| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| /* |
| * $Id: FilterExprIteratorSimple.java 468655 2006-10-28 07:12:06Z minchau $ |
| */ |
| package org.apache.xpath.axes; |
| |
| import org.apache.xml.dtm.Axis; |
| import org.apache.xml.dtm.DTM; |
| import org.apache.xml.utils.PrefixResolver; |
| import org.apache.xpath.Expression; |
| import org.apache.xpath.ExpressionOwner; |
| import org.apache.xpath.VariableStack; |
| import org.apache.xpath.XPathContext; |
| import org.apache.xpath.XPathVisitor; |
| import org.apache.xpath.objects.XNodeSet; |
| |
| /** |
| * Class to use for one-step iteration that doesn't have a predicate, and |
| * doesn't need to set the context. |
| */ |
| public class FilterExprIteratorSimple extends LocPathIterator |
| { |
| static final long serialVersionUID = -6978977187025375579L; |
| /** The contained expression. Should be non-null. |
| * @serial */ |
| private Expression m_expr; |
| |
| /** The result of executing m_expr. Needs to be deep cloned on clone op. */ |
| transient private XNodeSet m_exprObj; |
| |
| private boolean m_mustHardReset = false; |
| private boolean m_canDetachNodeset = true; |
| |
| /** |
| * Create a FilterExprIteratorSimple object. |
| * |
| */ |
| public FilterExprIteratorSimple() |
| { |
| super(null); |
| } |
| |
| /** |
| * Create a FilterExprIteratorSimple object. |
| * |
| */ |
| public FilterExprIteratorSimple(Expression expr) |
| { |
| super(null); |
| m_expr = expr; |
| } |
| |
| /** |
| * Initialize the context values for this expression |
| * after it is cloned. |
| * |
| * @param context The XPath runtime context for this |
| * transformation. |
| */ |
| public void setRoot(int context, Object environment) |
| { |
| super.setRoot(context, environment); |
| m_exprObj = executeFilterExpr(context, m_execContext, getPrefixResolver(), |
| getIsTopLevel(), m_stackFrame, m_expr); |
| } |
| |
| /** |
| * Execute the expression. Meant for reuse by other FilterExpr iterators |
| * that are not derived from this object. |
| */ |
| public static XNodeSet executeFilterExpr(int context, XPathContext xctxt, |
| PrefixResolver prefixResolver, |
| boolean isTopLevel, |
| int stackFrame, |
| Expression expr ) |
| throws org.apache.xml.utils.WrappedRuntimeException |
| { |
| PrefixResolver savedResolver = xctxt.getNamespaceContext(); |
| XNodeSet result = null; |
| |
| try |
| { |
| xctxt.pushCurrentNode(context); |
| xctxt.setNamespaceContext(prefixResolver); |
| |
| // The setRoot operation can take place with a reset operation, |
| // and so we may not be in the context of LocPathIterator#nextNode, |
| // so we have to set up the variable context, execute the expression, |
| // and then restore the variable context. |
| |
| if (isTopLevel) |
| { |
| // System.out.println("calling m_expr.execute(getXPathContext())"); |
| VariableStack vars = xctxt.getVarStack(); |
| |
| // These three statements need to be combined into one operation. |
| int savedStart = vars.getStackFrame(); |
| vars.setStackFrame(stackFrame); |
| |
| result = (org.apache.xpath.objects.XNodeSet) expr.execute(xctxt); |
| result.setShouldCacheNodes(true); |
| |
| // These two statements need to be combined into one operation. |
| vars.setStackFrame(savedStart); |
| } |
| else |
| result = (org.apache.xpath.objects.XNodeSet) expr.execute(xctxt); |
| |
| } |
| catch (javax.xml.transform.TransformerException se) |
| { |
| |
| // TODO: Fix... |
| throw new org.apache.xml.utils.WrappedRuntimeException(se); |
| } |
| finally |
| { |
| xctxt.popCurrentNode(); |
| xctxt.setNamespaceContext(savedResolver); |
| } |
| return result; |
| } |
| |
| /** |
| * Returns the next node in the set and advances the position of the |
| * iterator in the set. After a NodeIterator is created, the first call |
| * to nextNode() returns the first node in the set. |
| * |
| * @return The next <code>Node</code> in the set being iterated over, or |
| * <code>null</code> if there are no more members in that set. |
