summaryrefslogtreecommitdiffstats
path: root/programs/lz4io.c
blob: 34d24bf3821f47a741ec46e67604acab713494a3 (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
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
/*
  LZ4io.c - LZ4 File/Stream Interface
  Copyright (C) Yann Collet 2011-2015

  GPL v2 License

  This program 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.

  This program 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 this program; if not, write to the Free Software Foundation, Inc.,
  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

  You can contact the author at :
  - LZ4 source repository : https://github.com/Cyan4973/lz4
  - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
*/
/*
  Note : this is stand-alone program.
  It is not part of LZ4 compression library, it is a user code of the LZ4 library.
  - The license of LZ4 library is BSD.
  - The license of xxHash library is BSD.
  - The license of this source file is GPLv2.
*/

/**************************************
*  Compiler Options
**************************************/
#ifdef _MSC_VER    /* Visual Studio */
#  define _CRT_SECURE_NO_WARNINGS
#  define _CRT_SECURE_NO_DEPRECATE     /* VS2005 */
#  pragma warning(disable : 4127)      /* disable: C4127: conditional expression is constant */
#endif

#define _LARGE_FILES           /* Large file support on 32-bits AIX */
#define _FILE_OFFSET_BITS 64   /* Large file support on 32-bits unix */


/*****************************
*  Includes
*****************************/
#include <stdio.h>     /* fprintf, fopen, fread, stdin, stdout */
#include <stdlib.h>    /* malloc, free */
#include <string.h>    /* strcmp, strlen */
#include <time.h>      /* clock */
#include <sys/types.h> /* stat64 */
#include <sys/stat.h>  /* stat64 */
#include "lz4io.h"
#include "lz4.h"      /* still required for legacy format */
#include "lz4hc.h"    /* still required for legacy format */
#include "lz4frame.h"


/******************************
*  OS-specific Includes
******************************/
#if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(_WIN32) || defined(__CYGWIN__)
#  include <fcntl.h>   /* _O_BINARY */
#  include <io.h>      /* _setmode, _fileno, _get_osfhandle */
#  define SET_BINARY_MODE(file) _setmode(_fileno(file), _O_BINARY)
#  include <Windows.h> /* DeviceIoControl, HANDLE, FSCTL_SET_SPARSE */
#  define SET_SPARSE_FILE_MODE(file) { DWORD dw; DeviceIoControl((HANDLE) _get_osfhandle(_fileno(file)), FSCTL_SET_SPARSE, 0, 0, 0, 0, &dw, 0); }
#  if defined(_MSC_VER) && (_MSC_VER >= 1400)  /* Avoid MSVC fseek()'s 2GiB barrier */
#    define fseek _fseeki64
#  endif
#else
#  define SET_BINARY_MODE(file)
#  define SET_SPARSE_FILE_MODE(file)
#endif


/*****************************
*  Constants
*****************************/
#define KB *(1 <<10)
#define MB *(1 <<20)
#define GB *(1U<<30)

#define _1BIT  0x01
#define _2BITS 0x03
#define _3BITS 0x07
#define _4BITS 0x0F
#define _8BITS 0xFF

#define MAGICNUMBER_SIZE    4
#define LZ4IO_MAGICNUMBER   0x184D2204
#define LZ4IO_SKIPPABLE0    0x184D2A50
#define LZ4IO_SKIPPABLEMASK 0xFFFFFFF0
#define LEGACY_MAGICNUMBER  0x184C2102

#define CACHELINE 64
#define LEGACY_BLOCKSIZE   (8 MB)
#define MIN_STREAM_BUFSIZE (192 KB)
#define LZ4IO_BLOCKSIZEID_DEFAULT 7

#define sizeT sizeof(size_t)
#define maskT (sizeT - 1)


/**************************************
*  Macros
**************************************/
#define DISPLAY(...)         fprintf(stderr, __VA_ARGS__)
#define DISPLAYLEVEL(l, ...) if (g_displayLevel>=l) { DISPLAY(__VA_ARGS__); }
static int g_displayLevel = 0;   /* 0 : no display  ; 1: errors  ; 2 : + result + interaction + warnings ; 3 : + progression; 4 : + information */

