/**
* Copyright 2011-2014 Asakusa Framework Team.
*
* Licensed 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.asakusafw.directio.hive.parquet;
import java.util.List;
import parquet.io.api.Converter;
import parquet.io.api.GroupConverter;
import com.asakusafw.directio.hive.serde.PropertyDescriptor;
import com.asakusafw.runtime.value.ValueOption;
/**
* An implementation of parquet file data converter for Asakusa data models.
* @since 0.7.0
*/
public class DataModelConverter extends GroupConverter {
private final PropertyDescriptor[] properties;
private Object currentObject;
private final ValueOption<?>[] values;
private final ValueConverter[] converters;
/**
* Creates a new instance.
* @param properties the properties in the target data model
*/
public DataModelConverter(List<? extends PropertyDescriptor> properties) {
this.properties = properties.toArray(new PropertyDescriptor[properties.size()]);
this.converters = new ValueConverter[properties.size()];
this.values = new ValueOption<?>[properties.size()];
for (int i = 0, n = this.properties.length; i < n; i++) {
PropertyDescriptor property = this.properties[i];
this.converters[i] = ParquetValueDrivers.of(property.getTypeInfo(), property.getValueClass())
.getConverter();
}
}
/**
* Sets the next target data model.
* @param nextObject the next target data model
*/
public void prepare(Object nextObject) {
if (currentObject != nextObject) {
PropertyDescriptor[] ps = properties;
ValueOption<?>[] vs = values;
ValueConverter[] cs = converters;
for (int i = 0; i < ps.length; i++) {
ValueOption<?> value = ps[i].extract(nextObject);
vs[i] = value;
cs[i].set(value);
}
currentObject = nextObject;
}
}
/**
* Returns the current object.
* @return the current object
*/
public Object getCurrentObject() {
return currentObject;
}
@SuppressWarnings("deprecation")
@Override
public void start() {
ValueOption<?>[] vs = values;
for (int i = 0; i < vs.length; i++) {
ValueOption<?> v = vs[i];
if (v != null) {
v.setNull();
}
}
}
@Override
public void end() {
// nothing to do
}
@Override
public Converter getConverter(int index) {
return converters[index];
}
}