Set maximum output size for scaled-image-cache images

Accessable via:
  SkScaledImageCache::{G,S}etMaximumOutputSizeForHighQualityFilter

Also, a unit test.

BUG=389439
R=humper@google.com, tomhudson@google.com, reveman@chromium.org, vangelis@chromium.org, reed@google.com

Author: halcanary@google.com

Review URL: https://codereview.chromium.org/394003003

1 files changed, 23 insertions, 12 deletions

diff --git a/src/core/SkScaledImageCache.h b/src/core/SkScaledImageCache.h
index fe072306d3..817147e3b8 100644
--- a/src/core/SkScaledImageCache.h
+++ b/src/core/SkScaledImageCache.h
@@ -60,9 +60,12 @@ public:
 
     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();
 
@@ -76,9 +79,9 @@ public:
     /**
      *  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);
 
@@ -86,7 +89,7 @@ public:
      *  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);
 
@@ -144,15 +147,22 @@ public:
      */
     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; };
 
@@ -175,8 +185,9 @@ private:
     // 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,