Author: hlship
Date: Sun Mar 9 10:41:16 2008
New Revision: 635315
URL: http://svn.apache.org/viewvc?rev=635315&view=rev
Log:
TAPESTRY-2245: GridDataSource getAvailableRows() method called inefficiently
Modified:
tapestry/tapestry5/trunk/tapestry-core/src/main/java/org/apache/tapestry/corelib/components/Grid.java
Modified:
tapestry/tapestry5/trunk/tapestry-core/src/main/java/org/apache/tapestry/corelib/components/Grid.java
URL:
http://svn.apache.org/viewvc/tapestry/tapestry5/trunk/tapestry-core/src/main/java/org/apache/tapestry/corelib/components/Grid.java?rev=635315&r1=635314&r2=635315&view=diff
==============================================================================
---
tapestry/tapestry5/trunk/tapestry-core/src/main/java/org/apache/tapestry/corelib/components/Grid.java
(original)
+++
tapestry/tapestry5/trunk/tapestry-core/src/main/java/org/apache/tapestry/corelib/components/Grid.java
Sun Mar 9 10:41:16 2008
@@ -57,6 +57,12 @@
private GridDataSource _source;
/**
+ * A wrapper around the provided GridDataSource that caches access to the
availableRows property. This is the source
+ * provided to sub-components.
+ */
+ private GridDataSource _cachingSource;
+
+ /**
* The number of rows of data displayed on each page. If there are more
rows than will fit, the Grid will divide up
* the rows into "pages" and (normally) provide a pager to allow the user
to navigate within the overall result
* set.
@@ -207,7 +213,43 @@
private FormSupport _formSupport;
/**
- * Default implementation only allows a single column to be the sort
column, and stores the sort information as
+ * A version of GridDataSource that caches the availableRows property.
This addresses TAPESTRY-2245.
+ */
+ class CachingDataSource implements GridDataSource
+ {
+ private boolean _availableRowsCached;
+
+ private int _availableRows;
+
+ public int getAvailableRows()
+ {
+ if (!_availableRowsCached)
+ {
+ _availableRows = _source.getAvailableRows();
+ _availableRowsCached = true;
+ }
+
+ return _availableRows;
+ }
+
+ public void prepare(int startIndex, int endIndex, List<SortConstraint>
sortConstraints)
+ {
+ _source.prepare(startIndex, endIndex, sortConstraints);
+ }
+
+ public Object getRowValue(int index)
+ {
+ return _source.getRowValue(index);
+ }
+
+ public Class getRowType()
+ {
+ return _source.getRowType();
+ }
+ }
+
+ /**
+ * Default implementation that only allows a single column to be the sort
column, and stores the sort information as
* persistent fields of the Grid component.
*/
class DefaultGridSortModel implements GridSortModel
@@ -314,14 +356,16 @@
setupDataSource();
- return _source.getAvailableRows() == 0 ? _empty : null;
+ return _cachingSource.getAvailableRows() == 0 ? _empty : null;
}
void setupDataSource()
{
// If there's no rows, display the empty block placeholder.
- int availableRows = _source.getAvailableRows();
+ _cachingSource = new CachingDataSource();
+
+ int availableRows = _cachingSource.getAvailableRows();
if (availableRows == 0) return;
@@ -338,7 +382,7 @@
int endIndex = Math.min(startIndex + _rowsPerPage - 1, availableRows -
1);
- _source.prepare(startIndex, endIndex, _sortModel.getSortContraints());
+ _cachingSource.prepare(startIndex, endIndex,
_sortModel.getSortContraints());
}
@@ -347,7 +391,7 @@
// Skip rendering of component (template, body, etc.) when there's
nothing to display.
// The empty placeholder will already have rendered.
- if (_source.getAvailableRows() == 0) return false;
+ if (_cachingSource.getAvailableRows() == 0) return false;
return null;
}
@@ -359,7 +403,7 @@
public GridDataSource getDataSource()
{
- return _source;
+ return _cachingSource;
}
public GridSortModel getSortModel()
