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 * 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.test.component.compress;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;

import org.apache.sysds.runtime.compress.CompressedMatrixBlock;
import org.apache.sysds.runtime.compress.CompressionSettings;
import org.apache.sysds.runtime.compress.CompressionStatistics;
import org.apache.sysds.runtime.compress.colgroup.ColGroup;
import org.apache.sysds.runtime.functionobjects.Multiply;
import org.apache.sysds.runtime.matrix.data.LibMatrixCountDistinct;
import org.apache.sysds.runtime.matrix.data.MatrixBlock;
import org.apache.sysds.runtime.matrix.operators.AggregateUnaryOperator;
import org.apache.sysds.runtime.matrix.operators.CountDistinctOperator;
import org.apache.sysds.runtime.matrix.operators.CountDistinctOperator.CountDistinctTypes;
import org.apache.sysds.runtime.matrix.operators.RightScalarOperator;
import org.apache.sysds.runtime.matrix.operators.ScalarOperator;
import org.apache.sysds.runtime.util.DataConverter;
import org.apache.sysds.test.TestUtils;
import org.apache.sysds.test.component.compress.TestConstants.MatrixTypology;
import org.apache.sysds.test.component.compress.TestConstants.SparsityType;
import org.apache.sysds.test.component.compress.TestConstants.ValueRange;
import org.apache.sysds.test.component.compress.TestConstants.ValueType;
import org.junit.Ignore;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.openjdk.jol.datamodel.X86_64_DataModel;
import org.openjdk.jol.info.ClassLayout;
import org.openjdk.jol.layouters.HotSpotLayouter;
import org.openjdk.jol.layouters.Layouter;

@RunWith(value = Parameterized.class)
public class CompressedMatrixTest extends AbstractCompressedUnaryTests {

	public CompressedMatrixTest(SparsityType sparType, ValueType valType, ValueRange valRange,
		CompressionSettings compSettings, MatrixTypology matrixTypology) {
		super(sparType, valType, valRange, compSettings, matrixTypology, 1);
	}

	@Test
	public void testGetValue() {
		try {
			if(!(cmb instanceof CompressedMatrixBlock))
				return; // Input was not compressed then just pass test

			for(int i = 0; i < rows; i++)
				for(int j = 0; j < cols; j++) {
					double ulaVal = input[i][j];
					double claVal = cmb.getValue(i, j); // calls quickGetValue internally
					if(compressionSettings.lossy) {
						TestUtils.compareCellValue(ulaVal, claVal, lossyTolerance, false);
					}
					else {
						TestUtils.compareScalarBitsJUnit(ulaVal, claVal, 0); // Should be exactly same value
					}
				}
		}
		catch(Exception e) {
			e.printStackTrace();
			throw new RuntimeException(this.toString() + "\n" + e.getMessage(), e);
		}
	}

	@Test
	public void testAppend() {
		try {
			if(!(cmb instanceof CompressedMatrixBlock))
				return; // Input was not compressed then just pass test

			MatrixBlock vector = DataConverter
				.convertToMatrixBlock(TestUtils.generateTestMatrix(rows, 1, 1, 1, 1.0, 3));

			// matrix-vector uncompressed
			MatrixBlock ret1 = mb.append(vector, new MatrixBlock());

			// matrix-vector compressed
			MatrixBlock ret2 = cmb.append(vector, new MatrixBlock());
			if(ret2 instanceof CompressedMatrixBlock)
				ret2 = ((CompressedMatrixBlock) ret2).decompress();

			// compare result with input
			double[][] d1 = DataConverter.convertToDoubleMatrix(ret1);
			double[][] d2 = DataConverter.convertToDoubleMatrix(ret2);
			if(compressionSettings.lossy) {
				TestUtils.compareMatrices(d1, d2, lossyTolerance);
			}
			else {
				TestUtils.compareMatricesBitAvgDistance(d1, d2, 0, 1, "Test Append Matrix");
			}
		}
		catch(Exception e) {
			e.printStackTrace();
			throw new RuntimeException(this.toString() + "\n" + e.getMessage(), e);
		}
	}

	@Test
	public void testScalarOperations() {
		try {
			if(!(cmb instanceof CompressedMatrixBlock))
				return; // Input was not compressed then just pass test

			double mult = 7;
			// matrix-scalar uncompressed
			ScalarOperator sop = new RightScalarOperator(Multiply.getMultiplyFnObject(), mult, _k);
			MatrixBlock ret1 = mb.scalarOperations(sop, new MatrixBlock());

