/**
* 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.drill.exec.physical.impl.TopN;
import java.util.concurrent.TimeUnit;
import javax.inject.Named;
import org.apache.drill.exec.exception.SchemaChangeException;
import org.apache.drill.exec.memory.BufferAllocator;
import org.apache.drill.exec.ops.FragmentContext;
import org.apache.drill.exec.physical.impl.sort.RecordBatchData;
import org.apache.drill.exec.record.BatchSchema;
import org.apache.drill.exec.record.ExpandableHyperContainer;
import org.apache.drill.exec.record.MaterializedField;
import org.apache.drill.exec.record.RecordBatch;
import org.apache.drill.exec.record.VectorContainer;
import org.apache.drill.exec.record.selection.SelectionVector2;
import org.apache.drill.exec.record.selection.SelectionVector4;
import com.google.common.base.Stopwatch;
public abstract class PriorityQueueTemplate implements PriorityQueue {
static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(PriorityQueueTemplate.class);
private SelectionVector4 heapSv4;//This holds the heap
private SelectionVector4 finalSv4;//This is for final sorted output
private ExpandableHyperContainer hyperBatch;
private FragmentContext context;
private BufferAllocator allocator;
private int limit;
private int queueSize = 0;
private int batchCount = 0;
private boolean hasSv2;
@Override
public void init(int limit, FragmentContext context, BufferAllocator allocator, boolean hasSv2) throws SchemaChangeException {
this.limit = limit;
this.context = context;
this.allocator = allocator;
BufferAllocator.PreAllocator preAlloc = allocator.getNewPreAllocator();
preAlloc.preAllocate(4 * (limit + 1));
heapSv4 = new SelectionVector4(preAlloc.getAllocation(), limit, Character.MAX_VALUE);
this.hasSv2 = hasSv2;
}
public void resetQueue(VectorContainer container, SelectionVector4 v4) throws SchemaChangeException {
assert container.getSchema().getSelectionVectorMode() == BatchSchema.SelectionVectorMode.FOUR_BYTE;
BatchSchema schema = container.getSchema();
VectorContainer newContainer = new VectorContainer();
for (MaterializedField field : schema) {
int[] ids = container.getValueVectorId(field.getPath()).getFieldIds();
newContainer.add(container.getValueAccessorById(field.getValueClass(), ids).getValueVectors());
}
newContainer.buildSchema(BatchSchema.SelectionVectorMode.FOUR_BYTE);
this.hyperBatch = new ExpandableHyperContainer(newContainer);
this.batchCount = hyperBatch.iterator().next().getValueVectors().length;
BufferAllocator.PreAllocator preAlloc = allocator.getNewPreAllocator();
preAlloc.preAllocate(4 * (limit + 1));
this.heapSv4 = new SelectionVector4(preAlloc.getAllocation(), limit, Character.MAX_VALUE);
for (int i = 0; i < v4.getTotalCount(); i++) {
heapSv4.set(i, v4.get(i));
}
v4.clear();
}
@Override
public void add(FragmentContext context, RecordBatchData batch) throws SchemaChangeException{
Stopwatch watch = new Stopwatch();
watch.start();
if (hyperBatch == null) {
hyperBatch = new ExpandableHyperContainer(batch.getContainer());
} else {
hyperBatch.addBatch(batch.getContainer());
}
doSetup(context, hyperBatch, null); // may not need to do this every time
int count = 0;
SelectionVector2 sv2 = null;
if (hasSv2) {
sv2 = batch.getSv2();
}
for (; queueSize < limit && count < batch.getRecordCount(); count++) {
heapSv4.set(queueSize, batchCount, hasSv2 ? sv2.getIndex(count) : count);
queueSize++;
siftUp();
}
for (; count < batch.getRecordCount(); count++) {
heapSv4.set(limit, batchCount, hasSv2 ? sv2.getIndex(count) : count);
if (compare(limit, 0) < 0) {
swap(limit, 0);
siftDown();
}
}
batchCount++;
if (hasSv2) {
sv2.clear();
}
logger.debug("Took {} us to add {} records", watch.elapsed(TimeUnit.MICROSECONDS), count);
}
@Override
public void generate() throws SchemaChangeException {
Stopwatch watch = new Stopwatch();
watch.start();
BufferAllocator.PreAllocator preAlloc = allocator.getNewPreAllocator();
preAlloc.preAllocate(4 * queueSize);
finalSv4 = new SelectionVector4(preAlloc.getAllocation(), queueSize, 4000);
for (int i = queueSize - 1; i >= 0; i--) {
finalSv4.set(i, pop());
}
logger.debug("Took {} us to generate output of {}", watch.elapsed(TimeUnit.MICROSECONDS), finalSv4.getTotalCount());
}
@Override
public VectorContainer getHyperBatch() {
return hyperBatch;
}
@Override
public SelectionVector4 getHeapSv4() {
return heapSv4;
}
@Override
public SelectionVector4 getFinalSv4() {
return finalSv4;
}
@Override
public void cleanup() {
heapSv4.clear();
hyperBatch.clear();
}
private void siftUp() {
int p = queueSize - 1;
while (p > 0) {
if (compare(p, (p - 1) / 2) > 0) {
swap(p, (p - 1) / 2);
p = (p - 1) / 2;
} else {
break;
}
}
}
private void siftDown() {
int p = 0;
int next;
while (p * 2 + 1 < queueSize) {
if (p * 2 + 2 >= queueSize) {
next = p * 2 + 1;
} else {
if (compare(p * 2 + 1, p * 2 + 2) >= 0) {
next = p * 2 + 1;
} else {
next = p * 2 + 2;
}
}
if (compare(p, next) < 0) {
swap(p, next);
p = next;
} else {
break;
}
}
}
public int pop() {
int value = heapSv4.get(0);
swap(0, queueSize - 1);
queueSize--;
siftDown();
return value;
}
public void swap(int sv0, int sv1) {
int tmp = heapSv4.get(sv0);
heapSv4.set(sv0, heapSv4.get(sv1));
heapSv4.set(sv1, tmp);
}
public int compare(int leftIndex, int rightIndex) {
int sv1 = heapSv4.get(leftIndex);
int sv2 = heapSv4.get(rightIndex);
return doEval(sv1, sv2);
}
public abstract void doSetup(@Named("context") FragmentContext context, @Named("incoming") VectorContainer incoming, @Named("outgoing") RecordBatch outgoing);
public abstract int doEval(@Named("leftIndex") int leftIndex, @Named("rightIndex") int rightIndex);
}