Java tutorial
/* * 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.prestosql.operator.index; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableMap; import com.google.common.util.concurrent.Futures; import com.google.common.util.concurrent.ListenableFuture; import com.google.common.util.concurrent.SettableFuture; import io.airlift.units.DataSize; import io.prestosql.operator.LookupSourceFactory; import io.prestosql.operator.LookupSourceProvider; import io.prestosql.operator.OuterPositionIterator; import io.prestosql.operator.PagesIndex; import io.prestosql.operator.StaticLookupSourceProvider; import io.prestosql.operator.TaskContext; import io.prestosql.spi.type.Type; import io.prestosql.sql.gen.JoinCompiler; import io.prestosql.sql.planner.Symbol; import java.util.List; import java.util.Map; import java.util.OptionalInt; import java.util.Set; import java.util.function.Supplier; import static com.google.common.base.Preconditions.checkState; import static com.google.common.util.concurrent.Futures.transform; import static com.google.common.util.concurrent.MoreExecutors.directExecutor; import static java.util.Objects.requireNonNull; public class IndexLookupSourceFactory implements LookupSourceFactory { private final List<Type> outputTypes; private final Map<Symbol, Integer> layout; private final Supplier<IndexLoader> indexLoaderSupplier; private TaskContext taskContext; private final SettableFuture<?> whenTaskContextSet = SettableFuture.create(); public IndexLookupSourceFactory(Set<Integer> lookupSourceInputChannels, List<Integer> keyOutputChannels, OptionalInt keyOutputHashChannel, List<Type> outputTypes, Map<Symbol, Integer> layout, IndexBuildDriverFactoryProvider indexBuildDriverFactoryProvider, DataSize maxIndexMemorySize, IndexJoinLookupStats stats, boolean shareIndexLoading, PagesIndex.Factory pagesIndexFactory, JoinCompiler joinCompiler) { this.outputTypes = ImmutableList.copyOf(requireNonNull(outputTypes, "outputTypes is null")); this.layout = ImmutableMap.copyOf(requireNonNull(layout, "layout is null")); if (shareIndexLoading) { IndexLoader shared = new IndexLoader(lookupSourceInputChannels, keyOutputChannels, keyOutputHashChannel, outputTypes, indexBuildDriverFactoryProvider, 10_000, maxIndexMemorySize, stats, pagesIndexFactory, joinCompiler); this.indexLoaderSupplier = () -> shared; } else { this.indexLoaderSupplier = () -> new IndexLoader(lookupSourceInputChannels, keyOutputChannels, keyOutputHashChannel, outputTypes, indexBuildDriverFactoryProvider, 10_000, maxIndexMemorySize, stats, pagesIndexFactory, joinCompiler); } } @Override public List<Type> getTypes() { return outputTypes; } @Override public List<Type> getOutputTypes() { return outputTypes; } @Override public Map<Symbol, Integer> getLayout() { return layout; } @Override public void setTaskContext(TaskContext taskContext) { this.taskContext = taskContext; whenTaskContextSet.set(null); } @Override public ListenableFuture<LookupSourceProvider> createLookupSourceProvider() { checkState(taskContext != null, "taskContext not set"); IndexLoader indexLoader = indexLoaderSupplier.get(); indexLoader.setContext(taskContext); return Futures.immediateFuture(new StaticLookupSourceProvider(new IndexLookupSource(indexLoader))); } @Override public ListenableFuture<?> whenBuildFinishes() { return Futures.transformAsync(whenTaskContextSet, ignored -> transform(this.createLookupSourceProvider(), lookupSourceProvider -> { // Close the lookupSourceProvider we just created. // The only reason we created it is to wait until lookup source is ready. lookupSourceProvider.close(); return null; }, directExecutor()), directExecutor()); } @Override public int partitions() { throw new UnsupportedOperationException(); } @Override public OuterPositionIterator getOuterPositionIterator() { throw new UnsupportedOperationException(); } @Override public void destroy() { // nothing to do } }