/******************************************************************************* | |
* Copyright (c) 2011, 2013 Oracle and/or its affiliates. All rights reserved. | |
* This program and the accompanying materials are made available under the | |
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0 | |
* which accompanies this distribution. | |
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html | |
* and the Eclipse Distribution License is available at | |
* http://www.eclipse.org/org/documents/edl-v10.php. | |
* | |
* Contributors: | |
* James Sutherland - initial API and implementation | |
******************************************************************************/ | |
package org.eclipse.persistence.queries; | |
import java.io.Serializable; | |
import java.util.ArrayList; | |
import java.util.HashMap; | |
import java.util.List; | |
import java.util.Map; | |
import org.eclipse.persistence.annotations.BatchFetchType; | |
import org.eclipse.persistence.descriptors.ClassDescriptor; | |
import org.eclipse.persistence.expressions.Expression; | |
import org.eclipse.persistence.internal.expressions.QueryKeyExpression; | |
import org.eclipse.persistence.internal.sessions.AbstractRecord; | |
import org.eclipse.persistence.mappings.DatabaseMapping; | |
/** | |
* BatchFetchPolicy defines batch reading configuration. | |
* | |
* @see org.eclipse.persistence.queries.ObjectLevelReadQuery#setBatchFetchPolicy(BatchFetchPolicy) | |
* @author James Sutherland | |
*/ | |
public class BatchFetchPolicy implements Serializable, Cloneable { | |
/** Define the type of batch fetching to use. */ | |
protected BatchFetchType type; | |
/** Define the batch size for IN style batch fetching. */ | |
protected int size = 500; | |
/** Define the attributes to be batch fetched. */ | |
protected List<Expression> attributeExpressions; | |
/** Define the mapping to be batch fetched. */ | |
protected List<DatabaseMapping> batchedMappings; | |
/** PERF: Used internally to store the prepared mapping queries. */ | |
protected transient Map<DatabaseMapping, ReadQuery> mappingQueries; | |
/** PERF: Cache the local batch read attribute names. */ | |
protected List<String> attributes; | |
/** Stores temporary list of rows from parent batch query per batched mapping. */ | |
protected transient Map<Object, List<AbstractRecord>> dataResults; | |
/** Stores temporary map of batched objects (this queries results). */ | |
protected transient Map<Object, Object> batchObjects; | |
public BatchFetchPolicy() { | |
this.type = BatchFetchType.JOIN; | |
} | |
public BatchFetchPolicy(BatchFetchType type) { | |
this.type = type; | |
} | |
public BatchFetchPolicy clone() { | |
BatchFetchPolicy clone = null; | |
try { | |
clone = (BatchFetchPolicy)super.clone(); | |
} catch (CloneNotSupportedException error) { | |
throw new InternalError(error.getMessage()); | |
} | |
if (clone.dataResults != null) { | |
clone.dataResults.put(clone, clone.dataResults.get(this)); | |
} | |
return clone; | |
} | |
/** | |
* Return if using the IN fetch type. | |
*/ | |
public boolean isIN() { | |
return this.type == BatchFetchType.IN; | |
} | |
/** | |
* Return if using the JOIN fetch type. | |
*/ | |
public boolean isJOIN() { | |
return this.type == BatchFetchType.JOIN; | |
} | |
/** | |
* Return if using the EXISTS fetch type. | |
*/ | |
public boolean isEXISTS() { | |
return this.type == BatchFetchType.EXISTS; | |
} | |
/** | |
* Return the batch fetch type, (JOIN, IN, EXISTS). | |
*/ | |
public BatchFetchType getType() { | |
return type; | |
} | |
/** | |
* Set the batch fetch type, (JOIN, IN, EXISTS). | |
*/ | |
public void setType(BatchFetchType type) { | |
this.type = type; | |
} | |
/** | |
* Return the batch fetch size. | |
*/ | |
public int getSize() { | |
return size; | |
} | |
/** | |
* Set the batch fetch size. | |
*/ | |
public void setSize(int size) { | |
this.size = size; | |
} | |
/** | |
* PERF: Return the internally stored prepared mapping queries. | |
*/ | |
public Map<DatabaseMapping, ReadQuery> getMappingQueries() { | |
return mappingQueries; | |
} | |
/** | |
* PERF: Set the internally stored prepared mapping queries. | |
*/ | |
public void setMappingQueries(Map<DatabaseMapping, ReadQuery> mappingQueries) { | |
this.mappingQueries = mappingQueries; | |
} | |
/** | |
* PERF: Return the cached local (only) batch read attribute names. | |
*/ | |
public List<String> getAttributes() { | |
return attributes; | |
} | |
/** | |
* PERF: Set the cached local (only) batch read attribute names. | |
*/ | |
public void setAttributes(List<String> attributes) { | |
