text: /**********************************************************************
    Copyright(c) 2011-2016 Intel Corporation All rights reserved.
  
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:
      * Redistributions of source code must retain the above copyright
        notice, this list of conditions and the following disclaimer.
      * Redistributions in binary form must reproduce the above copyright
        notice, this list of conditions and the following disclaimer in
        the documentation and/or other materials provided with the
        distribution.
      * Neither the name of Intel Corporation nor the names of its
        contributors may be used to endorse or promote products derived
        from this software without specific prior written permission.
  
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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  **********************************************************************/
  
  /* This program can be used to generate custom a custom huffman encoding to get
   * better data compression. This is most useful when the type of data being
   * compressed is well known.
   *
   * To use generate_custom_hufftables, pass a sequence of files to the program
   * that together form an accurate representation of the data that is being
   * compressed. Generate_custom_hufftables will then produce the file
   * hufftables_c.c, which should be moved to replace its counterpart in the igzip
   * source folder. After recompiling the Isa-l library, the igzip compression
   * functions will use the new hufftables.
   *
   * Generate_custom_hufftables should be compiled with the same compile time
   * parameters as the igzip source code. Generating custom hufftables with
   * different compile time parameters may cause igzip to produce invalid output
   * for the reasons described below. The default parameters used by
   * generate_custom_hufftables are the same as the default parameters used by
   * igzip.
   *
   * *WARNING* generate custom hufftables must be compiled with a IGZIP_HIST_SIZE
   * that is at least as large as the IGZIP_HIST_SIZE used by igzip. By default
   * IGZIP_HIST_SIZE is 32K, the maximum usable IGZIP_HIST_SIZE is 32K. The reason
   * for this is to generate better compression. Igzip cannot produce look back
   * distances with sizes larger than the IGZIP_HIST_SIZE igzip was compiled with,
   * so look back distances with sizes larger than IGZIP_HIST_SIZE are not
   * assigned a huffman code. The definition of LONGER_HUFFTABLES must be
   * consistent as well since that definition changes the size of the structures
   * printed by this tool.
   *
   */
  
  #include <stdint.h>
  #include <stdio.h>
  #include <inttypes.h>
  #include <string.h>
  #include <stdlib.h>
  #include "igzip_lib.h"
  
  #include "huff_codes.h"
  #include "huffman.h"
  
  /*These max code lengths are limited by how the data is stored in
   * hufftables.asm. The deflate standard max is 15.*/
  
  #define MAX_HEADER_SIZE ISAL_DEF_MAX_HDR_SIZE
  
  #define GZIP_HEADER_SIZE 10
  #define GZIP_TRAILER_SIZE 8
  #define ZLIB_HEADER_SIZE 2
  #define ZLIB_TRAILER_SIZE 4
  
  /**
   * @brief Prints a table of uint8_t elements to a file.
   * @param outfile: the file the table is printed to.
   * @param table: the table to be printed.
   * @param length: number of elements to be printed.
   * @param header: header to append in front of the table.
   * @param footer: footer to append at the end of the table.
   * @param begin_line: string printed at beginning of new line
   */
  void fprint_uint8_table(FILE * outfile, uint8_t * table, uint64_t length, char *header,
  			char *footer, char *begin_line)
  {
  	int i;
  	fprintf(outfile, "%s", header);
  	for (i = 0; i < length - 1; i++) {
  		if ((i & 7) == 0)
  			fprintf(outfile, "\n%s", begin_line);
  		else
  			fprintf(outfile, " ");
  		fprintf(outfile, "0x%02x,", table[i]);
  	}
  
  	if ((i & 7) == 0)
  		fprintf(outfile, "\n%s", begin_line);
  	else
  		fprintf(outfile, " ");
  	fprintf(outfile, "0x%02x", table[i]);
  	fprintf(outfile, "%s", footer);
  
  }
  
  /**
   * @brief Prints a table of uint16_t elements to a file.
   * @param outfile: the file the table is printed to.
   * @param table: the table to be printed.
   * @param length: number of elements to be printed.
   * @param header: header to append in front of the table.
   * @param footer: footer to append at the end of the table.
   * @param begin_line: string printed at beginning of new line
   */
  void fprint_uint16_table(FILE * outfile, uint16_t * table, uint64_t length, char *header,
  			 char *footer, char *begin_line)
  {
  	int i;
  	fprintf(outfile, "%s", header);
  	for (i = 0; i < length - 1; i++) {
  		if ((i & 7) == 0)
  			fprintf(outfile, "\n%s", begin_line);
  		else
  			fprintf(outfile, " ");
  		fprintf(outfile, "0x%04x,", table[i]);
  	}
  
  	if ((i & 7) == 0)
  		fprintf(outfile, "\n%s", begin_line);
  	else
  		fprintf(outfile, " ");
  	fprintf(outfile, "0x%04x", table[i]);
  	fprintf(outfile, "%s", footer);
  