#define DISPLAYUPDATE(l, ...) if (g_displayLevel>=l) { \
            if ((LZ4IO_GetMilliSpan(g_time) > refreshRate) || (g_displayLevel>=4)) \
            { g_time = clock(); DISPLAY(__VA_ARGS__); \
            if (g_displayLevel>=4) fflush(stdout); } }
static const unsigned refreshRate = 150;
static clock_t g_time = 0;


/**************************************
*  Local Parameters
**************************************/
static int g_overwrite = 1;
static int g_blockSizeId = LZ4IO_BLOCKSIZEID_DEFAULT;
static int g_blockChecksum = 0;
static int g_streamChecksum = 1;
static int g_blockIndependence = 1;
static int g_sparseFileSupport = 0;
static int g_contentSizeFlag = 0;

static const int minBlockSizeID = 4;
static const int maxBlockSizeID = 7;


/**************************************
*  Exceptions
***************************************/
#define DEBUG 0
#define DEBUGOUTPUT(...) if (DEBUG) DISPLAY(__VA_ARGS__);
#define EXM_THROW(error, ...)                                             \
{                                                                         \
    DEBUGOUTPUT("Error defined at %s, line %i : \n", __FILE__, __LINE__); \
    DISPLAYLEVEL(1, "Error %i : ", error);                                \
    DISPLAYLEVEL(1, __VA_ARGS__);                                         \
    DISPLAYLEVEL(1, "\n");                                                \
    exit(error);                                                          \
}


/**************************************
*  Version modifiers
**************************************/
#define EXTENDED_ARGUMENTS
#define EXTENDED_HELP
#define EXTENDED_FORMAT
#define DEFAULT_DECOMPRESSOR decodeLZ4S


/* ************************************************** */
/* ****************** Parameters ******************** */
/* ************************************************** */

/* Default setting : overwrite = 1; return : overwrite mode (0/1) */
int LZ4IO_setOverwrite(int yes)
{
   g_overwrite = (yes!=0);
   return g_overwrite;
}

/* blockSizeID : valid values : 4-5-6-7 */
int LZ4IO_setBlockSizeID(int bsid)
{
    static const int blockSizeTable[] = { 64 KB, 256 KB, 1 MB, 4 MB };
    if ((bsid < minBlockSizeID) || (bsid > maxBlockSizeID)) return -1;
    g_blockSizeId = bsid;
    return blockSizeTable[g_blockSizeId-minBlockSizeID];
}

int LZ4IO_setBlockMode(LZ4IO_blockMode_t blockMode)
{
    g_blockIndependence = (blockMode == LZ4IO_blockIndependent);
    return g_blockIndependence;
}

/* Default setting : no checksum */
int LZ4IO_setBlockChecksumMode(int xxhash)
{
    g_blockChecksum = (xxhash != 0);
    return g_blockChecksum;
}

/* Default setting : checksum enabled */
int LZ4IO_setStreamChecksumMode(int xxhash)
{
    g_streamChecksum = (xxhash != 0);
    return g_streamChecksum;
}

/* Default setting : 0 (no notification) */
int LZ4IO_setNotificationLevel(int level)
{
    g_displayLevel = level;
    return g_displayLevel;
}

/* Default setting : 0 (disabled) */
int LZ4IO_setSparseFile(int enable)
{
    g_sparseFileSupport = (enable!=0);
    return g_sparseFileSupport;
}

/* Default setting : 0 (disabled) */
int LZ4IO_setContentSize(int enable)
{
    g_contentSizeFlag = (enable!=0);
    return g_contentSizeFlag;
}

static unsigned LZ4IO_GetMilliSpan(clock_t nPrevious)
{
    clock_t nCurrent = clock();
    unsigned nSpan = (unsigned)(((nCurrent - nPrevious) * 1000) / CLOCKS_PER_SEC);
    return nSpan;
}

static unsigned long long LZ4IO_GetFileSize(const char* infilename)
{
    int r;
#if defined(_MSC_VER)
    struct _stat64 statbuf;
    r = _stat64(infilename, &statbuf);
#else
    struct stat statbuf;
    r = stat(infilename, &statbuf);
#endif
    if (r || !S_ISREG(statbuf.st_mode)) return 0;   /* No good... */
    return (unsigned long long)statbuf.st_size;
}


