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The runtime library of DBFlute
/*
* Copyright 2014-2019 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
* either express or implied. See the License for the specific language
* governing permissions and limitations under the License.
*/
package org.dbflute.s2dao.rowcreator;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.dbflute.bhv.core.context.ResourceContext;
import org.dbflute.jdbc.ValueType;
import org.dbflute.s2dao.metadata.TnPropertyType;
import org.dbflute.s2dao.metadata.TnRelationPropertyType;
import org.dbflute.s2dao.rowcreator.impl.TnRelationKeyCompound;
import org.dbflute.s2dao.rowcreator.impl.TnRelationKeyEmpty;
import org.dbflute.s2dao.rowcreator.impl.TnRelationKeySimple;
/**
* The cache of relation row.
* This is not thread safe so you should create per one select.
* @author modified by jflute (originated in S2Dao)
*/
public class TnRelationRowCache {
// ===================================================================================
// Definition
// ==========
private static final TnRelationKey EMPTY_KEY = new TnRelationKeyEmpty();
// ===================================================================================
// Attribute
// =========
/** The list of row map. map:{relationPath = map:{relationKey = row}} (NotNull: if canCache is true) */
protected final Map> _rowMap;
/** Can the relation row cache? */
protected final boolean _canCache;
// ===================================================================================
// Constructor
// ===========
/**
* @param relSize The size of relation.
* @param canCache Can the relation row cache?
*/
public TnRelationRowCache(int relSize, boolean canCache) {
_rowMap = canCache ? new HashMap>(relSize) : null;
_canCache = canCache;
}
// ===================================================================================
// Cache Handling
// ==============
/**
* Get relation row from cache by relation key.
* @param relationNoSuffix The relation No suffix that indicates the location of the relation.
* @param relKey The key of relation. (NotNull)
* @return The relation row. (NullAllowed)
*/
public Object getRelationRow(String relationNoSuffix, TnRelationKey relKey) {
if (!_canCache) {
return null;
}
final Map elementMap = _rowMap.get(relationNoSuffix);
if (elementMap == null) {
return null;
}
return elementMap.get(relKey);
}
/**
* Add relation row to cache.
* @param relationNoSuffix The relation No suffix that indicates the location of the relation.
* @param relKey The key of relation. (NotNull)
* @param relationRow The relation row. (NullAllowed)
*/
public void addRelationRow(String relationNoSuffix, TnRelationKey relKey, Object relationRow) {
if (!_canCache) {
return;
}
Map elementMap = _rowMap.get(relationNoSuffix);
if (elementMap == null) {
elementMap = new HashMap();
_rowMap.put(relationNoSuffix, elementMap);
}
elementMap.put(relKey, relationRow);
}
// ===================================================================================
// Key Creation
// ============
/**
* Create the key of relation.
* @param rs The result set. (NotNull)
* @param rpt The property type of relation. (NotNull)
* @param selectColumnMap The name map of select column. {flexible-name = column-DB-name} (NotNull)
* @param selectIndexMap The map of select index. map:{entityNo(e.g. loc00 or _0_3) = map:{selectColumnKeyName = selectIndex}} (NullAllowed: If it's null, it doesn't use select index.)
* @param relationNoSuffix The suffix of relation No. (NotNull)
* @return The key of relation. (NullAllowed: null means no data of the relation)
* @throws SQLException When it fails to handle the SQL.
*/
public TnRelationKey createRelationKey(ResultSet rs, TnRelationPropertyType rpt // basic resource
, Map selectColumnMap, Map> selectIndexMap // select resource
, String relationNoSuffix) throws SQLException { // relation resource
if (!_canCache) {
return EMPTY_KEY;
}
final TnRelationKey relKey;
if (rpt.hasSimpleUniqueKey()) {
relKey = doCreateRelationKeySimple(rs, rpt, selectColumnMap, selectIndexMap, relationNoSuffix);
} else if (rpt.hasCompoundUniqueKey()) {
relKey = doCreateRelationKeyCompound(rs, rpt, selectColumnMap, selectIndexMap, relationNoSuffix);
} else { // empty
relKey = null; // treated as no data of the relation
}
return relKey;
}
protected TnRelationKey doCreateRelationKeySimple(ResultSet rs, TnRelationPropertyType rpt, Map selectColumnMap,
Map> selectIndexMap, String relationNoSuffix) throws SQLException {
final TnPropertyType pt = rpt.getSimpleUniquePropertyType();
final String columnKeyName = buildColumnKeyName(pt, relationNoSuffix);
final Object keyValue = setupKeyElement(rs, rpt, selectColumnMap, selectIndexMap, columnKeyName, pt, relationNoSuffix);
return keyValue != null ? new TnRelationKeySimple(columnKeyName, keyValue) : null;
}
protected TnRelationKey doCreateRelationKeyCompound(ResultSet rs, TnRelationPropertyType rpt, Map selectColumnMap,
Map> selectIndexMap, String relationNoSuffix) throws SQLException {
final List uniquePropertyTypeList = rpt.getUniquePropertyTypeList();
Map relKeyValues = null;
for (TnPropertyType pt : uniquePropertyTypeList) {
final String columnKeyName = buildColumnKeyName(pt, relationNoSuffix);
final Object keyValue = setupKeyElement(rs, rpt, selectColumnMap, selectIndexMap, columnKeyName, pt, relationNoSuffix);
if (keyValue == null) {
if (relKeyValues != null) {
relKeyValues.clear();
}
break; // if either one is null, treated as no data
}
if (relKeyValues == null) { // lazy-load for performance
relKeyValues = new HashMap(uniquePropertyTypeList.size());
}
relKeyValues.put(columnKeyName, keyValue);
}
return (relKeyValues != null && !relKeyValues.isEmpty()) ? new TnRelationKeyCompound(relKeyValues) : null;
}
protected String buildColumnKeyName(TnPropertyType pt, String relationNoSuffix) {
return pt.getColumnDbName() + relationNoSuffix;
}
protected Object setupKeyElement(ResultSet rs, TnRelationPropertyType rpt, Map selectColumnMap,
Map> selectIndexMap, String columnKeyName, TnPropertyType pt, String relationNoSuffix)
throws SQLException {
if (isOutOfRelationSelectIndex(relationNoSuffix, columnKeyName, selectIndexMap)) {
// basically unreachable, same reason with next if statement, check just in case
return null;
}
if (!selectColumnMap.containsKey(columnKeyName)) {
// basically unreachable
// because the referred column (basically PK or FK) must exist
// if the relation's select clause is specified
return null;
}
final ValueType valueType = pt.getValueType();
final Object value;
if (selectIndexMap != null) {
value = ResourceContext.getRelationValue(rs, relationNoSuffix, columnKeyName, valueType, selectIndexMap);
} else {
value = valueType.getValue(rs, columnKeyName);
}
// null-able when the referred column data is null
// (treated as no relation data)
return value;
}
protected boolean isOutOfRelationSelectIndex(String relationNoSuffix, String columnDbName,
Map> selectIndexMap) throws SQLException {
return ResourceContext.isOutOfRelationSelectIndex(relationNoSuffix, columnDbName, selectIndexMap);
}
// ===================================================================================
// Accessor
// ========
public Map> getRowMap() {
return _rowMap;
}
}
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