dedup images/blobs/pictures by ID in old serialization format

src/core/SkPictureRecord.cpp

Index: src/core/SkPictureRecord.cpp
diff --git a/src/core/SkPictureRecord.cpp b/src/core/SkPictureRecord.cpp
index d7716998802a914f00a8c89f6dfed562018b9af9..8eab63016b82998365c8a12ea3ef376046bad1b4 100644
--- a/src/core/SkPictureRecord.cpp
+++ b/src/core/SkPictureRecord.cpp
@@ -867,18 +867,24 @@ void SkPictureRecord::onDrawAnnotation(const SkRect& rect, const char key[], SkD
 
 ///////////////////////////////////////////////////////////////////////////////
 
+template <typename T> int find_or_append_uniqueID(SkTDArray<const T*>& array, const T* obj) {
+    int index = array.select([&](const T* elem) {
+        return elem->uniqueID() == obj->uniqueID();
+    });
+    if (index < 0) {
+        index = array.count();

[mtklein, 2016/08/29 14:34:46]

Seems like we could return count instead of -1, so this becomes

if (index == array.count()) {
  *array.append() = SkRef(obj);
}
return index;

[reed1, 2016/08/29 14:41:26]

That would make this site a tiny bit simpler, but I was following the previous
convention for find() which returns negative on failure. For me this makes
callers slightly simpler in general, since they don't need to always query
count() to know if it failed.

If we decide to return count() instead, I'd vote for also changing find()'s
convention (and updating its callers) to keep find and select consistent.

+        *array.append() = SkRef(obj);
+    }
+    return index;
+}
+
 sk_sp<SkSurface> SkPictureRecord::onNewSurface(const SkImageInfo& info, const SkSurfaceProps&) {
     return nullptr;
 }
 
 void SkPictureRecord::addImage(const SkImage* image) {
-    int index = fImageRefs.find(image);
-    if (index >= 0) {
-        this->addInt(index);
-    } else {
-        *fImageRefs.append() = SkRef(image);
-        this->addInt(fImageRefs.count()-1);
-    }
+    // convention for images is 0-based index
+    this->addInt(find_or_append_uniqueID(fImageRefs, image));
 }
 
 void SkPictureRecord::addMatrix(const SkMatrix& matrix) {
@@ -914,14 +920,8 @@ void SkPictureRecord::addPatch(const SkPoint cubics[12]) {
 }
 
 void SkPictureRecord::addPicture(const SkPicture* picture) {
-    int index = fPictureRefs.find(picture);
-    if (index < 0) {    // not found
-        index = fPictureRefs.count();
-        *fPictureRefs.append() = picture;
-        picture->ref();
-    }
     // follow the convention of recording a 1-based index
-    this->addInt(index + 1);
+    this->addInt(find_or_append_uniqueID(fPictureRefs, picture) + 1);
 }
 
 void SkPictureRecord::addDrawable(SkDrawable* drawable) {
@@ -982,12 +982,9 @@ void SkPictureRecord::addText(const void* text, size_t byteLength) {
     fWriter.writePad(text, byteLength);
 }
 
-void SkPictureRecord::addTextBlob(const SkTextBlob *blob) {
-    int index = fTextBlobRefs.count();
-    *fTextBlobRefs.append() = blob;
-    blob->ref();
+void SkPictureRecord::addTextBlob(const SkTextBlob* blob) {
     // follow the convention of recording a 1-based index
-    this->addInt(index + 1);
+    this->addInt(find_or_append_uniqueID(fTextBlobRefs, blob) + 1);
 }
 
 ///////////////////////////////////////////////////////////////////////////////