v / vlib / compress / zlib / interop / zlib_ref.c
150 lines · 147 sloc · 3.27 KB · 83fd036a98cc7d2e91992898416169f47329240f
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1#include <stdio.h>


2#include <stdlib.h>


3#include <string.h>


4#include <zlib.h>


5


6static int rf(const char* p, unsigned char** o, size_t* n)


7{


8    FILE* f = fopen(p, "rb");


9    if (!f) return 1;


10    if (fseek(f, 0, SEEK_END) != 0)


11    {


12        fclose(f);


13        return 1;


14    }


15    long s = ftell(f);


16    if (s < 0)


17    {


18        fclose(f);


19        return 1;


20    }


21    if (fseek(f, 0, SEEK_SET) != 0)


22    {


23        fclose(f);


24        return 1;


25    }


26    *n = (size_t)s;


27    *o = *n ? (unsigned char*)malloc(*n) : NULL;


28    if (*n && !*o)


29    {


30        fclose(f);


31        return 1;


32    }


33    if (*n && fread(*o, 1, *n, f) != *n)


34    {


35        free(*o);


36        fclose(f);


37        return 1;


38    }


39    fclose(f);


40    return 0;


41}


42


43static int wf(const char* p, const unsigned char* b, size_t n)


44{


45    FILE* f = fopen(p, "wb");


46    if (!f) return 1;


47    if (n && fwrite(b, 1, n, f) != n)


48    {


49        fclose(f);


50        return 1;


51    }


52    fclose(f);


53    return 0;


54}


55


56int main(int argc, char** argv)


57{


58    static const unsigned char dummy = 0;


59    if (argc != 4)


60    {


61        fputs("usage: zlib_ref compress|decompress in out\n", stderr);


62        return 2;


63    }


64    unsigned char* in = NULL;


65    size_t in_n = 0;


66    if (rf(argv[2], &in, &in_n))


67    {


68        fputs("read error\n", stderr);


69        return 1;


70    }


71    const unsigned char* in_ptr = in_n ? in : &dummy;


72    if (strcmp(argv[1], "compress") == 0)


73    {


74        uLongf out_n = compressBound((uLong)in_n);


75        unsigned char* out = (unsigned char*)malloc(out_n ? out_n : 1);


76        if (!out)


77        {


78            free(in);


79            return 1;


80        }


81        if (compress2(out, &out_n, in_ptr, (uLong)in_n, Z_DEFAULT_COMPRESSION) != Z_OK)


82        {


83            fputs("compress2 failed\n", stderr);


84            free(in);


85            free(out);


86            return 1;


87        }


88        if (wf(argv[3], out, (size_t)out_n))


89        {


90            fputs("write error\n", stderr);


91            free(in);


92            free(out);


93            return 1;


94        }


95        free(out);


96    }


97    else if (strcmp(argv[1], "decompress") == 0)


98    {


99        uLongf out_n = in_n * 8 + 64;


100        if (out_n < 256) out_n = 256;


101        unsigned char* out = NULL;


102        int rc = Z_BUF_ERROR;


103        while (rc == Z_BUF_ERROR)


104        {


105            unsigned char* next = (unsigned char*)realloc(out, out_n);


106            if (!next)


107            {


108                free(in);


109                free(out);


110                return 1;


111            }


112            out = next;


113            uLongf cap = out_n;


114            rc = uncompress(out, &cap, in_ptr, (uLong)in_n);


115            if (rc == Z_OK)


116            {


117                out_n = cap;


118                break;


119            }


120            if (rc == Z_BUF_ERROR)


121            {


122                out_n *= 2;


123                if (out_n < 256) out_n = 256;


124            }


125        }


126        if (rc != Z_OK)


127        {


128            fputs("uncompress failed\n", stderr);


129            free(in);


130            free(out);


131            return 1;


132        }


133        if (wf(argv[3], out, (size_t)out_n))


134        {


135            fputs("write error\n", stderr);


136            free(in);


137            free(out);


138            return 1;


139        }


140        free(out);


141    }


142    else


143    {


144        fputs("unknown mode\n", stderr);


145        free(in);


146        return 2;


147    }


148    free(in);


149    return 0;


150}


151