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Posted to commits@xalan.apache.org by zo...@apache.org on 2006/06/07 21:54:46 UTC
svn commit: r412507 -
/xalan/java/trunk/src/org/apache/xalan/xsltc/compiler/KeyCall.java
Author: zongaro
Date: Wed Jun 7 12:54:45 2006
New Revision: 412507
URL: http://svn.apache.org/viewvc?rev=412507&view=rev
Log:
Part of fix for XALANJ-2294 and XALANJ-2295.
Generated byte code previously looked up nodes to be retrieved by a reference
to the key or id function by cloning an IntegerArray containing the first set
of nodes and merging in subsequent nodes retrieved. The generated code
contained any required looping code to loop over nodes in a node set that
appeared in a call to key or id. The effect of all this was that every node in
the resulting node set was processed at least once, regardless of whether all
the node returned were actually used - they might not need to be if a positional
predicate is used, for instance.
The old KeyIndex.lookupId and KeyIndex.lookupKey are now deprecated, but
preserved for any previously compiled translets. Instead, new generated code
uses the KeyIndex.getKeyIndexIterator methods to get an iterator that will
return the nodes for a particular reference to the key or id function. The
nodes returned by KeyIndexIterator will be in document order with duplicates
filtered, so the DupFilterIterator that was previously created is no longer
necessary.
Also, fix for XALANJ-2292. The byte code generation assumed that if the
second argument to a reference to the key function was not a node set or a
string, that it had to be converted to a string. However, if the argument is
a parameter whose value is a node set, all the nodes in the node set should
play a role in computing the result of the function, not just the first.
The KeyIndex.KeyIndexIterator is responsible for processing the argument to the
key or id function, iterating over nodes in a node set if required, rather than
leaving that responsibility to generated byte code, because we don't generally
know whether the argument will be an iterator.
Reviewed by Christine Li (jycli () ca ! ibm ! com)
Modified:
xalan/java/trunk/src/org/apache/xalan/xsltc/compiler/KeyCall.java
Modified: xalan/java/trunk/src/org/apache/xalan/xsltc/compiler/KeyCall.java
URL: http://svn.apache.org/viewvc/xalan/java/trunk/src/org/apache/xalan/xsltc/compiler/KeyCall.java?rev=412507&r1=412506&r2=412507&view=diff
==============================================================================
--- xalan/java/trunk/src/org/apache/xalan/xsltc/compiler/KeyCall.java (original)
+++ xalan/java/trunk/src/org/apache/xalan/xsltc/compiler/KeyCall.java Wed Jun 7 12:54:45 2006
@@ -124,16 +124,20 @@
// Run type check on the value for this key. This value can be of
// any data type, so this should never cause any type-check errors.
- // If the value is not a node-set then it should be converted to a
- // string before the lookup is done. If the value is a node-set then
- // this process (convert to string, then do lookup) should be applied
- // to every node in the set, and the result from all lookups should
- // be added to the resulting node-set.
+ // If the value is a reference, then we have to defer the decision
+ // of how to process it until run-time.
+ // If the value is known not to be a node-set, then it should be
+ // converted to a string before the lookup is done. If the value is
+ // known to be a node-set then this process (convert to string, then
+ // do lookup) should be applied to every node in the set, and the
+ // result from all lookups should be added to the resulting node-set.
_valueType = _value.typeCheck(stable);
- if (_valueType != Type.NodeSet && _valueType != Type.String)
- {
+ if (_valueType != Type.NodeSet
+ && _valueType != Type.Reference
+ && _valueType != Type.String) {
_value = new CastExpr(_value, Type.String);
+ _valueType = _value.typeCheck(stable);
}
return returnType;
@@ -142,11 +146,8 @@
/**
* This method is called when the constructor is compiled in
* Stylesheet.compileConstructor() and not as the syntax tree is traversed.
- * This method is a wrapper for the real translation method, which is
- * the private method translateCall() below. All this method does is to
- * wrap the KeyIndex that this function returns inside a duplicate filter.
- * The duplicate filter is used both to eliminate duplicates and to
- * cache the nodes in the index.
+ * <p>This method will generate byte code that produces an iterator
+ * for the nodes in the node set for the key or id function call.
* @param classGen The Java class generator
* @param methodGen The method generator
*/
@@ -154,54 +155,6 @@
MethodGenerator methodGen) {
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
-
- final int getNodeHandle = cpg.addInterfaceMethodref(DOM_INTF,
- "getNodeHandle",
- "(I)"+NODE_SIG);
-
- // Wrap the KeyIndex (iterator) inside a duplicate filter iterator
- // to pre-read the indexed nodes and cache them.