/* ************************************************************************ **
** ********************** LZ4 File / Pipe compression ********************* **
** ************************************************************************ */

static int LZ4IO_GetBlockSize_FromBlockId (int id) { return (1 << (8 + (2 * id))); }
static int LZ4IO_isSkippableMagicNumber(unsigned int magic) { return (magic & LZ4IO_SKIPPABLEMASK) == LZ4IO_SKIPPABLE0; }


static int get_fileHandle(const char* input_filename, const char* output_filename, FILE** pfinput, FILE** pfoutput)
{

    if (!strcmp (input_filename, stdinmark))
    {
        DISPLAYLEVEL(4,"Using stdin for input\n");
        *pfinput = stdin;
        SET_BINARY_MODE(stdin);
    }
    else
    {
        *pfinput = fopen(input_filename, "rb");
    }

    if (!strcmp (output_filename, stdoutmark))
    {
        DISPLAYLEVEL(4,"Using stdout for output\n");
        *pfoutput = stdout;
        SET_BINARY_MODE(stdout);
    }
    else
    {
        /* Check if destination file already exists */
        *pfoutput=0;
        if (output_filename != nulmark) *pfoutput = fopen( output_filename, "rb" );
        if (*pfoutput!=0)
        {
            fclose(*pfoutput);
            if (!g_overwrite)
            {
                char ch;
                DISPLAYLEVEL(2, "Warning : %s already exists\n", output_filename);
                DISPLAYLEVEL(2, "Overwrite ? (Y/N) : ");
                if (g_displayLevel <= 1) EXM_THROW(11, "Operation aborted : %s already exists", output_filename);   /* No interaction possible */
                ch = (char)getchar();
                if ((ch!='Y') && (ch!='y')) EXM_THROW(11, "Operation aborted : %s already exists", output_filename);
            }
        }
        *pfoutput = fopen( output_filename, "wb" );
    }

    if ( *pfinput==0 ) EXM_THROW(12, "Pb opening %s", input_filename);
    if ( *pfoutput==0) EXM_THROW(13, "Pb opening %s", output_filename);

    return 0;
}



/***************************************
*   Legacy Compression
***************************************/

/* unoptimized version; solves endianess & alignment issues */
static void LZ4IO_writeLE32 (void* p, unsigned value32)
{
    unsigned char* dstPtr = (unsigned char*)p;
    dstPtr[0] = (unsigned char)value32;
    dstPtr[1] = (unsigned char)(value32 >> 8);
    dstPtr[2] = (unsigned char)(value32 >> 16);
    dstPtr[3] = (unsigned char)(value32 >> 24);
}

/* LZ4IO_compressFilename_Legacy :
 * This function is intentionally "hidden" (not published in .h)
 * It generates compressed streams using the old 'legacy' format */
int LZ4IO_compressFilename_Legacy(const char* input_filename, const char* output_filename, int compressionlevel)
{
    int (*compressionFunction)(const char*, char*, int);
    unsigned long long filesize = 0;
    unsigned long long compressedfilesize = MAGICNUMBER_SIZE;
    char* in_buff;
    char* out_buff;
    FILE* finput;
    FILE* foutput;
    clock_t start, end;
    size_t sizeCheck;


    /* Init */
    start = clock();
    if (compressionlevel < 3) compressionFunction = LZ4_compress; else compressionFunction = LZ4_compressHC;

    get_fileHandle(input_filename, output_filename, &finput, &foutput);
    if ((g_displayLevel==2) && (compressionlevel==1)) g_displayLevel=3;

    /* Allocate Memory */
    in_buff = (char*)malloc(LEGACY_BLOCKSIZE);
    out_buff = (char*)malloc(LZ4_compressBound(LEGACY_BLOCKSIZE));
    if (!in_buff || !out_buff) EXM_THROW(21, "Allocation error : not enough memory");

    /* Write Archive Header */
    LZ4IO_writeLE32(out_buff, LEGACY_MAGICNUMBER);
    sizeCheck = fwrite(out_buff, 1, MAGICNUMBER_SIZE, foutput);
    if (sizeCheck!=MAGICNUMBER_SIZE) EXM_THROW(22, "Write error : cannot write header");

