| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.apache.shardingsphere.sharding.merge.dql.groupby; |
| |
| import com.google.common.base.Preconditions; |
| import com.google.common.collect.Maps; |
| import org.apache.shardingsphere.sharding.merge.dql.groupby.aggregation.AggregationUnit; |
| import org.apache.shardingsphere.sharding.merge.dql.groupby.aggregation.AggregationUnitFactory; |
| import org.apache.shardingsphere.sharding.merge.dql.orderby.OrderByStreamMergedResult; |
| import org.apache.shardingsphere.infra.metadata.schema.ShardingSphereSchema; |
| import org.apache.shardingsphere.infra.binder.segment.select.projection.impl.AggregationDistinctProjection; |
| import org.apache.shardingsphere.infra.binder.segment.select.projection.impl.AggregationProjection; |
| import org.apache.shardingsphere.infra.binder.statement.dml.SelectStatementContext; |
| import org.apache.shardingsphere.infra.executor.sql.execute.result.query.QueryResult; |
| |
| import java.sql.SQLException; |
| import java.util.ArrayList; |
| import java.util.Calendar; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Map.Entry; |
| |
| /** |
| * Stream merged result for group by. |
| */ |
| public final class GroupByStreamMergedResult extends OrderByStreamMergedResult { |
| |
| private final SelectStatementContext selectStatementContext; |
| |
| private final List<Object> currentRow; |
| |
| private List<?> currentGroupByValues; |
| |
| public GroupByStreamMergedResult(final Map<String, Integer> labelAndIndexMap, final List<QueryResult> queryResults, |
| final SelectStatementContext selectStatementContext, final ShardingSphereSchema schema) throws SQLException { |
| super(queryResults, selectStatementContext, schema); |
| this.selectStatementContext = selectStatementContext; |
| currentRow = new ArrayList<>(labelAndIndexMap.size()); |
| currentGroupByValues = getOrderByValuesQueue().isEmpty() |
| ? Collections.emptyList() : new GroupByValue(getCurrentQueryResult(), selectStatementContext.getGroupByContext().getItems()).getGroupValues(); |
| } |
| |
| @Override |
| public boolean next() throws SQLException { |
| currentRow.clear(); |
| if (getOrderByValuesQueue().isEmpty()) { |
| return false; |
| } |
| if (isFirstNext()) { |
| super.next(); |
| } |
| if (aggregateCurrentGroupByRowAndNext()) { |
| currentGroupByValues = new GroupByValue(getCurrentQueryResult(), selectStatementContext.getGroupByContext().getItems()).getGroupValues(); |
| } |
| return true; |
| } |
| |
| private boolean aggregateCurrentGroupByRowAndNext() throws SQLException { |
| boolean result = false; |
| boolean cachedRow = false; |
| Map<AggregationProjection, AggregationUnit> aggregationUnitMap = Maps.toMap( |
| selectStatementContext.getProjectionsContext().getAggregationProjections(), input -> AggregationUnitFactory.create(input.getType(), input instanceof AggregationDistinctProjection)); |
| while (currentGroupByValues.equals(new GroupByValue(getCurrentQueryResult(), selectStatementContext.getGroupByContext().getItems()).getGroupValues())) { |
| aggregate(aggregationUnitMap); |
| if (!cachedRow) { |
| cacheCurrentRow(); |
| cachedRow = true; |
| } |
| result = super.next(); |
| if (!result) { |
| break; |
| } |
| } |
| setAggregationValueToCurrentRow(aggregationUnitMap); |
| return result; |
| } |
| |
| private void aggregate(final Map<AggregationProjection, AggregationUnit> aggregationUnitMap) throws SQLException { |
| for (Entry<AggregationProjection, AggregationUnit> entry : aggregationUnitMap.entrySet()) { |
| List<Comparable<?>> values = new ArrayList<>(2); |
| if (entry.getKey().getDerivedAggregationProjections().isEmpty()) { |
| values.add(getAggregationValue(entry.getKey())); |
| } else { |
| for (AggregationProjection each : entry.getKey().getDerivedAggregationProjections()) { |
| values.add(getAggregationValue(each)); |
| } |
| } |
| entry.getValue().merge(values); |
| } |
| } |
| |
| private void cacheCurrentRow() throws SQLException { |
| for (int i = 0; i < getCurrentQueryResult().getMetaData().getColumnCount(); i++) { |
| currentRow.add(getCurrentQueryResult().getValue(i + 1, Object.class)); |
| } |
| } |
| |
| private Comparable<?> getAggregationValue(final AggregationProjection aggregationProjection) throws SQLException { |
| Object result = getCurrentQueryResult().getValue(aggregationProjection.getIndex(), Object.class); |
| Preconditions.checkState(null == result || result instanceof Comparable, "Aggregation value must implements Comparable"); |
| return (Comparable<?>) result; |
| } |
| |
| private void setAggregationValueToCurrentRow(final Map<AggregationProjection, AggregationUnit> aggregationUnitMap) { |
| for (Entry<AggregationProjection, AggregationUnit> entry : aggregationUnitMap.entrySet()) { |
| currentRow.set(entry.getKey().getIndex() - 1, entry.getValue().getResult()); |
| } |
| } |
| |
| @Override |
| public Object getValue(final int columnIndex, final Class<?> type) { |
| Object result = currentRow.get(columnIndex - 1); |
| setWasNull(null == result); |
| return result; |
| } |
| |
| @Override |
| public Object getCalendarValue(final int columnIndex, final Class<?> type, final Calendar calendar) { |
| Object result = currentRow.get(columnIndex - 1); |
| setWasNull(null == result); |
| return result; |
| } |
| } |