  }
  
  /**
   * @brief Prints a table of uint32_t elements to a file.
   * @param outfile: the file the table is printed to.
   * @param table: the table to be printed.
   * @param length: number of elements to be printed.
   * @param header: header to append in front of the table.
   * @param footer: footer to append at the end of the table.
   * @param begin_line: string printed at beginning of new line
   */
  void fprint_uint32_table(FILE * outfile, uint32_t * table, uint64_t length, char *header,
  			 char *footer, char *begin_line)
  {
  	int i;
  	fprintf(outfile, "%s", header);
  	for (i = 0; i < length - 1; i++) {
  		if ((i & 3) == 0)
  			fprintf(outfile, "\n%s", begin_line);
  		else
  			fprintf(outfile, " ");
  		fprintf(outfile, "0x%08x,", table[i]);
  	}
  
  	if ((i & 3) == 0)
  		fprintf(outfile, "%s", begin_line);
  	else
  		fprintf(outfile, " ");
  	fprintf(outfile, "0x%08x", table[i]);
  	fprintf(outfile, "%s", footer);
  
  }
  
  void fprint_hufftables(FILE * output_file, char *hufftables_name,
  		       struct isal_hufftables *hufftables)
  {
  	fprintf(output_file, "struct isal_hufftables %s = {\n\n", hufftables_name);
  
  	fprint_uint8_table(output_file, hufftables->deflate_hdr,
  			   hufftables->deflate_hdr_count +
  			   (hufftables->deflate_hdr_extra_bits + 7) / 8,
  			   "\t.deflate_hdr = {", "},\n\n", "\t\t");
  
  	fprintf(output_file, "\t.deflate_hdr_count = %d,\n", hufftables->deflate_hdr_count);
  	fprintf(output_file, "\t.deflate_hdr_extra_bits = %d,\n\n",
  		hufftables->deflate_hdr_extra_bits);
  
  	fprint_uint32_table(output_file, hufftables->dist_table, IGZIP_DIST_TABLE_SIZE,
  			    "\t.dist_table = {", "},\n\n", "\t\t");
  
  	fprint_uint32_table(output_file, hufftables->len_table, IGZIP_LEN_TABLE_SIZE,
  			    "\t.len_table = {", "},\n\n", "\t\t");
  
  	fprint_uint16_table(output_file, hufftables->lit_table, IGZIP_LIT_TABLE_SIZE,
  			    "\t.lit_table = {", "},\n\n", "\t\t");
  	fprint_uint8_table(output_file, hufftables->lit_table_sizes, IGZIP_LIT_TABLE_SIZE,
  			   "\t.lit_table_sizes = {", "},\n\n", "\t\t");
  
  	fprint_uint16_table(output_file, hufftables->dcodes,
  			    ISAL_DEF_DIST_SYMBOLS - IGZIP_DECODE_OFFSET,
  			    "\t.dcodes = {", "},\n\n", "\t\t");
  	fprint_uint8_table(output_file, hufftables->dcodes_sizes,
  			   ISAL_DEF_DIST_SYMBOLS - IGZIP_DECODE_OFFSET,
  			   "\t.dcodes_sizes = {", "}\n", "\t\t");
  	fprintf(output_file, "};\n");
  }
  
  void fprint_header(FILE * output_file)
  {
  
  	fprintf(output_file, "#include <stdint.h>\n");
  	fprintf(output_file, "#include <igzip_lib.h>\n\n");
  
  	fprintf(output_file, "#if IGZIP_HIST_SIZE > %d\n"
  		"# error \"Invalid history size for the custom hufftable\"\n"
  		"#endif\n", IGZIP_HIST_SIZE);
  
  #ifdef LONGER_HUFFTABLE
  	fprintf(output_file, "#ifndef LONGER_HUFFTABLE\n"
  		"# error \"Custom hufftable requires LONGER_HUFFTABLE to be defined \"\n"
  		"#endif\n");
  #else
  	fprintf(output_file, "#ifdef LONGER_HUFFTABLE\n"
  		"# error \"Custom hufftable requires LONGER_HUFFTABLE to not be defined \"\n"
  		"#endif\n");
  #endif
  	fprintf(output_file, "\n");
  
  	fprintf(output_file, "const uint8_t gzip_hdr[] = {\n"
  		"\t0x1f, 0x8b, 0x08, 0x00, 0x00,\n" "\t0x00, 0x00, 0x00, 0x00, 0xff\t};\n\n");
  
