WebCore/xml/XPathStep.h
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/xml/XPathStep.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2005 Frerich Raabe <raabe@kde.org>
+ * Copyright (C) 2006, 2009 Apple Inc.
+ *
+ * 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 THE AUTHOR ``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 AUTHOR 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.
+ */
+
+#ifndef XPathStep_h
+#define XPathStep_h
+
+#if ENABLE(XPATH)
+
+#include "Node.h"
+#include "XPathExpressionNode.h"
+#include "XPathNodeSet.h"
+
+namespace WebCore {
+
+    namespace XPath {
+
+        class Predicate;
+        
+        class Step : public ParseNode, public Noncopyable {
+        public:
+            enum Axis {
+                AncestorAxis, AncestorOrSelfAxis, AttributeAxis,
+                ChildAxis, DescendantAxis, DescendantOrSelfAxis,
+                FollowingAxis, FollowingSiblingAxis, NamespaceAxis,
+                ParentAxis, PrecedingAxis, PrecedingSiblingAxis,
+                SelfAxis
+            };
+            
+            class NodeTest : public FastAllocBase {
+            public:
+                enum Kind {
+                    TextNodeTest, CommentNodeTest, ProcessingInstructionNodeTest, AnyNodeTest, NameTest
+                };
+                
+                NodeTest(Kind kind) : m_kind(kind) {}
+                NodeTest(Kind kind, const String& data) : m_kind(kind), m_data(data) {}
+                NodeTest(Kind kind, const String& data, const String& namespaceURI) : m_kind(kind), m_data(data), m_namespaceURI(namespaceURI) {}
+                
+                Kind kind() const { return m_kind; }
+                const AtomicString& data() const { return m_data; }
+                const AtomicString& namespaceURI() const { return m_namespaceURI; }
+                Vector<Predicate*>& mergedPredicates() { return m_mergedPredicates; }
+                const Vector<Predicate*>& mergedPredicates() const { return m_mergedPredicates; }
+                
+            private:
+                Kind m_kind;
+                AtomicString m_data;
+                AtomicString m_namespaceURI;
+
+                // When possible, we merge some or all predicates with node test for better performance.
+                Vector<Predicate*> m_mergedPredicates;
+            };
+
+            Step(Axis, const NodeTest& nodeTest, const Vector<Predicate*>& predicates = Vector<Predicate*>());
+            ~Step();
+
+            void optimize();
+
+            void evaluate(Node* context, NodeSet&) const;
+
+            Axis axis() const { return m_axis; }
+            const NodeTest& nodeTest() const { return m_nodeTest; }
+
+        private:
+            friend void optimizeStepPair(Step*, Step*, bool&);
+            bool predicatesAreContextListInsensitive() const;
+
+            void parseNodeTest(const String&);
+            void nodesInAxis(Node* context, NodeSet&) const;
+            String namespaceFromNodetest(const String& nodeTest) const;
+
+            Axis m_axis;
+            NodeTest m_nodeTest;
+            Vector<Predicate*> m_predicates;
+        };
+
+        void optimizeStepPair(Step*, Step*, bool& dropSecondStep);
+    }
+
+}
+
+#endif // ENABLE(XPATH)
+
+#endif // XPathStep_h