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Diffstat (limited to 'app/lzo/examples/overlap.c')
| -rw-r--r-- | app/lzo/examples/overlap.c | 322 |
1 files changed, 0 insertions, 322 deletions
diff --git a/app/lzo/examples/overlap.c b/app/lzo/examples/overlap.c deleted file mode 100644 index b2337680..00000000 --- a/app/lzo/examples/overlap.c +++ /dev/null @@ -1,322 +0,0 @@ -/* overlap.c -- example program: overlapping (de)compression - - This file is part of the LZO real-time data compression library. - - Copyright (C) 2011 Markus Franz Xaver Johannes Oberhumer - Copyright (C) 2010 Markus Franz Xaver Johannes Oberhumer - Copyright (C) 2009 Markus Franz Xaver Johannes Oberhumer - 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 do overlapping compression and -// in-place decompression. -// -// Please study LZO.FAQ and simple.c first. -**************************************************************************/ - -#include "lzo/lzoconf.h" -#include "lzo/lzo1x.h" - -/* portability layer */ -static const char *progname = NULL; -#define WANT_LZO_MALLOC 1 -#define WANT_LZO_FREAD 1 -#define WANT_LZO_WILDARGV 1 -#define WANT_XMALLOC 1 -#include "examples/portab.h" - - -/* Overhead (in bytes) for the in-place decompression buffer. - * Most files need only 16 ! - * (try 'overlap -16 file' or even 'overlap -8 file') - * - * Worst case (for files that are compressible by only a few bytes) - * is 'in_len / 16 + 64 + 3'. See step 5a) below. - * - * For overlapping compression '0xbfff + in_len / 16 + 64 + 3' bytes - * will be needed. See step 4a) below. - */ - -static lzo_uint opt_overhead = 0; /* assume worst case */ - - -#if 0 && defined(LZO_USE_ASM) - /* just for testing */ -# include <lzo_asm.h> -# define lzo1x_decompress lzo1x_decompress_asm_fast -#endif - - -static unsigned long total_files = 0; -static unsigned long total_in = 0; - - -/************************************************************************* -// -**************************************************************************/ - -int do_file ( const char *in_name ) -{ - int r; - FILE *fp = NULL; - long l; - - lzo_voidp wrkmem = NULL; - - lzo_bytep in = NULL; - lzo_uint in_len; /* uncompressed length */ - - lzo_bytep out = NULL; - lzo_uint out_len; /* compressed length */ - - lzo_bytep overlap = NULL; - lzo_uint overhead; - lzo_uint offset; - - lzo_uint new_len = 0; - -/* - * Step 1: open the input file - */ - fp = fopen(in_name, "rb"); - if (fp == NULL) - { - printf("%s: %s: cannot open file\n", progname, in_name); - goto next_file; - } - fseek(fp, 0, SEEK_END); - l = ftell(fp); - fseek(fp, 0, SEEK_SET); - if (l <= 0) - { - printf("%s: %s: empty file -- skipping\n", progname, in_name); - goto next_file; - } - in_len = (lzo_uint) l; - -/* - * Step 2: allocate compression buffers and read the file - */ - in = (lzo_bytep) xmalloc(in_len); - out = (lzo_bytep) xmalloc(in_len + in_len / 16 + 64 + 3); - wrkmem = (lzo_voidp) xmalloc(LZO1X_1_MEM_COMPRESS); - in_len = (lzo_uint) lzo_fread(fp, in, in_len); - fclose(fp); fp = NULL; - printf("%s: %s: read %lu bytes\n", progname, in_name, (unsigned long) in_len); - - total_files++; - total_in += (unsigned long) in_len; - -/* - * Step 3: compress from 'in' to 'out' with LZO1X-1 - */ - r = lzo1x_1_compress(in,in_len,out,&out_len,wrkmem); - if (r != LZO_E_OK || out_len > in_len + in_len / 16 + 64 + 3) - { - /* this should NEVER happen */ - printf("internal error - compression failed: %d\n", r); - exit(1); - } - printf("%-26s %8lu -> %8lu\n", "LZO1X-1:", (unsigned long) in_len, (unsigned long) out_len); - - -/***** Step 4: overlapping compression *****/ - -/* - * Step 4a: allocate the 'overlap' buffer for overlapping compression - */ - overhead = in_len > 0xbfff ? 