/*
* 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.xsort;
import com.typesafe.config.ConfigException;
import io.netty.buffer.DrillBuf;
import java.util.Queue;
import javax.inject.Named;
import org.apache.drill.exec.ExecConstants;
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.record.RecordBatch;
import org.apache.drill.exec.record.VectorContainer;
import org.apache.drill.exec.record.selection.SelectionVector4;
import org.apache.hadoop.util.IndexedSortable;
import com.google.common.base.Preconditions;
import com.google.common.base.Stopwatch;
import com.google.common.collect.Queues;
public abstract class MSortTemplate implements MSorter, IndexedSortable {
// private static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(MSortTemplate.class);
private SelectionVector4 vector4;
private SelectionVector4 aux;
private long compares;
private Queue<Integer> runStarts = Queues.newLinkedBlockingQueue();
private FragmentContext context;
/**
* This is only useful for debugging and/or unit testing. Controls the maximum size of batches exposed to downstream
*/
private int desiredRecordBatchCount;
@Override
public void setup(final FragmentContext context, final BufferAllocator allocator, final SelectionVector4 vector4, final VectorContainer hyperBatch) throws SchemaChangeException{
// we pass in the local hyperBatch since that is where we'll be reading data.
Preconditions.checkNotNull(vector4);
this.vector4 = vector4.createNewWrapperCurrent();
this.context = context;
vector4.clear();
doSetup(context, hyperBatch, null);
runStarts.add(0);
int batch = 0;
final int totalCount = this.vector4.getTotalCount();
for (int i = 0; i < totalCount; i++) {
final int newBatch = this.vector4.get(i) >>> 16;
if (newBatch == batch) {
continue;
} else if (newBatch == batch + 1) {
runStarts.add(i);
batch = newBatch;
} else {
throw new UnsupportedOperationException(String.format("Missing batch. batch: %d newBatch: %d", batch, newBatch));
}
}
final DrillBuf drillBuf = allocator.buffer(4 * totalCount);
try {
desiredRecordBatchCount = context.getConfig().getInt(ExecConstants.EXTERNAL_SORT_MSORT_MAX_BATCHSIZE);
} catch(ConfigException.Missing e) {
// value not found, use default value instead
desiredRecordBatchCount = Character.MAX_VALUE;
}
aux = new SelectionVector4(drillBuf, totalCount, desiredRecordBatchCount);
}
/**
* For given recordCount how much memory does MSorter needs for its own purpose. This is used in
* ExternalSortBatch to make decisions about whether to spill or not.
*
* @param recordCount
* @return
*/
public static long memoryNeeded(final int recordCount) {
// We need 4 bytes (SV4) for each record.
return recordCount * 4;
}
private int merge(final int leftStart, final int rightStart, final int rightEnd, final int outStart) {
int l = leftStart;
int r = rightStart;
int o = outStart;
while (l < rightStart && r < rightEnd) {
if (compare(l, r) <= 0) {
aux.set(o++, vector4.get(l++));
} else {
aux.set(o++, vector4.get(r++));
}
}
while (l < rightStart) {
aux.set(o++, vector4.get(l++));
}
while (r < rightEnd) {
aux.set(o++, vector4.get(r++));
}
assert o == outStart + (rightEnd - leftStart);
return o;
}
@Override
public SelectionVector4 getSV4() {
return vector4;
}
@Override
public void sort(final VectorContainer container) {
final Stopwatch watch = Stopwatch.createStarted();
while (runStarts.size() > 1) {
// check if we're cancelled/failed frequently
if (!context.shouldContinue()) {
return;
}
int outIndex = 0;
final Queue<Integer> newRunStarts = Queues.newLinkedBlockingQueue();
newRunStarts.add(outIndex);
final int size = runStarts.size();
for (int i = 0; i < size / 2; i++) {
final int left = runStarts.poll();
final int right = runStarts.poll();
Integer end = runStarts.peek();
if (end == null) {
end = vector4.getTotalCount();
}
outIndex = merge(left, right, end, outIndex);
if (outIndex < vector4.getTotalCount()) {
newRunStarts.add(outIndex);
}
}
if (outIndex < vector4.getTotalCount()) {
copyRun(outIndex, vector4.getTotalCount());
}
final SelectionVector4 tmp = aux.createNewWrapperCurrent(desiredRecordBatchCount);
aux.clear();
aux = vector4.createNewWrapperCurrent(desiredRecordBatchCount);
vector4.clear();
vector4 = tmp.createNewWrapperCurrent(desiredRecordBatchCount);
tmp.clear();
runStarts = newRunStarts;
}
aux.clear();
}
private void copyRun(final int start, final int end) {
for (int i = start; i < end; i++) {
aux.set(i, vector4.get(i));
}
}
@Override
public void swap(final int sv0, final int sv1) {
final int tmp = vector4.get(sv0);
vector4.set(sv0, vector4.get(sv1));
vector4.set(sv1, tmp);
}
@Override
public int compare(final int leftIndex, final int rightIndex) {
final int sv1 = vector4.get(leftIndex);
final int sv2 = vector4.get(rightIndex);
compares++;
try {
return doEval(sv1, sv2);
} catch (SchemaChangeException e) {
throw new UnsupportedOperationException(e);
}
}
@Override
public void clear() {
if(vector4 != null) {
vector4.clear();
}
if(aux != null) {
aux.clear();
}
}
public abstract void doSetup(@Named("context") FragmentContext context,
@Named("incoming") VectorContainer incoming,
@Named("outgoing") RecordBatch outgoing)
throws SchemaChangeException;
public abstract int doEval(@Named("leftIndex") int leftIndex,
@Named("rightIndex") int rightIndex)
throws SchemaChangeException;
}