- /*
- * Copyright 1999-2004 The Apache Software Foundation.
- *
- * Licensed 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: DescendantIterator.java,v 1.22 2004/02/17 04:32:08 minchau Exp $
- */
- package com.sun.org.apache.xpath.internal.axes;
-
- import com.sun.org.apache.xml.internal.dtm.Axis;
- import com.sun.org.apache.xml.internal.dtm.DTM;
- import com.sun.org.apache.xml.internal.dtm.DTMAxisTraverser;
- import com.sun.org.apache.xml.internal.dtm.DTMFilter;
- import com.sun.org.apache.xml.internal.dtm.DTMIterator;
- import com.sun.org.apache.xpath.internal.Expression;
- import com.sun.org.apache.xpath.internal.XPathContext;
- import com.sun.org.apache.xpath.internal.compiler.Compiler;
- import com.sun.org.apache.xpath.internal.compiler.OpCodes;
- import com.sun.org.apache.xpath.internal.patterns.NodeTest;
-
- /**
- * This class implements an optimized iterator for
- * descendant, descendant-or-self, or "//foo" patterns.
- * @see com.sun.org.apache.xpath.internal.axes.LocPathIterator
- * @xsl.usage advanced
- */
- public class DescendantIterator extends LocPathIterator
- {
- /**
- * Create a DescendantIterator object.
- *
- * @param compiler A reference to the Compiler that contains the op map.
- * @param opPos The position within the op map, which contains the
- * location path expression for this itterator.
- *
- * @throws javax.xml.transform.TransformerException
- */
- DescendantIterator(Compiler compiler, int opPos, int analysis)
- throws javax.xml.transform.TransformerException
- {
-
- super(compiler, opPos, analysis, false);
-
- int firstStepPos = compiler.getFirstChildPos(opPos);
- int stepType = compiler.getOp(firstStepPos);
-
- boolean orSelf = (OpCodes.FROM_DESCENDANTS_OR_SELF == stepType);
- boolean fromRoot = false;
- if (OpCodes.FROM_SELF == stepType)
- {
- orSelf = true;
- // firstStepPos += 8;
- }
- else if(OpCodes.FROM_ROOT == stepType)
- {
- fromRoot = true;
- // Ugly code... will go away when AST work is done.
- int nextStepPos = compiler.getNextStepPos(firstStepPos);
- if(compiler.getOp(nextStepPos) == OpCodes.FROM_DESCENDANTS_OR_SELF)
- orSelf = true;
- // firstStepPos += 8;
- }
-
- // Find the position of the last step.
- int nextStepPos = firstStepPos;
- while(true)
- {
- nextStepPos = compiler.getNextStepPos(nextStepPos);
- if(nextStepPos > 0)
- {
- int stepOp = compiler.getOp(nextStepPos);
- if(OpCodes.ENDOP != stepOp)
- firstStepPos = nextStepPos;
- else
- break;
- }
- else
- break;
-
- }
-
- // Fix for http://nagoya.apache.org/bugzilla/show_bug.cgi?id=1336
- if((analysis & WalkerFactory.BIT_CHILD) != 0)
- orSelf = false;
-
- if(fromRoot)
- {
- if(orSelf)
- m_axis = Axis.DESCENDANTSORSELFFROMROOT;
- else
- m_axis = Axis.DESCENDANTSFROMROOT;
- }
- else if(orSelf)
- m_axis = Axis.DESCENDANTORSELF;
- else
- m_axis = Axis.DESCENDANT;
-
- int whatToShow = compiler.getWhatToShow(firstStepPos);
-
- if ((0 == (whatToShow
- & (DTMFilter.SHOW_ATTRIBUTE | DTMFilter.SHOW_ELEMENT
- | DTMFilter.SHOW_PROCESSING_INSTRUCTION))) ||
- (whatToShow == DTMFilter.SHOW_ALL))
- initNodeTest(whatToShow);
- else
- {
- initNodeTest(whatToShow, compiler.getStepNS(firstStepPos),
- compiler.getStepLocalName(firstStepPos));
- }
- initPredicateInfo(compiler, firstStepPos);
- }
-
- /**
- * Create a DescendantIterator object.
- *
- * @param compiler A reference to the Compiler that contains the op map.
- * @param opPos The position within the op map, which contains the
- * location path expression for this itterator.
- *
- * @throws javax.xml.transform.TransformerException
- */
- public DescendantIterator()
- {
- super(null);
- m_axis = Axis.DESCENDANTSORSELFFROMROOT;
- int whatToShow = DTMFilter.SHOW_ALL;
- initNodeTest(whatToShow);
- }
-
-
- /**
- * Get a cloned Iterator that is reset to the beginning
- * of the query.
- *
- * @return A cloned NodeIterator set of the start of the query.
- *
- * @throws CloneNotSupportedException
- */
- public DTMIterator cloneWithReset() throws CloneNotSupportedException
- {
-
- DescendantIterator clone = (DescendantIterator) super.cloneWithReset();
- clone.m_traverser = m_traverser;
-
- clone.resetProximityPositions();
-
- return clone;
- }
-
- /**
- * 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.
