| /* |
| * 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.solr.handler.dataimport; |
| |
| import java.lang.invoke.MethodHandles; |
| import java.util.Iterator; |
| import java.util.Map; |
| |
| import org.apache.solr.handler.dataimport.DIHCacheSupport.Relation; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import com.google.common.collect.Iterators; |
| import com.google.common.collect.PeekingIterator; |
| |
| class Zipper { |
| |
| private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass()); |
| private final DIHCacheSupport.Relation relation; |
| |
| @SuppressWarnings("rawtypes") |
| private Comparable parentId; |
| @SuppressWarnings("rawtypes") |
| private Comparable lastChildId; |
| |
| private Iterator<Map<String,Object>> rowIterator; |
| private PeekingIterator<Map<String,Object>> peeker; |
| |
| /** @return initialized zipper or null */ |
| public static Zipper createOrNull(Context context){ |
| if("zipper".equals(context.getEntityAttribute("join"))){ |
| DIHCacheSupport.Relation r = new DIHCacheSupport.Relation(context); |
| if(r.doKeyLookup){ |
| return new Zipper(r); |
| } |
| } |
| return null; |
| } |
| |
| |
| private Zipper(Relation relation) { |
| this.relation = relation; |
| } |
| |
| @SuppressWarnings({"rawtypes", "unchecked"}) |
| public Map<String,Object> supplyNextChild( |
| Iterator<Map<String,Object>> rowIterator) { |
| preparePeeker(rowIterator); |
| |
| while(peeker.hasNext()){ |
| Map<String,Object> current = peeker.peek(); |
| Comparable childId = (Comparable) current.get(relation.primaryKey); |
| |
| if(lastChildId!=null && lastChildId.compareTo(childId)>0){ |
| throw new IllegalArgumentException("expect increasing foreign keys for "+relation+ |
| " got: "+lastChildId+","+childId); |
| } |
| lastChildId = childId; |
| int cmp = childId.compareTo(parentId); |
| if(cmp==0){ |
| Map<String,Object> child = peeker.next(); |
| assert child==current: "peeker should be right but "+current+" != " + child; |
| log.trace("yeild child {} entry {}",relation, current); |
| return child;// TODO it's for one->many for many->one it should be just peek() |
| }else{ |
| if(cmp<0){ // child belongs to 10th and parent is 20th, skip for the next one |
| Map<String,Object> child = peeker.next(); |
| assert child==current: "peeker should be right but "+current+" != " + child; |
| log.trace("skip child {}, {} > {}",relation, parentId, childId); |
| }else{ // child belongs to 20th and parent is 10th, no more children, go to next parent |
| log.trace("childen is over {}, {} < {}", relation, parentId, current); |
| return null; |
| } |
| } |
| } |
| |
| return null; |
| } |
| |
| private void preparePeeker(Iterator<Map<String,Object>> rowIterator) { |
| if(this.rowIterator==null){ |
| this.rowIterator = rowIterator; |
| peeker = Iterators.peekingIterator(rowIterator); |
| }else{ |
| assert this.rowIterator==rowIterator: "rowIterator should never change but "+this.rowIterator+ |
| " supplied before has been changed to "+rowIterator; |
| } |
| } |
| |
| @SuppressWarnings({"rawtypes", "unchecked"}) |
| public void onNewParent(Context context) { |
| Comparable newParent = (Comparable) context.resolve(relation.foreignKey); |
| if(parentId!=null && parentId.compareTo(newParent)>=0){ |
| throw new IllegalArgumentException("expect strictly increasing primary keys for "+relation+ |
| " got: "+parentId+","+newParent); |
| } |
| log.trace("{}: {}->{}",relation, newParent, parentId); |
| parentId = newParent; |
| } |
| |
| } |