detach has been invoked, calls to
* nextNode orpreviousNode will raise the
* exception INVALID_STATE_ERR.
*/
public void detach()
{
if(m_allowDetach)
{
m_cachedNodes = null;
m_execContext = null;
// m_prefixResolver = null;
// m_cdtm = null;
if (null != m_iterators)
{
int n = m_iterators.length;
for (int i = 0; i < n; i++)
{
m_iterators[i].detach();
}
}
// int n = m_iterators.length;
//
// for (int i = 0; i < n; i++)
// {
// m_iterators[i].detach();
// }
m_clones.freeInstance(this);
}
}
/** Pool of UnionPathIterators. (The need for this has to be re-evaluated. -sb) */
protected IteratorPool m_clones = new IteratorPool(this);
/**
* Execute this iterator, meaning create a clone that can
* store state, and initialize it for fast execution from
* the current runtime state. When this is called, no actual
* query from the current context node is performed.
*
* @param xctxt The XPath execution context.
*
* @return An XNodeSet reference that holds this iterator.
*
* @throws javax.xml.transform.TransformerException
*/
public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
{
UnionPathIterator clone =
(UnionPathIterator) m_clones.getInstance();
int current = xctxt.getCurrentNode();
clone.setRoot(current, xctxt);
return new XNodeSet(clone);
}
/** If this iterator needs to cache nodes that are fetched, they
* are stored here. */
transient NodeSet m_cachedNodes = null;
/** The index of the next node to be fetched. Useful if this
* is a cached iterator, and is being used as random access
* NodeList. */
transient protected int m_next = 0;
/**
* If setShouldCacheNodes(true) is called, then nodes will
* be cached. They are not cached by default.
*
* @param b True if this iterator should cache nodes.
*/
public void setShouldCacheNodes(boolean b)
{
if (b)
m_cachedNodes = new NodeSet();
else
m_cachedNodes = null;
}
/**
* Tells if this iterator can have nodes added to it or set via
* the setItem(int node, int index) method.
*
* @return True if the nodelist can be mutated.
*/
public boolean isMutable()
{
return (m_cachedNodes != null);
}
/**
* Set the current position in the node set.
* @param i Must be a valid index.
*/
public void setCurrentPos(int i)
{
if (null == m_cachedNodes)
throw new RuntimeException(
"This NodeSet can not do indexing or counting functions!");
m_next = i;
m_cachedNodes.setCurrentPos(i);
}
/**
* Get the length of the list.
*
* @return The length of this list, or zero is this is not a cached list.
*/
public int size()
{
if (null == m_cachedNodes)
return 0;
return m_cachedNodes.size();
}
/**
* Tells if this NodeSet is "fresh", in other words, if
* the first nextNode() that is called will return the
* first node in the set.
*
* @return True if the iteration has not yet begun.
*/
public boolean isFresh()
{
return (m_next == 0);
}
/**
* Returns the previous node in the set and moves the position of the
* iterator backwards in the set.
* @return The previous Node in the set being iterated over,
* ornull if there are no more members in that set.
*/
public int previousNode()
{
if (null == m_cachedNodes)
throw new RuntimeException(
"This NodeSet can not iterate to a previous node!");
return m_cachedNodes.previousNode();
}
/**
* This attribute determines which node types are presented via the
* iterator. The available set of constants is defined in the
* DTMFilter interface.
*
* @return A bit set that tells what node types to show (DTMFilter.SHOW_ALL at
* the iterator level).
*/
public int getWhatToShow()
{
// TODO: ??
return DTMFilter.SHOW_ALL & ~DTMFilter.SHOW_ENTITY_REFERENCE;
}
/**
* The filter used to screen nodes.
*
* @return null.
*/
public DTMFilter getFilter()
{
return null;
}
/**
* The root node of the Iterator, as specified when it was created.
*
* @return The context node of this iterator.
*/
public int getRoot()
{
return m_context;
}
/**
* The value of this flag determines whether the children of entity
* reference nodes are visible to the iterator. If false, they will be
* skipped over.
* Node in the set being iterated over, or
* null if there are no more members in that set.
*/
public int nextNode()
{
// // If the cache is on, and the node has already been found, then
// // just return from the list.
// if ((null != m_cachedNodes)
// && (m_cachedNodes.getCurrentPos() < m_cachedNodes.size()))
// {
// return m_cachedNodes.nextNode();
// }
// If the cache is on, and the node has already been found, then
// just return from the list.
if ((null != m_cachedNodes)
&& (m_next < m_cachedNodes.size()))
{
int next = m_cachedNodes.elementAt(m_next);
m_next++;
m_currentContextNode = next;
return next;
}
if (m_foundLast)
return DTM.NULL;
// Loop through the iterators getting the current fetched
// node, and get the earliest occuring in document order
int earliestNode = DTM.NULL;
if (null != m_iterators)
{
int n = m_iterators.length;
int iteratorUsed = -1;
for (int i = 0; i < n; i++)
{
int node = m_iterators[i].getCurrentNode();
if (DTM.NULL == node)
continue;
else if (DTM.NULL == earliestNode)
{
iteratorUsed = i;
earliestNode = node;
}
else
{
if (node == earliestNode)
{
// Found a duplicate, so skip past it.
