/*!
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU Lesser General Public License for more details.
*
* Copyright (c) 2002-2013 Pentaho Corporation.. All rights reserved.
*/
package org.pentaho.reporting.engine.classic.core.layout.output;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.pentaho.reporting.engine.classic.core.AttributeNames;
import org.pentaho.reporting.engine.classic.core.DataRow;
import org.pentaho.reporting.engine.classic.core.Element;
import org.pentaho.reporting.engine.classic.core.ReportElement;
import org.pentaho.reporting.engine.classic.core.Section;
import org.pentaho.reporting.engine.classic.core.metadata.AttributeMetaData;
import org.pentaho.reporting.engine.classic.core.metadata.ElementMetaData;
import org.pentaho.reporting.libraries.base.util.ObjectUtilities;
public class ElementChangeChecker
{
private static class NeedEvalResult implements Serializable
{
private boolean needToRun;
private long changeTracker;
private long styleChangeTracker;
private long styleModificationCounter;
private HashMap<String, Object> fieldsAndValues;
private NeedEvalResult(final boolean needToRun, final ReportElement e,
final HashMap<String,Object> fieldsAndValues)
{
this.needToRun = needToRun;
this.changeTracker = e.getChangeTracker();
this.fieldsAndValues = fieldsAndValues;
this.styleChangeTracker = e.getStyle().getChangeTracker();
this.styleModificationCounter = e.getStyle().getModificationCount();
}
public boolean isNeedToRun()
{
return needToRun;
}
public long getChangeTracker()
{
return changeTracker;
}
public boolean isValid (final ReportElement e, final DataRow dataRow)
{
if (changeTracker != e.getChangeTracker() ||
styleChangeTracker != e.getStyle().getChangeTracker() ||
styleModificationCounter != e.getStyle().getModificationCount())
{
return false;
}
for (final Map.Entry<String, Object> entry : fieldsAndValues.entrySet())
{
final String field = entry.getKey();
final Object oldValue = entry.getValue();
final Object currentValue = dataRow.get(field);
if (ObjectUtilities.equal(oldValue, currentValue) == false)
{
return false;
}
}
return true;
}
}
private static class ElementMetaDataEvaluationResult implements Serializable
{
private long changeTracker;
private long styleChangeTracker;
private long styleModificationCounter;
private HashMap<String, Object> seenFields;
private ElementMetaDataEvaluationResult(final ReportElement e,
final HashMap<String, Object> seenFields)
{
this.seenFields = seenFields;
changeTracker = e.getChangeTracker();
styleChangeTracker = e.getStyle().getChangeTracker();
styleModificationCounter = e.getStyle().getModificationCount();
}
public boolean isValid(final ReportElement e, final DataRow dataRow)
{
if (changeTracker != e.getChangeTracker() ||
styleChangeTracker != e.getStyle().getChangeTracker() ||
styleModificationCounter != e.getStyle().getModificationCount())
{
return false;
}
for (final Map.Entry<String, Object> entry : seenFields.entrySet())
{
final String field = entry.getKey();
final Object oldValue = entry.getValue();
final Object currentValue = dataRow.get(field);
if (ObjectUtilities.equal(oldValue, currentValue) == false)
{
return false;
}
}
return true;
}
}
private static class PerformanceCollector
{
public int totalEvaluations;
public int evaluations;
public int skippedEvaluations;
}
private final Log performanceLogger = LogFactory.getLog(getClass());
private PerformanceCollector performanceCollector;
private String attrName;
private String elementAttribute;
private DataRow currentDataRow;
private HashMap<String,Object> currentFieldsAndValues;
public ElementChangeChecker()
{
performanceCollector = new PerformanceCollector();
attrName = "ElementChangeTracker-NeedResult@" + System.identityHashCode(this);
elementAttribute = "ElementChangeTracker-DetailResult@" + System.identityHashCode(this);
currentFieldsAndValues = new HashMap<String, Object>();
}
public boolean isBandChanged(final Section b, final DataRow dataRow)
{
this.currentFieldsAndValues.clear();
this.currentDataRow = dataRow;
try
{
return processRootBand(b);
}
finally
{
this.currentFieldsAndValues.clear();
this.currentDataRow = null;
}
}
/**
* Evaluates all style expressions from all elements and updates the style-sheet if needed.