    /* Main Loop */
    while (1)
    {
        unsigned int outSize;
        /* Read Block */
        int inSize = (int) fread(in_buff, (size_t)1, (size_t)LEGACY_BLOCKSIZE, finput);
        if( inSize<=0 ) break;
        filesize += inSize;

        /* Compress Block */
        outSize = compressionFunction(in_buff, out_buff+4, inSize);
        compressedfilesize += outSize+4;
        DISPLAYUPDATE(3, "\rRead : %i MB  ==> %.2f%%   ", (int)(filesize>>20), (double)compressedfilesize/filesize*100);

        /* Write Block */
        LZ4IO_writeLE32(out_buff, outSize);
        sizeCheck = fwrite(out_buff, 1, outSize+4, foutput);
        if (sizeCheck!=(size_t)(outSize+4)) EXM_THROW(23, "Write error : cannot write compressed block");
    }

    /* Status */
    end = clock();
    DISPLAYLEVEL(2, "\r%79s\r", "");
    DISPLAYLEVEL(2,"Compressed %llu bytes into %llu bytes ==> %.2f%%\n",
        (unsigned long long) filesize, (unsigned long long) compressedfilesize, (double)compressedfilesize/filesize*100);
    {
        double seconds = (double)(end - start)/CLOCKS_PER_SEC;
        DISPLAYLEVEL(4,"Done in %.2f s ==> %.2f MB/s\n", seconds, (double)filesize / seconds / 1024 / 1024);
    }

    /* Close & Free */
    free(in_buff);
    free(out_buff);
    fclose(finput);
    fclose(foutput);

    return 0;
}


/*********************************************
*  Compression using Frame format
*********************************************/

int LZ4IO_compressFilename(const char* input_filename, const char* output_filename, int compressionLevel)
{
    unsigned long long filesize = 0;
    unsigned long long compressedfilesize = 0;
    char* in_buff;
    char* out_buff;
    FILE* finput;
    FILE* foutput;
    clock_t start, end;
    int blockSize;
    size_t sizeCheck, headerSize, readSize, outBuffSize;
    LZ4F_compressionContext_t ctx;
    LZ4F_errorCode_t errorCode;
    LZ4F_preferences_t prefs;


    /* Init */
    start = clock();
    memset(&prefs, 0, sizeof(prefs));
    if ((g_displayLevel==2) && (compressionLevel>=3)) g_displayLevel=3;
    errorCode = LZ4F_createCompressionContext(&ctx, LZ4F_VERSION);
    if (LZ4F_isError(errorCode)) EXM_THROW(30, "Allocation error : can't create LZ4F context : %s", LZ4F_getErrorName(errorCode));
    get_fileHandle(input_filename, output_filename, &finput, &foutput);
    blockSize = LZ4IO_GetBlockSize_FromBlockId (g_blockSizeId);

    /* Set compression parameters */
    prefs.autoFlush = 1;
    prefs.compressionLevel = compressionLevel;
    prefs.frameInfo.blockMode = (blockMode_t)g_blockIndependence;
    prefs.frameInfo.blockSizeID = (blockSizeID_t)g_blockSizeId;
    prefs.frameInfo.contentChecksumFlag = (contentChecksum_t)g_streamChecksum;
    if (g_contentSizeFlag)
    {
      unsigned long long fileSize = LZ4IO_GetFileSize(input_filename);
      prefs.frameInfo.contentSize = fileSize;   /* == 0 if input == stdin */
    }

    /* Allocate Memory */
    in_buff  = (char*)malloc(blockSize);
    outBuffSize = LZ4F_compressBound(blockSize, &prefs);
    out_buff = (char*)malloc(outBuffSize);
    if (!in_buff || !out_buff) EXM_THROW(31, "Allocation error : not enough memory");

    /* Write Archive Header */
    headerSize = LZ4F_compressBegin(ctx, out_buff, outBuffSize, &prefs);
    if (LZ4F_isError(headerSize)) EXM_THROW(32, "File header generation failed : %s", LZ4F_getErrorName(headerSize));
    sizeCheck = fwrite(out_buff, 1, headerSize, foutput);
    if (sizeCheck!=headerSize) EXM_THROW(33, "Write error : cannot write header");
    compressedfilesize += headerSize;

