| /* |
| * 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; |
| |
| import com.google.common.base.Preconditions; |
| import org.apache.druid.segment.column.RowSignature; |
| import org.apache.druid.timeline.SegmentId; |
| import org.joda.time.Interval; |
| |
| import javax.annotation.Nonnull; |
| import javax.annotation.Nullable; |
| |
| /** |
| * A {@link Segment} that is based on a stream of objects. |
| */ |
| public class RowBasedSegment<RowType> extends AbstractSegment |
| { |
| private final SegmentId segmentId; |
| private final StorageAdapter storageAdapter; |
| |
| /** |
| * Create a row-based segment. |
| * |
| * The provided "rowIterable" must be in time-order according to the provided {@link RowAdapter#timestampFunction()}. |
| * The cursor returned by {@link RowBasedStorageAdapter#makeCursors} makes no attempt to verify this, and callers |
| * will expect it. |
| * |
| * The provided "rowSignature" will be used for reporting available columns and their capabilities to users of |
| * {@link #asStorageAdapter()}. Note that the {@link ColumnSelectorFactory} implementation returned by this segment's |
| * storage adapter will allow creation of selectors on any field, using the {@link RowAdapter#columnFunction} for that |
| * field, even if it doesn't appear in "rowSignature". |
| * |
| * @param segmentId segment identifier; will be returned by {@link #getId()} |
| * @param rowIterable objects that comprise this segment |
| * @param rowAdapter adapter used for reading these objects |
| * @param rowSignature signature of the columns in these objects |
| */ |
| public RowBasedSegment( |
| final SegmentId segmentId, |
| final Iterable<RowType> rowIterable, |
| final RowAdapter<RowType> rowAdapter, |
| final RowSignature rowSignature |
| ) |
| { |
| this.segmentId = Preconditions.checkNotNull(segmentId, "segmentId"); |
| this.storageAdapter = new RowBasedStorageAdapter<>( |
| rowIterable, |
| rowAdapter, |
| rowSignature |
| ); |
| } |
| |
| @Override |
| @Nonnull |
| public SegmentId getId() |
| { |
| return segmentId; |
| } |
| |
| @Override |
| @Nonnull |
| public Interval getDataInterval() |
| { |
| return storageAdapter.getInterval(); |
| } |
| |
| @Nullable |
| @Override |
| public QueryableIndex asQueryableIndex() |
| { |
| return null; |
| } |
| |
| @Override |
| @Nonnull |
| public StorageAdapter asStorageAdapter() |
| { |
| return storageAdapter; |
| } |
| |
| @Override |
| public void close() |
| { |
| // Do nothing. |
| } |
| } |