this.attributes = attributes; | |
} | |
public void setAttributeExpressions(List<Expression> attributeExpressions) { | |
this.attributeExpressions = attributeExpressions; | |
} | |
/** | |
* INTERNAL: | |
* Return all attributes specified for batch reading. | |
*/ | |
public List<Expression> getAttributeExpressions() { | |
if (this.attributeExpressions == null) { | |
this.attributeExpressions = new ArrayList<Expression>(); | |
} | |
return this.attributeExpressions; | |
} | |
/** | |
* INTERNAL: | |
* Return true is this query has batching | |
*/ | |
public boolean hasAttributes() { | |
return (this.attributeExpressions != null) && (!this.attributeExpressions.isEmpty()) | |
|| (this.batchedMappings != null); | |
} | |
/** | |
* INTERNAL: | |
* Return any mappings that are always batched. | |
*/ | |
public List<DatabaseMapping> getBatchedMappings() { | |
return batchedMappings; | |
} | |
/** | |
* INTERNAL: | |
* Set any mappings that are always batched. | |
*/ | |
public void setBatchedMappings(List<DatabaseMapping> batchedMappings) { | |
this.batchedMappings = batchedMappings; | |
} | |
/** | |
* INTERNAL: | |
* Return if the attribute is specified for batch reading. | |
*/ | |
public boolean isAttributeBatchRead(String attributeName) { | |
if (this.attributeExpressions == null) { | |
return false; | |
} | |
List<Expression> batchReadAttributeExpressions = this.attributeExpressions; | |
int size = batchReadAttributeExpressions.size(); | |
for (int index = 0; index < size; index++) { | |
QueryKeyExpression expression = (QueryKeyExpression)batchReadAttributeExpressions.get(index); | |
while (!expression.getBaseExpression().isExpressionBuilder()) { | |
expression = (QueryKeyExpression)expression.getBaseExpression(); | |
} | |
if (expression.getName().equals(attributeName)) { | |
return true; | |
} | |
} | |
return false; | |
} | |
/** | |
* INTERNAL: | |
* Return if the attribute is specified for batch reading. | |
*/ | |
public boolean isAttributeBatchRead(ClassDescriptor mappingDescriptor, String attributeName) { | |
if (this.attributeExpressions == null) { | |
return false; | |
} | |
if (this.attributes != null) { | |
return this.attributes.contains(attributeName); | |
} | |
return isAttributeBatchRead(attributeName); | |
} | |
/** | |
* INTERNAL: | |
* Add the row to the set of data results. | |
* This is used for IN batching in batches. | |
*/ | |
public void addDataResults(AbstractRecord row) { | |
if (this.dataResults == null) { | |
this.dataResults = new HashMap<Object, List<AbstractRecord>>(); | |
this.dataResults.put(this, new ArrayList<AbstractRecord>()); | |
} | |
for (List<AbstractRecord> results : this.dataResults.values()) { | |
results.add(row); | |
} | |
} | |
/** | |
* INTERNAL: | |
* Return the remaining data results for the mapping. | |
* This is used for IN batching in batches. | |
*/ | |
public List<AbstractRecord> getDataResults(DatabaseMapping mapping) { | |
List<AbstractRecord> result = this.dataResults.get(mapping); | |
if (result == null) { | |
result = this.dataResults.get(this); | |
this.dataResults.put(mapping, result); | |
} | |
return result; | |
} | |
/** | |
* INTERNAL: | |
* Set the remaining data results for the mapping. | |
* This is used for IN batching in batches. | |
*/ | |
public void setDataResults(DatabaseMapping mapping, List<AbstractRecord> rows) { | |
this.dataResults.put(mapping, rows); | |
} | |
/** | |
* INTERNAL: | |
* Set the rows to the set of data results for each mapping. | |
* This is used for IN batching in batches. | |
*/ | |
public void setDataResults(List<AbstractRecord> rows) { | |
this.dataResults = new HashMap<Object, List<AbstractRecord>>(); | |
this.dataResults.put(this, rows); | |
} | |
/** | |
* INTERNAL: | |
* Return temporary list of rows from parent batch query per batched mapping. | |
* This is used for IN batching in batches. | |
*/ | |
public Map<Object, List<AbstractRecord>> getDataResults() { | |
return this.dataResults; | |
} | |
/** | |
* INTERNAL: | |
* Set temporary list of rows from parent batch query per batched mapping. | |
* This is used for IN batching in batches. | |
*/ | |
public void setDataResults(Map<Object, List<AbstractRecord>> dataResults) { | |
this.dataResults = dataResults; | |
} | |
/** | |
* INTERNAL: | |
* Return temporary map of batched objects. | |
*/ | |
public Map<Object, Object> getBatchObjects() { | |
return batchObjects; | |
} | |
/** | |
* INTERNAL: | |
* Set temporary map of batched objects. | |
*/ | |
public void setBatchObjects(Map<Object, Object> batchObjects) { | |
this.batchObjects = batchObjects; | |
} | |
} |