    /* read first block */
    readSize = fread(in_buff, (size_t)1, (size_t)blockSize, finput);
    filesize += readSize;

    /* Main Loop */
    while (readSize>0)
    {
        size_t outSize;

        /* Compress Block */
        outSize = LZ4F_compressUpdate(ctx, out_buff, outBuffSize, in_buff, readSize, NULL);
        if (LZ4F_isError(outSize)) EXM_THROW(34, "Compression failed : %s", LZ4F_getErrorName(outSize));
        compressedfilesize += outSize;
        DISPLAYUPDATE(3, "\rRead : %i MB   ==> %.2f%%   ", (int)(filesize>>20), (double)compressedfilesize/filesize*100);

        /* Write Block */
        sizeCheck = fwrite(out_buff, 1, outSize, foutput);
        if (sizeCheck!=outSize) EXM_THROW(35, "Write error : cannot write compressed block");

        /* Read next block */
        readSize = fread(in_buff, (size_t)1, (size_t)blockSize, finput);
        filesize += readSize;
    }

    /* End of Stream mark */
    headerSize = LZ4F_compressEnd(ctx, out_buff, outBuffSize, NULL);
    if (LZ4F_isError(headerSize)) EXM_THROW(36, "End of file generation failed : %s", LZ4F_getErrorName(headerSize));

    sizeCheck = fwrite(out_buff, 1, headerSize, foutput);
    if (sizeCheck!=headerSize) EXM_THROW(37, "Write error : cannot write end of stream");
    compressedfilesize += headerSize;

    /* Close & Free */
    free(in_buff);
    free(out_buff);
    fclose(finput);
    fclose(foutput);
    errorCode = LZ4F_freeCompressionContext(ctx);
    if (LZ4F_isError(errorCode)) EXM_THROW(38, "Error : can't free LZ4F context resource : %s", LZ4F_getErrorName(errorCode));

    /* Final Status */
    end = clock();
    DISPLAYLEVEL(2, "\r%79s\r", "");
    DISPLAYLEVEL(2, "Compressed %llu bytes into %llu bytes ==> %.2f%%\n",
        (unsigned long long) filesize, (unsigned long long) compressedfilesize, (double)compressedfilesize/filesize*100);
    {
        double seconds = (double)(end - start)/CLOCKS_PER_SEC;
        DISPLAYLEVEL(4, "Done in %.2f s ==> %.2f MB/s\n", seconds, (double)filesize / seconds / 1024 / 1024);
    }

    return 0;
}


#define FNSPACE 30
int LZ4IO_compressMultipleFilenames(const char** inFileNamesTable, int ifntSize, const char* suffix, int compressionlevel)
{
    int i;
    char* outFileName = (char*)malloc(FNSPACE);
    size_t ofnSize = FNSPACE;
    const size_t suffixSize = strlen(suffix);

    for (i=0; i<ifntSize; i++)
    {
        size_t ifnSize = strlen(inFileNamesTable[i]);
        if (ofnSize <= ifnSize+suffixSize+1) { free(outFileName); ofnSize = ifnSize + 20; outFileName = (char*)malloc(ofnSize); }
        strcpy(outFileName, inFileNamesTable[i]);
        strcat(outFileName, suffix);
        LZ4IO_compressFilename(inFileNamesTable[i], outFileName, compressionlevel);
    }
    free(outFileName);
    return 0;
}


/* ********************************************************************* */
/* ********************** LZ4 file-stream Decompression **************** */
/* ********************************************************************* */

static unsigned LZ4IO_readLE32 (const void* s)
{
    const unsigned char* srcPtr = (const unsigned char*)s;
    unsigned value32 = srcPtr[0];
    value32 += (srcPtr[1]<<8);
    value32 += (srcPtr[2]<<16);
    value32 += (srcPtr[3]<<24);
    return value32;
}

static unsigned long long decodeLegacyStream(FILE* finput, FILE* foutput)
{
    unsigned long long filesize = 0;
    char* in_buff;
    char* out_buff;