			// matrix-scalar compressed
			MatrixBlock ret2 = cmb.scalarOperations(sop, new MatrixBlock());
			if(ret2 instanceof CompressedMatrixBlock)
				ret2 = ((CompressedMatrixBlock) ret2).decompress();

			// compare result with input
			double[][] d1 = DataConverter.convertToDoubleMatrix(ret1);
			double[][] d2 = DataConverter.convertToDoubleMatrix(ret2);
			if(compressionSettings.lossy) {
				double modifiedTolerance = lossyTolerance * mult + lossyTolerance * 0.00001;
				TestUtils.compareMatrices(d1, d2, modifiedTolerance, compressionSettings.toString());
			}
			else {
				TestUtils.compareMatricesBitAvgDistance(d1, d2, 150, 1, compressionSettings.toString());
			}
		}
		catch(Exception e) {
			e.printStackTrace();
			throw new RuntimeException(this.toString() + "\n" + e.getMessage(), e);
		}
	}

	@Test
	public void testCountDistinct() {
		try {
			if(!(cmb instanceof CompressedMatrixBlock))
				return; // Input was not compressed then just pass test

			CountDistinctOperator op = new CountDistinctOperator(CountDistinctTypes.COUNT);
			int ret1 = LibMatrixCountDistinct.estimateDistinctValues(mb, op);
			int ret2 = LibMatrixCountDistinct.estimateDistinctValues(cmb, op);
			String base = compressionSettings.toString() + "\n";
			if(compressionSettings.lossy) {
				// The number of distinct values should be same or lower in lossy mode.
				// assertTrue(base + "lossy distinct count " +ret2+ "is less than full " + ret1, ret1 >= ret2);

				// above assumption is false, since the distinct count when using multiple different scales becomes
				// larger due to differences in scale.
				assertTrue(base + "lossy distinct count " + ret2 + "is greater than 0", 0 < ret2);
			}
			else {
				assertEquals(base, ret1, ret2);
			}

		}
		catch(Exception e) {
			e.printStackTrace();
			throw new RuntimeException(this.toString() + "\n" + e.getMessage(), e);
		}
	}

	@Override
	public void testUnaryOperators(AggType aggType) {
		AggregateUnaryOperator auop = super.getUnaryOperator(aggType, 1);
		testUnaryOperators(aggType, auop);
	}

	@Test
	public void testSerialization() {
		try {
			if(!(cmb instanceof CompressedMatrixBlock))
				return; // Input was not compressed then just pass test

			// serialize compressed matrix block
			ByteArrayOutputStream bos = new ByteArrayOutputStream();
			DataOutputStream fos = new DataOutputStream(bos);
			cmb.write(fos);

			// deserialize compressed matrix block
			ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());
			DataInputStream fis = new DataInputStream(bis);
			CompressedMatrixBlock cmb2 = new CompressedMatrixBlock();
			cmb2.readFields(fis);

			// decompress the compressed matrix block
			MatrixBlock tmp = cmb2.decompress();

			// compare result with input
			double[][] d1 = DataConverter.convertToDoubleMatrix(mb);
			double[][] d2 = DataConverter.convertToDoubleMatrix(tmp);
			if(compressionSettings.lossy) {
				TestUtils.compareMatrices(d1, d2, lossyTolerance);
			}
			else {
				TestUtils.compareMatricesBitAvgDistance(d1, d2, 0, 0, compressionSettings.toString());
			}
		}
		catch(Exception e) {
			e.printStackTrace();
			throw new RuntimeException(this.toString() + "\n" + e.getMessage(), e);
		}
	}

	@Test
	public void testCompressionRatio() {
		try {
			if(!(cmb instanceof CompressedMatrixBlock))
				return;
			CompressionStatistics cStat = cmbStats;
			assertTrue("Compression ration if compressed should be larger than 1", cStat.ratio > 1);
		}
		catch(Exception e) {
			e.printStackTrace();
			throw new RuntimeException(this.toString() + "\n" + e.getMessage(), e);
		}
	}

