/*
 * 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.sysds.runtime.compress.io;

import org.apache.spark.api.java.function.Function;
import org.apache.sysds.runtime.compress.CompressedMatrixBlock;
import org.apache.sysds.runtime.compress.CompressedMatrixBlockFactory;
import org.apache.sysds.runtime.matrix.data.MatrixBlock;

public class CompressUnwrap implements Function<CompressedWriteBlock, MatrixBlock> {
	private static final long serialVersionUID = 966405324406154236L;

	public CompressUnwrap() {
	}

	@Override
	public MatrixBlock call(CompressedWriteBlock arg0) throws Exception {
		final MatrixBlock g = arg0.get();
		if(g instanceof CompressedMatrixBlock)
			return new CompressedMatrixBlock((CompressedMatrixBlock) g);
		else if(g.isEmpty())
			return CompressedMatrixBlockFactory.createConstant(g.getNumRows(), g.getNumColumns(), 0.0);
		else
			return new MatrixBlock(g);
	}
}