m_iterators[i].nextNode();
}
else
{
DTM dtm = getDTM(node);
if (dtm.isNodeAfter(node, earliestNode))
{
iteratorUsed = i;
earliestNode = node;
}
}
}
}
if (DTM.NULL != earliestNode)
{
m_iterators[iteratorUsed].nextNode();
if (null != m_cachedNodes)
m_cachedNodes.addElement(earliestNode);
m_next++;
}
else
m_foundLast = true;
}
m_lastFetched = earliestNode;
return earliestNode;
}
/**
* If an index is requested, NodeSet will call this method
* to run the iterator to the index. By default this sets
* m_next to the index. If the index argument is -1, this
* signals that the iterator should be run to the end.
*
* @param index The index to run to, or -1 if the iterator
* should run to the end.
*/
public void runTo(int index)
{
if (m_foundLast || ((index >= 0) && (index <= getCurrentPos())))
return;
int n;
if (-1 == index)
{
while (DTM.NULL != (n = nextNode()));
}
else
{
while (DTM.NULL != (n = nextNode()))
{
if (getCurrentPos() >= index)
break;
}
}
}
/**
* Get the current position, which is one less than
* the next nextNode() call will retrieve. i.e. if
* you call getCurrentPos() and the return is 0, the next
* fetch will take place at index 1.
*
* @return A value greater than or equal to zero that indicates the next
* node position to fetch.
*/
public int getCurrentPos()
{
return m_next;
}
/**
* The number of nodes in the list. The range of valid child node indices
* is 0 to length-1 inclusive.
*
* @return The number of nodes in the list, always greater or equal to zero.
*/
public int getLength()
{
// %REVIEW% ??
// resetToCachedList();
return m_cachedNodes.getLength();
}
/**
* Returns the index th item in the collection. If
* index is greater than or equal to the number of nodes in
* the list, this returns null .
* @param index Index into the collection.
* @return The node at the index th position in the
* NodeList , or null if that is not a valid
* index.
*/
public int item(int index)
{
// resetToCachedList(); %TBD% ??
return m_cachedNodes.item(index);
}
/**
* Sets the node at the specified index of this vector to be the
* specified node. The previous component at that position is discarded.
*
* The index must be a value greater than or equal to 0 and less * than the current size of the vector. * The iterator must be in cached mode.
* *Meant to be used for sorted iterators.
* * @param node Node to set * @param index Index of where to set the node */ public void setItem(int node, int index) { m_cachedNodes.setElementAt(node, index); } /** * Set the current context node for this iterator. * * @param n Must be a non-null reference to the node context. */ public final void setRoot(int n) { m_context = n; } /** * Set the environment in which this iterator operates, which should provide: * a node (the context node... same value as "root" defined below) * a pair of non-zero positive integers (the context position and the context size) * a set of variable bindings * a function library * the set of namespace declarations in scope for the expression. * *At this time the exact implementation of this environment is application * dependent. Probably a proper interface will be created fairly soon.
* * @param environment The environment object. */ public void setEnvironment(Object environment) { // no-op for now. } /** * Get an instance of the DTMManager. Since a node * iterator may be passed without a DTMManager, this allows the * caller to easily get the DTMManager using just the iterator. * * @return a non-null DTMManager reference. */ public DTMManager getDTMManager() { return m_execContext.getDTMManager(); } /** * Return the last fetched node. * * @return The last fetched node, or null if the last fetch was null. */ public int getCurrentNode() { return m_lastFetched; } /** * 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) { for (int i = 0; i < m_iterators.length; i++) { DTMIterator iter = m_iterators[i]; if(iter instanceof Expression) { ((Expression)iter).fixupVariables(vars, globalsSize); } } } /** * Tells if we've found the last node yet. */ transient protected boolean m_foundLast = false; /** * The execution context for the expression. */ transient protected XPathContext m_execContext; /** * The node context for the expression. */ transient protected int m_context = DTM.NULL; /** * The node context from where the Location Path is being * executed from (i.e. for current() support). */ transient protected int m_currentContextNode = DTM.NULL; /** * Get an instance of a DTM that "owns" a node handle. Since a node * iterator may be passed without a DTMManager, this allows the * caller to easily get the DTM using just the iterator. * * @param nodeHandle the nodeHandle. * * @return a non-null DTM reference. */ public DTM getDTM(int nodeHandle) { return m_execContext.getDTM(nodeHandle); } /** * The node context from where the expression is being * executed from (i.e. for current() support). * * @return The top-level node context of the entire expression. */ public int getCurrentContextNode() { return m_currentContextNode; } /** * The location path iterators, one for each * location * path contained in the union expression. * @serial */ protected DTMIterator[] m_iterators; /** * The last index in the list. */ transient private int m_last = 0; /** * Get the index of the last node in the itteration. */ public int getLast() { return m_last; } /** * Set the index of the last node in the itteration. */ public void setLast(int last) { m_last = last; } }