	@Test
	public void testCompressionEstimationVSCompression() {
		try {
			if(!(cmb instanceof CompressedMatrixBlock))
				return;
			CompressionStatistics cStat = cmbStats;
			long colsEstimate = cStat.estimatedSizeCols;
			long actualSize = cStat.size;
			long originalSize = cStat.originalSize;
			int allowedTolerance = 4096;

			if(compressionSettings.samplingRatio < 1.0) {
				allowedTolerance = sampleTolerance;
			}

			StringBuilder builder = new StringBuilder();
			builder.append("\n\t" + String.format("%-40s - %12d", "Actual compressed size: ", actualSize));
			builder.append("\n\t" + String.format("%-40s - %12d with tolerance: %5d",
				"<= estimated isolated ColGroups: ",
				colsEstimate,
				allowedTolerance));
			builder.append("\n\t" + String.format("%-40s - %12d", "<= Original size: ", originalSize));
			builder.append("\n\tcol groups types: " + cStat.getGroupsTypesString());
			builder.append("\n\tcol groups sizes: " + cStat.getGroupsSizesString());
			builder.append("\n\t" + this.toString());
			boolean res = Math.abs(actualSize - colsEstimate) <= allowedTolerance;
			assertTrue(builder.toString(), res);
		}
		catch(Exception e) {
			e.printStackTrace();
			throw new RuntimeException(this.toString() + "\n" + e.getMessage(), e);
		}
	}

	@Ignore
	@Test
	public void testCompressionEstimationVSJolEstimate() {
		try {
			if(!(cmb instanceof CompressedMatrixBlock))
				return;
			CompressionStatistics cStat = cmbStats;
			long actualSize = cStat.size;
			long originalSize = cStat.originalSize;
			long JolEstimatedSize = getJolSize(((CompressedMatrixBlock) cmb), cmbStats);

			StringBuilder builder = new StringBuilder();
			builder.append("\n\t" + String.format("%-40s - %12d", "Actual compressed size: ", actualSize));
			builder.append("\n\t" + String.format("%-40s - %12d", "<= Original size: ", originalSize));
			builder.append("\n\t" + String.format("%-40s - %12d", "and equal to JOL Size: ", JolEstimatedSize));
			// builder.append("\n\t " + getJolSizeString(cmb));
			builder.append("\n\tcol groups types: " + cStat.getGroupsTypesString());
			builder.append("\n\tcol groups sizes: " + cStat.getGroupsSizesString());
			builder.append("\n\t" + this.toString());

			// NOTE: The Jol estimate is wrong for shared dictionaries because
			// it treats the object hierarchy as a tree and not a graph
			assertTrue(builder.toString(),
				actualSize <= originalSize &&
					(compressionSettings.allowSharedDictionary || actualSize == JolEstimatedSize));
		}
		catch(Exception e) {
			e.printStackTrace();
			throw new RuntimeException(this.toString() + "\n" + e.getMessage(), e);
		}
	}

	@Test
	public void testCompressionScale() {
		// This test is here for a sanity check such that we verify that the compression
		// ratio from our Matrix
		// Compressed Block is not unreasonably good.
		try {
			if(!(cmb instanceof CompressedMatrixBlock))
				return;

			CompressionStatistics cStat = cmbStats;

			double compressRatio = cStat.ratio;
			long actualSize = cStat.size;
			long originalSize = cStat.originalSize;

			StringBuilder builder = new StringBuilder();
			builder.append("Compression Ratio sounds suspiciously good at: " + compressRatio);
			builder.append("\n\tActual compressed size: " + actualSize);
			builder.append(" original size: " + originalSize);
			builder.append("\n\tcol groups types: " + cStat.getGroupsTypesString());
			builder.append("\n\tcol groups sizes: " + cStat.getGroupsSizesString());
			builder.append("\n\t" + this.toString());

			assertTrue(builder.toString(), compressRatio < 1000.0);
		}
		catch(Exception e) {
			e.printStackTrace();
			throw new RuntimeException(this.toString() + "\n" + e.getMessage(), e);
		}
	}

	private static long getJolSize(CompressedMatrixBlock cmb, CompressionStatistics cStat) {
		Layouter l = new HotSpotLayouter(new X86_64_DataModel());
		long jolEstimate = 0;
		for(Object ob : new Object[] {cmb, cmb.getColGroups()}) {
			jolEstimate += ClassLayout.parseInstance(ob, l).instanceSize();
		}
		for(ColGroup cg : cmb.getColGroups()) {
			jolEstimate += cg.estimateInMemorySize();
		}
		return jolEstimate;
	}

}