diff options
Diffstat (limited to 'examples/dict.c')
| -rw-r--r-- | examples/dict.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/examples/dict.c b/examples/dict.c new file mode 100644 index 0000000..eec7675 --- /dev/null +++ b/examples/dict.c @@ -0,0 +1,278 @@ +/* dict.c -- example program: how to use preset dictionaries + + This file is part of the LZO real-time data compression library. + + Copyright (C) 2008 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2007 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2006 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2005 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2004 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2003 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2002 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2001 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2000 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 1999 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 1998 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 1997 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 1996 Markus Franz Xaver Johannes Oberhumer + All Rights Reserved. + + The LZO library is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 2 of + the License, or (at your option) any later version. + + The LZO 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with the LZO library; see the file COPYING. + If not, write to the Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + + Markus F.X.J. Oberhumer + <markus@oberhumer.com> + http://www.oberhumer.com/opensource/lzo/ + */ + + +/************************************************************************* +// This program shows how to use preset dictionaries. +// +// Please study LZO.FAQ and simple.c first. +**************************************************************************/ + +#include "lzo/lzoconf.h" +#include "lzo/lzo1x.h" + +/* portability layer */ +#define WANT_LZO_MALLOC 1 +#define WANT_LZO_FREAD 1 +#define WANT_LZO_WILDARGV 1 +#include "examples/portab.h" + + +static const char *progname = NULL; + +#define DICT_LEN 0xbfff +static lzo_bytep dict; +static lzo_uint dict_len = 0; +static lzo_uint32 dict_adler32; + + +/************************************************************************* +// +**************************************************************************/ + +static lzo_uint total_n = 0; +static lzo_uint total_c_len = 0; +static lzo_uint total_d_len = 0; + +static void print_file ( const char *name, lzo_uint d_len, lzo_uint c_len ) +{ + double perc; + + perc = (d_len > 0) ? c_len * 100.0 / d_len : 0; + printf(" | %-30s %9ld -> %9ld %7.2f%% |\n", + name, (long) d_len, (long) c_len, perc); + + total_n++; + total_c_len += c_len; + total_d_len += d_len; +} + + +/************************************************************************* +// +**************************************************************************/ + +int do_file ( const char *in_name, int level ) +{ + int r; + lzo_bytep in; + lzo_bytep out; + lzo_bytep newb; + lzo_bytep wrkmem; + lzo_uint in_len; + lzo_uint out_len; + lzo_uint new_len; + long l; + FILE *f; + +/* + * Step 1: open the input file + */ + f = fopen(in_name,"rb"); + if (f == 0) + { + printf("%s: cannot open file %s\n", progname, in_name); + return 0; /* no error */ + } + fseek(f,0,SEEK_END); + l = ftell(f); + fseek(f,0,SEEK_SET); + if (l <= 0) + { + printf("%s: %s: empty file -- skipping\n", progname, in_name); + fclose(f); + return 0; + } + in_len = (lzo_uint) l; + +/* + * Step 2: allocate compression buffers and read the file + */ + in = (lzo_bytep) lzo_malloc(in_len); + out = (lzo_bytep) lzo_malloc(in_len + in_len / 16 + 64 + 3); + newb = (lzo_bytep) lzo_malloc(in_len); + wrkmem = (lzo_bytep) lzo_malloc(LZO1X_999_MEM_COMPRESS); + if (in == NULL || out == NULL || newb == NULL || wrkmem == NULL) + { + printf("%s: out of memory\n", progname); + exit(1); + } + in_len = (lzo_uint) lzo_fread(f,in,in_len); + fclose(f); + +/* + * Step 3: compress from `in' to `out' with LZO1X-999 + */ + r = lzo1x_999_compress_level(in,in_len,out,&out_len,wrkmem, + dict, dict_len, 0, level); + if (r != LZO_E_OK) + { + /* this should NEVER happen */ + printf("internal error - compression failed: %d\n", r); + return 1; + } + + print_file(in_name,in_len,out_len); + +/* + * Step 4: decompress again, now going from `out' to `newb' + */ + new_len = in_len; + r = lzo1x_decompress_dict_safe(out,out_len,newb,&new_len,NULL,dict,dict_len); + if (r != LZO_E_OK) + { + /* this should NEVER happen */ + printf("internal error - decompression failed: %d\n", r); + return 1; + } + +/* + * Step 5: verify decompression + */ + if (new_len != in_len || lzo_memcmp(in,newb,in_len) != 0) + { + /* this should NEVER happen */ + printf("internal error - decompression data error\n"); + return 1; + } + + /* free buffers in reverse order to help malloc() */ + lzo_free(wrkmem); + lzo_free(newb); + lzo_free(out); + lzo_free(in); + return 0; +} + + +/************************************************************************* +// +**************************************************************************/ + +int __lzo_cdecl_main main(int argc, char *argv[]) +{ + int i = 1; + int r; + const char *dict_name; + FILE *f; + time_t t_total; + int level = 7; + + lzo_wildargv(&argc, &argv); + + printf("\nLZO real-time data compression library (v%s, %s).\n", + lzo_version_string(), lzo_version_date()); + printf("Copyright (C) 1996-2008 Markus Franz Xaver Johannes Oberhumer\nAll Rights Reserved.\n\n"); + + progname = argv[0]; + + if (i < argc && argv[i][0] == '-' && isdigit(argv[i][1])) + level = atoi(&argv[i++][1]); + + if (i + 1 >= argc || level < 1 || level > 9) + { + printf("usage: %s [-level] [ dictionary-file | -n ] file...\n", progname); + exit(1); + } + printf("Compression level is LZO1X-999/%d\n", level); + +/* + * Step 1: initialize the LZO library + */ + if (lzo_init() != LZO_E_OK) + { + printf("internal error - lzo_init() failed !!!\n"); + printf("(this usually indicates a compiler bug - try recompiling\nwithout optimizations, and enable `-DLZO_DEBUG' for diagnostics)\n"); + exit(1); + } + +/* + * Step 2: prepare the dictionary + */ + dict = (lzo_bytep) lzo_malloc(DICT_LEN); + if (dict == NULL) + { + printf("%s: out of memory\n", progname); + exit(1); + } + dict_name = argv[i++]; + if (strcmp(dict_name,"-n") == 0) + { + dict_name = "empty"; + dict_len = 0; + } + else + { + f = fopen(dict_name,"rb"); + if (!f) + { + printf("%s: cannot open dictionary file %s\n", progname, dict_name); + exit(1); + } + dict_len = (lzo_uint) lzo_fread(f,dict,DICT_LEN); + fclose(f); + } + + dict_adler32 = lzo_adler32(0,NULL,0); + dict_adler32 = lzo_adler32(dict_adler32,dict,dict_len); + printf("Using dictionary '%s', %ld bytes, ID 0x%08lx.\n", + dict_name, (long) dict_len, (long) dict_adler32); + +/* + * Step 3: process files + */ + t_total = time(NULL); + for (r = 0; r == 0 && i < argc; i++) + r = do_file(argv[i], level); + t_total = time(NULL) - t_total; + + lzo_free(dict); + + if (total_n > 1) + print_file("***TOTALS***",total_d_len,total_c_len); + + printf("Dictionary compression test %s, execution time %lu seconds.\n", + r == 0 ? "passed" : "FAILED", (unsigned long) t_total); + return r; +} + +/* +vi:ts=4:et +*/ + |