    /* Allocate Memory */
    in_buff = (char*)malloc(LZ4_compressBound(LEGACY_BLOCKSIZE));
    out_buff = (char*)malloc(LEGACY_BLOCKSIZE);
    if (!in_buff || !out_buff) EXM_THROW(51, "Allocation error : not enough memory");

    /* Main Loop */
    while (1)
    {
        int decodeSize;
        size_t sizeCheck;
        unsigned int blockSize;

        /* Block Size */
        sizeCheck = fread(in_buff, 1, 4, finput);
        if (sizeCheck==0) break;                   /* Nothing to read : file read is completed */
        blockSize = LZ4IO_readLE32(in_buff);       /* Convert to Little Endian */
        if (blockSize > LZ4_COMPRESSBOUND(LEGACY_BLOCKSIZE))
        {   /* Cannot read next block : maybe new stream ? */
            fseek(finput, -4, SEEK_CUR);
            break;
        }

        /* Read Block */
        sizeCheck = fread(in_buff, 1, blockSize, finput);
        if (sizeCheck!=blockSize) EXM_THROW(52, "Read error : cannot access compressed block !");

        /* Decode Block */
        decodeSize = LZ4_decompress_safe(in_buff, out_buff, blockSize, LEGACY_BLOCKSIZE);
        if (decodeSize < 0) EXM_THROW(53, "Decoding Failed ! Corrupted input detected !");
        filesize += decodeSize;

        /* Write Block */
        sizeCheck = fwrite(out_buff, 1, decodeSize, foutput);
        if (sizeCheck != (size_t)decodeSize) EXM_THROW(54, "Write error : cannot write decoded block into output\n");
    }

    /* Free */
    free(in_buff);
    free(out_buff);

    return filesize;
}


static unsigned long long decodeLZ4S(FILE* finput, FILE* foutput)
{
    unsigned long long filesize = 0;
    void* inBuff;
    void* outBuff;
#   define HEADERMAX 20
    char  headerBuff[HEADERMAX];
    size_t sizeCheck;
    const size_t inBuffSize = 256 KB;
    const size_t outBuffSize = 256 KB;
    LZ4F_decompressionContext_t ctx;
    LZ4F_errorCode_t errorCode;
    unsigned storedSkips = 0;

    /* init */
    errorCode = LZ4F_createDecompressionContext(&ctx, LZ4F_VERSION);
    if (LZ4F_isError(errorCode)) EXM_THROW(60, "Can't create context : %s", LZ4F_getErrorName(errorCode));
    LZ4IO_writeLE32(headerBuff, LZ4IO_MAGICNUMBER);   /* regenerated here, as it was already read from finput */

    /* Allocate Memory */
    inBuff = malloc(256 KB);
    outBuff = malloc(256 KB);
    if (!inBuff || !outBuff) EXM_THROW(61, "Allocation error : not enough memory");

    /* Init feed with magic number (already consumed from FILE) */
    {
        size_t inSize = 4;
        size_t outSize=0;
        LZ4IO_writeLE32(inBuff, LZ4IO_MAGICNUMBER);
        errorCode = LZ4F_decompress(ctx, outBuff, &outSize, inBuff, &inSize, NULL);
        if (LZ4F_isError(errorCode)) EXM_THROW(62, "Header error : %s", LZ4F_getErrorName(errorCode));
    }


    /* Main Loop */
    for (;;)
    {
        size_t readSize;
        size_t pos = 0;

        /* Read input */
        readSize = fread(inBuff, 1, inBuffSize, finput);
        if (!readSize) break;   /* empty file or stream */

        while (pos < readSize)
        {
            /* Decode Input (at least partially) */
            size_t remaining = readSize - pos;
            size_t decodedBytes = outBuffSize;
            errorCode = LZ4F_decompress(ctx, outBuff, &decodedBytes, (char*)inBuff+pos, &remaining, NULL);
            if (LZ4F_isError(errorCode)) EXM_THROW(66, "Decompression error : %s", LZ4F_getErrorName(errorCode));
            pos += remaining;

