Changeset 266198 in webkit

Timestamp:

Aug 26, 2020, 3:34:49 PM (6 years ago)

Author:

Wenson Hsieh

Message:

Avoid unnecessarily copying a Vector in WebCore::transformsForValue
​https://bugs.webkit.org/show_bug.cgi?id=215858

Reviewed by Tim Horton.

Avoid copying the Vector of TransformOperations in this helper function by directly appending newly created
transform operations to the given TransformOperations. This does, however, mean that we need to clear these
items in the case where conversion fails and we return false.

• css/TransformFunctions.cpp:

(WebCore::transformsForValue):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• css/TransformFunctions.cpp (modified) (12 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2020-08-26  Wenson Hsieh  <wenson_hsieh@apple.com>
+
+        Avoid unnecessarily copying a Vector in WebCore::transformsForValue
+        https://bugs.webkit.org/show_bug.cgi?id=215858
+
+        Reviewed by Tim Horton.
+
+        Avoid copying the `Vector` of `TransformOperation`s in this helper function by directly appending newly created
+        transform operations to the given `TransformOperations`. This does, however, mean that we need to clear these
+        items in the case where conversion fails and we return false.
+
+        * css/TransformFunctions.cpp:
+        (WebCore::transformsForValue):
+
 2020-08-26  Dean Jackson  <dino@apple.com>
 

trunk/Source/WebCore/css/TransformFunctions.cpp

@@ -105 +105 @@
 bool transformsForValue(const CSSValue& value, const CSSToLengthConversionData& conversionData, TransformOperations& outOperations)
 {
-    if (!is<CSSValueList>(value)) {
-        outOperations.clear();
+    ASSERT(!outOperations.size());
+    if (!is<CSSValueList>(value))
         return false;
-    }
-
-    TransformOperations operations;
+
+    auto& operations = outOperations.operations();
     for (auto& currentValue : downcast<CSSValueList>(value)) {
         if (!is<CSSFunctionValue>(currentValue))
@@ -149 +148 @@
                 }
             }
-            operations.operations().append(ScaleTransformOperation::create(sx, sy, 1.0, transformOperationType(transformValue.name())));
+            operations.append(ScaleTransformOperation::create(sx, sy, 1.0, transformOperationType(transformValue.name())));
             break;
         }
@@ -175 +174 @@
                 }
             }
-            operations.operations().append(ScaleTransformOperation::create(sx, sy, sz, transformOperationType(transformValue.name())));
+            operations.append(ScaleTransformOperation::create(sx, sy, sz, transformOperationType(transformValue.name())));
             break;
         }
@@ -195 +194 @@
             }
 
-            if (tx.isUndefined() || ty.isUndefined())
+            if (tx.isUndefined() || ty.isUndefined()) {
+                operations.clear();
                 return false;
-
-            operations.operations().append(TranslateTransformOperation::create(tx, ty, Length(0, Fixed), transformOperationType(transformValue.name())));
+            }
+
+            operations.append(TranslateTransformOperation::create(tx, ty, Length(0, Fixed), transformOperationType(transformValue.name())));
             break;
         }
@@ -224 +225 @@
             }
 
-            if (tx.isUndefined() || ty.isUndefined() || tz.isUndefined())
+            if (tx.isUndefined() || ty.isUndefined() || tz.isUndefined()) {
+                operations.clear();
                 return false;
-
-            operations.operations().append(TranslateTransformOperation::create(tx, ty, tz, transformOperationType(transformValue.name())));
+            }
+
+            operations.append(TranslateTransformOperation::create(tx, ty, tz, transformOperationType(transformValue.name())));
             break;
         }
         case CSSValueRotate: {
             double angle = firstValue.computeDegrees();
-            operations.operations().append(RotateTransformOperation::create(0, 0, 1, angle, transformOperationType(transformValue.name())));
+            operations.append(RotateTransformOperation::create(0, 0, 1, angle, transformOperationType(transformValue.name())));
             break;
         }
@@ -249 +252 @@
             else
                 z = 1;
-            operations.operations().append(RotateTransformOperation::create(x, y, z, angle, transformOperationType(transformValue.name())));
+            operations.append(RotateTransformOperation::create(x, y, z, angle, transformOperationType(transformValue.name())));
             break;
         }
@@ -262 +265 @@
             double z = thirdValue.doubleValue();
             double angle = fourthValue.computeDegrees();
-            operations.operations().append(RotateTransformOperation::create(x, y, z, angle, transformOperationType(transformValue.name())));
+            operations.append(RotateTransformOperation::create(x, y, z, angle, transformOperationType(transformValue.name())));
             break;
         }
@@ -282 +285 @@
                 }
             }
-            operations.operations().append(SkewTransformOperation::create(angleX, angleY, transformOperationType(transformValue.name())));
+            operations.append(SkewTransformOperation::create(angleX, angleY, transformOperationType(transformValue.name())));
             break;
         }
@@ -294 +297 @@
             double e = conversionData.zoom() * downcast<CSSPrimitiveValue>(*transformValue.itemWithoutBoundsCheck(4)).doubleValue();
             double f = conversionData.zoom() * downcast<CSSPrimitiveValue>(*transformValue.itemWithoutBoundsCheck(5)).doubleValue();
-            operations.operations().append(MatrixTransformOperation::create(a, b, c, d, e, f));
+            operations.append(MatrixTransformOperation::create(a, b, c, d, e, f));
             break;
         }
@@ -316 +319 @@
                 downcast<CSSPrimitiveValue>(*transformValue.itemWithoutBoundsCheck(14)).doubleValue(),
                 downcast<CSSPrimitiveValue>(*transformValue.itemWithoutBoundsCheck(15)).doubleValue());
-            operations.operations().append(Matrix3DTransformOperation::create(matrix));
+            operations.append(Matrix3DTransformOperation::create(matrix));
             break;
         }
@@ -329 +332 @@
             }
 
-            if (p.isUndefined())
+            if (p.isUndefined()) {
+                operations.clear();
                 return false;
-
-            operations.operations().append(PerspectiveTransformOperation::create(p));
+            }
+
+            operations.append(PerspectiveTransformOperation::create(p));
             break;
         }
@@ -341 +346 @@
     }
 
-    outOperations = operations;
     return true;
 }