pd.if.org Git - zpackage/blob - lib/uncompress.c

   1 #include <stdio.h>
   2 #include <sys/types.h>
   3 #include <sys/stat.h>
   4 #include <fcntl.h>
   5 #include <unistd.h>
   6 #include <errno.h>
   7
   8 #include <sys/mman.h>
   9
  10 #include <sqlite3.h>
  11
  12 #include "sha256.h"
  13
  14 #include "lzma.h"
  15
  16 void uncompresslzma(void *buf, size_t bufsize, FILE *out) {
  17         lzma_stream s = LZMA_STREAM_INIT;
  18         lzma_stream *strm;
  19
  20         uint8_t outbuf[BUFSIZ];
  21
  22         int ret;
  23
  24         strm = &s;
  25
  26         ret = lzma_stream_decoder(strm, UINT64_MAX, 0);
  27         /* The only reasonable error here is LZMA_MEM_ERROR. */
  28         if (ret != LZMA_OK) {
  29                 fprintf(stderr, "%s", ret == LZMA_MEM_ERROR ? strerror(ENOMEM)
  30                                 : "Internal error (bug)");
  31                 exit(EXIT_FAILURE);
  32         }
  33
  34         strm->avail_in = bufsize;
  35         strm->next_in = buf;
  36         strm->avail_out = BUFSIZ;
  37         strm->next_out = outbuf;
  38
  39         lzma_action action = LZMA_RUN;
  40
  41         while (1) {
  42                 ret = lzma_code(strm, action);
  43
  44                 // Write and check write error before checking decoder error.
  45                 // This way as much data as possible gets written to output
  46                 // even if decoder detected an error.
  47                 if (strm->avail_out == 0 || ret != LZMA_OK) {
  48                         const size_t write_size = BUFSIZ - strm->avail_out;
  49
  50                         if (fwrite(outbuf, 1, write_size, out) != write_size) {
  51                                 // Wouldn't be a surprise if writing to stderr
  52                                 // would fail too but at least try to show an
  53                                 // error message.
  54                                 fprintf(stderr, "Cannot write to output file stream: "
  55                                                 "%s", strerror(errno));
  56                                 exit(EXIT_FAILURE);
  57                         }
  58
  59                         strm->next_out = outbuf;
  60                         strm->avail_out = BUFSIZ;
  61                 }
  62
  63                 if (ret != LZMA_OK) {
  64                         if (ret == LZMA_STREAM_END) {
  65                                 // lzma_stream_decoder() already guarantees
  66                                 // that there's no trailing garbage.
  67                                 assert(strm->avail_in == 0);
  68                                 //assert(action == LZMA_FINISH);
  69                                 return;
  70                         }
  71
  72                         const char *msg;
  73                         switch (ret) {
  74                                 case LZMA_MEM_ERROR:
  75                                         msg = strerror(ENOMEM);
  76                                         break;
  77
  78                                 case LZMA_FORMAT_ERROR:
  79                                         msg = "File format not recognized";
  80                                         break;
  81
  82                                 case LZMA_OPTIONS_ERROR:
  83                                         // FIXME: Better message?
  84                                         msg = "Unsupported compression options";
  85                                         break;
  86
  87                                 case LZMA_DATA_ERROR:
  88                                         msg = "File is corrupt";
  89                                         break;
  90
  91                                 case LZMA_BUF_ERROR:
  92                                         msg = "Unexpected end of input";
  93                                         break;
  94
  95                                 default:
  96                                         msg = "Internal error (bug)";
  97                                         break;
  98                         }
  99
 100                         fprintf(stderr, "xz: %s\n", msg);
 101                         exit(EXIT_FAILURE);
 102                 }
 103         }
 104 }