            if (decodedBytes)
            {
                /* Write Block */
                filesize += decodedBytes;
                if (g_sparseFileSupport)
                {
                    size_t* const oBuffStartT = (size_t*)outBuff;   /* since outBuff is malloc'ed, it's aligned on size_t */
                    size_t* oBuffPosT = oBuffStartT;
                    size_t  oBuffSizeT = decodedBytes / sizeT;
                    size_t* const oBuffEndT = oBuffStartT + oBuffSizeT;
                    static const size_t bs0T = (32 KB) / sizeT;
                    while (oBuffPosT < oBuffEndT)
                    {
                        size_t seg0SizeT = bs0T;
                        size_t nb0T;
                        int seekResult;
                        if (seg0SizeT > oBuffSizeT) seg0SizeT = oBuffSizeT;
                        oBuffSizeT -= seg0SizeT;
                        for (nb0T=0; (nb0T < seg0SizeT) && (oBuffPosT[nb0T] == 0); nb0T++) ;
                        storedSkips += (unsigned)(nb0T * sizeT);
                        if (storedSkips > 1 GB)   /* avoid int overflow */
                        {
                            seekResult = fseek(foutput, 1 GB, SEEK_CUR);
                            if (seekResult != 0) EXM_THROW(68, "1 GB skip error (sparse file)");
                            storedSkips -= 1 GB;
                        }
                        if (nb0T != seg0SizeT)   /* not all 0s */
                        {
                            seekResult = fseek(foutput, storedSkips, SEEK_CUR);
                            if (seekResult) EXM_THROW(68, "Skip error (sparse file)");
                            storedSkips = 0;
                            seg0SizeT -= nb0T;
                            oBuffPosT += nb0T;
                            sizeCheck = fwrite(oBuffPosT, sizeT, seg0SizeT, foutput);
                            if (sizeCheck != seg0SizeT) EXM_THROW(68, "Write error : cannot write decoded block");
                        }
                        oBuffPosT += seg0SizeT;
                    }
                    if (decodedBytes & maskT)   /* size not multiple of sizeT (necessarily end of block) */
                    {
                        const char* const restStart = (char*)oBuffEndT;
                        const char* restPtr = restStart;
                        size_t  restSize =  decodedBytes & maskT;
                        const char* const restEnd = restStart + restSize;
                        for (; (restPtr < restEnd) && (*restPtr == 0); restPtr++) ;
                        storedSkips += (unsigned) (restPtr - restStart);
                        if (restPtr != restEnd)
                        {
                            int seekResult = fseek(foutput, storedSkips, SEEK_CUR);
                            if (seekResult) EXM_THROW(68, "Skip error (end of block)");
                            storedSkips = 0;
                            sizeCheck = fwrite(restPtr, 1, restEnd - restPtr, foutput);
                            if (sizeCheck != (size_t)(restEnd - restPtr)) EXM_THROW(68, "Write error : cannot write decoded end of block");
                        }
                    }
                }
                else
                {
                    sizeCheck = fwrite(outBuff, 1, decodedBytes, foutput);
                    if (sizeCheck != decodedBytes) EXM_THROW(68, "Write error : cannot write decoded block");
                }
            }
        }

    }

    if ((g_sparseFileSupport) && (storedSkips>0))
    {
        int seekResult;
        storedSkips --;
        seekResult = fseek(foutput, storedSkips, SEEK_CUR);
        if (seekResult != 0) EXM_THROW(69, "Final skip error (sparse file)\n");
        memset(outBuff, 0, 1);
        sizeCheck = fwrite(outBuff, 1, 1, foutput);
        if (sizeCheck != 1) EXM_THROW(69, "Write error : cannot write last zero\n");
    }

