Set maximum output size for scaled-image-cache images

src/core/SkScaledImageCache.h

 /*
  * 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
 
@@ skipping 42 matching lines @@
                           int32_t width,
                           int32_t height,
                           const SkBitmap& bitmap);
 
     static ID* AddAndLock(const SkBitmap& original, SkScalar scaleX,
                           SkScalar scaleY, const SkBitmap& bitmap);
     static ID* AddAndLockMip(const SkBitmap& original, const SkMipMap* mipMap);
 
     static void Unlock(ID*);
 
-    static size_t GetBytesUsed();
-    static size_t GetByteLimit();
-    static size_t SetByteLimit(size_t newLimit);
+    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 getBytesUsed() and
-     *  getByteLimit() will return 0, and setByteLimit will ignore its argument
-     *  and return 0.
+     *  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 setByteLimit.
+     *  changed at runtime with setTotalByteLimit.
      */
     SkScaledImageCache(size_t byteLimit);
 
     ~SkScaledImageCache();
 
     /**
      *  Search the cache for a matching bitmap (using generationID,
      *  width, and height as a search key). If found, return it in
      *  returnedBitmap, and return its ID pointer. Use the returned
      *  ptr to unlock the cache when you are done using
@@ skipping 37 matching lines @@
     ID* addAndLockMip(const SkBitmap& original, 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 getBytesUsed() const { return fBytesUsed; }
-    size_t getByteLimit() const { return fByteLimit; }
+    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 setByteLimit(size_t newLimit);
+    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;
     struct Key;
 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  fBytesUsed;
-    size_t  fByteLimit;
+    size_t  fTotalBytesUsed;
+    size_t  fTotalByteLimit;
+    size_t  fSingleAllocationByteLimit;
     int     fCount;
 
     Rec* findAndLock(uint32_t generationID, SkScalar sx, SkScalar sy,
                      const SkIRect& bounds);
     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