geirm 00/12/12 15:45:38
Modified: src/java/org/apache/velocity/runtime/directive Foreach.java
Log:
Support for node-local context data introspection caching : don't do introspection
every visit now, but use data from the InternalContext cache if things are hunky.
Revision Changes Path
1.28 +89 -39
jakarta-velocity/src/java/org/apache/velocity/runtime/directive/Foreach.java
Index: Foreach.java
===================================================================
RCS file:
/home/cvs/jakarta-velocity/src/java/org/apache/velocity/runtime/directive/Foreach.java,v
retrieving revision 1.27
retrieving revision 1.28
diff -u -r1.27 -r1.28
--- Foreach.java 2000/12/04 02:06:52 1.27
+++ Foreach.java 2000/12/12 23:45:38 1.28
@@ -78,6 +78,7 @@
import org.apache.velocity.runtime.exception.ReferenceException;
import org.apache.velocity.util.introspection.Introspector;
+import org.apache.velocity.util.introspection.IntrospectionCacheData;
/**
* Foreach directive used for moving through arrays,
@@ -85,7 +86,7 @@
*
* @author <a href="mailto:[EMAIL PROTECTED]">Jason van Zyl</a>
* @author <a href="mailto:[EMAIL PROTECTED]">Geir Magnusson Jr.</a>
- * @version $Id: Foreach.java,v 1.27 2000/12/04 02:06:52 geirm Exp $
+ * @version $Id: Foreach.java,v 1.28 2000/12/12 23:45:38 geirm Exp $
*/
public class Foreach extends Directive
{
@@ -105,6 +106,8 @@
return BLOCK;
}
+ private final static int UNKNOWN = -1;
+
/**
* Flag to indicate that the list object being used
* in an array.
@@ -122,16 +125,7 @@
* is a Map.
*/
private final static int INFO_MAP = 3;
-
- /**
- * Flag to indicate that the list object is
- * empty. This is perfectly valid, and nothing
- * will be rendered. When the list object
- * contains values, then the flag will be
- * altered and the rendering will occur.
- */
- private final static int INFO_EMPTY_LIST_OBJECT = 4;
-
+
/**
* The name of the variable to use when placing
* the counter value into the context. Right
@@ -174,73 +168,126 @@
elementKey = node.jjtGetChild(0).getFirstToken().image.substring(1);
}
+ /**
+ * returns an Iterator to the collection in the #foreach()
+ *
+ * @param context current context
+ * @param node AST node
+ * @return Iterator to do the dataset
+ */
private Iterator getIterator( Context context, Node node )
{
- Object listObject = null;
-
/*
* get our list object, and punt if it's null.
*/
- listObject = node.jjtGetChild(2).value(context);
+ Object listObject = node.jjtGetChild(2).value(context);
if (listObject == null)
return null;
+ /*
+ * See if we already know what type this is. Use the introspection cache
+ */
+
+ int type = UNKNOWN;
+
+ IntrospectionCacheData icd = context.icacheGet( this );
+ Class c = listObject.getClass();
+
+ /*
+ * if we have an entry in the cache, and the Class we have
+ * cached is the same as the Class of the data object
+ * then we are ok
+ */
+
+ if ( icd != null && icd.contextData == c )
+ {
+ /* dig the type out of the cata object */
+ type = ((Integer) icd.thingy ).intValue();
+ }
+
/*
- * Figure out what type of object the list
+ * If we still don't know what this is,
+ * figure out what type of object the list
* element is, and get the iterator for it
*/
- if (Introspector.implementsMethod(listObject, "iterator"))
+ if ( type == UNKNOWN )
{
- if (((Collection) listObject).size() == 0)
- return null;
+ if (listObject instanceof Object[])
+ type = INFO_ARRAY;
+ else if (Introspector.implementsMethod(listObject, "iterator"))
+ type = INFO_ITERATOR;
+ else if (Introspector.implementsMethod(listObject, "values"))
+ type = INFO_MAP;
- return ((Collection) listObject).iterator();
+ /*
+ * if we did figure it out, cache it
+ */
+
+ if ( type != UNKNOWN )
+ {
+ icd = new IntrospectionCacheData();
+ icd.thingy = new Integer( type );
+ icd.contextData = c;
+ context.icachePut( this, icd );
+ }
}
- else if (listObject instanceof Object[])
- {
+
+ /*
+ * now based on the type from either cache or examination...
+ */
+
+ switch( type ) {
+
+ case INFO_ITERATOR :
+
+ if (((Collection) listObject).size() == 0)
+ return null;
+
+ return ((Collection) listObject).iterator();
+
+ case INFO_ARRAY:
+
Object[] arrayObject = ((Object[]) listObject);
if (arrayObject.length == 0)
- return null;
+ return null;
return new ArrayIterator( arrayObject );
- }
- else if (Introspector.implementsMethod(listObject, "values"))
- {
+
+ case INFO_MAP:
+
if (((Map) listObject).size() == 0)
return null;
-
+
return ((Map) listObject).values().iterator();
- }
- else
- {
- /*
- * we have no clue what this is
- */
+
+ default:
+
+ /* we have no clue what this is */
Runtime.warn ("Could not determine type of iterator for #foreach loop
for " + node.jjtGetChild(2).getFirstToken().image);
return null;
- }
+ }
}
+ /**
+ * renders the #foreach() block
+ */
public boolean render(Context context, Writer writer, Node node)
throws IOException
- {
- int counter;
- Iterator i;
-
+ {
/*
* do our introspection to see what our collection is
*/
- i = getIterator( context, node );
+ Iterator i = getIterator( context, node );
if ( i == null)
return false;
- counter = COUNTER_INITIAL_VALUE;
+ int counter = COUNTER_INITIAL_VALUE;
/*
* save the element key if there is one
@@ -270,3 +317,6 @@
}
}
+
+
+
