Centralize more querySelector logic behind QuerySelectorCache.

third_party/WebKit/Source/core/dom/SelectorQuery.cpp

 /*
  * Copyright (C) 2011, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2014 Samsung Electronics. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
  *     documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "core/dom/SelectorQuery.h"
 
+#include <memory>
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/HTMLNames.h"
 #include "core/css/SelectorChecker.h"
 #include "core/css/parser/CSSParser.h"
 #include "core/dom/Document.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/Node.h"
+#include "core/dom/NthIndexCache.h"
 #include "core/dom/StaticNodeList.h"
 #include "core/dom/shadow/ElementShadow.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "wtf/PtrUtil.h"
-#include <memory>
 
 namespace blink {
 
 using namespace HTMLNames;
 
 struct SingleElementSelectorQueryTrait {
   typedef Element* OutputType;
   static const bool shouldOnlyMatchFirstElement = true;
   ALWAYS_INLINE static void appendElement(OutputType& output,
                                           Element& element) {
@@ skipping 87 matching lines @@
        currentElement = currentElement->parentElement()) {
     for (const auto& selector : m_selectors) {
       if (selectorMatches(*selector, *currentElement, targetElement))
         return currentElement;
     }
   }
   return nullptr;
 }
 
 StaticElementList* SelectorQuery::queryAll(ContainerNode& rootNode) const {
+  NthIndexCache nthIndexCache(rootNode.document());
   HeapVector<Member<Element>> result;
   execute<AllElementsSelectorQueryTrait>(rootNode, result);
   return StaticElementList::adopt(result);
 }
 
 Element* SelectorQuery::queryFirst(ContainerNode& rootNode) const {
+  NthIndexCache nthIndexCache(rootNode.document());
   Element* matchedElement = nullptr;
   execute<SingleElementSelectorQueryTrait>(rootNode, matchedElement);
   return matchedElement;
 }
 
 template <typename SelectorQueryTrait>
 static void collectElementsByClassName(
     ContainerNode& rootNode,
     const AtomicString& className,
     typename SelectorQueryTrait::OutputType& output) {
@@ skipping 425 matching lines @@
     m_selectors.uncheckedAppend(selector);
     m_usesDeepCombinatorOrShadowPseudo |=
         selector->hasDeepCombinatorOrShadowPseudo();
     m_needsUpdatedDistribution |= selector->needsUpdatedDistribution();
   }
 }
 
 SelectorQuery* SelectorQueryCache::add(const AtomicString& selectors,
                                        const Document& document,
                                        ExceptionState& exceptionState) {
+  if (selectors.isEmpty()) {
+    exceptionState.throwDOMException(SyntaxError,
+                                     "The provided selector is empty.");
+    return nullptr;
+  }
+
   HashMap<AtomicString, std::unique_ptr<SelectorQuery>>::iterator it =
       m_entries.find(selectors);
   if (it != m_entries.end())
     return it->value.get();
 
   CSSSelectorList selectorList = CSSParser::parseSelector(
       CSSParserContext::create(document, KURL(), emptyString,
                                CSSParserContext::StaticProfile),
       nullptr, selectors);
 
@@ skipping 10 matching lines @@
   return m_entries
       .insert(selectors, SelectorQuery::adopt(std::move(selectorList)))
       .storedValue->value.get();
 }
 
 void SelectorQueryCache::invalidate() {
   m_entries.clear();
 }
 
 }  // namespace blink