SkData -> SkPicture::SnapshotArray

include/core/SkPicture.h

Index: include/core/SkPicture.h
diff --git a/include/core/SkPicture.h b/include/core/SkPicture.h
index dc522a5c9d9229c771041e5c7a1c98bd0fdfc3da..6f9624ea7504d8cb11c95e56e7e55c310091c05b 100644
--- a/include/core/SkPicture.h
+++ b/include/core/SkPicture.h
@@ -202,6 +202,19 @@ public:
      */
     bool hasText() const;
 
+    // A refcounted array of refcounted const SkPicture pointers.
+    struct SnapshotArray : public SkNVRefCnt {
+        explicit SnapshotArray(size_t count) { fArray.setCount(count); }
+        ~SnapshotArray() { fArray.unrefAll(); }
+
+        const SkPicture*& operator[](size_t i)       { return fArray[i]; }

[reed1, 2014/11/20 20:36:47]

this looks tricky, since it allows the receiver to modify an entry. Can we
change the constructor to take ownership of an already-built array? If so, that
would more naturally look like a build -> transport pattern.

Worse case, change the method name to something like writable_set(int index,
pic*) which asserts 1 owner?

[mtklein, 2014/11/21 16:03:50]

Went with set().  I don't think we can assert single ownership... doesn't that
defeat the point of refcounting the snapshots?

+        const SkPicture*  operator[](size_t i) const { return fArray[i]; }
+        size_t count() const { return fArray.count(); }
+        const SkPicture* const* begin() const { return fArray.begin(); }
+    private:
+        SkTDArray<const SkPicture*> fArray;
+    };
+
 private:
     // V2 : adds SkPixelRef's generation ID.
     // V3 : PictInfo tag at beginning, and EOF tag at the end
@@ -255,9 +268,8 @@ private:
     void createHeader(SkPictInfo* info) const;
     static bool IsValidPictInfo(const SkPictInfo& info);
 
-    // Takes ownership of the SkRecord, refs the (optional) drawablePicts and BBH.
-    SkPicture(const SkRect& cullRect, SkRecord*, SkData* drawablePicts,
-              SkBBoxHierarchy*);
+    // Takes ownership of the SkRecord, refs the (optional) SnapshotArray and BBH.
+    SkPicture(const SkRect& cullRect, SkRecord*, SnapshotArray*, SkBBoxHierarchy*);
 
     static SkPicture* Forwardport(const SkPictInfo&, const SkPictureData*);
     static SkPictureData* Backport(const SkRecord&, const SkPictInfo&,
@@ -270,7 +282,7 @@ private:
     mutable SkTDArray<DeletionListener*> fDeletionListeners;  // pointers are refed
     SkAutoTDelete<SkRecord>       fRecord;
     SkAutoTUnref<SkBBoxHierarchy> fBBH;
-    SkAutoTUnref<SkData>          fDrawablePicts;
+    SkAutoTUnref<SnapshotArray>   fDrawablePicts;
 
     // helpers for fDrawablePicts
     int drawableCount() const;