| /* |
| * 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 SkResourceCache_DEFINED |
| #define SkResourceCache_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 SkResourceCache { |
| public: |
| 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; |
| } |
| |
| 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; } |
| }; |
| |
| struct Rec { |
| typedef SkResourceCache::Key Key; |
| |
| Rec() : fLockCount(1) {} |
| virtual ~Rec() {} |
| |
| uint32_t getHash() const { return this->getKey().hash(); } |
| |
| virtual const Key& getKey() const = 0; |
| virtual size_t bytesUsed() const = 0; |
| |
| // for SkTDynamicHash::Traits |
| static uint32_t Hash(const Key& key) { return key.hash(); } |
| static const Key& GetKey(const Rec& rec) { return rec.getKey(); } |
| |
| private: |
| Rec* fNext; |
| Rec* fPrev; |
| int32_t fLockCount; |
| int32_t fPad; |
| |
| friend class SkResourceCache; |
| }; |
| |
| typedef const Rec* ID; |
| |
| /** |
| * 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 const Rec* FindAndLock(const Key& key); |
| static const Rec* AddAndLock(Rec*); |
| static void Add(Rec*); |
| 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(); |
| |
| /** |
| * Use this allocator for bitmaps, so they can use ashmem when available. |
| * Returns NULL if the ResourceCache has not been initialized with a DiscardableFactory. |
| */ |
| 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. |
| */ |
| SkResourceCache(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 SkResourceCache(size_t byteLimit); |
| ~SkResourceCache(); |
| |
| const Rec* findAndLock(const Key& key); |
| const Rec* addAndLock(Rec*); |
| void add(Rec*); |
| |
| /** |
| * 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; |
| |
| 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; |
| |
| 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 |