summaryrefslogtreecommitdiff
path: root/examples/lzopack.c
blob: 1f7d0e216397c6bf927a0c3417b1409acc96595e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
/* lzopack.c -- LZO example program: a simple file packer

   This file is part of the LZO real-time data compression library.

   Copyright (C) 1996-2014 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/
 */


/*************************************************************************
// NOTE: this is an example program, so do not use to backup your data.
//
// This program lacks things like sophisticated file handling but is
// pretty complete regarding compression - it should provide a good
// starting point for adaption for your applications.
//
// 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"


static unsigned long total_in = 0;
static unsigned long total_out = 0;
static lzo_bool opt_debug = 0;

/* magic file header for lzopack-compressed files */
static const unsigned char magic[7] =
    { 0x00, 0xe9, 0x4c, 0x5a, 0x4f, 0xff, 0x1a };


/*************************************************************************
// file IO
**************************************************************************/

static lzo_uint xread(FILE *fp, lzo_voidp buf, lzo_uint len, lzo_bool allow_eof)
{
    lzo_uint l;

    l = (lzo_uint) lzo_fread(fp, buf, len);
    if (l > len)
    {
        fprintf(stderr, "\n%s: internal error - something is wrong with your C library !!!\n", progname);
        exit(1);
    }
    if (l != len && !allow_eof)
    {
        fprintf(stderr, "\n%s: read error - premature end of file\n", progname);
        exit(1);
    }
    total_in += (unsigned long) l;
    return l;
}

static lzo_uint xwrite(FILE *fp, const lzo_voidp buf, lzo_uint len)
{
    if (fp != NULL && lzo_fwrite(fp, buf, len) != len)
    {
        fprintf(stderr, "\n%s: write error  (disk full ?)\n", progname);
        exit(1);
    }
    total_out += (unsigned long) len;
    return len;
}


static int xgetc(FILE *fp)
{
    unsigned char c;
    xread(fp, (lzo_voidp) &c, 1, 0);
    return c;
}

static void xputc(FILE *fp, int c)
{
    unsigned char cc = (unsigned char) (c & 0xff);
    xwrite(fp, (const lzo_voidp) &cc, 1);
}

/* read and write portable 32-bit integers */

static lzo_uint32_t xread32(FILE *fp)
{
    unsigned char b[4];
    lzo_uint32_t v;

    xread(fp, b, 4, 0);
    v  = (lzo_uint32_t) b[3] <<  0;
    v |= (lzo_uint32_t) b[2] <<  8;
    v |= (lzo_uint32_t) b[1] << 16;
    v |= (lzo_uint32_t) b[0] << 24;
    return v;
}

static void xwrite32(FILE *fp, lzo_uint v)
{
    unsigned char b[4];

    b[3] = (unsigned char) ((v >>  0) & 0xff);
    b[2] = (unsigned char) ((v >>  8) & 0xff);
    b[1] = (unsigned char) ((v >> 16) & 0xff);
    b[0] = (unsigned char) ((v >> 24) & 0xff);
    xwrite(fp, b, 4);
}


/*************************************************************************
// compress
//
// possible improvement: we could use overlapping compression to
//   save some memory - see overlap.c. This would require some minor
//   changes in the decompression code as well, because if a block
//   turns out to be incompressible we would still have to store it in its
//   "compressed" (i.e. then slightly enlarged) form because the original
//   (uncompressed) data would have been lost during the overlapping
//   compression.
**************************************************************************/

static int do_compress(FILE *fi, FILE *fo, int compression_level, lzo_uint block_size)
{
    int r = 0;
    lzo_bytep in = NULL;
    lzo_bytep out = NULL;
    lzo_voidp wrkmem = NULL;
    lzo_uint in_len;
    lzo_uint out_len;
    lzo_uint wrkmem_size;
    lzo_uint32_t flags = 1;     /* do compute a checksum */
    int method = 1;             /* compression method: LZO1X */
    lzo_uint32_t checksum;

    total_in = total_out = 0;

