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/*
* Licensed 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 io.trino.operator.project;
import com.google.common.annotations.VisibleForTesting;
import io.trino.annotation.NotThreadSafe;
import io.trino.array.ReferenceCountMap;
import io.trino.memory.context.LocalMemoryContext;
import io.trino.operator.DriverYieldSignal;
import io.trino.operator.Work;
import io.trino.operator.WorkProcessor;
import io.trino.operator.WorkProcessor.ProcessState;
import io.trino.spi.Page;
import io.trino.spi.block.Block;
import io.trino.spi.block.DictionaryBlock;
import io.trino.spi.block.DictionaryId;
import io.trino.spi.connector.ConnectorSession;
import io.trino.sql.gen.ExpressionProfiler;
import io.trino.sql.gen.columnar.FilterEvaluator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.OptionalInt;
import java.util.function.Function;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Verify.verify;
import static com.google.common.base.Verify.verifyNotNull;
import static com.google.common.collect.ImmutableList.toImmutableList;
import static io.trino.operator.WorkProcessor.ProcessState.finished;
import static io.trino.operator.WorkProcessor.ProcessState.ofResult;
import static io.trino.operator.WorkProcessor.ProcessState.yielded;
import static io.trino.operator.project.SelectedPositions.positionsRange;
import static io.trino.spi.block.DictionaryId.randomDictionaryId;
import static java.util.Objects.requireNonNull;
@NotThreadSafe
public class PageProcessor
{
public static final int MAX_BATCH_SIZE = 8 * 1024;
static final int MAX_PAGE_SIZE_IN_BYTES = 16 * 1024 * 1024;
static final int MIN_PAGE_SIZE_IN_BYTES = 4 * 1024 * 1024;
private final ExpressionProfiler expressionProfiler;
private final DictionarySourceIdFunction dictionarySourceIdFunction = new DictionarySourceIdFunction();
private final Optional filterEvaluator;
private final Optional dynamicFilterEvaluator;
private final List projections;
private int projectBatchSize;
public PageProcessor(Optional filterEvaluator, Optional dynamicFilterEvaluator, List projections, OptionalInt initialBatchSize)
{
this(filterEvaluator, dynamicFilterEvaluator, projections, initialBatchSize, new ExpressionProfiler());
}
@VisibleForTesting
public PageProcessor(Optional filterEvaluator, Optional dynamicFilterEvaluator, List projections, OptionalInt initialBatchSize, ExpressionProfiler expressionProfiler)
{
this.filterEvaluator = requireNonNull(filterEvaluator, "filterEvaluator is null");
this.dynamicFilterEvaluator = requireNonNull(dynamicFilterEvaluator, "dynamicFilterEvaluator is null");
this.projections = projections.stream()
.map(projection -> {
if (projection.getInputChannels().size() == 1 && projection.isDeterministic()) {
return new DictionaryAwarePageProjection(projection, dictionarySourceIdFunction, projection instanceof InputPageProjection);
}
return projection;
})
.collect(toImmutableList());
this.projectBatchSize = initialBatchSize.orElse(1);
this.expressionProfiler = requireNonNull(expressionProfiler, "expressionProfiler is null");
}
@VisibleForTesting
public PageProcessor(Optional filterEvaluator, List projections)
{
this(filterEvaluator, Optional.empty(), projections, OptionalInt.of(1));
}
@VisibleForTesting
public Iterator> process(ConnectorSession session, DriverYieldSignal yieldSignal, LocalMemoryContext memoryContext, Page page)
{
WorkProcessor processor = createWorkProcessor(session, yieldSignal, memoryContext, new PageProcessorMetrics(), page);
return processor.yieldingIterator();
}
public WorkProcessor createWorkProcessor(
ConnectorSession session,
DriverYieldSignal yieldSignal,
LocalMemoryContext memoryContext,
PageProcessorMetrics metrics,
Page page)
{
// limit the scope of the dictionary ids to just one page
dictionarySourceIdFunction.reset();
if (page.getPositionCount() == 0) {
return WorkProcessor.of();
}
SelectedPositions activePositions = positionsRange(0, page.getPositionCount());
FilterEvaluator.SelectionResult staticFilterResult = new FilterEvaluator.SelectionResult(activePositions, 0);
if (filterEvaluator.isPresent()) {