  	fprintf(output_file, "const uint32_t gzip_hdr_bytes = %d;\n", GZIP_HEADER_SIZE);
  	fprintf(output_file, "const uint32_t gzip_trl_bytes = %d;\n\n", GZIP_TRAILER_SIZE);
  
  	fprintf(output_file, "const uint8_t zlib_hdr[] = { 0x78, 0x01 };\n\n");
  	fprintf(output_file, "const uint32_t zlib_hdr_bytes = %d;\n", ZLIB_HEADER_SIZE);
  	fprintf(output_file, "const uint32_t zlib_trl_bytes = %d;\n", ZLIB_TRAILER_SIZE);
  }
  
  static uint32_t convert_dist_to_dist_sym(uint32_t dist)
  {
  	assert(dist <= 32768 && dist > 0);
  	if (dist <= 32768) {
  		uint32_t msb = dist > 4 ? bsr(dist - 1) - 2 : 0;
  		return (msb * 2) + ((dist - 1) >> msb);
  	} else {
  		return ~0;
  	}
  }
  
  /**
   * @brief  Returns the deflate symbol value for a repeat length.
   */
  static uint32_t convert_length_to_len_sym(uint32_t length)
  {
  	assert(length > 2 && length < 259);
  
  	/* Based on tables on page 11 in RFC 1951 */
  	if (length < 11)
  		return 257 + length - 3;
  	else if (length < 19)
  		return 261 + (length - 3) / 2;
  	else if (length < 35)
  		return 265 + (length - 3) / 4;
  	else if (length < 67)
  		return 269 + (length - 3) / 8;
  	else if (length < 131)
  		return 273 + (length - 3) / 16;
  	else if (length < 258)
  		return 277 + (length - 3) / 32;
  	else
  		return 285;
  }
  
  void isal_update_histogram_dict(uint8_t * start_stream, int dict_length, int length,
  				struct isal_huff_histogram *histogram)
  {
  	uint32_t literal = 0, hash;
  	uint16_t seen, *last_seen = histogram->hash_table;
  	uint8_t *current, *end_stream, *next_hash, *end, *end_dict;
  	uint32_t match_length;
  	uint32_t dist;
  	uint64_t *lit_len_histogram = histogram->lit_len_histogram;
  	uint64_t *dist_histogram = histogram->dist_histogram;
  
  	if (length <= 0)
  		return;
  
  	end_stream = start_stream + dict_length + length;
  	end_dict = start_stream + dict_length;
  
  	memset(last_seen, 0, sizeof(histogram->hash_table));	/* Initialize last_seen to be 0. */
  
  	for (current = start_stream; current < end_dict - 4; current++) {
  		literal = load_u32(current);
  		hash = compute_hash(literal) & LVL0_HASH_MASK;
  		last_seen[hash] = (current - start_stream) & 0xFFFF;
  	}
  
  	for (current = start_stream + dict_length; current < end_stream - 3; current++) {
  		literal = load_u32(current);
  		hash = compute_hash(literal) & LVL0_HASH_MASK;
  		seen = last_seen[hash];
  		last_seen[hash] = (current - start_stream) & 0xFFFF;
  		dist = (current - start_stream - seen) & 0xFFFF;
  		if (dist - 1 < D - 1) {
  			assert(start_stream <= current - dist);
  			match_length =
  			    compare258(current - dist, current, end_stream - current);
  			if (match_length >= SHORTEST_MATCH) {
  				next_hash = current;
  #ifdef ISAL_LIMIT_HASH_UPDATE
  				end = next_hash + 3;
  #else
  				end = next_hash + match_length;
  #endif
  				if (end > end_stream - 3)
  					end = end_stream - 3;
  				next_hash++;
  				for (; next_hash < end; next_hash++) {
  					literal = load_u32(next_hash);
  					hash = compute_hash(literal) & LVL0_HASH_MASK;
  					last_seen[hash] = (next_hash - start_stream) & 0xFFFF;
  				}
  
  				dist_histogram[convert_dist_to_dist_sym(dist)] += 1;
  				lit_len_histogram[convert_length_to_len_sym(match_length)] +=
  				    1;
  				current += match_length - 1;
  				continue;
  			}
  		}
  		lit_len_histogram[literal & 0xFF] += 1;
  	}
  
  	for (; current < end_stream; current++)
  		lit_len_histogram[*current] += 1;
  
  	lit_len_histogram[256] += 1;
  	return;
  }
  
  int main(int argc, char *argv[])
  {
  	long int file_length;
  	int argi = 1;
  	uint8_t *stream = NULL;
  	struct isal_hufftables hufftables;
  	struct isal_huff_histogram histogram;
  	struct isal_zstream tmp_stream;
  	FILE *file = NULL;
  	FILE *dict_file = NULL;
  	FILE *hist_file = NULL;
  	long int dict_file_length = 0;
  	long int hist_file_length = 0;
  	uint8_t *dict_stream = NULL;
  
