Commit 663462c2 authored by Birte Kristina Friesel's avatar Birte Kristina Friesel
Browse files

type 2 is working \o/

parent 99d861a2

src/app/deflatetest/main.cc

+60 −17
Original line number Diff line number Diff line
@@ -100,23 +100,27 @@ static uint16_t udeflate_get_bits(uint8_t num_bits) 
 * sets. We don't do that; instead, we expect the uncompressed source to

 * be no more than a few kB of data.

 */

uint8_t udeflate_bl_count[12];

uint16_t udeflate_next_code[12];



// TODO specify bl_count and next_code lists

// (length and distance codes may use separate alphabets)

static void udeflate_build_alphabet(uint8_t* lengths, uint16_t size)

// used for huffman alphabet in type 2 and literal/length alphabet in type 1&2

uint8_t udeflate_bl_count_ll[12];

uint16_t udeflate_next_code_ll[12];



// used for distance alphabet in types 1&2

uint8_t udeflate_bl_count_d[12];

uint16_t udeflate_next_code_d[12];



static void udeflate_build_alphabet(uint8_t* lengths, uint16_t size, uint8_t* bl_count, uint16_t* next_code)

{

	uint16_t i;

	uint16_t code = 0;

	uint8_t max_len = 0;

	uint16_t max_len = 0;

	for (i = 0; i < 12; i++) {

		udeflate_bl_count[i] = 0;

		bl_count[i] = 0;

	}



	for (i = 0; i < size; i++) {

		if (lengths[i]) {

			udeflate_bl_count[lengths[i]]++;

			bl_count[lengths[i]]++;

		}

		if (lengths[i] > max_len) {

			max_len = lengths[i];
@@ -124,26 +128,26 @@ static void udeflate_build_alphabet(uint8_t* lengths, uint16_t size) 
	}



	for (i = 1; i < max_len+1; i++) {

		code = (code + udeflate_bl_count[i-1]) << 1;

		udeflate_next_code[i] = code;

		code = (code + bl_count[i-1]) << 1;

		next_code[i] = code;

	}



	for (i = 0; i < 12; i++) {

		kout << "bl_count[" << i << "] = " << udeflate_bl_count[i] << endl;

		kout << "bl_count[" << i << "] = " << bl_count[i] << endl;

	}

	for (i = 0; i < 12; i++) {

		kout << "next_code[" << i << "] = " << udeflate_next_code[i] << endl;

		kout << "next_code[" << i << "] = " << next_code[i] << endl;

	}

}



static uint16_t udeflate_huff(uint8_t* lengths, uint16_t size)

static uint16_t udeflate_huff(uint8_t* lengths, uint16_t size, uint8_t* bl_count, uint16_t* next_code)

{

	uint16_t next_word = udeflate_get_word();

	for (uint8_t num_bits = 1; num_bits < 12; num_bits++) {

		uint16_t next_bits = udeflate_rev_word(next_word, num_bits);

		// TODO benötigt bit reversal bei der Abgleichung code <-> next_bits

		// (geeignete is_bit_eq(next_bits, code_candidate, num_bits) Funktion?)

		if (udeflate_bl_count[num_bits] && next_bits >= udeflate_next_code[num_bits] && next_bits < udeflate_next_code[num_bits] + udeflate_bl_count[num_bits] ) {

		if (bl_count[num_bits] && next_bits >= next_code[num_bits] && next_bits < next_code[num_bits] + bl_count[num_bits] ) {

			kout << "found huffman code, length = " << num_bits << endl;

			udeflate_bit_offset += num_bits;

			while (udeflate_bit_offset >= 8) {
@@ -151,7 +155,7 @@ static uint16_t udeflate_huff(uint8_t* lengths, uint16_t size) 
				udeflate_bit_offset -= 8;

			}

			uint8_t len_pos = next_bits;

			uint8_t cur_pos = udeflate_next_code[num_bits];

			uint8_t cur_pos = next_code[num_bits];

			for (uint16_t i = 0; i < size; i++) {

				if (lengths[i] == num_bits) {

					if (cur_pos == len_pos) {
@@ -165,6 +169,39 @@ static uint16_t udeflate_huff(uint8_t* lengths, uint16_t size) 
	return 65535;

}



static int8_t udeflate_huffman(uint8_t* ll_lengths, uint16_t ll_size, uint8_t* d_lengths, uint8_t d_size)

{

	uint16_t code;

	uint16_t dcode;

	uint16_t output_pos = 0;

	while (1) {

		code = udeflate_huff(ll_lengths, ll_size, udeflate_bl_count_ll, udeflate_next_code_ll);

		kout << "code " << code << endl;

		if (code < 256) {

			deflate_output[output_pos] = code;

			output_pos++;

		} else if (code == 256) {

			return 0;

		} else {

			uint16_t len_val = udeflate_length_offsets[code - 257];

			uint8_t extra_bits = udeflate_length_bits[code - 257];

			if (extra_bits) {

				len_val += udeflate_get_bits(extra_bits);

			}

			dcode = udeflate_huff(d_lengths, d_size, udeflate_bl_count_d, udeflate_next_code_d);

			uint16_t dist_val = udeflate_distance_offsets[dcode];

			extra_bits = udeflate_distance_bits[dcode];

			if (extra_bits) {

				dist_val += udeflate_get_bits(extra_bits);

			}

			while (len_val--) {

				deflate_output[output_pos] = deflate_output[output_pos-dist_val];

				output_pos++;

			}

		}

	}

}



static int8_t udeflate_dynamic_huffman()

{

	uint8_t i;
@@ -182,11 +219,11 @@ static int8_t udeflate_dynamic_huffman() 
		udeflate_hc_lengths[udeflate_hclen_index[i]] = 0;

	}



	udeflate_build_alphabet(udeflate_hc_lengths, sizeof(udeflate_hc_lengths));

	udeflate_build_alphabet(udeflate_hc_lengths, sizeof(udeflate_hc_lengths), udeflate_bl_count_ll, udeflate_next_code_ll);



	uint16_t items_processed = 0;

	while (items_processed < hlit + hdist) {

		uint8_t code = udeflate_huff(udeflate_hc_lengths, 19);

		uint8_t code = udeflate_huff(udeflate_hc_lengths, 19, udeflate_bl_count_ll, udeflate_next_code_ll);

		kout << "code = " << code << endl;

		if (code == 16) {

			uint8_t copy_count = 3 + udeflate_get_bits(2);
@@ -215,6 +252,11 @@ static int8_t udeflate_dynamic_huffman() 
		}

	}



	udeflate_build_alphabet(udeflate_lld_lengths, hlit, udeflate_bl_count_ll, udeflate_next_code_ll);

	udeflate_build_alphabet(udeflate_lld_lengths + hlit, hdist, udeflate_bl_count_d, udeflate_next_code_d);



	return udeflate_huffman(udeflate_lld_lengths, hlit, udeflate_lld_lengths + hlit, hdist);



	return 0;

}
@@ -266,6 +308,7 @@ int main(void) 
	for (uint8_t i = 0; i < 5; i++) {

		int8_t ret = udeflate_zlib((unsigned char*)deflate_input, sizeof(deflate_input));

		kout << "udeflate returned " << ret << endl;

		kout << "Output: " << (char*)deflate_output << endl;

	}



	arch.idle();