Add a first pass of a class descendant invalidator, and a containing RuleSetAnalyzer

Source/core/css/analyzer/DescendantInvalidationSet.cpp

Index: Source/core/css/analyzer/DescendantInvalidationSet.cpp
diff --git a/Source/core/css/analyzer/DescendantInvalidationSet.cpp b/Source/core/css/analyzer/DescendantInvalidationSet.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..7d4f9e0211210e36a36bd9f9031062c4aae208f7
--- /dev/null
+++ b/Source/core/css/analyzer/DescendantInvalidationSet.cpp
@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2014 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * 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.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
+ * OWNER OR 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 "config.h"
+#include "core/css/analyzer/DescendantInvalidationSet.h"
+
+#include "core/css/resolver/StyleResolver.h"
+#include "core/dom/Element.h"
+
+namespace WebCore {
+
+DescendantInvalidationSet::DescendantInvalidationSet()
+    : m_allDescendantsMightBeInvalid(false)
+{
+}
+
+void DescendantInvalidationSet::combine(const DescendantInvalidationSet& other)
+{
+    m_allDescendantsMightBeInvalid = m_allDescendantsMightBeInvalid || other.m_allDescendantsMightBeInvalid;
+    // No longer bother combining data structures, since the whole subtree is deemed invalid.
+    if (m_allDescendantsMightBeInvalid)
+        return;
+
+    HashSet<AtomicString>::const_iterator end = other.m_classes.end();
+    for (HashSet<AtomicString>::const_iterator it = other.m_classes.begin(); it != end; ++it)
+        addClass(*it);
+
+    end = other.m_ids.end();
+    for (HashSet<AtomicString>::const_iterator it = other.m_ids.begin(); it != end; ++it)
+        addId(*it);
+
+    end = other.m_tagNames.end();
+    for (HashSet<AtomicString>::const_iterator it = other.m_tagNames.begin(); it != end; ++it)
+        addTagName(*it);
+}
+
+void DescendantInvalidationSet::addClass(const AtomicString& className)
+{
+    m_classes.add(className);
+}
+
+void DescendantInvalidationSet::addId(const AtomicString& id)
+{
+    m_ids.add(id);
+}
+
+void DescendantInvalidationSet::addTagName(const AtomicString& tagName)
+{
+    m_tagNames.add(tagName);
+}
+
+static bool debug = false;
+
+void DescendantInvalidationSet::appendClasses(Vector<AtomicString>& classes)
+{
+    if (debug && classes.size() == 0)
+        printf("empty class list!!!\n");
+
+    for (HashSet<AtomicString>::const_iterator it = m_classes.begin(); it != m_classes.end(); ++it) {
+        if (debug)
+            printf("added invalidation class for subtree: %s\n", it->ascii().data());
+        classes.append(*it);
+    }
+}
+
+} // namespace WebCore