// 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.List;
import java.util.Map;
import org.apache.hadoop.io.FloatWritable;
import com.facebook.hive.orc.InStream;
import com.facebook.hive.orc.OrcProto;
import com.facebook.hive.orc.SerializationUtils;
import com.facebook.hive.orc.StreamName;
import com.facebook.hive.orc.OrcProto.RowIndex;
import com.facebook.hive.orc.OrcProto.RowIndexEntry;
import com.facebook.hive.orc.lazy.OrcLazyObject.ValueNotPresentException;
public class LazyFloatTreeReader extends LazyTreeReader {
private InStream stream;
private float latestRead = 0; //< Last float that was read from stream.
public LazyFloatTreeReader(int columnId, long rowIndexStride) {
super(columnId, rowIndexStride);
}
@Override
public void startStripe(Map<StreamName, InStream> streams, List<OrcProto.ColumnEncoding> encodings,
RowIndex[] indexes, long rowBaseInStripe) throws IOException {
super.startStripe(streams, encodings, indexes, rowBaseInStripe);
StreamName name = new StreamName(columnId,
OrcProto.Stream.Kind.DATA);
stream = streams.get(name);
if (indexes[columnId] != null) {
loadIndeces(indexes[columnId].getEntryList(), 0);
}
}
@Override
public void seek(int index) throws IOException {
stream.seek(index);
}
@Override
public int loadIndeces(List<RowIndexEntry> rowIndexEntries, int startIndex) {
int updatedStartIndex = super.loadIndeces(rowIndexEntries, startIndex);
return stream.loadIndeces(rowIndexEntries, updatedStartIndex);
}
/**
* Read a float value from the stream.
*/
private float readFloat() throws IOException {
latestRead = SerializationUtils.readFloat(stream);
return latestRead;
}
FloatWritable createWritable(Object previous, float value) throws IOException {
FloatWritable result = null;
if (previous == null) {
result = new FloatWritable();
} else {
result = (FloatWritable) previous;
}
result.set(value);
return result;
}
@Override
public Object createWritableFromLatest(Object previous) throws IOException {
return createWritable(previous, latestRead);
}
/**
* Give the next float as a primitive.
*/
@Override
public float nextFloat(boolean readStream) throws IOException, ValueNotPresentException {
if (!readStream) {
return latestRead;
}
if (!valuePresent) {
throw new ValueNotPresentException("Cannot materialize float..");
}
return readFloat();
}
@Override
public Object next(Object previous) throws IOException {
FloatWritable result = null;
if (valuePresent) {
result = createWritable(previous, readFloat());
}
return result;
}
@Override
public void skipRows(long numNonNullValues) throws IOException {
for(int i=0; i < numNonNullValues; ++i) {
SerializationUtils.readFloat(stream);
}
}
@Override
public void close() throws IOException {
super.close();
if (stream != null) {
stream.close();
}
}
}