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 com.facebook.presto.tpch; import com.facebook.presto.spi.ConnectorColumnHandle; import com.facebook.presto.spi.ConnectorIndexHandle; import com.facebook.presto.spi.ConnectorIndexResolver; import com.facebook.presto.spi.ConnectorResolvedIndex; import com.facebook.presto.spi.ConnectorTableHandle; import com.facebook.presto.spi.Index; import com.facebook.presto.spi.RecordSet; import com.facebook.presto.spi.TupleDomain; import com.facebook.presto.spi.type.Type; import com.facebook.presto.split.MappedRecordSet; import com.google.common.base.Function; import com.google.common.base.Optional; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableSet; import com.google.common.collect.Lists; import com.google.common.collect.Maps; import java.util.List; import java.util.Map; import java.util.Set; import static com.google.common.base.Preconditions.checkArgument; import static com.google.common.base.Preconditions.checkNotNull; import static com.google.common.base.Preconditions.checkState; import static com.google.common.base.Predicates.in; import static com.google.common.base.Predicates.not; import static com.google.common.collect.Iterables.any; import static com.google.common.collect.Iterables.transform; public class TpchIndexResolver implements ConnectorIndexResolver { private final String connectorId; private final TpchIndexedData indexedData; public TpchIndexResolver(String connectorId, TpchIndexedData indexedData) { this.connectorId = checkNotNull(connectorId, "connectorId is null"); this.indexedData = checkNotNull(indexedData, "indexedData is null"); } @Override public ConnectorResolvedIndex resolveIndex(ConnectorTableHandle tableHandle, Set<ConnectorColumnHandle> indexableColumns, TupleDomain<ConnectorColumnHandle> tupleDomain) { checkArgument(tableHandle instanceof TpchTableHandle, "tableHandle is not an instance of TpchTableHandle: %s", tableHandle); TpchTableHandle tpchTableHandle = (TpchTableHandle) tableHandle; // Keep the fixed values that don't overlap with the indexableColumns // Note: technically we could more efficiently utilize the overlapped columns, but this way is simpler for now Map<ConnectorColumnHandle, Comparable<?>> fixedValues = Maps.filterKeys(tupleDomain.extractFixedValues(), not(in(indexableColumns))); // determine all columns available for index lookup ImmutableSet.Builder<String> builder = ImmutableSet.builder(); builder.addAll(transform(indexableColumns, columnNameGetter())); builder.addAll(transform(fixedValues.keySet(), columnNameGetter())); Set<String> lookupColumnNames = builder.build(); // do we have an index? if (!indexedData.getIndexedTable(tpchTableHandle.getTableName(), tpchTableHandle.getScaleFactor(), lookupColumnNames).isPresent()) { return null; } TupleDomain<ConnectorColumnHandle> filteredTupleDomain = tupleDomain; if (!tupleDomain.isNone()) { filteredTupleDomain = TupleDomain .withColumnDomains(Maps.filterKeys(tupleDomain.getDomains(), not(in(fixedValues.keySet())))); } return new ConnectorResolvedIndex(new TpchIndexHandle(connectorId, tpchTableHandle.getTableName(), tpchTableHandle.getScaleFactor(), lookupColumnNames, TupleDomain.withFixedValues(fixedValues)), filteredTupleDomain); } @Override public Index getIndex(ConnectorIndexHandle indexHandle, List<ConnectorColumnHandle> lookupSchema, List<ConnectorColumnHandle> outputSchema) { checkArgument(indexHandle instanceof TpchIndexHandle, "indexHandle is not an instance of TpchIndexHandle: %s", indexHandle); TpchIndexHandle tpchIndexHandle = (TpchIndexHandle) indexHandle; Map<ConnectorColumnHandle, Comparable<?>> fixedValues = tpchIndexHandle.getFixedValues() .extractFixedValues(); checkArgument(!any(lookupSchema, in(fixedValues.keySet())), "Lookup columnHandles are not expected to overlap with the fixed value predicates"); // Establish an order for the fixedValues List<ConnectorColumnHandle> fixedValueColumns = ImmutableList.copyOf(fixedValues.keySet()); // Extract the fixedValues as their raw values and types ImmutableList.Builder<Object> valueBuilder = ImmutableList.builder(); ImmutableList.Builder<Type> typeBuilder = ImmutableList.builder(); for (ConnectorColumnHandle fixedValueColumn : fixedValueColumns) { valueBuilder.add(fixedValues.get(fixedValueColumn)); typeBuilder.add(((TpchColumnHandle) fixedValueColumn).getType()); } final List<Object> rawFixedValues = valueBuilder.build(); final List<Type> rawFixedTypes = typeBuilder.build(); // Establish the schema after we append the fixed values to the lookup keys. List<ConnectorColumnHandle> finalLookupSchema = ImmutableList.<ConnectorColumnHandle>builder() .addAll(lookupSchema).addAll(fixedValueColumns).build(); Optional<TpchIndexedData.IndexedTable> indexedTable = indexedData.getIndexedTable( tpchIndexHandle.getTableName(), tpchIndexHandle.getScaleFactor(), tpchIndexHandle.getIndexColumnNames()); checkState(indexedTable.isPresent()); TpchIndexedData.IndexedTable table = indexedTable.get(); // Compute how to map from the final lookup schema to the table index key order final List<Integer> keyRemap = computeRemap(handleToNames(finalLookupSchema), table.getKeyColumns()); Function<RecordSet, RecordSet> keyFormatter = new Function<RecordSet, RecordSet>() { @Override public RecordSet apply(RecordSet key) { return new MappedRecordSet(new AppendingRecordSet(key, rawFixedValues, rawFixedTypes), keyRemap); } }; // Compute how to map from the output of the indexed data to the expected output schema final List<Integer> outputRemap = computeRemap(table.getOutputColumns(), handleToNames(outputSchema)); Function<RecordSet, RecordSet> outputFormatter = new Function<RecordSet, RecordSet>() { @Override public RecordSet apply(RecordSet output) { return new MappedRecordSet(output, outputRemap); } }; return new TpchIndex(keyFormatter, outputFormatter, table); } private static List<Integer> computeRemap(List<String> startSchema, List<String> endSchema) { ImmutableList.Builder<Integer> builder = ImmutableList.builder(); for (String columnName : endSchema) { int index = startSchema.indexOf(columnName); checkArgument(index != -1, "Column name in end that is not in the start"); builder.add(index); } return builder.build(); } private static List<String> handleToNames(List<ConnectorColumnHandle> columnHandles) { return Lists.transform(columnHandles, columnNameGetter()); } private static Function<ConnectorColumnHandle, String> columnNameGetter() { return new Function<ConnectorColumnHandle, String>() { @Override public String apply(ConnectorColumnHandle columnHandle) { checkArgument(columnHandle instanceof TpchColumnHandle, "columnHandle is not an instance of TpchColumnHandle: %s", columnHandle); return ((TpchColumnHandle) columnHandle).getColumnName(); } }; } }