src/main/java/org/apache/sysds/runtime/compress/estim/CompressedSizeEstimatorFactory.java

/*
 * 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
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 */

package org.apache.sysds.runtime.compress.estim;

import org.apache.sysds.runtime.compress.CompressionSettings;
import org.apache.sysds.runtime.matrix.data.MatrixBlock;

public class CompressedSizeEstimatorFactory {

	public static CompressedSizeEstimator getSizeEstimator(MatrixBlock data, CompressionSettings compSettings) {
		long elements = compSettings.transposeInput ? data.getNumColumns() : data.getNumRows();
		elements = data.getNonZeros() / (compSettings.transposeInput ? data.getNumRows() : data.getNumColumns());

		return (compSettings.samplingRatio >= 1.0 || elements < 1000) ? new CompressedSizeEstimatorExact(data,
			compSettings) : new CompressedSizeEstimatorSample(data, compSettings,
				(int) Math.ceil(elements * compSettings.samplingRatio));
	}
}