Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
[FLINK-2105] Implement Sort-Merge Outer Join algorithm
This closes #907
- Loading branch information
Showing
11 changed files
with
974 additions
and
36 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
189 changes: 189 additions & 0 deletions
189
...src/main/java/org/apache/flink/runtime/operators/sort/AbstractMergeOuterJoinIterator.java
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,189 @@ | ||
| /* | ||
| * 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.flink.runtime.operators.sort; | ||
|
|
||
| import org.apache.flink.api.common.functions.FlatJoinFunction; | ||
| import org.apache.flink.api.common.typeutils.TypeComparator; | ||
| import org.apache.flink.api.common.typeutils.TypePairComparator; | ||
| import org.apache.flink.api.common.typeutils.TypeSerializer; | ||
| import org.apache.flink.runtime.io.disk.iomanager.IOManager; | ||
| import org.apache.flink.runtime.jobgraph.tasks.AbstractInvokable; | ||
| import org.apache.flink.runtime.memorymanager.MemoryAllocationException; | ||
| import org.apache.flink.runtime.memorymanager.MemoryManager; | ||
| import org.apache.flink.util.Collector; | ||
| import org.apache.flink.util.MutableObjectIterator; | ||
|
|
||
| import java.util.Iterator; | ||
|
|
||
| /** | ||
| * An implementation of the {@link org.apache.flink.runtime.operators.util.JoinTaskIterator} that realizes the | ||
| * outer join through a sort-merge join strategy. | ||
| */ | ||
| public abstract class AbstractMergeOuterJoinIterator<T1, T2, O> extends AbstractMergeIterator<T1, T2, O> { | ||
|
|
||
| public static enum OuterJoinType {LEFT, RIGHT, FULL} | ||
|
|
||
| private final OuterJoinType outerJoinType; | ||
|
|
||
| private boolean initialized = false; | ||
| private boolean it1Empty = false; | ||
| private boolean it2Empty = false; | ||
|
|
||
|
|
||
| public AbstractMergeOuterJoinIterator( | ||
| OuterJoinType outerJoinType, | ||
| MutableObjectIterator<T1> input1, | ||
| MutableObjectIterator<T2> input2, | ||
| TypeSerializer<T1> serializer1, TypeComparator<T1> comparator1, | ||
| TypeSerializer<T2> serializer2, TypeComparator<T2> comparator2, | ||
| TypePairComparator<T1, T2> pairComparator, | ||
| MemoryManager memoryManager, | ||
| IOManager ioManager, | ||
| int numMemoryPages, | ||
| AbstractInvokable parentTask) | ||
| throws MemoryAllocationException { | ||
| super(input1, input2, serializer1, comparator1, serializer2, comparator2, pairComparator, memoryManager, ioManager, numMemoryPages, parentTask); | ||
|
|
||
| this.outerJoinType = outerJoinType; | ||
| } | ||
|
|
||
| /** | ||
| * Calls the <code>JoinFunction#join()</code> method for all two key-value pairs that share the same key and come | ||
| * from different inputs. Furthermore, depending on the outer join type (LEFT, RIGHT, FULL), all key-value pairs where no | ||
| * matching partner from the other input exists are joined with null. | ||
| * The output of the <code>join()</code> method is forwarded. | ||
| * | ||
| * @throws Exception Forwards all exceptions from the user code and the I/O system. | ||
| * @see org.apache.flink.runtime.operators.util.JoinTaskIterator#callWithNextKey(org.apache.flink.api.common.functions.FlatJoinFunction, org.apache.flink.util.Collector) | ||
| */ | ||
| @Override | ||
| public boolean callWithNextKey(final FlatJoinFunction<T1, T2, O> joinFunction, final Collector<O> collector) throws Exception { | ||
| if (!initialized) { | ||
| //first run, set iterators to first elements | ||
| it1Empty = !this.iterator1.nextKey(); | ||
| it2Empty = !this.iterator2.nextKey(); | ||
| initialized = true; | ||
| } | ||
|
|
||
| if (it1Empty && it2Empty) { | ||
| return false; | ||
| } else if (it2Empty) { | ||
| if (outerJoinType == OuterJoinType.LEFT || outerJoinType == OuterJoinType.FULL) { | ||
