/**
* Get a cloned WalkingIterator that holds the same position as this iterator.
*
* @return A clone of this iterator that holds the same node position.
* @throws CloneNotSupportedException
*/
public Object clone() throws CloneNotSupportedException {
WalkingIterator clone = (WalkingIterator) super.clone();
// clone.m_varStackPos = this.m_varStackPos;
// clone.m_varStackContext = this.m_varStackContext;
if (null != m_firstWalker) {
clone.m_firstWalker = m_firstWalker.cloneDeep(clone, null);
}
return clone;
}
/** @see ExpressionOwner#setExpression(Expression) */
public void setExpression(Expression exp) {
if (!(exp instanceof LocPathIterator)) {
// Yuck. Need FilterExprIter. Or make it so m_exprs can be just
// plain expressions?
WalkingIterator wi = new WalkingIterator(getPrefixResolver());
FilterExprWalker few = new FilterExprWalker(wi);
wi.setFirstWalker(few);
few.setInnerExpression(exp);
wi.exprSetParent(UnionPathIterator.this);
few.exprSetParent(wi);
exp.exprSetParent(few);
exp = wi;
} else exp.exprSetParent(UnionPathIterator.this);
m_exprs[m_index] = (LocPathIterator) exp;
}
/**
* Initialize the location path iterators. Recursive.
*
* @param compiler The Compiler which is creating this expression.
* @param opPos The position of this iterator in the opcode list from the compiler.
* @param count The insert position of the iterator.
* @throws javax.xml.transform.TransformerException
*/
protected void loadLocationPaths(Compiler compiler, int opPos, int count)
throws javax.xml.transform.TransformerException {
// TODO: Handle unwrapped FilterExpr
int steptype = compiler.getOp(opPos);
if (steptype == OpCodes.OP_LOCATIONPATH) {
loadLocationPaths(compiler, compiler.getNextOpPos(opPos), count + 1);
m_exprs[count] = createDTMIterator(compiler, opPos);
m_exprs[count].exprSetParent(this);
} else {
// Have to check for unwrapped functions, which the LocPathIterator
// doesn't handle.
switch (steptype) {
case OpCodes.OP_VARIABLE:
case OpCodes.OP_EXTFUNCTION:
case OpCodes.OP_FUNCTION:
case OpCodes.OP_GROUP:
loadLocationPaths(compiler, compiler.getNextOpPos(opPos), count + 1);
WalkingIterator iter = new WalkingIterator(compiler.getNamespaceContext());
iter.exprSetParent(this);
if (compiler.getLocationPathDepth() <= 0) iter.setIsTopLevel(true);
iter.m_firstWalker = new com.sun.org.apache.xpath.internal.axes.FilterExprWalker(iter);
iter.m_firstWalker.init(compiler, opPos, steptype);
m_exprs[count] = iter;
break;
default:
m_exprs = new LocPathIterator[count];
}
}
}
/**
* Get the index of the last node that can be itterated to.
*
* @param xctxt XPath runtime context.
* @return the index of the last node that can be itterated to.
*/
public int getLastPos(XPathContext xctxt) {
int pos = getProximityPosition();
AxesWalker walker;
try {
walker = (AxesWalker) clone();
} catch (CloneNotSupportedException cnse) {
return -1;
}
walker.setPredicateCount(walker.getPredicateCount() - 1);
walker.setNextWalker(null);
walker.setPrevWalker(null);
WalkingIterator lpi = wi();
AxesWalker savedWalker = lpi.getLastUsedWalker();
try {
lpi.setLastUsedWalker(walker);
int next;
while (DTM.NULL != (next = walker.nextNode())) {
pos++;
}
// TODO: Should probably save this in the iterator.
} finally {
lpi.setLastUsedWalker(savedWalker);
}
// System.out.println("pos: "+pos);
return pos;
}
/**
* Do a deep clone of this walker, including next and previous walkers. If the this AxesWalker is
* on the clone list, don't clone but return the already cloned version.
*
* @param cloneOwner non-null reference to the cloned location path iterator to which this clone
* will be added.
* @param cloneList non-null vector of sources in odd elements, and the corresponding clones in
* even vectors.
* @return non-null clone, which may be a new clone, or may be a clone contained on the cloneList.
*/
AxesWalker cloneDeep(WalkingIterator cloneOwner, Vector cloneList)
throws CloneNotSupportedException {
AxesWalker clone = findClone(this, cloneList);
if (null != clone) return clone;
clone = (AxesWalker) this.clone();
clone.setLocPathIterator(cloneOwner);
if (null != cloneList) {
cloneList.addElement(this);
cloneList.addElement(clone);
}
if (wi().m_lastUsedWalker == this) cloneOwner.m_lastUsedWalker = clone;
if (null != m_nextWalker) clone.m_nextWalker = m_nextWalker.cloneDeep(cloneOwner, cloneList);
// If you don't check for the cloneList here, you'll go into an
// recursive infinate loop.
if (null != cloneList) {
if (null != m_prevWalker) clone.m_prevWalker = m_prevWalker.cloneDeep(cloneOwner, cloneList);
} else {
if (null != m_nextWalker) clone.m_nextWalker.m_prevWalker = clone;
}
return clone;
}
