modules/autocad.c

   1 // This file is part of Deark.
   2 // Copyright (C) 2017 Jason Summers
   3 // See the file COPYING for terms of use.
   4
   5 // AutoCAD Slide Library (.slb)
   6
   7 #include <deark-config.h>
   8 #include <deark-private.h>
   9 DE_DECLARE_MODULE(de_module_autocad_slb);
  10
  11 static void de_run_autocad_slb(deark *c, de_module_params *mparams)
  12 {
  13         i64 pos;
  14         i64 nslides = 0;
  15         i64 k;
  16         struct slideinfo {
  17                 i64 pos;
  18                 i64 len;
  19         };
  20         i64 si_numalloc;
  21         struct slideinfo *si = NULL;
  22         de_ucstring *slidename = NULL;
  23
  24         de_dbg(c, "[pass 1: recording addresses]");
  25         si_numalloc = 64;
  26         si = de_mallocarray(c, si_numalloc, sizeof(struct slideinfo));
  27         pos = 32;
  28         while(1) {
  29                 i64 k;
  30
  31                 if(pos > (c->infile->len-36)) {
  32                         de_err(c, "Unterminated directory");
  33                         goto done;
  34                 }
  35                 if(de_getbyte(pos)==0) {
  36                         break;
  37                 }
  38
  39                 k = nslides; // Index of the new slide
  40                 nslides++;
  41
  42                 if(nslides > si_numalloc) {
  43                         i64 old_numalloc, new_numalloc;
  44
  45                         if(!de_good_image_count(c, nslides)) {
  46                                 de_err(c, "Too many slides");
  47                                 goto done;
  48                         }
  49                         old_numalloc = si_numalloc;
  50                         new_numalloc = old_numalloc*2;
  51                         si = de_reallocarray(c, si, old_numalloc, sizeof(struct slideinfo),
  52                                 new_numalloc);
  53                         si_numalloc *= new_numalloc;
  54                 }
  55
  56                 si[k].pos = de_getu32le(pos+32);
  57
  58                 if(si[k].pos > c->infile->len) {
  59                                 de_err(c, "Invalid directory");
  60                                 goto done;
  61                 }
  62                 if(k>0) {
  63                         if(si[k].pos < si[k-1].pos) {
  64                                 de_err(c, "Invalid directory");
  65                                 goto done;
  66                         }
  67                 }
  68
  69                 if(k>0) {
  70                         // Set the previous slide's length.
  71                         si[k-1].len = si[k].pos - si[k-1].pos;
  72                 }
  73                 // Start by assuming this slide ends at the end of the file. If this
  74                 // turns out not to be the last slide, this value will be changed later.
  75                 si[k].len = c->infile->len - si[k].pos;
  76
  77                 pos += 36;
  78         }
  79
  80         de_dbg(c, "[pass 2: extracting slides]");
  81         pos = 32;
  82         slidename = ucstring_create(c);
  83         for(k=0; k<nslides; k++) {
  84                 de_finfo *fi = NULL;
  85
  86                 de_dbg(c, "slide dir entry at %d", (int)pos);
  87                 de_dbg_indent(c, 1);
  88
  89                 ucstring_empty(slidename);
  90                 dbuf_read_to_ucstring(c->infile, pos, 31, slidename,
  91                         DE_CONVFLAG_STOP_AT_NUL, DE_ENCODING_ASCII);
  92
  93                 de_dbg(c, "address: %u", (unsigned int)si[k].pos);
  94                 de_dbg(c, "calculated len: %u", (unsigned int)si[k].len);
  95
  96                 fi = de_finfo_create(c);
  97                 de_finfo_set_name_from_ucstring(c, fi, slidename, 0);
  98                 dbuf_create_file_from_slice(c->infile, si[k].pos, si[k].len, "sld", fi, 0);
  99                 de_finfo_destroy(c, fi);
 100
 101                 de_dbg_indent(c, -1);
 102                 pos += 36;
 103         }
 104
 105 done:
 106         ucstring_destroy(slidename);
 107         de_free(c, si);
 108 }
 109
 110 static int de_identify_autocad_slb(deark *c)
 111 {
 112         if(!dbuf_memcmp(c->infile, 0, "AutoCAD Slide Library 1.0\r\n\x1a", 28))
 113                 return 100;
 114         return 0;
 115 }
 116
 117 void de_module_autocad_slb(deark *c, struct deark_module_info *mi)
 118 {
 119         mi->id = "autocad_slb";
 120         mi->desc = "AutoCAD Slide Library";
 121         mi->run_fn = de_run_autocad_slb;
 122         mi->identify_fn = de_identify_autocad_slb;
 123 }