| /* |
| * 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.query.rowsandcols; |
| |
| import org.apache.druid.frame.Frame; |
| import org.apache.druid.frame.FrameType; |
| import org.apache.druid.frame.allocation.ArenaMemoryAllocatorFactory; |
| import org.apache.druid.frame.write.FrameWriter; |
| import org.apache.druid.frame.write.FrameWriterFactory; |
| import org.apache.druid.frame.write.FrameWriters; |
| import org.apache.druid.java.util.common.ISE; |
| import org.apache.druid.java.util.common.Intervals; |
| import org.apache.druid.java.util.common.granularity.Granularities; |
| import org.apache.druid.java.util.common.guava.Sequence; |
| import org.apache.druid.query.rowsandcols.column.Column; |
| import org.apache.druid.query.rowsandcols.concrete.ColumnBasedFrameRowsAndColumns; |
| import org.apache.druid.segment.CloseableShapeshifter; |
| import org.apache.druid.segment.ColumnSelectorFactory; |
| import org.apache.druid.segment.Cursor; |
| import org.apache.druid.segment.StorageAdapter; |
| import org.apache.druid.segment.VirtualColumns; |
| import org.apache.druid.segment.column.RowSignature; |
| |
| import javax.annotation.Nonnull; |
| import java.util.Collection; |
| import java.util.Collections; |
| |
| /** |
| * Provides {@link RowsAndColumns} on top of a {@link StorageAdapter}. |
| */ |
| public class StorageAdapterRowsAndColumns implements CloseableShapeshifter, RowsAndColumns |
| { |
| private final StorageAdapter storageAdapter; |
| private RowsAndColumns materialized; |
| |
| public StorageAdapterRowsAndColumns(StorageAdapter storageAdapter) |
| { |
| this.storageAdapter = storageAdapter; |
| } |
| |
| @SuppressWarnings("unchecked") |
| @Override |
| public <T> T as(Class<T> clazz) |
| { |
| if (StorageAdapter.class == clazz) { |
| return (T) storageAdapter; |
| } |
| return null; |
| } |
| |
| @Override |
| public Collection<String> getColumnNames() |
| { |
| return storageAdapter.getRowSignature().getColumnNames(); |
| } |
| |
| @Override |
| public int numRows() |
| { |
| return storageAdapter.getNumRows(); |
| } |
| |
| @Override |
| public Column findColumn(String name) |
| { |
| return getRealRAC().findColumn(name); |
| } |
| |
| @Override |
| public void close() |
| { |
| } |
| |
| protected RowsAndColumns getRealRAC() |
| { |
| if (materialized == null) { |
| materialized = materialize(storageAdapter); |
| } |
| return materialized; |
| } |
| |
| @Nonnull |
| private static RowsAndColumns materialize(StorageAdapter as) |
| { |
| final Sequence<Cursor> cursors = as.makeCursors( |
| null, |
| Intervals.ETERNITY, |
| VirtualColumns.EMPTY, |
| Granularities.ALL, |
| false, |
| null |
| ); |
| |
| RowSignature rowSignature = as.getRowSignature(); |
| |
| FrameWriter writer = cursors.accumulate(null, (accumulated, in) -> { |
| if (accumulated != null) { |
| // We should not get multiple cursors because we set the granularity to ALL. So, this should never |
| // actually happen, but it doesn't hurt us to defensive here, so we test against it. |
| throw new ISE("accumulated[%s] non-null, why did we get multiple cursors?", accumulated); |
| } |
| |
| final ColumnSelectorFactory columnSelectorFactory = in.getColumnSelectorFactory(); |
| |
| final FrameWriterFactory frameWriterFactory = FrameWriters.makeFrameWriterFactory( |
| FrameType.COLUMNAR, |
| new ArenaMemoryAllocatorFactory(200 << 20), // 200 MB, because, why not? |
| rowSignature, |
| Collections.emptyList() |
| ); |
| |
| final FrameWriter frameWriter = frameWriterFactory.newFrameWriter(columnSelectorFactory); |
| while (!in.isDoneOrInterrupted()) { |
| frameWriter.addSelection(); |
| in.advance(); |
| } |
| return frameWriter; |
| }); |
| |
| if (writer == null) { |
| return new EmptyRowsAndColumns(); |
| } else { |
| final byte[] bytes = writer.toByteArray(); |
| return new ColumnBasedFrameRowsAndColumns(Frame.wrap(bytes), rowSignature); |
| } |
| } |
| } |