staticFilterResult = filterEvaluator.get().evaluate(session, activePositions, page);
metrics.recordFilterTime(staticFilterResult.filterTimeNanos());
}
FilterEvaluator.SelectionResult result = staticFilterResult;
if (dynamicFilterEvaluator.isPresent()) {
result = dynamicFilterEvaluator.get().evaluate(session, staticFilterResult.selectedPositions(), page);
metrics.recordDynamicFilterMetrics(result.filterTimeNanos(), staticFilterResult.selectedPositions().size());
}
SelectedPositions selectedPositions = result.selectedPositions();
if (selectedPositions.isEmpty()) {
return WorkProcessor.of();
}
if (projections.isEmpty()) {
// retained memory for empty page is negligible
return WorkProcessor.of(new Page(selectedPositions.size()));
}
return WorkProcessor.create(new ProjectSelectedPositions(session, yieldSignal, memoryContext, metrics, page, selectedPositions));
}
private class ProjectSelectedPositions
implements WorkProcessor.Process
{
private final ConnectorSession session;
private final DriverYieldSignal yieldSignal;
private final LocalMemoryContext memoryContext;
private final PageProcessorMetrics metrics;
private Page page;
private final Block[] previouslyComputedResults;
private SelectedPositions selectedPositions;
private long retainedSizeInBytes;
// remember if we need to re-use the same batch size if we yield last time
private boolean lastComputeYielded;
private int lastComputeBatchSize;
private Work pageProjectWork;
private ProjectSelectedPositions(
ConnectorSession session,
DriverYieldSignal yieldSignal,
LocalMemoryContext memoryContext,
PageProcessorMetrics metrics,
Page page,
SelectedPositions selectedPositions)
{
checkArgument(!selectedPositions.isEmpty(), "selectedPositions is empty");
this.session = session;
this.yieldSignal = yieldSignal;
this.metrics = metrics;
this.page = page;
this.memoryContext = memoryContext;
this.selectedPositions = selectedPositions;
this.previouslyComputedResults = new Block[projections.size()];
}
@Override
public ProcessState process()
{
int batchSize;
while (true) {
if (selectedPositions.isEmpty()) {
verify(!lastComputeYielded);
return finished();
}
// we always process one chunk
if (lastComputeYielded) {
// re-use the batch size from the last checkpoint
verify(lastComputeBatchSize > 0);
batchSize = lastComputeBatchSize;
lastComputeYielded = false;
lastComputeBatchSize = 0;
}
else {
batchSize = Math.min(selectedPositions.size(), projectBatchSize);
}
ProcessBatchResult result = processBatch(batchSize);
if (result.isYieldFinish()) {
// if we are running out of time, save the batch size and continue next time
lastComputeYielded = true;
lastComputeBatchSize = batchSize;
updateRetainedSize();
return yielded();
}
if (result.isPageTooLarge()) {
// if the page buffer filled up, so halve the batch size and retry
verify(batchSize > 1);
projectBatchSize = projectBatchSize / 2;
continue;
}
verify(result.isSuccess());
Page resultPage = result.getPage();
updateBatchSize(resultPage.getPositionCount(), resultPage.getSizeInBytes());
// remove batch from selectedPositions and previouslyComputedResults
selectedPositions = selectedPositions.subRange(batchSize, selectedPositions.size());
for (int i = 0; i < previouslyComputedResults.length; i++) {
if (previouslyComputedResults[i] != null && previouslyComputedResults[i].getPositionCount() > batchSize) {
previouslyComputedResults[i] = previouslyComputedResults[i].getRegion(batchSize, previouslyComputedResults[i].getPositionCount() - batchSize);
}
else {
previouslyComputedResults[i] = null;
}
}
if (!selectedPositions.isEmpty()) {
// there are still some positions to process therefore we need to retain page and account its memory
updateRetainedSize();
}
else {
page = null;
for (int i = 0; i < previouslyComputedResults.length; i++) {
previouslyComputedResults[i] = null;
}
memoryContext.setBytes(0);
}
return ofResult(resultPage);
}
}
private void updateBatchSize(int positionCount, long pageSize)
{
// if we produced a large page or if the expression is expensive, halve the batch size for the next call
if (positionCount > 1 && (pageSize > MAX_PAGE_SIZE_IN_BYTES || expressionProfiler.isExpressionExpensive())) {