*
* @param b the band.
* @return true if the element needs reprinting.
*/
protected final boolean processRootBand(final Section b)
{
if (b == null)
{
return false;
}
final NeedEvalResult needToRun = (NeedEvalResult) b.getAttribute(AttributeNames.Internal.NAMESPACE, attrName);
if (needToRun != null)
{
if (needToRun.isNeedToRun() == false)
{
if (needToRun.isValid(b, currentDataRow))
{
recordCacheHit(b);
return false;
}
}
}
recordCacheMiss(b);
final boolean needToRunVal = processBand(b);
b.setAttribute(AttributeNames.Internal.NAMESPACE, attrName,
new NeedEvalResult(needToRunVal, b, (HashMap<String, Object>) currentFieldsAndValues.clone()), false);
return true;
}
protected boolean evaluateElement(final ReportElement e)
{
final ElementMetaDataEvaluationResult evalResult =
(ElementMetaDataEvaluationResult) e.getAttribute(AttributeNames.Internal.NAMESPACE, elementAttribute);
if (evalResult != null && evalResult.isValid(e, currentDataRow))
{
currentFieldsAndValues.putAll(evalResult.seenFields);
return false;
}
final HashMap<String, Object> values = new HashMap<String, Object>();
final ElementMetaData metaData = e.getElementType().getMetaData();
final AttributeMetaData[] attributeDescriptions = metaData.getAttributeDescriptions();
for (int i = 0; i < attributeDescriptions.length; i++)
{
final AttributeMetaData attributeDescription = attributeDescriptions[i];
final Object attribute = e.getAttribute(attributeDescription.getNameSpace(), attributeDescription.getName());
if (attribute == null)
{
continue;
}
final String[] referencedFields = attributeDescription.getReferencedFields(e, attribute);
for (int j = 0; j < referencedFields.length; j++)
{
final String field = referencedFields[j];
final Object value = currentDataRow.get(field);
values.put(field, value);
currentFieldsAndValues.put(field, value);
}
}
final ElementMetaDataEvaluationResult current = new ElementMetaDataEvaluationResult(e, values);
e.setAttribute(AttributeNames.Internal.NAMESPACE, elementAttribute, current, false);
return true;
}
protected final boolean processBand(final Section b)
{
boolean hasAttrExpressions = evaluateElement(b);
final int length = b.getElementCount();
for (int i = 0; i < length; i++)
{
final Element element = b.getElement(i);
final ElementMetaData.TypeClassification reportElementType = element.getMetaData().getReportElementType();
if (reportElementType == ElementMetaData.TypeClassification.DATA ||
reportElementType == ElementMetaData.TypeClassification.CONTROL ||
reportElementType == ElementMetaData.TypeClassification.SUBREPORT ||
element instanceof Section == false)
{
if (evaluateElement(element))
{
hasAttrExpressions = true;
}
}
else
{
final Section section = (Section) element;
if (processBand(section))
{
hasAttrExpressions = true;
}
}
}
return hasAttrExpressions;
}
protected void recordCacheHit(final ReportElement e)
{
performanceCollector.totalEvaluations += 1;
performanceCollector.skippedEvaluations += 1;
}
protected void recordCacheMiss(final ReportElement e)
{
performanceCollector.totalEvaluations += 1;
performanceCollector.evaluations += 1;
}
protected void reportCachePerformance()
{
if (performanceLogger.isInfoEnabled())
{
performanceLogger.info(String.format("Performance: %s => total=%d, evaluated=%d (%f%%), avoided=%d (%f%%)", getClass(),
performanceCollector.totalEvaluations,
performanceCollector.evaluations,
100f * performanceCollector.evaluations / Math.max(1.0f, performanceCollector.totalEvaluations),
performanceCollector.skippedEvaluations,
100f * performanceCollector.skippedEvaluations / Math.max(1.0f, performanceCollector.totalEvaluations)));
}
}
}