| /* |
| * Copyright (c) 2011, 2021 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 v. 2.0 which is available at |
| * http://www.eclipse.org/legal/epl-2.0, |
| * or the Eclipse Distribution License v. 1.0 which is available at |
| * http://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause |
| */ |
| |
| // 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 (from mapping settings). */ |
| 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(BatchFetchType.JOIN); |
| } |
| |
| public BatchFetchPolicy(BatchFetchType type) { |
| this.type = type; |
| this.dataResults = new HashMap<Object, List<AbstractRecord>>(); |
| this.dataResults.put(this, new ArrayList<AbstractRecord>()); |
| } |
| |
| @Override |
| 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; |
| } |
| |
| /** |
| * INTERNAL: |
| * PERF: Return the internally stored prepared mapping queries. |
| */ |
| public Map<DatabaseMapping, ReadQuery> getMappingQueries() { |
| return mappingQueries; |
| } |
| |
| /** |
| * INTERNAL: |
| * PERF: Set the internally stored prepared mapping queries. |
| */ |
| public void setMappingQueries(Map<DatabaseMapping, ReadQuery> mappingQueries) { |
| this.mappingQueries = mappingQueries; |
| } |
| |
| /** |
| * INTERNAL: |
| * PERF: Return the cached local (only) batch read attribute names. |
| */ |
| public List<String> getAttributes() { |
| return attributes; |
| } |
| |
| /** |
| * INTERNAL: |
| * 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<>(); |
| } |
| 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) { |
| 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<>(); |
| 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 List<AbstractRecord> getAllDataResults() { |
| return this.dataResults.get(this); |
| } |
| |
| /** |
| * 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; |
| } |
| } |