/*
 * Step 1: write magic header, flags & block size, init checksum
 */
    xwrite(fo, magic, sizeof(magic));
    xwrite32(fo, flags);
    xputc(fo, method);              /* compression method */
    xputc(fo, compression_level);   /* compression level */
    xwrite32(fo, block_size);
    checksum = lzo_adler32(0, NULL, 0);

/*
 * Step 2: allocate compression buffers and work-memory
 */
    in = (lzo_bytep) xmalloc(block_size);
    out = (lzo_bytep) xmalloc(block_size + block_size / 16 + 64 + 3);
    if (compression_level == 9)
        wrkmem_size = LZO1X_999_MEM_COMPRESS;
    else
        wrkmem_size = LZO1X_1_MEM_COMPRESS;
    wrkmem = (lzo_voidp) xmalloc(wrkmem_size);
    if (in == NULL || out == NULL || wrkmem == NULL)
    {
        printf("%s: out of memory\n", progname);
        r = 1;
        goto err;
    }

/*
 * Step 3: process blocks
 */
    for (;;)
    {
        /* read block */
        in_len = xread(fi, in, block_size, 1);
        if (in_len == 0)
            break;

        /* update checksum */
        if (flags & 1)
            checksum = lzo_adler32(checksum, in, in_len);

        /* clear wrkmem (not needed, only for debug/benchmark purposes) */
        if (opt_debug)
            lzo_memset(wrkmem, 0xff, wrkmem_size);

        /* compress block */
        if (compression_level == 9)
            r = lzo1x_999_compress(in, in_len, out, &out_len, wrkmem);
        else
            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);
            r = 2;
            goto err;
        }

        /* write uncompressed block size */
        xwrite32(fo, in_len);

        if (out_len < in_len)
        {
            /* write compressed block */
            xwrite32(fo, out_len);
            xwrite(fo, out, out_len);
        }
        else
        {
            /* not compressible - write uncompressed block */
            xwrite32(fo, in_len);
            xwrite(fo, in, in_len);
        }
    }

    /* write EOF marker */
    xwrite32(fo, 0);

    /* write checksum */
    if (flags & 1)
        xwrite32(fo, checksum);

    r = 0;
err:
    lzo_free(wrkmem);
    lzo_free(out);
    lzo_free(in);
    return r;
}


/*************************************************************************
// decompress / test
//
// We are using overlapping (in-place) decompression to save some
// memory - see overlap.c.
**************************************************************************/

static int do_decompress(FILE *fi, FILE *fo)
{
    int r = 0;
    lzo_bytep buf = NULL;
    lzo_uint buf_len;
    unsigned char m [ sizeof(magic) ];
    lzo_uint32_t flags;
    int method;
    int compression_level;
    lzo_uint block_size;
    lzo_uint32_t checksum;

    total_in = total_out = 0;

/*
 * Step 1: check magic header, read flags & block size, init checksum
 */
    if (xread(fi, m, sizeof(magic), 1) != sizeof(magic) ||
        memcmp(m, magic, sizeof(magic)) != 0)
    {
        printf("%s: header error - this file is not compressed by lzopack\n", progname);
        r = 1;
        goto err;
    }
    flags = xread32(fi);
    method = xgetc(fi);
    compression_level = xgetc(fi);
    if (method != 1)
    {
        printf("%s: header error - invalid method %d (level %d)\n",
                progname, method, compression_level);
        r = 2;
        goto err;
    }
    block_size = xread32(fi);
    if (block_size < 1024 || block_size > 8L * 1024L * 1024L)
    {
        printf("%s: header error - invalid block size %ld\n",
                progname, (long) block_size);
        r = 3;
        goto err;
    }
    checksum = lzo_adler32(0, NULL, 0);

