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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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/*
 * 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 .
 *
 */

package it.unimi.dsi.compression;

import static org.junit.Assert.assertEquals;

import java.io.IOException;
import java.util.Random;

import it.unimi.dsi.bits.BitVector;
import it.unimi.dsi.fastutil.booleans.BooleanArrayList;
import it.unimi.dsi.fastutil.booleans.BooleanIterator;
import it.unimi.dsi.fastutil.io.FastByteArrayOutputStream;
import it.unimi.dsi.io.InputBitStream;
import it.unimi.dsi.io.OutputBitStream;

public abstract class CodecTestCase {
	protected static void checkPrefixCodec(final PrefixCodec codec, final Random r) throws IOException {
		final int[] symbol = new int[100];
		final BooleanArrayList bits = new BooleanArrayList();
		for(int i = 0; i < symbol.length; i++) symbol[i] = r.nextInt(codec.size());
		for (final int element : symbol) {
			final BitVector word = codec.codeWords()[element];
			for(long j = 0; j < word.length(); j++) bits.add(word.getBoolean(j));
		}

		final BooleanIterator booleanIterator = bits.iterator();
		final Decoder decoder = codec.decoder();
		for (final int element : symbol) {
			assertEquals(element, decoder.decode(booleanIterator));
		}

		final FastByteArrayOutputStream fbaos = new FastByteArrayOutputStream();
		@SuppressWarnings("resource")
		final
		OutputBitStream obs = new OutputBitStream(fbaos, 0);
		obs.write(bits.iterator());
		obs.flush();
		final InputBitStream ibs = new InputBitStream(fbaos.array);

		for (final int element : symbol) {
			assertEquals(element, decoder.decode(ibs));
		}
	}

	protected void checkLengths(final int[] frequency, final int[] codeLength, final BitVector[] codeWord) {
		for(int i = 0; i < frequency.length; i++)
			assertEquals(Integer.toString(i), codeLength[i], codeWord[i].length());
	}
}