  	if (argc == 1) {
  		printf("Error, no input file.\n");
  		return 1;
  	}
  
  	if (argc > 3 && argv[1][0] == '-' && argv[1][1] == 'd') {
  		dict_file = fopen(argv[2], "r");
  
  		fseek(dict_file, 0, SEEK_END);
  		dict_file_length = ftell(dict_file);
  		fseek(dict_file, 0, SEEK_SET);
  		dict_file_length -= ftell(dict_file);
  		dict_stream = malloc(dict_file_length);
  		if (dict_stream == NULL) {
  			printf("Failed to allocate memory to read in dictionary file\n");
  			fclose(dict_file);
  			return 1;
  		}
  		if (fread(dict_stream, 1, dict_file_length, dict_file) != dict_file_length) {
  			printf("Error occurred when reading dictionary file");
  			fclose(dict_file);
  			free(dict_stream);
  			return 1;
  		}
  		isal_update_histogram(dict_stream, dict_file_length, &histogram);
  
  		printf("Read %ld bytes of dictionary file %s\n", dict_file_length, argv[2]);
  		argi += 2;
  		fclose(dict_file);
  		free(dict_stream);
  	}
  
  	if ((argc > argi + 1) && argv[argi][0] == '-' && argv[argi][1] == 'h') {
  		hist_file = fopen(argv[argi + 1], "r+");
  		fseek(hist_file, 0, SEEK_END);
  		hist_file_length = ftell(hist_file);
  		fseek(hist_file, 0, SEEK_SET);
  		hist_file_length -= ftell(hist_file);
  		if (hist_file_length > sizeof(histogram)) {
  			printf("Histogram file too long\n");
  			return 1;
  		}
  		if (fread(&histogram, 1, hist_file_length, hist_file) != hist_file_length) {
  			printf("Error occurred when reading history file");
  			fclose(hist_file);
  			return 1;
  		}
  		fseek(hist_file, 0, SEEK_SET);
  
  		printf("Read %ld bytes of history file %s\n", hist_file_length,
  		       argv[argi + 1]);
  		argi += 2;
  	} else
  		memset(&histogram, 0, sizeof(histogram));	/* Initialize histograms. */
  
  	while (argi < argc) {
  		printf("Processing %s\n", argv[argi]);
  		file = fopen(argv[argi], "r");
  		if (file == NULL) {
  			printf("Error opening file\n");
  			return 1;
  		}
  		fseek(file, 0, SEEK_END);
  		file_length = ftell(file);
  		fseek(file, 0, SEEK_SET);
  		file_length -= ftell(file);
  		stream = malloc(file_length + dict_file_length);
  		if (stream == NULL) {
  			printf("Failed to allocate memory to read in file\n");
  			fclose(file);
  			return 1;
  		}
  		if (dict_file_length > 0)
  			memcpy(stream, dict_stream, dict_file_length);
  
  		if (fread(&stream[dict_file_length], 1, file_length, file) != file_length) {
  			printf("Error occurred when reading file");
  			fclose(file);
  			free(stream);
  			return 1;
  		}
  
  		/* Create a histogram of frequency of symbols found in stream to
  		 * generate the huffman tree.*/
  		if (0 == dict_file_length)
  			isal_update_histogram(stream, file_length, &histogram);
  		else
  			isal_update_histogram_dict(stream, dict_file_length, file_length,
  						   &histogram);
  
  		fclose(file);
  		free(stream);
  		argi++;
  	}
  
  	isal_create_hufftables(&hufftables, &histogram);
  
  	file = fopen("hufftables_c.c", "w");
  	if (file == NULL) {
  		printf("Error creating file hufftables_c.c\n");
  		return 1;
  	}
  
  	fprint_header(file);
  
  	fprintf(file, "\n");
  
  	fprint_hufftables(file, "hufftables_default", &hufftables);
  
  	fprintf(file, "\n");
  
  	isal_deflate_stateless_init(&tmp_stream);
  	isal_deflate_set_hufftables(&tmp_stream, NULL, IGZIP_HUFFTABLE_STATIC);
  	fprint_hufftables(file, "hufftables_static", tmp_stream.hufftables);
  
  	fclose(file);
  
  	if (hist_file) {
  		int len = fwrite(&histogram, 1, sizeof(histogram), hist_file);
  		printf("wrote %d bytes of histogram file\n", len);
  		fclose(hist_file);
  	}
  	return 0;
  }
  