0xbfff : in_len; - overhead += in_len / 16 + 64 + 3; - overlap = (lzo_bytep) xmalloc(in_len + overhead); - -/* - * Step 4b: prepare data in 'overlap' buffer. - * copy uncompressed data at the top of the overlap buffer - */ - /*** offset = in_len + overhead - in_len; ***/ - offset = overhead; - lzo_memcpy(overlap + offset, in, in_len); - -/* - * Step 4c: do an in-place compression within the 'overlap' buffer - */ - r = lzo1x_1_compress(overlap+offset,in_len,overlap,&new_len,wrkmem); - if (r != LZO_E_OK) - { - /* this should NEVER happen */ - printf("overlapping compression failed: %d\n", r); - exit(1); - } - -/* - * Step 4d: verify overlapping compression - */ - if (new_len != out_len || lzo_memcmp(out,overlap,out_len) != 0) - { - /* As compression is non-deterministic there can be a difference - * in the representation of the compressed data (but this usually - * happens very seldom). So we have to verify the overlapping - * compression by doing a temporary decompression. - */ - lzo_uint ll = in_len; - lzo_bytep tmp = (lzo_bytep) xmalloc(ll); - r = lzo1x_decompress_safe(overlap, new_len, tmp, &ll, NULL); - if (r != LZO_E_OK || ll != in_len || lzo_memcmp(in, tmp, ll) != 0) - { - /* this should NEVER happen */ - printf("overlapping compression data error\n"); - exit(1); - } - lzo_free(tmp); - } - - printf("overlapping compression: %8lu -> %8lu overhead: %7lu\n", - (unsigned long) in_len, (unsigned long) new_len, (unsigned long) overhead); - lzo_free(overlap); overlap = NULL; - - -/***** Step 5: overlapping decompression *****/ - -/* - * Step 5a: allocate the 'overlap' buffer for in-place decompression - */ - if (opt_overhead == 0 || out_len >= in_len) - overhead = in_len / 16 + 64 + 3; - else - overhead = opt_overhead; - overlap = (lzo_bytep) xmalloc(in_len + overhead); - -/* - * Step 5b: prepare data in 'overlap' buffer. - * copy compressed data at the top of the overlap buffer - */ - offset = in_len + overhead - out_len; - lzo_memcpy(overlap + offset, out, out_len); - -/* - * Step 5c: do an in-place decompression within the 'overlap' buffer - */ - new_len = in_len; - r = lzo1x_decompress(overlap+offset,out_len,overlap,&new_len,NULL); - if (r != LZO_E_OK) - { - /* this may happen if overhead is too small */ - printf("overlapping decompression failed: %d - increase 'opt_overhead'\n", r); - exit(1); - } - -/* - * Step 5d: verify decompression - */ - if (new_len != in_len || lzo_memcmp(in,overlap,in_len) != 0) - { - /* this may happen if overhead is too small */ - printf("overlapping decompression data error - increase 'opt_overhead'\n"); - exit(1); - } - printf("overlapping decompression: %8lu -> %8lu overhead: %7lu\n", - (unsigned long) out_len, (unsigned long) new_len, (unsigned long) overhead); - lzo_free(overlap); overlap = NULL; - - -next_file: - lzo_free(overlap); - lzo_free(wrkmem); - lzo_free(out); - lzo_free(in); - if (fp) fclose(fp); - - return 0; -} - - -/************************************************************************* -// -**************************************************************************/ - -int __lzo_cdecl_main main(int argc, char *argv[]) -{ - int r; - int i = 1; - - lzo_wildargv(&argc, &argv); - - printf("\nLZO real-time data compression library (v%s, %s).\n", - lzo_version_string(), lzo_version_date()); - printf("Copyright (C) 1996-2011 Markus Franz Xaver Johannes Oberhumer\nAll Rights Reserved.\n\n"); - - progname = argv[0]; - if (i < argc && argv[i][0] == '-') - opt_overhead = atoi(&argv[i++][1]); -#if 1 - if (opt_overhead != 0 && opt_overhead < 8) - { - printf("%s: invalid overhead value %ld\n", progname, (long)opt_overhead); - exit(1); - } -#endif - if (i >= argc) - { - printf("usage: %s [-overhead_in_bytes] file..\n", progname); - exit(1); - } - -/* - * 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: process files - */ - for (r = 0; r == 0 && i < argc; i++) - r = do_file(argv[i]); - - printf("\nDone. Successfully processed %lu bytes in %lu files.\n", - total_in, total_files); - return r; -} - -/* -vi:ts=4:et -*/ - |