sboag 01/03/27 20:42:01
Added: java/src/org/apache/xalan/transformer TransformSnapshot.java
TransformSnapshotImpl.java
Log:
Unfinished (in progress) implementation of TransformSnapshot mechanism,
which will hopefully allow a result ContentHandler to take a snapshot
at a given point, and the restart execution from that point at some
later time. For tooling support.on the last two.
Revision Changes Path
1.1
xml-xalan/java/src/org/apache/xalan/transformer/TransformSnapshot.java
Index: TransformSnapshot.java
===================================================================
package org.apache.xalan.transformer;
/**
* This is an opaque interface that allows the transformer to return a
* "snapshot" of it's current state, which can later be restored.
*/
public interface TransformSnapshot
{
}
1.1
xml-xalan/java/src/org/apache/xalan/transformer/TransformSnapshotImpl.java
Index: TransformSnapshotImpl.java
===================================================================
package org.apache.xalan.transformer;
import org.apache.xpath.XPathContext;
import org.apache.xpath.VariableStack;
import org.apache.xml.utils.NodeVector;
import org.apache.xml.utils.BoolStack;
import java.util.Stack;
import org.xml.sax.helpers.NamespaceSupport;
import java.util.Enumeration;
/**
* This class holds a "snapshot" of it's current transformer state,
* which can later be restored.
*
* This only saves state which can change over the course of the
side-effect-free
* (i.e. no extensions that call setURIResolver, etc.).
*/
class TransformSnapshotImpl implements TransformSnapshot
{
/**
* The stack of Variable stack frames.
*/
private VariableStack m_variableStacks;
/** The stack of <a
href="http://www.w3.org/TR/xslt#dt-current-node";>current node</a> objects.
* Not to be confused with the current node list. */
private NodeVector m_currentNodes;
/** A stack of the current sub-expression nodes. */
private NodeVector m_currentExpressionNodes;
/**
* The current context node list.
*/
private Stack m_contextNodeLists;
/**
* Stack of AxesIterators.
*/
private Stack m_axesIteratorStack;
/**
* Is > 0 when we're processing a for-each.
*/
private BoolStack m_currentTemplateRuleIsNull = new BoolStack();
/** A node vector used as a stack to track the current
* ElemTemplateElement. Needed for the
* org.apache.xalan.transformer.TransformState interface,
* so a tool can discover the calling template. */
private NodeVector m_currentTemplateElements = new NodeVector(64);
/** A node vector used as a stack to track the current
* ElemTemplate that was matched, as well as the node that
* was matched. Needed for the
* org.apache.xalan.transformer.TransformState interface,
* so a tool can discover the matched template, and matched
* node. */
private NodeVector m_currentMatchTemplates = new NodeVector();
/**
* The table of counters for xsl:number support.
* @see ElemNumber
*/
private CountersTable m_countersTable = null;
/**
* Stack for the purposes of flagging infinite recursion with
* attribute sets.
*/
private Stack m_attrSetStack = null;
/** Indicate whether a namespace context was pushed */
boolean m_nsContextPushed;
/**
* Use the SAX2 helper class to track result namespaces.
*/
private NamespaceSupport m_nsSupport;
/** The number of events queued */
int m_eventCount;
/** Queued start document */
QueuedStartDocument m_startDoc;
/** Queued start element */
QueuedStartElement m_startElement;
TransformSnapshotImpl(TransformerImpl transformer)
{
try
{
// Are all these clones deep enough?
ResultTreeHandler rtf = transformer.getResultTreeHandler();
m_startElement = (QueuedStartElement)rtf.m_startElement.clone();
m_startDoc = (QueuedStartDocument)rtf.m_startDoc.clone();
m_eventCount = rtf.m_eventCount;
// yuck. No clone. Hope this is good enough.
m_nsSupport = new NamespaceSupport();
Enumeration prefixes = rtf.m_nsSupport.getPrefixes();
while(prefixes.hasMoreElements())
{
String prefix = (String)prefixes.nextElement();
String uri = rtf.m_nsSupport.getURI(prefix);
m_nsSupport.declarePrefix(prefix, uri);
}
m_nsContextPushed = rtf.m_nsContextPushed;
XPathContext xpc = transformer.getXPathContext();
m_variableStacks = (VariableStack)xpc.getVarStack().clone();
m_currentNodes = (NodeVector)xpc.getCurrentNodeStack().clone();
m_currentExpressionNodes =
(NodeVector)xpc.getCurrentExpressionNodeStack().clone();
m_contextNodeLists = (Stack)xpc.getContextNodeListsStack().clone();
m_axesIteratorStack = (Stack)xpc.getAxesIteratorStackStacks().clone();
m_currentTemplateRuleIsNull =
(BoolStack)transformer.m_currentTemplateRuleIsNull.clone();
m_currentTemplateElements =
(NodeVector)transformer.m_currentTemplateElements.clone();
m_currentMatchTemplates =
(NodeVector)transformer.m_currentMatchTemplates.clone();
m_countersTable = (CountersTable)transformer.m_countersTable.clone();
m_attrSetStack = (Stack)transformer.m_attrSetStack.clone();
}
catch(CloneNotSupportedException cnse)
{
throw new org.apache.xml.utils.WrappedRuntimeException(cnse);
}
}
void apply(TransformerImpl transformer)
{
try
{
// Are all these clones deep enough?
ResultTreeHandler rtf = transformer.getResultTreeHandler();
rtf.m_startElement = (QueuedStartElement)m_startElement.clone();
rtf.m_startDoc = (QueuedStartDocument)m_startDoc.clone();
rtf.m_eventCount = m_eventCount;
// yuck. No clone. Hope this is good enough.
rtf.m_nsSupport = new NamespaceSupport();
Enumeration prefixes = m_nsSupport.getPrefixes();
while(prefixes.hasMoreElements())
{
String prefix = (String)prefixes.nextElement();
String uri = m_nsSupport.getURI(prefix);
rtf.m_nsSupport.declarePrefix(prefix, uri);
}
rtf.m_nsContextPushed = m_nsContextPushed;
XPathContext xpc = transformer.getXPathContext();
xpc.setVarStack((VariableStack)m_variableStacks.clone());
xpc.setCurrentNodeStack((NodeVector)m_currentNodes.clone());
xpc.setCurrentExpressionNodeStack((NodeVector)m_currentExpressionNodes.clone());
xpc.setContextNodeListsStack((Stack)m_contextNodeLists.clone());
xpc.setAxesIteratorStackStacks((Stack)m_axesIteratorStack.clone());
transformer.m_currentTemplateRuleIsNull =
(BoolStack)m_currentTemplateRuleIsNull.clone();
transformer.m_currentTemplateElements =
(NodeVector)m_currentTemplateElements.clone();
transformer.m_currentMatchTemplates =
(NodeVector)m_currentMatchTemplates.clone();
transformer.m_countersTable = (CountersTable)m_countersTable.clone();
transformer.m_attrSetStack = (Stack)m_attrSetStack.clone();
}
catch(CloneNotSupportedException cnse)
{
throw new org.apache.xml.utils.WrappedRuntimeException(cnse);
}
}
}
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