Initial commit

test/common/compression/huffman.h

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+#include <cxxtest/TestSuite.h>
+#include "common/compression/huffman.h"
+#include "common/bitstream.h"
+#include "common/memstream.h"
+
+/**
+* A test suite for the Huffman decoder in common/compression/huffman.h
+* The encoding used comes from the example on the Wikipedia page
+* for Huffman.
+* TODO: It could be improved by generating one at runtime.
+*/
+class HuffmanTestSuite : public CxxTest::TestSuite {
+	public:
+	void test_get_with_full_symbols() {
+
+		/*
+		 * The class can be initialized with or without providing
+		 * a max_length and a symbol table.
+		 * We test with a table.
+		 *
+		 * Encoding (arbitrary, for testing purpouses):
+		 * 0xA=010
+		 * 0xB=011
+		 * 0xC=11
+		 * 0xD=00
+		 * 0xE=10
+		 */
+
+		uint32 codeCount = 5;
+		uint8 maxLength = 3;
+		const uint8 lengths[] = {3,3,2,2,2};
+		const uint32 codes[]  = {0x2, 0x3, 0x3, 0x0, 0x2};
+		const uint32 symbols[]  = {0xA, 0xB, 0xC, 0xD, 0xE};
+
+		Common::Huffman<Common::BitStream8MSB> h(maxLength, codeCount, codes, lengths, symbols);
+
+		byte input[] = {0x4F, 0x20};
+		// Provided input...
+		uint32 expected[] = {0xA, 0xB, 0xC, 0xD, 0xE, 0xD, 0xD};
+		// ..and expected output.
+
+		/*
+		 * What should be going on:
+		 * 010 011 11 00 10 00 00 = A B C D E D D
+		 *  = 0100 1111 0010 0000 = 0x4F20
+		 */
+
+		Common::MemoryReadStream ms(input, sizeof(input));
+		Common::BitStream8MSB bs(ms);
+
+		TS_ASSERT_EQUALS(h.getSymbol(bs), expected[0]);
+		TS_ASSERT_EQUALS(h.getSymbol(bs), expected[1]);
+		TS_ASSERT_EQUALS(h.getSymbol(bs), expected[2]);
+		TS_ASSERT_EQUALS(h.getSymbol(bs), expected[3]);
+		TS_ASSERT_EQUALS(h.getSymbol(bs), expected[4]);
+		TS_ASSERT_EQUALS(h.getSymbol(bs), expected[5]);
+		TS_ASSERT_EQUALS(h.getSymbol(bs), expected[6]);
+	}
+
+	void test_get_without_symbols() {
+
+		/*
+		 * This is basically the same as test_get_with_full_symbols, but
+		 * I only pass the minimal required arguments.
+		 * Specifically, I avoid passing the symbols table, so that
+		 * array indices are used instead.
+		 *
+		 * Encoding becomes:
+		 *
+		 * 0=010
+		 * 1=011
+		 * 2=11
+		 * 3=00
+		 * 4=10
+		 */
+
+		uint32 codeCount = 5;
+		const uint8 lengths[] = {3,3,2,2,2};
+		const uint32 codes[]  = {0x2, 0x3, 0x3, 0x0, 0x2};
+
+		Common::Huffman<Common::BitStream8MSB> h(0, codeCount, codes, lengths, 0);
+
+		byte input[] = {0x4F, 0x20};
+		uint32 expected[] = {0, 1, 2, 3, 4, 3 ,3};
+
+		Common::MemoryReadStream ms(input, sizeof(input));
+		Common::BitStream8MSB bs(ms);
+
+		TS_ASSERT_EQUALS(h.getSymbol(bs), expected[0]);
+		TS_ASSERT_EQUALS(h.getSymbol(bs), expected[1]);
+		TS_ASSERT_EQUALS(h.getSymbol(bs), expected[2]);
+		TS_ASSERT_EQUALS(h.getSymbol(bs), expected[3]);
+		TS_ASSERT_EQUALS(h.getSymbol(bs), expected[4]);
+		TS_ASSERT_EQUALS(h.getSymbol(bs), expected[5]);
+		TS_ASSERT_EQUALS(h.getSymbol(bs), expected[6]);
+	}
+};