// Copyright (c) 2013, Facebook, Inc. All rights reserved.
/**
* 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 com.facebook.hive.orc.lazy;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import com.facebook.hive.orc.InStream;
import com.facebook.hive.orc.OrcProto;
import com.facebook.hive.orc.RunLengthIntegerReader;
import com.facebook.hive.orc.StreamName;
import com.facebook.hive.orc.WriterImpl;
import com.facebook.hive.orc.OrcProto.RowIndex;
import com.facebook.hive.orc.OrcProto.RowIndexEntry;
public class LazyListTreeReader extends LazyTreeReader {
private final LazyTreeReader elementReader;
private RunLengthIntegerReader lengths;
public LazyListTreeReader(int columnId, long rowIndexStride, LazyTreeReader elementReader) {
super(columnId, rowIndexStride);
this.elementReader = elementReader;
}
@Override
public Object next(Object previous) throws IOException {
List<Object> result = null;
if (valuePresent) {
if (previous == null) {
result = new ArrayList<Object>();
} else {
result = (ArrayList<Object>) previous;
}
int prevLength = result.size();
int length = nextLength();
// extend the list to the new length
for(int i=prevLength; i < length; ++i) {
result.add(null);
}
// read the new elements into the array
for(int i=0; i< length; i++) {
result.set(i, elementReader.getInComplexType(i < prevLength ?
result.get(i) : null, previousRow));
}
// remove any extra elements
for(int i=prevLength - 1; i >= length; --i) {
result.remove(i);
}
}
return result;
}
@Override
protected void seek(int rowIndexEntry, boolean backwards) throws IOException {
super.seek(rowIndexEntry, backwards);
elementReader.seek(rowIndexEntry, backwards);
}
@Override
public void startStripe(Map<StreamName, InStream> streams,
List<OrcProto.ColumnEncoding> encodings,
RowIndex[] indexes,
long rowBaseInStripe
) throws IOException {
super.startStripe(streams, encodings, indexes, rowBaseInStripe);
elementReader.startStripe(streams, encodings, indexes, rowBaseInStripe);
lengths = new RunLengthIntegerReader(streams.get(new StreamName(columnId,
OrcProto.Stream.Kind.LENGTH)), false, WriterImpl.INT_BYTE_SIZE);
if (indexes[columnId] != null) {
loadIndeces(indexes[columnId].getEntryList(), 0);
}
}
@Override
public void seek(int index) throws IOException {
lengths.seek(index);
}
@Override
public int loadIndeces(List<RowIndexEntry> rowIndexEntries, int startIndex) {
int updatedStartIndex = super.loadIndeces(rowIndexEntries, startIndex);
return lengths.loadIndeces(rowIndexEntries, updatedStartIndex);
}
public int nextLength() throws IOException {
return (int) lengths.next();
}
@Override
public void skipRows(long numNonNullValues) throws IOException {
long childSkip = 0;
for(long i=0; i < numNonNullValues; ++i) {
childSkip += lengths.next();
}
elementReader.skipRowsInComplexType(childSkip);
}
@Override
public void close() throws IOException {
super.close();
if (elementReader != null) {
elementReader.close();
}
if (lengths != null) {
lengths.close();
}
}
}