| /* |
| * 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.druid.segment.join.table; |
| |
| import com.google.common.base.Preconditions; |
| import com.google.common.collect.ImmutableSet; |
| import org.apache.druid.java.util.common.IAE; |
| import org.apache.druid.java.util.common.ISE; |
| import org.apache.druid.segment.RowAdapter; |
| import org.apache.druid.segment.column.RowSignature; |
| import org.apache.druid.segment.column.ValueType; |
| |
| import javax.annotation.Nullable; |
| import java.io.Closeable; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Optional; |
| import java.util.Set; |
| import java.util.function.Function; |
| import java.util.stream.Collectors; |
| |
| /** |
| * An IndexedTable composed of a List-based table and Map-based indexes. The implementation is agnostic to the |
| * specific row type; it uses a {@link RowAdapter} to work with any sort of object. |
| * The class allows passing in a cache key. If the key is non-null, results of any join on this table can be cached. |
| * That cache becomes invalidated if this key changes. Creators of this class can pass in a non-null cache key if its |
| * possible to construct a small identifier |
| * - that must change when contents of this indexed table chances |
| * - May remain unchanged when contents of this indexed table |
| * |
| * How the cache key is constructed itself, depends on how the RowBasedIndexedTable is being built. |
| */ |
| public class RowBasedIndexedTable<RowType> implements IndexedTable |
| { |
| private final List<RowType> table; |
| private final List<Index> indexes; |
| private final RowSignature rowSignature; |
| private final List<Function<RowType, Object>> columnFunctions; |
| private final Set<String> keyColumns; |
| private final String version; |
| @Nullable |
| private final byte[] cacheKey; |
| |
| public RowBasedIndexedTable( |
| final List<RowType> table, |
| final RowAdapter<RowType> rowAdapter, |
| final RowSignature rowSignature, |
| final Set<String> keyColumns, |
| final String version |
| ) |
| { |
| this(table, rowAdapter, rowSignature, keyColumns, version, null); |
| } |
| |
| public RowBasedIndexedTable( |
| final List<RowType> table, |
| final RowAdapter<RowType> rowAdapter, |
| final RowSignature rowSignature, |
| final Set<String> keyColumns, |
| final String version, |
| @Nullable |
| final byte[] cacheKey |
| ) |
| { |
| this.table = table; |
| this.rowSignature = rowSignature; |
| this.columnFunctions = |
| rowSignature.getColumnNames().stream().map(rowAdapter::columnFunction).collect(Collectors.toList()); |
| this.keyColumns = keyColumns; |
| this.version = version; |
| this.cacheKey = cacheKey; |
| |
| if (!ImmutableSet.copyOf(rowSignature.getColumnNames()).containsAll(keyColumns)) { |
| throw new ISE( |
| "keyColumns[%s] must all be contained in rowSignature[%s]", |
| String.join(", ", keyColumns), |
| rowSignature |
| ); |
| } |
| |
| indexes = new ArrayList<>(rowSignature.size()); |
| |
| for (int i = 0; i < rowSignature.size(); i++) { |
| final String column = rowSignature.getColumnName(i); |
| final Index m; |
| |
| if (keyColumns.contains(column)) { |
| final ValueType keyType = |
| rowSignature.getColumnType(column).orElse(IndexedTableJoinMatcher.DEFAULT_KEY_TYPE); |
| |
| final RowBasedIndexBuilder builder = new RowBasedIndexBuilder(keyType); |
| final Function<RowType, Object> columnFunction = columnFunctions.get(i); |
| |
| for (final RowType row : table) { |
| builder.add(columnFunction.apply(row)); |
| } |
| |
| m = builder.build(); |
| } else { |
| m = null; |
| } |
| |
| indexes.add(m); |
| } |
| } |
| |
| @Override |
| public String version() |
| { |
| return version; |
| } |
| |
| @Override |
| public Set<String> keyColumns() |
| { |
| return keyColumns; |
| } |
| |
| @Override |
| public RowSignature rowSignature() |
| { |
| return rowSignature; |
| } |
| |
| @Override |
| public Index columnIndex(int column) |
| { |
| return getKeyColumnIndex(column, indexes); |
| } |
| |
| @Override |
| public Reader columnReader(int column) |
| { |
| final Function<RowType, Object> columnFn = columnFunctions.get(column); |
| |
| if (columnFn == null) { |
| throw new IAE("Column[%d] is not a valid column", column); |
| } |
| |
| return row -> columnFn.apply(table.get(row)); |
| } |
| |
| @Override |
| public byte[] computeCacheKey() |
| { |
| return Preconditions.checkNotNull(cacheKey, "Cache key can't be null"); |
| } |
| |
| @Override |
| public boolean isCacheable() |
| { |
| return (null != cacheKey); |
| } |
| |
| @Override |
| public int numRows() |
| { |
| return table.size(); |
| } |
| |
| @Override |
| public Optional<Closeable> acquireReferences() |
| { |
| // nothing to close by default, whatever loaded this thing (probably) lives on heap |
| return Optional.of(() -> {}); |
| } |
| |
| @Override |
| public void close() |
| { |
| // nothing to close |
| } |
| |
| static Index getKeyColumnIndex(int column, List<Index> indexes) |
| { |
| final Index index = indexes.get(column); |
| |
| if (index == null) { |
| throw new IAE("Column[%d] is not a key column", column); |
| } |
| |
| return index; |
| } |
| } |