels. In this mode, the cache has |
| * not explicit budget, and so methods like getTotalBytesUsed() |
| * and getTotalByteLimit() will return 0, and setTotalByteLimit |
| * will ignore its argument and return 0. |
| */ |
| SkScaledImageCache(DiscardableFactory); |
| |
| /** |
| * Construct the cache, allocating memory with malloc, and respect the |
| * byteLimit, purging automatically when a new image is added to the cache |
| * that pushes the total bytesUsed over the limit. Note: The limit can be |
| * changed at runtime with setTotalByteLimit. |
| */ |
| explicit SkScaledImageCache(size_t byteLimit); |
| ~SkScaledImageCache(); |
| |
| /** |
| * Search the cache for a matching key. If found, return its bitmap and return its ID pointer. |
| * Use the returned ID to unlock the cache when you are done using outBitmap. |
| * |
| * If a match is not found, outBitmap will be unmodifed, and NULL will be returned. |
| */ |
| ID* findAndLock(const Key& key, SkBitmap* outBitmap); |
| ID* findAndLock(const Key& key, const SkMipMap** returnedMipMap); |
| |
| /** |
| * To add a new bitmap (or mipMap) to the cache, call |
| * AddAndLock. Use the returned ptr to unlock the cache when you |
| * are done using scaled. |
| * |
| * Use (generationID, width, and height) or (original, scaleX, |
| * scaleY) or (original) as a search key |
| */ |
| ID* addAndLock(const Key&, const SkBitmap& bitmap); |
| ID* addAndLock(const Key&, const SkMipMap* mipMap); |
| |
| /** |
| * 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 getTotalBytesUsed() const { return fTotalBytesUsed; } |
| size_t getTotalByteLimit() const { return fTotalByteLimit; } |
| |
| /** |
| * This is respected by SkBitmapProcState::possiblyScaleImage. |
| * 0 is no maximum at all; this is the default. |
| * setSingleAllocationByteLimit() returns the previous value. |
| */ |
| size_t setSingleAllocationByteLimit(size_t maximumAllocationSize); |
| size_t getSingleAllocationByteLimit() const; |
| /** |
| * 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 setTotalByteLimit(size_t newLimit); |
| |
| SkBitmap::Allocator* allocator() const { return fAllocator; }; |
| |
| /** |
| * Call SkDebugf() with diagnostic information about the state of the cache |
| */ |
| void dump() const; |
| |
| public: |
| struct Rec; |
| private: |
| Rec* fHead; |
| Rec* fTail; |
| |
| class Hash; |
| Hash* fHash; |
| |
| DiscardableFactory fDiscardableFactory; |
| // the allocator is NULL or one that matches discardables |
| SkBitmap::Allocator* fAllocator; |
| |
| size_t fTotalBytesUsed; |
| size_t fTotalByteLimit; |
| size_t fSingleAllocationByteLimit; |
| int fCount; |
| |
| Rec* findAndLock(const Key& key); |
| ID* addAndLock(Rec* rec); |
| |
| void purgeRec(Rec*); |
| void purgeAsNeeded(); |
| |
| // linklist management |
| void moveToHead(Rec*); |
| void addToHead(Rec*); |
| void detach(Rec*); |
| |
| void init(); // called by constructors |
| |
| #ifdef SK_DEBUG |
| void validate() const; |
| #else |
| void validate() const {} |
| #endif |
| }; |
| #endif |