| */ |
| public int nextNode() |
| { |
| if(m_foundLast) |
| return DTM.NULL; |
| |
| int next; |
| |
| if (null != m_exprObj) |
| { |
| m_lastFetched = next = m_exprObj.nextNode(); |
| } |
| else |
| m_lastFetched = next = DTM.NULL; |
| |
| // m_lastFetched = next; |
| if (DTM.NULL != next) |
| { |
| m_pos++; |
| return next; |
| } |
| else |
| { |
| m_foundLast = true; |
| |
| return DTM.NULL; |
| } |
| } |
| |
| /** |
| * Detaches the walker from the set which it iterated over, releasing |
| * any computational resources and placing the iterator in the INVALID |
| * state. |
| */ |
| public void detach() |
| { |
| if(m_allowDetach) |
| { |
| super.detach(); |
| m_exprObj.detach(); |
| m_exprObj = null; |
| } |
| } |
| |
| /** |
| * This function is used to fixup variables from QNames to stack frame |
| * indexes at stylesheet build time. |
| * @param vars List of QNames that correspond to variables. This list |
| * should be searched backwards for the first qualified name that |
| * corresponds to the variable reference qname. The position of the |
| * QName in the vector from the start of the vector will be its position |
| * in the stack frame (but variables above the globalsTop value will need |
| * to be offset to the current stack frame). |
| */ |
| public void fixupVariables(java.util.Vector vars, int globalsSize) |
| { |
| super.fixupVariables(vars, globalsSize); |
| m_expr.fixupVariables(vars, globalsSize); |
| } |
| |
| /** |
| * Get the inner contained expression of this filter. |
| */ |
| public Expression getInnerExpression() |
| { |
| return m_expr; |
| } |
| |
| /** |
| * Set the inner contained expression of this filter. |
| */ |
| public void setInnerExpression(Expression expr) |
| { |
| expr.exprSetParent(this); |
| m_expr = expr; |
| } |
| |
| /** |
| * Get the analysis bits for this walker, as defined in the WalkerFactory. |
| * @return One of WalkerFactory#BIT_DESCENDANT, etc. |
| */ |
| public int getAnalysisBits() |
| { |
| if (null != m_expr && m_expr instanceof PathComponent) |
| { |
| return ((PathComponent) m_expr).getAnalysisBits(); |
| } |
| return WalkerFactory.BIT_FILTER; |
| } |
| |
| /** |
| * Returns true if all the nodes in the iteration well be returned in document |
| * order. |
| * Warning: This can only be called after setRoot has been called! |
| * |
| * @return true as a default. |
| */ |
| public boolean isDocOrdered() |
| { |
| return m_exprObj.isDocOrdered(); |
| } |
| |
| class filterExprOwner implements ExpressionOwner |
| { |
| /** |
| * @see ExpressionOwner#getExpression() |
| */ |
| public Expression getExpression() |
| { |
| return m_expr; |
| } |
| |
| /** |
| * @see ExpressionOwner#setExpression(Expression) |
| */ |
| public void setExpression(Expression exp) |
| { |
| exp.exprSetParent(FilterExprIteratorSimple.this); |
| m_expr = exp; |
| } |
| |
| } |
| |
| /** |
| * This will traverse the heararchy, calling the visitor for |
| * each member. If the called visitor method returns |
| * false, the subtree should not be called. |
| * |
| * @param visitor The visitor whose appropriate method will be called. |
| */ |
| public void callPredicateVisitors(XPathVisitor visitor) |
| { |
| m_expr.callVisitors(new filterExprOwner(), visitor); |
| |
| super.callPredicateVisitors(visitor); |
| } |
| |
| /** |
| * @see Expression#deepEquals(Expression) |
| */ |
| public boolean deepEquals(Expression expr) |
| { |
| if (!super.deepEquals(expr)) |
| return false; |
| |
| FilterExprIteratorSimple fet = (FilterExprIteratorSimple) expr; |
| if (!m_expr.deepEquals(fet.m_expr)) |
| return false; |
| |
| return true; |
| } |
| |
| /** |
| * Returns the axis being iterated, if it is known. |
| * |
| * @return Axis.CHILD, etc., or -1 if the axis is not known or is of multiple |
| * types. |
| */ |
| public int getAxis() |
| { |
| if(null != m_exprObj) |
| return m_exprObj.getAxis(); |
| else |
| return Axis.FILTEREDLIST; |
| } |
| |
| |
| } |
| |