| /* |
| * 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.kylin.storage.hbase.cube.v1; |
| |
| import java.util.ArrayList; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.NoSuchElementException; |
| import java.util.Set; |
| |
| import org.apache.hadoop.hbase.client.Connection; |
| import org.apache.kylin.cube.CubeInstance; |
| import org.apache.kylin.cube.CubeSegment; |
| import org.apache.kylin.metadata.filter.TupleFilter; |
| import org.apache.kylin.metadata.model.TblColRef; |
| import org.apache.kylin.metadata.tuple.ITuple; |
| import org.apache.kylin.metadata.tuple.ITupleIterator; |
| import org.apache.kylin.metadata.tuple.TupleInfo; |
| import org.apache.kylin.storage.StorageContext; |
| import org.apache.kylin.storage.exception.ScanOutOfLimitException; |
| import org.apache.kylin.storage.hbase.steps.RowValueDecoder; |
| import org.apache.kylin.storage.translate.HBaseKeyRange; |
| |
| import com.google.common.collect.Lists; |
| import com.google.common.collect.Maps; |
| |
| /** |
| * @author xjiang |
| */ |
| public class SerializedHBaseTupleIterator implements ITupleIterator { |
| |
| private static final int PARTIAL_DEFAULT_LIMIT = 10000; |
| |
| private final StorageContext context; |
| private final int partialResultLimit; |
| private final List<CubeSegmentTupleIterator> segmentIteratorList; |
| private final Iterator<CubeSegmentTupleIterator> segmentIteratorIterator; |
| |
| private ITupleIterator segmentIterator; |
| private int scanCount; |
| private ITuple next; |
| |
| public SerializedHBaseTupleIterator(Connection conn, List<HBaseKeyRange> segmentKeyRanges, CubeInstance cube, // |
| Set<TblColRef> dimensions, TupleFilter filter, Set<TblColRef> groupBy, List<RowValueDecoder> rowValueDecoders, // |
| StorageContext context, TupleInfo returnTupleInfo) { |
| |
| this.context = context; |
| int limit = context.getLimit(); |
| this.partialResultLimit = Math.max(limit, PARTIAL_DEFAULT_LIMIT); |
| |
| this.segmentIteratorList = new ArrayList<CubeSegmentTupleIterator>(segmentKeyRanges.size()); |
| Map<CubeSegment, List<HBaseKeyRange>> rangesMap = makeRangesMap(segmentKeyRanges); |
| |
| for (Map.Entry<CubeSegment, List<HBaseKeyRange>> entry : rangesMap.entrySet()) { |
| CubeSegmentTupleIterator it = new CubeSegmentTupleIterator(entry.getKey(), entry.getValue(), conn, dimensions, filter, groupBy, rowValueDecoders, context, returnTupleInfo); |
| this.segmentIteratorList.add(it); |
| } |
| |
| this.segmentIteratorIterator = this.segmentIteratorList.iterator(); |
| if (this.segmentIteratorIterator.hasNext()) { |
| this.segmentIterator = this.segmentIteratorIterator.next(); |
| } else { |
| this.segmentIterator = ITupleIterator.EMPTY_TUPLE_ITERATOR; |
| } |
| } |
| |
| private Map<CubeSegment, List<HBaseKeyRange>> makeRangesMap(List<HBaseKeyRange> segmentKeyRanges) { |
| Map<CubeSegment, List<HBaseKeyRange>> map = Maps.newHashMap(); |
| for (HBaseKeyRange range : segmentKeyRanges) { |
| List<HBaseKeyRange> list = map.get(range.getCubeSegment()); |
| if (list == null) { |
| list = Lists.newArrayList(); |
| map.put(range.getCubeSegment(), list); |
| } |
| list.add(range); |
| } |
| return map; |
| } |
| |
| @Override |
| public boolean hasNext() { |
| if (next != null) |
| return true; |
| |
| // 1. check limit |
| if (context.isLimitEnabled() && scanCount >= context.getLimit() + context.getOffset()) { |
| return false; |
| } |
| // 2. check partial result |
| if (context.isAcceptPartialResult() && scanCount > partialResultLimit) { |
| context.setPartialResultReturned(true); |
| return false; |
| } |
| // 3. check threshold |
| if (scanCount >= context.getThreshold()) { |
| throw new ScanOutOfLimitException("Scan row count exceeded threshold: " + context.getThreshold() + ", please add filter condition to narrow down backend scan range, like where clause."); |
| } |
| // 4. check cube segments |
| if (segmentIterator.hasNext()) { |
| next = segmentIterator.next(); |
| scanCount++; |
| return true; |
| } else if (segmentIteratorIterator.hasNext()) { |
| segmentIterator.close(); |
| segmentIterator = segmentIteratorIterator.next(); |
| return hasNext(); |
| } |
| return false; |
| } |
| |
| @Override |
| public ITuple next() { |
| if (next == null) { |
| hasNext(); |
| if (next == null) |
| throw new NoSuchElementException(); |
| } |
| ITuple r = next; |
| next = null; |
| return r; |
| } |
| |
| @Override |
| public void remove() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public void close() { |
| // hasNext() loop may exit because of limit, threshold, etc. |
| // close all the remaining segmentIterator |
| segmentIterator.close(); |
| while (segmentIteratorIterator.hasNext()) { |
| segmentIterator = segmentIteratorIterator.next(); |
| segmentIterator.close(); |
| } |
| } |
| |
| } |