/*
 * Step 2: allocate buffer for in-place decompression
 */
    buf_len = block_size + block_size / 16 + 64 + 3;
    buf = (lzo_bytep) xmalloc(buf_len);
    if (buf == NULL)
    {
        printf("%s: out of memory\n", progname);
        r = 4;
        goto err;
    }

/*
 * Step 3: process blocks
 */
    for (;;)
    {
        lzo_bytep in;
        lzo_bytep out;
        lzo_uint in_len;
        lzo_uint out_len;

        /* read uncompressed size */
        out_len = xread32(fi);

        /* exit if last block (EOF marker) */
        if (out_len == 0)
            break;

        /* read compressed size */
        in_len = xread32(fi);

        /* sanity check of the size values */
        if (in_len > block_size || out_len > block_size ||
            in_len == 0 || in_len > out_len)
        {
            printf("%s: block size error - data corrupted\n", progname);
            r = 5;
            goto err;
        }

        /* place compressed block at the top of the buffer */
        in = buf + buf_len - in_len;
        out = buf;

        /* read compressed block data */
        xread(fi, in, in_len, 0);

        if (in_len < out_len)
        {
            /* decompress - use safe decompressor as data might be corrupted
             * during a file transfer */
            lzo_uint new_len = out_len;

            r = lzo1x_decompress_safe(in, in_len, out, &new_len, NULL);
            if (r != LZO_E_OK || new_len != out_len)
            {
                printf("%s: compressed data violation\n", progname);
                r = 6;
                goto err;
            }
            /* write decompressed block */
            xwrite(fo, out, out_len);
            /* update checksum */
            if (flags & 1)
                checksum = lzo_adler32(checksum, out, out_len);
        }
        else
        {
            /* write original (incompressible) block */
            xwrite(fo, in, in_len);
            /* update checksum */
            if (flags & 1)
                checksum = lzo_adler32(checksum, in, in_len);
        }
    }

    /* read and verify checksum */
    if (flags & 1)
    {
        lzo_uint32_t c = xread32(fi);
        if (c != checksum)
        {
            printf("%s: checksum error - data corrupted\n", progname);
            r = 7;
            goto err;
        }
    }

    r = 0;
err:
    lzo_free(buf);
    return r;
}


/*************************************************************************
//
**************************************************************************/

static void usage(void)
{
    printf("usage: %s [-9] input-file output-file  (compress)\n", progname);
    printf("usage: %s -d   input-file output-file  (decompress)\n", progname);
    printf("usage: %s -t   input-file...           (test)\n", progname);
    exit(1);
}


/* open input file */
static FILE *xopen_fi(const char *name)
{
    FILE *fp;

    fp = fopen(name, "rb");
    if (fp == NULL)
    {
        printf("%s: cannot open input file %s\n", progname, name);
        exit(1);
    }
#if defined(HAVE_STAT) && defined(S_ISREG)
    {
        struct stat st;
        int is_regular = 1;
        if (stat(name, &st) != 0 || !S_ISREG(st.st_mode))
            is_regular = 0;
        if (!is_regular)
        {
            printf("%s: %s is not a regular file\n", progname, name);
            fclose(fp); fp = NULL;
            exit(1);
        }
    }
#endif
    return fp;
}


/* open output file */
static FILE *xopen_fo(const char *name)
{
    FILE *fp;

#if 0
    /* this is an example program, so make sure we don't overwrite a file */
    fp = fopen(name, "rb");
    if (fp != NULL)
    {
        printf("%s: file %s already exists -- not overwritten\n", progname, name);
        fclose(fp); fp = NULL;
        exit(1);
    }
#endif
    fp = fopen(name, "wb");
    if (fp == NULL)
    {
        printf("%s: cannot open output file %s\n", progname, name);
        exit(1);
    }
    return fp;
}


/* close file */
static void xclose(FILE *fp)
{
    if (fp)
    {
        int err;
        err = ferror(fp);
        if (fclose(fp) != 0)
            err = 1;
        if (err)
        {
            printf("%s: error while closing file\n", progname);
            exit(1);
        }
    }
}


