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The DSI utilities are a mishmash of classes accumulated during the last twenty years in projects developed at the DSI (Dipartimento di Scienze dell'Informazione, i.e., Information Sciences Department), now DI (Dipartimento di Informatica, i.e., Informatics Department), of the Universita` degli Studi di Milano.
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package it.unimi.dsi.io;

/*
 * DSI utilities
 *
 * Copyright (C) 2010-2020 Sebastiano Vigna
 *
 *  This library is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU Lesser General Public License as published by the Free
 *  Software Foundation; either version 3 of the License, or (at your option)
 *  any later version.
 *
 *  This library is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 *  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 *  for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program; if not, see .
 *
 */

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

import java.io.File;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.util.Arrays;
import java.util.Random;

import org.junit.Test;

import it.unimi.dsi.fastutil.io.FastByteArrayOutputStream;
import it.unimi.dsi.fastutil.longs.LongArrayList;
import it.unimi.dsi.util.XoRoShiRo128PlusRandom;

@SuppressWarnings("resource")
public class InputBitStreamTest {

	@Test
	public void testReadAligned() throws IOException {
		final byte[] a = { 1 }, A = new byte[1];
		new InputBitStream(a).read(A, 8);
		assertTrue(Arrays.toString(a) + " != " + Arrays.toString(A), Arrays.equals(a, A));
		final byte[] b = { 1, 2 }, B = new byte[2];
		new InputBitStream(b).read(B, 16);
		assertTrue(Arrays.toString(b) + " != " + Arrays.toString(B), Arrays.equals(b, B));
		final byte[] c = { 1, 2, 3 }, C = new byte[3];
		new InputBitStream(c).read(C, 24);
		assertTrue(Arrays.toString(c) + " != " + Arrays.toString(C), Arrays.equals(c, C));
	}

	@Test
	public void testOverflow() throws IOException {
		final InputBitStream ibs = new InputBitStream(new byte[0]);
		ibs.readInt(0);
	}

	@Test
	public void testPosition() throws IOException {
		final InputBitStream ibs = new InputBitStream(new byte[100]);
		for(int i = 0; i < 800; i++) {
			ibs.position(i);
			assertEquals(i, ibs.position());
		}
		for(int i = 800; i-- != 0;) {
			ibs.position(i);
			assertEquals(i, ibs.position());
		}
	}

	@Test
	public void readWriteLongs() throws IOException, NoSuchMethodException, SecurityException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
		final Random random = new Random(0);
		final File tempFile = File.createTempFile("readWriteLongs", "os");
		tempFile.deleteOnExit();

		final String[] oneArgs = { "LongGamma", "LongShiftedGamma", "LongDelta", "LongNibble" };
		final String[] twoArgsLong = { "LongGolomb", "LongSkewedGolomb" };

		final LongArrayList longs = new LongArrayList();
		for (int i = 0; i < 10; i++) longs.add(5000000000L + random.nextInt());
		//for (int i = 24; i < 60; i++) longs.add(1L << i);
		final LongArrayList extraArgLong = new LongArrayList();
		for (int i = 0; i < 5; i++) extraArgLong.add(100000 + random.nextInt(1000000));

		// Write
		final OutputBitStream obs = new OutputBitStream(tempFile);

		for (final String methSuffix: oneArgs)
			for (final long longValue: longs)
				OutputBitStream.class.getMethod("write" + methSuffix, long.class).invoke(obs, Long.valueOf(longValue));
		for (final String methSuffix: twoArgsLong)
			for (final long longValue: longs)
				for (final long longXValue: extraArgLong)
					OutputBitStream.class.getMethod("write" + methSuffix, long.class, long.class).invoke(obs, Long.valueOf(longValue), Long.valueOf(longXValue));
		// Special methods
		for (final long longValue: longs) {
			obs.writeLong(longValue, Long.SIZE);
			obs.writeLongMinimalBinary(longValue, longValue + 5);
			for (int i = 3; i < 10; i++) obs.writeLongZeta(longValue, i);
		}
		obs.writeLongUnary(15 + 1L << 20);

		obs.close();

		// Read
		final InputBitStream ibs = new InputBitStream(tempFile);

		for (final String methSuffix: oneArgs)
			for (final long longValue: longs)
				assertEquals(Long.valueOf(longValue), InputBitStream.class.getMethod("read" + methSuffix).invoke(ibs));
		for (final String methSuffix: twoArgsLong)
			for (final long longValue: longs)
				for (final long longXValue: extraArgLong)
					assertEquals(Long.valueOf(longValue), InputBitStream.class.getMethod("read" + methSuffix, long.class).invoke(ibs, Long.valueOf(longXValue)));
		for (final long longValue: longs) {
			assertEquals(longValue, ibs.readLong(Long.SIZE));
			assertEquals(longValue, ibs.readLongMinimalBinary(longValue + 5));
			for (int i = 3; i < 10; i++) assertEquals(longValue, ibs.readLongZeta(i));
		}
		assertEquals(15 + 1L << 20, ibs.readLongUnary());

		ibs.close();

	}

	@Test
	public void testUnary() throws IOException {
		final XoRoShiRo128PlusRandom random = new XoRoShiRo128PlusRandom(0);
		final FastByteArrayOutputStream fbaos = new FastByteArrayOutputStream();
		final OutputBitStream obs = new OutputBitStream(fbaos);
		for(int i = 0; i < 100000000; i++) obs.writeUnary(Long.numberOfTrailingZeros(random.nextLong()));
		obs.flush();
		final InputBitStream ibs = new InputBitStream(fbaos.array);
		random.setSeed(0);
		for(int i = 0; i < 100000000; i++) assertEquals(Long.numberOfTrailingZeros(random.nextLong()), ibs.readUnary());
	}

	@Test
	public void testLongUnary() throws IOException {
		final XoRoShiRo128PlusRandom random = new XoRoShiRo128PlusRandom(0);
		final FastByteArrayOutputStream fbaos = new FastByteArrayOutputStream();
		final OutputBitStream obs = new OutputBitStream(fbaos);
		for(int i = 0; i < 100000000; i++) obs.writeLongUnary(Long.numberOfTrailingZeros(random.nextLong()));
		obs.flush();
		final InputBitStream ibs = new InputBitStream(fbaos.array);
		random.setSeed(0);
		for(int i = 0; i < 100000000; i++) assertEquals(Long.numberOfTrailingZeros(random.nextLong()), ibs.readLongUnary());
	}

	public static void main(final String arg[]) throws IOException {
		final XoRoShiRo128PlusRandom random = new XoRoShiRo128PlusRandom(0);
		final FastByteArrayOutputStream fbaos = new FastByteArrayOutputStream();
		final OutputBitStream obs = new OutputBitStream(fbaos);
		for(int i = 0; i < 100000000; i++) obs.writeUnary(Long.numberOfTrailingZeros(random.nextLong()));
		obs.flush();
		final InputBitStream ibs = new InputBitStream(fbaos.array);
		for(int i = 0; i < 100000000; i++) ibs.readUnary();

		ibs.position(0);
		for(int i = 0; i < 100000000; i++) ibs.readUnary();

		ibs.position(0);
		for(int i = 0; i < 100000000; i++) ibs.readUnary();
	}
}