| /* |
| * 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.iotdb.tsfile.read.query.timegenerator; |
| |
| import org.apache.iotdb.tsfile.exception.write.UnSupportedDataTypeException; |
| import org.apache.iotdb.tsfile.read.common.Path; |
| import org.apache.iotdb.tsfile.read.expression.ExpressionType; |
| import org.apache.iotdb.tsfile.read.expression.IBinaryExpression; |
| import org.apache.iotdb.tsfile.read.expression.IExpression; |
| import org.apache.iotdb.tsfile.read.expression.impl.SingleSeriesExpression; |
| import org.apache.iotdb.tsfile.read.filter.basic.Filter; |
| import org.apache.iotdb.tsfile.read.query.timegenerator.node.AndNode; |
| import org.apache.iotdb.tsfile.read.query.timegenerator.node.LeafNode; |
| import org.apache.iotdb.tsfile.read.query.timegenerator.node.Node; |
| import org.apache.iotdb.tsfile.read.query.timegenerator.node.OrNode; |
| import org.apache.iotdb.tsfile.read.reader.IBatchReader; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.HashMap; |
| import java.util.List; |
| |
| /** |
| * All SingleSeriesExpression involved in a IExpression will be transferred to a TimeGenerator tree |
| * whose leaf nodes are all SeriesReaders, The TimeGenerator tree can generate the next timestamp |
| * that satisfies the filter condition. Then we use this timestamp to get values in other series |
| * that are not included in IExpression |
| */ |
| public abstract class TimeGenerator { |
| |
| private HashMap<Path, List<LeafNode>> leafNodeCache = new HashMap<>(); |
| private HashMap<Path, List<Object>> leafValuesCache; |
| protected Node operatorNode; |
| private boolean hasOrNode; |
| |
| public boolean hasNext() throws IOException { |
| return operatorNode.hasNext(); |
| } |
| |
| public long next() throws IOException { |
| if (!hasOrNode) { |
| if (leafValuesCache == null) { |
| leafValuesCache = new HashMap<>(); |
| } |
| leafNodeCache.forEach( |
| (path, nodes) -> |
| leafValuesCache |
| .computeIfAbsent(path, k -> new ArrayList<>()) |
| .add(nodes.get(0).currentValue())); |
| } |
| return operatorNode.next(); |
| } |
| |
| /** ATTENTION: this method should only be used when there is no `OR` node */ |
| public Object[] getValues(Path path) throws IOException { |
| if (hasOrNode) { |
| throw new IOException( |
| "getValues() method should not be invoked when there is OR operator in where clause"); |
| } |
| if (leafValuesCache.get(path) == null) { |
| throw new IOException( |
| "getValues() method should not be invoked by non-existent path in where clause"); |
| } |
| return leafValuesCache.remove(path).toArray(); |
| } |
| |
| /** ATTENTION: this method should only be used when there is no `OR` node */ |
| public Object getValue(Path path) throws IOException { |
| if (hasOrNode) { |
| throw new IOException( |
| "getValue() method should not be invoked when there is OR operator in where clause"); |
| } |
| if (leafValuesCache.get(path) == null) { |
| throw new IOException( |
| "getValue() method should not be invoked by non-existent path in where clause"); |
| } |
| return leafValuesCache.get(path).remove(0); |
| } |
| |
| public void constructNode(IExpression expression) throws IOException { |
| operatorNode = construct(expression); |
| } |
| |
| /** construct the tree that generate timestamp. */ |
| protected Node construct(IExpression expression) throws IOException { |
| |
| if (expression.getType() == ExpressionType.SERIES) { |
| SingleSeriesExpression singleSeriesExp = (SingleSeriesExpression) expression; |
| IBatchReader seriesReader = generateNewBatchReader(singleSeriesExp); |
| Path path = singleSeriesExp.getSeriesPath(); |
| |
| // put the current reader to valueCache |
| LeafNode leafNode = new LeafNode(seriesReader); |
| leafNodeCache.computeIfAbsent(path, p -> new ArrayList<>()).add(leafNode); |
| |
| return leafNode; |
| } else { |
| Node leftChild = construct(((IBinaryExpression) expression).getLeft()); |
| Node rightChild = construct(((IBinaryExpression) expression).getRight()); |
| |
| if (expression.getType() == ExpressionType.OR) { |
| hasOrNode = true; |
| return new OrNode(leftChild, rightChild, isAscending()); |
| } else if (expression.getType() == ExpressionType.AND) { |
| return new AndNode(leftChild, rightChild, isAscending()); |
| } |
| throw new UnSupportedDataTypeException( |
| "Unsupported ExpressionType when construct OperatorNode: " + expression.getType()); |
| } |
| } |
| |
| protected abstract IBatchReader generateNewBatchReader(SingleSeriesExpression expression) |
| throws IOException; |
| |
| public boolean hasOrNode() { |
| return hasOrNode; |
| } |
| |
| protected abstract boolean isAscending(); |
| |
| public abstract Filter getTimeFilter(); |
| } |