- final int dupInit = cpg.addMethodref(DUP_FILTERED_ITERATOR,
- "<init>",
- "("+NODE_ITERATOR_SIG+")V");
-
-
- // Backwards branches are prohibited if an uninitialized object is
- // on the stack by section 4.9.4 of the JVM Specification, 2nd Ed.
- // We don't know whether this code might contain backwards branches
- // so we mustn't create the new object until after we've created
- // the suspect arguments to its constructor. Instead we calculate
- // the values of the arguments to the constructor first, store them
- // in temporary variables, create the object and reload the
- // arguments from the temporaries to avoid the problem.
-
- LocalVariableGen keyIterator = translateCall(classGen, methodGen);
-
- il.append(new NEW(cpg.addClass(DUP_FILTERED_ITERATOR)));
- il.append(DUP);
- // Mark the end of the live range of the keyIterator variable
- keyIterator.setEnd(il.append(new ALOAD(keyIterator.getIndex())));
- il.append(new INVOKESPECIAL(dupInit));
- }
-
- /**
- * Translate the actual index lookup - leaves KeyIndex (iterator) stored
- * in a temporary that the caller will need to load.
- * @param classGen The Java class generator
- * @param methodGen The method generator
- * @return A <code>org.apache.bcel.generic.LocalVariableGen</code>
- * object that will contain the iterator for the key call.
- */
- private LocalVariableGen translateCall(ClassGenerator classGen,
- MethodGenerator methodGen) {
-
- final ConstantPoolGen cpg = classGen.getConstantPool();
- final InstructionList il = methodGen.getInstructionList();
-
- // Returns the string value for a node in the DOM
- final int getNodeValue = cpg.addInterfaceMethodref(DOM_INTF,
- GET_NODE_VALUE,
- "(I)"+STRING_SIG);
// Returns the KeyIndex object of a given name
final int getKeyIndex = cpg.addMethodref(TRANSLET_CLASS,
@@ -209,151 +162,42 @@
"(Ljava/lang/String;)"+
KEY_INDEX_SIG);
- // Initialises a KeyIndex to return nodes with specific values
- final int lookupId = cpg.addMethodref(KEY_INDEX_CLASS,
- "lookupId",
- "(Ljava/lang/Object;)V");
- final int lookupKey = cpg.addMethodref(KEY_INDEX_CLASS,
- "lookupKey",
- "(Ljava/lang/Object;)V");
-
- // Merges the nodes in two KeyIndex objects
- final int merge = cpg.addMethodref(KEY_INDEX_CLASS,
- "merge",
- "("+KEY_INDEX_SIG+")V");
-
- // Constructor for KeyIndex class
- final int indexConstructor = cpg.addMethodref(TRANSLET_CLASS,
- "createKeyIndex",
- "()"+KEY_INDEX_SIG);
-
// KeyIndex.setDom(Dom) => void
- final int keyDom = cpg.addMethodref(XSLT_PACKAGE + ".dom.KeyIndex",
- "setDom",
- "("+DOM_INTF_SIG+")V");
-
-
- // This local variable holds the index/iterator we will return
- final LocalVariableGen returnIndex =
- methodGen.addLocalVariable("returnIndex",
- Util.getJCRefType(KEY_INDEX_SIG),
- null, null);
-
- // If the second paramter is a node-set we need to go through each
- // node in the set, convert each one to a string and do a look up in
- // the named index, and then merge all the resulting node sets.
- if (_valueType == Type.NodeSet) {
- // Save current node and current iterator on the stack
- il.append(methodGen.loadCurrentNode());
- il.append(methodGen.loadIterator());
-
- // Get new iterator from 2nd parameter node-set & store in variable
- _value.translate(classGen, methodGen);
- _value.startIterator(classGen, methodGen);
- il.append(methodGen.storeIterator());
-
- // Create the KeyIndex object (the iterator) we'll return
- il.append(classGen.loadTranslet());
- il.append(new INVOKEVIRTUAL(indexConstructor));
- il.append(DUP);
- il.append(methodGen.loadDOM());
- il.append(new INVOKEVIRTUAL(keyDom));
- returnIndex.setStart(il.append(new ASTORE(returnIndex.getIndex())));
-
- // Initialise the index specified in the first parameter of key()
- il.append(classGen.loadTranslet());
- if (_name == null) {
- il.append(new PUSH(cpg,"##id"));
- }
- else if (_resolvedQName != null) {
- il.append(new PUSH(cpg, _resolvedQName.toString()));
- }
- else {
- _name.translate(classGen, methodGen);
- }
-
- il.append(new INVOKEVIRTUAL(getKeyIndex));
-
- // This local variable holds the index we're using for search
- final LocalVariableGen searchIndex =
- methodGen.addLocalVariable("searchIndex",
- Util.getJCRefType(KEY_INDEX_SIG),
- null, null);
-
- searchIndex.setStart(il.append(new ASTORE(searchIndex.getIndex())));
-
- // LOOP STARTS HERE
-
- // Now we're ready to start traversing the node-set given in
- // the key() function's second argument....