- *
- * @throws DOMException
- * INVALID_STATE_ERR: Raised if this method is called after the
- * <code>detach</code> method was invoked.
- */
- public int nextNode()
- {
- if(m_foundLast)
- return DTM.NULL;
-
- if(DTM.NULL == m_lastFetched)
- {
- resetProximityPositions();
- }
-
- int next;
-
- com.sun.org.apache.xpath.internal.VariableStack vars;
- int savedStart;
- if (-1 != m_stackFrame)
- {
- vars = m_execContext.getVarStack();
-
- // These three statements need to be combined into one operation.
- savedStart = vars.getStackFrame();
-
- vars.setStackFrame(m_stackFrame);
- }
- else
- {
- // Yuck. Just to shut up the compiler!
- vars = null;
- savedStart = 0;
- }
-
- try
- {
- do
- {
- if(0 == m_extendedTypeID)
- {
- next = m_lastFetched = (DTM.NULL == m_lastFetched)
- ? m_traverser.first(m_context)
- : m_traverser.next(m_context, m_lastFetched);
- }
- else
- {
- next = m_lastFetched = (DTM.NULL == m_lastFetched)
- ? m_traverser.first(m_context, m_extendedTypeID)
- : m_traverser.next(m_context, m_lastFetched,
- m_extendedTypeID);
- }
-
- if (DTM.NULL != next)
- {
- if(DTMIterator.FILTER_ACCEPT == acceptNode(next))
- break;
- else
- continue;
- }
- else
- break;
- }
- while (next != DTM.NULL);
-
- if (DTM.NULL != next)
- {
- m_pos++;
- return next;
- }
- else
- {
- m_foundLast = true;
-
- return DTM.NULL;
- }
- }
- finally
- {
- if (-1 != m_stackFrame)
- {
- // These two statements need to be combined into one operation.
- vars.setStackFrame(savedStart);
- }
- }
- }
-
- /**
- * Initialize the context values for this expression
- * after it is cloned.
- *
- * @param execContext The XPath runtime context for this
- * transformation.
- */
- public void setRoot(int context, Object environment)
- {
- super.setRoot(context, environment);
- m_traverser = m_cdtm.getAxisTraverser(m_axis);
-
- String localName = getLocalName();
- String namespace = getNamespace();
- int what = m_whatToShow;
- // System.out.println("what: ");
- // NodeTest.debugWhatToShow(what);
- if(DTMFilter.SHOW_ALL == what
- || localName == NodeTest.WILD
- || namespace == NodeTest.WILD)
- {
- m_extendedTypeID = 0;
- }
- else
- {
- int type = getNodeTypeTest(what);
- m_extendedTypeID = m_cdtm.getExpandedTypeID(namespace, localName, type);
- }
-
- }
-
- /**
- * Return the first node out of the nodeset, if this expression is
- * a nodeset expression. This is the default implementation for
- * nodesets.
- * <p>WARNING: Do not mutate this class from this function!</p>
- * @param xctxt The XPath runtime context.
- * @return the first node out of the nodeset, or DTM.NULL.
- */
- public int asNode(XPathContext xctxt)
- throws javax.xml.transform.TransformerException
- {
- if(getPredicateCount() > 0)
- return super.asNode(xctxt);
-
- int current = xctxt.getCurrentNode();
-
- DTM dtm = xctxt.getDTM(current);
- DTMAxisTraverser traverser = dtm.getAxisTraverser(m_axis);
-
- String localName = getLocalName();
- String namespace = getNamespace();
- int what = m_whatToShow;
-
- // System.out.print(" (DescendantIterator) ");
-
- // System.out.println("what: ");
- // NodeTest.debugWhatToShow(what);
- if(DTMFilter.SHOW_ALL == what
- || localName == NodeTest.WILD
- || namespace == NodeTest.WILD)
- {
- return traverser.first(current);
- }
- else
- {
- int type = getNodeTypeTest(what);
- int extendedType = dtm.getExpandedTypeID(namespace, localName, type);
- return traverser.first(current, extendedType);
- }
- }
-
- /**
- * Detaches the iterator from the set which it iterated over, releasing
- * any computational resources and placing the iterator in the INVALID
- * state. After<code>detach</code> has been invoked, calls to
- * <code>nextNode</code> or<code>previousNode</code> will raise the
- * exception INVALID_STATE_ERR.
- */
- public void detach()
- {
- if (m_allowDetach) {
- m_traverser = null;
- m_extendedTypeID = 0;
-
- // Always call the superclass detach last!
- super.detach();
- }
- }
-
- /**
- * 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()
- {
- return m_axis;
- }
-
-
- /** The traverser to use to navigate over the descendants. */
- transient protected DTMAxisTraverser m_traverser;
-
- /** The axis that we are traversing. */
- protected int m_axis;
-
- /** The extended type ID, not set until setRoot. */
- protected int m_extendedTypeID;
-
- /**
- * @see Expression#deepEquals(Expression)
- */
- public boolean deepEquals(Expression expr)
- {
- if(!super.deepEquals(expr))
- return false;
-
- if(m_axis != ((DescendantIterator)expr).m_axis)
- return false;
-
- return true;
- }
-
-
- }