| /* |
| * 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.phoenix.iterate; |
| |
| import java.io.IOException; |
| import java.sql.SQLException; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.hadoop.hbase.Cell; |
| import org.apache.hadoop.hbase.regionserver.RegionScanner; |
| import org.apache.hadoop.hbase.util.Pair; |
| import org.apache.phoenix.schema.PTable.QualifierEncodingScheme; |
| import org.apache.phoenix.schema.tuple.EncodedColumnQualiferCellsList; |
| import org.apache.phoenix.schema.tuple.MultiKeyValueTuple; |
| import org.apache.phoenix.schema.tuple.PositionBasedMultiKeyValueTuple; |
| import org.apache.phoenix.schema.tuple.Tuple; |
| import org.apache.phoenix.util.EncodedColumnsUtil; |
| import org.apache.phoenix.util.ServerUtil; |
| |
| |
| public class RegionScannerResultIterator extends BaseResultIterator { |
| private final RegionScanner scanner; |
| private final Pair<Integer, Integer> minMaxQualifiers; |
| private final boolean useQualifierAsIndex; |
| private final QualifierEncodingScheme encodingScheme; |
| |
| public RegionScannerResultIterator(RegionScanner scanner, Pair<Integer, Integer> minMaxQualifiers, QualifierEncodingScheme encodingScheme) { |
| this.scanner = scanner; |
| this.useQualifierAsIndex = EncodedColumnsUtil.useQualifierAsIndex(minMaxQualifiers); |
| this.minMaxQualifiers = minMaxQualifiers; |
| this.encodingScheme = encodingScheme; |
| } |
| |
| @Override |
| public Tuple next() throws SQLException { |
| // XXX: No access here to the region instance to enclose this with startRegionOperation / |
| // stopRegionOperation |
| synchronized (scanner) { |
| try { |
| // TODO: size |
| List<Cell> results = useQualifierAsIndex ? new EncodedColumnQualiferCellsList(minMaxQualifiers.getFirst(), minMaxQualifiers.getSecond(), encodingScheme) : new ArrayList<Cell>(); |
| // Results are potentially returned even when the return value of s.next is false |
| // since this is an indication of whether or not there are more values after the |
| // ones returned |
| boolean hasMore = scanner.nextRaw(results); |
| |
| if (!hasMore && results.isEmpty()) { |
| return null; |
| } |
| // We instantiate a new tuple because in all cases currently we hang on to it |
| // (i.e. to compute and hold onto the TopN). |
| Tuple tuple = useQualifierAsIndex ? new PositionBasedMultiKeyValueTuple() : new MultiKeyValueTuple(); |
| tuple.setKeyValues(results); |
| return tuple; |
| } catch (IOException e) { |
| throw ServerUtil.parseServerException(e); |
| } |
| } |
| } |
| |
| @Override |
| public String toString() { |
| return "RegionScannerResultIterator [scanner=" + scanner + "]"; |
| } |
| } |