| joinLeftKeyValuesWithNull(iterator1.getValues(), joinFunction, collector); | ||
| it1Empty = !iterator1.nextKey(); | ||
| return true; | ||
| } else { | ||
| //consume rest of left side | ||
| while (iterator1.nextKey()) ; | ||
| it1Empty = true; | ||
| return false; | ||
| } | ||
| } else if (it1Empty) { | ||
| if (outerJoinType == OuterJoinType.RIGHT || outerJoinType == OuterJoinType.FULL) { | ||
| joinRightKeyValuesWithNull(iterator2.getValues(), joinFunction, collector); | ||
| it2Empty = !iterator2.nextKey(); | ||
| return true; | ||
| } else { | ||
| //consume rest of right side | ||
| while (iterator2.nextKey()) ; | ||
| it2Empty = true; | ||
| return false; | ||
| } | ||
| } else { | ||
| final TypePairComparator<T1, T2> comparator = super.pairComparator; | ||
| comparator.setReference(this.iterator1.getCurrent()); | ||
| T2 current2 = this.iterator2.getCurrent(); | ||
|
|
||
| // zig zag | ||
| while (true) { | ||
| // determine the relation between the (possibly composite) keys | ||
| final int comp = comparator.compareToReference(current2); | ||
|
|
||
| if (comp == 0) { | ||
| break; | ||
| } | ||
|
|
||
| if (comp < 0) { | ||
| //right key < left key | ||
| if (outerJoinType == OuterJoinType.RIGHT || outerJoinType == OuterJoinType.FULL) { | ||
| //join right key values with null in case of right or full outer join | ||
| joinRightKeyValuesWithNull(iterator2.getValues(), joinFunction, collector); | ||
| it2Empty = !iterator2.nextKey(); | ||
| return true; | ||
| } else { | ||
| //skip this right key if it is a left outer join | ||
| if (!this.iterator2.nextKey()) { | ||
| //if right side is empty, join current left key values with null | ||
| joinLeftKeyValuesWithNull(iterator1.getValues(), joinFunction, collector); | ||
| it1Empty = !iterator1.nextKey(); | ||
| it2Empty = true; | ||
| return true; | ||
| } | ||
| current2 = this.iterator2.getCurrent(); | ||
| } | ||
| } else { | ||
| //right key > left key | ||
| if (outerJoinType == OuterJoinType.LEFT || outerJoinType == OuterJoinType.FULL) { | ||
| //join left key values with null in case of left or full outer join | ||
| joinLeftKeyValuesWithNull(iterator1.getValues(), joinFunction, collector); | ||
| it1Empty = !iterator1.nextKey(); | ||
| return true; | ||
| } else { | ||
| //skip this left key if it is a right outer join | ||
| if (!this.iterator1.nextKey()) { | ||
| //if right side is empty, join current right key values with null | ||
| joinRightKeyValuesWithNull(iterator2.getValues(), joinFunction, collector); | ||
| it1Empty = true; | ||
| it2Empty = !iterator2.nextKey(); | ||
| return true; | ||
| } | ||
| comparator.setReference(this.iterator1.getCurrent()); | ||
| } | ||
| } | ||
| } | ||
|
|
||
| // here, we have a common key! call the join function with the cross product of the | ||
| // values | ||
| final Iterator<T1> values1 = this.iterator1.getValues(); | ||
| final Iterator<T2> values2 = this.iterator2.getValues(); | ||
|
|
||
| crossMatchingGroup(values1, values2, joinFunction, collector); | ||
| it1Empty = !iterator1.nextKey(); | ||
| it2Empty = !iterator2.nextKey(); | ||
| return true; | ||
| } | ||
| } | ||
|
|
||
| private void joinLeftKeyValuesWithNull(Iterator<T1> values, FlatJoinFunction<T1, T2, O> joinFunction, Collector<O> collector) throws Exception { | ||
| while (values.hasNext()) { | ||
| T1 next = values.next(); | ||
| this.copy1 = createCopy(serializer1, next, copy1); | ||
| joinFunction.join(copy1, null, collector); | ||
| } | ||
| } | ||
|
|
||
| private void joinRightKeyValuesWithNull(Iterator<T2> values, FlatJoinFunction<T1, T2, O> joinFunction, Collector<O> collector) throws Exception { | ||
| while (values.hasNext()) { | ||
| T2 next = values.next(); | ||
| this.copy2 = createCopy(serializer2, next, copy2); | ||
| joinFunction.join(null, copy2, collector); | ||
| } | ||
| } | ||
|
|
||
| } |
Oops, something went wrong.