projectBatchSize = projectBatchSize / 2;
}
// if we produced a small page, double the batch size for the next call
if (pageSize < MIN_PAGE_SIZE_IN_BYTES && projectBatchSize < MAX_BATCH_SIZE && !expressionProfiler.isExpressionExpensive()) {
projectBatchSize = projectBatchSize * 2;
}
}
private void updateRetainedSize()
{
// increment the size only when it is the first reference
retainedSizeInBytes = Page.getInstanceSizeInBytes(page.getChannelCount());
ReferenceCountMap referenceCountMap = new ReferenceCountMap();
for (int channel = 0; channel < page.getChannelCount(); channel++) {
Block block = page.getBlock(channel);
// TODO: block might be partially loaded
if (block.isLoaded()) {
block.retainedBytesForEachPart((object, size) -> {
if (referenceCountMap.incrementAndGet(object) == 1) {
retainedSizeInBytes += size;
}
});
}
}
for (Block previouslyComputedResult : previouslyComputedResults) {
if (previouslyComputedResult != null) {
previouslyComputedResult.retainedBytesForEachPart((object, size) -> {
if (referenceCountMap.incrementAndGet(object) == 1) {
retainedSizeInBytes += size;
}
});
}
}
memoryContext.setBytes(retainedSizeInBytes);
}
private ProcessBatchResult processBatch(int batchSize)
{
Block[] blocks = new Block[projections.size()];
long pageSize = 0;
SelectedPositions positionsBatch = selectedPositions.subRange(0, batchSize);
for (int i = 0; i < projections.size(); i++) {
if (yieldSignal.isSet()) {
return ProcessBatchResult.processBatchYield();
}
if (positionsBatch.size() > 1 && pageSize > MAX_PAGE_SIZE_IN_BYTES) {
return ProcessBatchResult.processBatchTooLarge();
}
// if possible, use previouslyComputedResults produced in prior optimistic failure attempt
PageProjection projection = projections.get(i);
if (previouslyComputedResults[i] != null && previouslyComputedResults[i].getPositionCount() >= batchSize) {
blocks[i] = previouslyComputedResults[i].getRegion(0, batchSize);
}
else {
if (pageProjectWork == null) {
pageProjectWork = projection.project(session, yieldSignal, projection.getInputChannels().getInputChannels(page), positionsBatch);
}
expressionProfiler.start();
boolean finished = pageProjectWork.process();
long projectionTimeNanos = expressionProfiler.stop(positionsBatch.size());
metrics.recordProjectionTime(projectionTimeNanos);
if (!finished) {
return ProcessBatchResult.processBatchYield();
}
previouslyComputedResults[i] = pageProjectWork.getResult();
pageProjectWork = null;
blocks[i] = previouslyComputedResults[i];
}
blocks[i] = blocks[i].getLoadedBlock();
pageSize += blocks[i].getSizeInBytes();
}
return ProcessBatchResult.processBatchSuccess(new Page(positionsBatch.size(), blocks));
}
}
@VisibleForTesting
public List getProjections()
{
return projections;
}
@NotThreadSafe
private static class DictionarySourceIdFunction
implements Function
{
private final Map dictionarySourceIds = new HashMap<>();
@Override
public DictionaryId apply(DictionaryBlock block)
{
return dictionarySourceIds.computeIfAbsent(block.getDictionarySourceId(), _ -> randomDictionaryId());
}
public void reset()
{
dictionarySourceIds.clear();
}
}
private static class ProcessBatchResult
{
private final ProcessBatchState state;
private final Page page;
private ProcessBatchResult(ProcessBatchState state, Page page)
{
this.state = state;
this.page = page;
}
public static ProcessBatchResult processBatchYield()
{
return new ProcessBatchResult(ProcessBatchState.YIELD, null);
}
public static ProcessBatchResult processBatchTooLarge()
{
return new ProcessBatchResult(ProcessBatchState.PAGE_TOO_LARGE, null);
}
public static ProcessBatchResult processBatchSuccess(Page page)
{
return new ProcessBatchResult(ProcessBatchState.SUCCESS, requireNonNull(page));
}
public boolean isYieldFinish()
{
return state == ProcessBatchState.YIELD;
}
public boolean isPageTooLarge()
{
return state == ProcessBatchState.PAGE_TOO_LARGE;
}
public boolean isSuccess()
{
return state == ProcessBatchState.SUCCESS;
}
public Page getPage()
{
verify(state == ProcessBatchState.SUCCESS);
return verifyNotNull(page);
}
private enum ProcessBatchState
{
YIELD,
PAGE_TOO_LARGE,
SUCCESS
}
}
}
