Share the same cache in HTMLCollection and DynamicNodeLists

Share the same cache in HTMLCollection and DynamicNodeLists
https://bugs.webkit.org/show_bug.cgi?id=90118

Reviewed by Anders Carlsson.

This patch introduces two new base classes DynamicNodeListCacheBase and HTMLCollectionCacheBase to share
the cache object between DynamicNodeList and HTMLCollection. HTMLCollectionCacheBase inherits from
DynamicNodeListCacheBase and contains extra caches and bit flags for HTMLCollection. DynamicNodeList::Cache
and HTMLCollection::Cache had been removed and flattened into these two classes for the easy inheritance.

In DynamicNodeList, we have a very straight forward one-to-one mapping from old Caches member variables:

m_caches.lastItem -> cachedItem()
m_caches.lastItemOffset -> cachedItemOffset()
m_caches.cachedLength -> cachedLength()
m_caches.isItemCacheValid -> isItemCacheValid()
m_caches.isLengthCacheValid -> isLengthCacheValid()
m_caches.type -> removed because it was never used.
m_caches.rootedAtDocument -> isRootedAtDocument()
m_caches.shouldInvalidateOnAttributeChange -> shouldInvalidateOnAttributeChange()

In HTMLCollection, there is one semantic change in the way item cache is managed. Previously, we only had
m_cache.current which was used as both cachedItem() and isItemCacheValid() (not valid when current is null).
There are some asymmetric code changes due to one-to-many relationship. Also, all method names have been updated
to use that of DynamicNodeList terminology. Thus we have the following correspondence:

m_cache.current -> cachedItem() / isItemCacheValid()
m_cache.position -> cachedItemOffset()
m_cache.length -> cachedLength()
m_cache.elementsArrayPosition -> cachedElementsArrayOffset()
m_cache.hasLength -> isLengthCacheValid()
m_cache.hasNameCache -> hasNameCache() / setHasNameCache()
m_cache.idCache -> idCache() / addIdCache()
m_cache.nameCache -> idCache() / addNameCache()

In addition, we had to rename HTMLCollection::clearCache to invalidateCache to avoid the name collision with
HTMLCollectionCacheBase::clearCache.

* dom/ChildNodeList.cpp:
(WebCore::ChildNodeList::length):
(WebCore::ChildNodeList::item):
* dom/DynamicNodeList.cpp:
(WebCore::DynamicSubtreeNodeList::length):
(WebCore::DynamicSubtreeNodeList::itemForwardsFromCurrent):
(WebCore::DynamicSubtreeNodeList::itemBackwardsFromCurrent):
(WebCore::DynamicSubtreeNodeList::item):
* dom/DynamicNodeList.h:
(DynamicNodeListCacheBase):
(WebCore::DynamicNodeListCacheBase::DynamicNodeListCacheBase):
(WebCore::DynamicNodeListCacheBase::isRootedAtDocument):
(WebCore::DynamicNodeListCacheBase::shouldInvalidateOnAttributeChange):
(WebCore::DynamicNodeListCacheBase::isItemCacheValid):
(WebCore::DynamicNodeListCacheBase::cachedItem):
(WebCore::DynamicNodeListCacheBase::cachedItemOffset):
(WebCore::DynamicNodeListCacheBase::isLengthCacheValid):
(WebCore::DynamicNodeListCacheBase::cachedLength):
(WebCore::DynamicNodeListCacheBase::setLengthCache):
(WebCore::DynamicNodeListCacheBase::setItemCache):
(WebCore::DynamicNodeListCacheBase::clearCache):
(WebCore):
(WebCore::DynamicNodeList::DynamicNodeList):
(WebCore::DynamicNodeList::invalidateCache):
(WebCore::DynamicNodeList::rootNode):
(DynamicNodeList):
* html/HTMLAllCollection.cpp:
(WebCore::HTMLAllCollection::namedItemWithIndex):
* html/HTMLCollection.cpp:
(WebCore::HTMLCollection::HTMLCollection):
(WebCore::HTMLCollection::invalidateCacheIfNeeded):
(WebCore::HTMLCollection::invalidateCache):
(WebCore::HTMLCollection::isAcceptableElement):
(WebCore::HTMLCollection::itemAfter):
(WebCore::HTMLCollection::length):
(WebCore::HTMLCollection::item):
(WebCore::HTMLCollection::checkForNameMatch):
(WebCore::HTMLCollection::namedItem):
(WebCore::HTMLCollection::updateNameCache):
(WebCore::HTMLCollection::hasNamedItem):
(WebCore::HTMLCollection::namedItems):
(WebCore::HTMLCollectionCacheBase::append):
* html/HTMLCollection.h:
(HTMLCollectionCacheBase):
(WebCore::HTMLCollectionCacheBase::HTMLCollectionCacheBase):
(WebCore::HTMLCollectionCacheBase::type):
(WebCore::HTMLCollectionCacheBase::clearCache):
(WebCore::HTMLCollectionCacheBase::setItemCache):
(WebCore::HTMLCollectionCacheBase::cachedElementsArrayOffset):
(WebCore::HTMLCollectionCacheBase::includeChildren):
(WebCore::HTMLCollectionCacheBase::cacheTreeVersion):
(WebCore::HTMLCollectionCacheBase::idCache):
(WebCore::HTMLCollectionCacheBase::nameCache):
(WebCore::HTMLCollectionCacheBase::appendIdCache):
(WebCore::HTMLCollectionCacheBase::appendNameCache):
(WebCore::HTMLCollectionCacheBase::hasNameCache):
(WebCore::HTMLCollectionCacheBase::setHasNameCache):
(WebCore):
(WebCore::HTMLCollection::isEmpty):
(WebCore::HTMLCollection::hasExactlyOneItem):
(WebCore::HTMLCollection::base):
(HTMLCollection):
* html/HTMLFormCollection.cpp:
(WebCore::HTMLFormCollection::item):
(WebCore::HTMLFormCollection::updateNameCache):
* html/HTMLNameCollection.cpp:
(WebCore::HTMLNameCollection::itemAfter):
* html/HTMLNameCollection.h:
(HTMLNameCollection):
* html/HTMLSelectElement.cpp:
(WebCore::HTMLSelectElement::invalidateSelectedItems):
* html/HTMLTableRowsCollection.cpp:
(WebCore::HTMLTableRowsCollection::itemAfter):
* html/HTMLTableRowsCollection.h:
(HTMLTableRowsCollection):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@121580 268f45cc-cd09-0410-ab3c-d52691b4dbfc