pd.if.org Git - zpackage/blob - compress.c

   1 /*
   2  * add a file/files to an sqlite db
   3  * in the 'files' table.
   4  */
   5
   6 #include <stdio.h>
   7 #include <sys/types.h>
   8 #include <sys/stat.h>
   9 #include <fcntl.h>
  10 #include <unistd.h>
  11
  12 #include <sys/mman.h>
  13
  14 #include "lzma.h"
  15
  16 #include "sha256.h"
  17
  18 void *compresslzma(void *buf, size_t bufsize, size_t *len) {
  19         /* xz compress it */
  20         size_t outsize;
  21         void *outbuf;
  22         size_t outlen = 0;
  23
  24         outsize = lzma_stream_buffer_bound(bufsize);
  25         outbuf = malloc(outsize);
  26         /* TODO adjust encoding level for size */
  27         lzma_easy_buffer_encode(6, LZMA_CHECK_CRC64, NULL,
  28                         buf, bufsize,
  29                         outbuf, &outlen, outsize
  30                         );
  31         *len = outlen;
  32         return outbuf;
  33 }
  34
  35 int main(int ac, char **av){
  36         int i, j;
  37
  38         /* insert each file */
  39         for (i = 1; i < ac; i++) {
  40                 int fd;
  41                 void *content;
  42                 struct stat sbuf;
  43                 unsigned char tmp[32];
  44                 char hash[65]; /* hash in hex */
  45                 hash_state md;
  46
  47                 fd = open(av[i], O_RDONLY);
  48                 if (fd == -1) {
  49                         exit(1);
  50                 }
  51                 if (fstat(fd, &sbuf) == -1) {
  52                         exit(1);
  53                 }
  54                 /* not a regular file? */
  55                 if (!S_ISREG(sbuf.st_mode)) {
  56                         exit(1);
  57                 }
  58
  59                 content = mmap(0, sbuf.st_size, PROT_READ,MAP_PRIVATE, fd, 0);
  60                 if (!content) {
  61                         exit(2);
  62                 }
  63
  64                 sha256_init(&md);
  65                 sha256_process(&md, content, sbuf.st_size);
  66                 sha256_done(&md, tmp);
  67                 for (j=0;j<32;j++) {
  68                         sprintf(hash+j*2, "%02x", (unsigned)tmp[j]);
  69                 }
  70                 hash[64] = 0;
  71                 fprintf(stderr, "file %s: %s\n", av[i], hash);
  72
  73                 /* xz compress it */
  74                 size_t outlen = 0;
  75                 FILE *save;
  76                 void *outbuf;
  77
  78                 outbuf = compresslzma(content, sbuf.st_size, &outlen);
  79                 save = fopen("foo.xz", "w");
  80                 fwrite(outbuf, outlen, 1, save);
  81                 fclose(save);
  82                 free(outbuf);
  83
  84                 //Find out the maximum size of the compressed output for single-call compression:
  85 //                      zlib: compressBound()
  86 //                      liblzma: lzma_stream_buffer_bound()
  87
  88 //                      Compressing:
  89 //zlib: compress() or compress2()
  90  //     liblzma: lzma_easy_buffer_encode() or lzma_stream_buffer_encode()
  91
  92   //    Decompressing:
  93 //zlib: uncompress()
  94  //     liblzma: lzma_stream_buffer_decode()
  95
  96   //    See container.h (src/liblzma/api/lzma/container.h in the source tree) for details how to use these functions.
  97
  98                 /* either way we're done with this now */
  99                 munmap(content, sbuf.st_size);
 100         }
 101         return 0;
 102 }