- final BranchHandle nextNode = il.append(new GOTO(null));
- final InstructionHandle loop = il.append(NOP);
-
- // Push returnIndex on stack to prepare for call to merge()
- il.append(new ALOAD(returnIndex.getIndex()));
-
- // Lookup index using the string value from the current node
- il.append(new ALOAD(searchIndex.getIndex()));
- il.append(DUP);
- il.append(methodGen.loadDOM());
- il.append(methodGen.loadCurrentNode());
- il.append(new INVOKEINTERFACE(getNodeValue, 2));
- if (_name == null) {
- il.append(new INVOKEVIRTUAL(lookupId));
- }
- else {
- il.append(new INVOKEVIRTUAL(lookupKey));
- }
-
- // Call to returnIndex.merge(searchIndex);
- il.append(new INVOKEVIRTUAL(merge));
-
- // Go on with next node in the 2nd parameter node-set
- nextNode.setTarget(il.append(methodGen.loadIterator()));
- il.append(methodGen.nextNode());
- il.append(DUP);
- il.append(methodGen.storeCurrentNode());
- il.append(new IFGT(loop));
-
- // LOOP ENDS HERE
-
- // Restore current node and current iterator from the stack
- searchIndex.setEnd(il.append(methodGen.storeIterator()));
- il.append(methodGen.storeCurrentNode());
- }
- // If the second parameter is a single value we just lookup the named
- // index and initialise the iterator to return nodes with this value.
- else {
- // Call getKeyIndex in AbstractTranslet with the name of the key
- // to get the index for this key (which is also a node iterator).
- il.append(classGen.loadTranslet());
- if (_name == null) {
- il.append(new PUSH(cpg,"##id"));
- }
- else if (_resolvedQName != null) {
- il.append(new PUSH(cpg, _resolvedQName.toString()));
- }
- else {
- _name.translate(classGen, methodGen);
- }
- il.append(new INVOKEVIRTUAL(getKeyIndex));
-
- // Now use the value in the second argument to determine what nodes
- // the iterator should return.
- il.append(DUP);
-
- _value.translate(classGen, methodGen);
-
- if (_name == null) {
- il.append(new INVOKEVIRTUAL(lookupId));
- }
- else {
- il.append(new INVOKEVIRTUAL(lookupKey));
- }
+ final int keyDom = cpg.addMethodref(KEY_INDEX_CLASS,
+ "setDom",
+ "("+DOM_INTF_SIG+")V");
- returnIndex.setStart(il.append(new ASTORE(returnIndex.getIndex())));
- }
-
- return returnIndex;
+ // Initialises a KeyIndex to return nodes with specific values
+ final int getKeyIterator =
+ cpg.addMethodref(KEY_INDEX_CLASS,
+ "getKeyIndexIterator",
+ "(" + _valueType.toSignature() + "Z)"
+ + KEY_INDEX_ITERATOR_SIG);
+
+ // Initialise the index specified in the first parameter of key()
+ il.append(classGen.loadTranslet());
+ if (_name == null) {
+ il.append(new PUSH(cpg,"##id"));
+ } else if (_resolvedQName != null) {
+ il.append(new PUSH(cpg, _resolvedQName.toString()));
+ } else {
+ _name.translate(classGen, methodGen);
+ }
+
+ // Generate following byte code:
+ //
+ // KeyIndex ki = translet.getKeyIndex(_name)
+ // ki.setDom(translet.dom);
+ // ki.getKeyIndexIterator(_value, true) - for key()
+ // OR
+ // ki.getKeyIndexIterator(_value, false) - for id()
+ il.append(new INVOKEVIRTUAL(getKeyIndex));
+ il.append(DUP);
+ il.append(methodGen.loadDOM());
+ il.append(new INVOKEVIRTUAL(keyDom));
+
+ _value.translate(classGen, methodGen);
+ il.append((_name != null) ? ICONST_1: ICONST_0);
+ il.append(new INVOKEVIRTUAL(getKeyIterator));
}
}
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