Index: third_party/WebKit/Source/platform/graphics/paint/GeometryMapperTransformCache.cpp |
diff --git a/third_party/WebKit/Source/platform/graphics/paint/GeometryMapperTransformCache.cpp b/third_party/WebKit/Source/platform/graphics/paint/GeometryMapperTransformCache.cpp |
new file mode 100644 |
index 0000000000000000000000000000000000000000..f05db6f5d27a228224033f4615096ebd2710ec47 |
--- /dev/null |
+++ b/third_party/WebKit/Source/platform/graphics/paint/GeometryMapperTransformCache.cpp |
@@ -0,0 +1,52 @@ |
+// Copyright 2017 The Chromium Authors. All rights reserved. |
+// Use of this source code is governed by a BSD-style license that can be |
+// found in the LICENSE file. |
+ |
+#include "platform/graphics/paint/GeometryMapperTransformCache.h" |
+ |
+namespace blink { |
+ |
+// All transform caches invalidate themselves by tracking a local cache |
+// generation, and invalidating their cache if their cache generation disagrees |
+// with s_transformCacheGeneration. |
+static unsigned s_transformCacheGeneration = 0; |
+ |
+GeometryMapperTransformCache::GeometryMapperTransformCache() |
+ : m_cacheGeneration(s_transformCacheGeneration) {} |
+ |
+void GeometryMapperTransformCache::clearCache() { |
+ s_transformCacheGeneration++; |
+} |
+ |
+void GeometryMapperTransformCache::invalidateCacheIfNeeded() { |
+ if (m_cacheGeneration != s_transformCacheGeneration) { |
+ m_transformCache.clear(); |
+ m_cacheGeneration = s_transformCacheGeneration; |
+ } |
+} |
+ |
+const TransformationMatrix* GeometryMapperTransformCache::getCachedTransform( |
+ const TransformPaintPropertyNode* ancestorTransform) { |
+ invalidateCacheIfNeeded(); |
+ for (const auto& entry : m_transformCache) { |
+ if (entry.ancestorNode == ancestorTransform) { |
+ return &entry.toAncestor; |
+ } |
+ } |
+ return nullptr; |
+} |
+ |
+void GeometryMapperTransformCache::setCachedTransform( |
+ const TransformPaintPropertyNode* ancestorTransform, |
+ const TransformationMatrix& matrix) { |
+ invalidateCacheIfNeeded(); |
+#if DCHECK_IS_ON() |
+ for (const auto& entry : m_transformCache) { |
+ if (entry.ancestorNode == ancestorTransform) |
+ DCHECK(false); // There should be no existing entry. |
+ } |
+#endif |
+ m_transformCache.push_back(TransformCacheEntry(ancestorTransform, matrix)); |
+} |
+ |
+} // namespace blink |