Allow SkLazyPixelRef to use SkScaledImageCache

src/lazy/SkLazyPixelRef.h

Index: src/lazy/SkLazyPixelRef.h
diff --git a/src/lazy/SkLazyPixelRef.h b/src/lazy/SkLazyPixelRef.h
index 8f7a751e953693efd0b81cc9e0bafd24dba6154c..284ea3c0dd3ebb468ff98b0c18dccd561d16a7f0 100644
--- a/src/lazy/SkLazyPixelRef.h
+++ b/src/lazy/SkLazyPixelRef.h
@@ -10,8 +10,10 @@
 
 #include "SkBitmapFactory.h"
 #include "SkImage.h"
+#include "SkImageCache.h"
 #include "SkPixelRef.h"
 #include "SkFlattenable.h"
+#include "SkScaledImageCache.h"
 
 class SkColorTable;
 class SkData;
@@ -33,8 +35,9 @@ public:
      *  Create a new SkLazyPixelRef.
      *  @param SkData Encoded data representing the pixels.
      *  @param DecodeProc Called to decode the pixels when needed. Must be non-NULL.
-     *  @param SkImageCache Object that handles allocating and freeing the pixel memory, as needed.
-     *         Must not be NULL.
+     *  @param SkImageCache Object that handles allocating and freeing
+     *         the pixel memory, as needed.  If NULL, use the global
+     *         SkScaledImageCache.
      */
     SkLazyPixelRef(SkData*, SkBitmapFactory::DecodeProc, SkImageCache*);
 
@@ -50,6 +53,13 @@ public:
     static void ResetCacheStats() { gCacheHits = gCacheMisses = 0; }
 #endif
 
+    /**
+     *  The allocator is used when (fImageCache==NULL) to allocate
+     *  concrete PixelRefs as needed.  If NULL, use the default allocator.
+     *  This is passed directly into SkBitmap::allocPixels().
+     */
+    virtual void setAllocator(SkBitmap::Allocator * allocator = NULL);

[reed1, 2013/10/24 21:07:04]

Why is this API introduced at this time?

[hal.canary, 2013/10/25 16:37:10]

It needs to be done, since "Make current image cache in skia use a simple
allocator interface that maps to the DM allocator in chromium and uses malloc
elsewhere." is in the roadmap.

It makes sense to do it now, since it fits into the decode_into_bitmap()
function.

+
     // No need to flatten this object. When flattening an SkBitmap, SkOrderedWriteBuffer will check
     // the encoded data and write that instead.
     // Future implementations of SkFlattenableWriteBuffer will need to special case for
@@ -69,9 +79,13 @@ private:
     SkData*                     fData;
     SkBitmapFactory::DecodeProc fDecodeProc;
     SkImageCache*               fImageCache;
-    intptr_t                    fCacheId;
+    union {
+        SkImageCache::ID        fCacheId;
+        SkScaledImageCache::ID* fScaledCacheId;

[scroggo, 2013/10/24 20:41:39]

I thought you were going to change the declaration of ID from a struct to an
intptr_t?

[hal.canary, 2013/10/25 16:37:10]

I would have, but this way allows me to skip a dozen useless cast operations,
each of which is an opportunity to make a mistake.

+    };
     size_t                      fRowBytes;
     SkImage::Info               fLazilyCachedInfo;
+    SkBitmap::Allocator*        fAllocator;
 
 #if LAZY_CACHE_STATS
     static int32_t              gCacheHits;
@@ -80,6 +94,9 @@ private:
 
     // lazily initialized our cached info. Returns NULL on failure.
     const SkImage::Info* getCachedInfo();
+    void* lockScaledImageCachePixels();
+    void* lockImageCachePixels();
+
 
     typedef SkPixelRef INHERITED;
 };