/*************************************************************************
//
**************************************************************************/

int __lzo_cdecl_main main(int argc, char *argv[])
{
    int i = 1;
    int r = 0;
    FILE *fi = NULL;
    FILE *fo = NULL;
    const char *in_name = NULL;
    const char *out_name = NULL;
    unsigned opt_decompress = 0;
    unsigned opt_test = 0;
    int opt_compression_level = 1;
    lzo_uint opt_block_size;
    const char *s;

    lzo_wildargv(&argc, &argv);

    progname = argv[0];
    for (s = progname; *s; s++)
        if ((*s == '/' || *s == '\\') && s[1])
            progname = s + 1;

    printf("\nLZO real-time data compression library (v%s, %s).\n",
           lzo_version_string(), lzo_version_date());
    printf("Copyright (C) 1996-2014 Markus Franz Xaver Johannes Oberhumer\nAll Rights Reserved.\n\n");

#if 0
    printf(
"*** DISCLAIMER ***\n"
"   This is an example program, do not use to backup your data !\n"
"   Get LZOP if you're interested into a full-featured packer.\n"
"   See http://www.oberhumer.com/opensource/lzop/\n"
"\n");
#endif


/*
 * 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: setup memory
 */
    opt_block_size = 256 * 1024L;

#if defined(LZO_MM_AHSHIFT)
    /* reduce memory requirements for ancient 16-bit DOS 640kB real-mode */
    if (LZO_MM_AHSHIFT != 3)
        opt_block_size = 16 * 1024L;
#endif


/*
 * Step 3: get options
 */

    while (i < argc && argv[i][0] == '-')
    {
        if (strcmp(argv[i],"-d") == 0)
            opt_decompress = 1;
        else if (strcmp(argv[i],"-t") == 0)
            opt_test = 1;
        else if (strcmp(argv[i],"-9") == 0)
            opt_compression_level = 9;
        else if (argv[i][1] == 'b' && argv[i][2])
        {
            long b = atol(&argv[i][2]);
            if (b >= 1024L && b <= 8*1024*1024L)
                opt_block_size = (lzo_uint) b;
            else
            {
                printf("%s: invalid block_size in option '%s'.\n", progname, argv[i]);
                usage();
            }
        }
        else if (strcmp(argv[i],"--debug") == 0)
            opt_debug += 1;
        else
            usage();
        i++;
    }
    if (opt_test && i >= argc)
        usage();
    if (!opt_test && i + 2 != argc)
        usage();


/*
 * Step 4: process file(s)
 */

    if (opt_test)
    {
        while (i < argc && r == 0)
        {
            in_name = argv[i++];
            fi = xopen_fi(in_name);
            r = do_decompress(fi, NULL);
            if (r == 0)
                printf("%s: %s tested ok (%lu -> %lu bytes)\n",
                        progname, in_name, total_in, total_out);
            xclose(fi); fi = NULL;
        }
    }
    else if (opt_decompress)
    {
        in_name = argv[i++];
        out_name = argv[i++];
        fi = xopen_fi(in_name);
        fo = xopen_fo(out_name);
        r = do_decompress(fi, fo);
        if (r == 0)
            printf("%s: decompressed %lu into %lu bytes\n",
                    progname, total_in, total_out);
    }
    else /* compress */
    {
        in_name = argv[i++];
        out_name = argv[i++];
        fi = xopen_fi(in_name);
        fo = xopen_fo(out_name);
        r = do_compress(fi, fo, opt_compression_level, opt_block_size);
        if (r == 0)
            printf("%s: compressed %lu into %lu bytes\n",
                    progname, total_in, total_out);
    }

    xclose(fi); fi = NULL;
    xclose(fo); fo = NULL;
    return r;
}


/* vim:set ts=4 sw=4 et: */