    /* Free */
    free(inBuff);
    free(outBuff);
    errorCode = LZ4F_freeDecompressionContext(ctx);
    if (LZ4F_isError(errorCode)) EXM_THROW(69, "Error : can't free LZ4F context resource : %s", LZ4F_getErrorName(errorCode));

    return filesize;
}


static unsigned long long LZ4IO_passThrough(FILE* finput, FILE* foutput, unsigned char U32store[MAGICNUMBER_SIZE])
{
    void* buffer = malloc(64 KB);
    size_t read = 1, sizeCheck;
    unsigned long long total = MAGICNUMBER_SIZE;

    sizeCheck = fwrite(U32store, 1, MAGICNUMBER_SIZE, foutput);
    if (sizeCheck != MAGICNUMBER_SIZE) EXM_THROW(50, "Pass-through error at start");

    while (read)
    {
        read = fread(buffer, 1, 64 KB, finput);
        total += read;
        sizeCheck = fwrite(buffer, 1, read, foutput);
        if (sizeCheck != read) EXM_THROW(50, "Pass-through error");
    }

    free(buffer);
    return total;
}


#define ENDOFSTREAM ((unsigned long long)-1)
static unsigned long long selectDecoder( FILE* finput,  FILE* foutput)
{
    unsigned char U32store[MAGICNUMBER_SIZE];
    unsigned magicNumber, size;
    int errorNb;
    size_t nbReadBytes;
    static unsigned nbCalls = 0;

    /* init */
    nbCalls++;

    /* Check Archive Header */
    nbReadBytes = fread(U32store, 1, MAGICNUMBER_SIZE, finput);
    if (nbReadBytes==0) return ENDOFSTREAM;                  /* EOF */
    if (nbReadBytes != MAGICNUMBER_SIZE) EXM_THROW(40, "Unrecognized header : Magic Number unreadable");
    magicNumber = LZ4IO_readLE32(U32store);   /* Little Endian format */
    if (LZ4IO_isSkippableMagicNumber(magicNumber)) magicNumber = LZ4IO_SKIPPABLE0;  /* fold skippable magic numbers */

    switch(magicNumber)
    {
    case LZ4IO_MAGICNUMBER:
        return DEFAULT_DECOMPRESSOR(finput, foutput);
    case LEGACY_MAGICNUMBER:
        DISPLAYLEVEL(4, "Detected : Legacy format \n");
        return decodeLegacyStream(finput, foutput);
    case LZ4IO_SKIPPABLE0:
        DISPLAYLEVEL(4, "Skipping detected skippable area \n");
        nbReadBytes = fread(U32store, 1, 4, finput);
        if (nbReadBytes != 4) EXM_THROW(42, "Stream error : skippable size unreadable");
        size = LZ4IO_readLE32(U32store);     /* Little Endian format */
        errorNb = fseek(finput, size, SEEK_CUR);
        if (errorNb != 0) EXM_THROW(43, "Stream error : cannot skip skippable area");
        return selectDecoder(finput, foutput);
    EXTENDED_FORMAT;
    default:
        if (nbCalls == 1)   /* just started */
        {
            if (g_overwrite)
                return LZ4IO_passThrough(finput, foutput, U32store);
            EXM_THROW(44,"Unrecognized header : file cannot be decoded");   /* Wrong magic number at the beginning of 1st stream */
        }
        DISPLAYLEVEL(2, "Stream followed by unrecognized data\n");
        return ENDOFSTREAM;
    }
}


int LZ4IO_decompressFilename(const char* input_filename, const char* output_filename)
{
    unsigned long long filesize = 0, decodedSize=0;
    FILE* finput;
    FILE* foutput;
    clock_t start, end;


    /* Init */
    start = clock();
    get_fileHandle(input_filename, output_filename, &finput, &foutput);

    /* sparse file */
    if (g_sparseFileSupport && foutput) { SET_SPARSE_FILE_MODE(foutput); }

    /* Loop over multiple streams */
    do
    {
        decodedSize = selectDecoder(finput, foutput);
        if (decodedSize != ENDOFSTREAM)
            filesize += decodedSize;
    } while (decodedSize != ENDOFSTREAM);

    /* Final Status */
    end = clock();
    DISPLAYLEVEL(2, "\r%79s\r", "");
    DISPLAYLEVEL(2, "Successfully decoded %llu bytes \n", filesize);
    {
        double seconds = (double)(end - start)/CLOCKS_PER_SEC;
        DISPLAYLEVEL(4, "Done in %.2f s ==> %.2f MB/s\n", seconds, (double)filesize / seconds / 1024 / 1024);
    }

    /* Close */
    fclose(finput);
    fclose(foutput);

    /*  Error status = OK */
    return 0;
}