[GRASS-dev] Re: [GRASS GIS] #1006: r.terraflow fails to stat() stream file on Windows

[GRASS GIS]

#1006: r.terraflow fails to stat() stream file on Windows
------------------------------+---------------------------------------------
  Reporter:  marisn           |       Owner:  grass-dev at lists.osgeo.org
      Type:  defect           |      Status:  new                      
  Priority:  critical         |   Milestone:  6.4.0                    
 Component:  Raster           |     Version:  svn-releasebranch64      
Resolution:                   |    Keywords:  wingrass, r.terraflow    
  Platform:  MSWindows Vista  |         Cpu:  x86-32                   
------------------------------+---------------------------------------------
Comment (by hamish):

 In comment:12, Hamish wrote:
 > > ok, so str->stream_len() is not getting set correctly.
 ...
 > > stream_len() is defined in include/iostream/ami_stream.h (number of
 items in each stream)


 In comment:22, Glynn wrote:
 > A more portable way to determine the length of a file is to use
 fseek(SEEK_END), e.g.:
 {{{
         long save = ftell(fp);
         fseek(fp, 0, SEEK_END);
         long size = ftell(fp);
         fseek(fp, save, SEEK_SET);
         return size;
 }}}


 ok, thanks. how's this:

 (patch vs. 6.5svn)
 {{{
 Index: include/iostream/ami_stream.h
 ===================================================================
 --- include/iostream/ami_stream.h       (revision 41749)
 +++ include/iostream/ami_stream.h       (working copy)
 @@ -351,21 +351,32 @@
  template<class T>
  off_t AMI_STREAM<T>::stream_len(void) {

 +  long posn_save, st_size;
 +
    fflush(fp);

 -  struct stat buf;
 -  if (stat(path, &buf) == -1) {
 -    perror("AMI_STREAM::stream_len(): fstat failed ");
 -       perror(path);
 -    assert(0);
 -    exit(1);
 +  posn_save = ftell(fp);
 +  if(posn_save == -1) {
 +     perror("ERROR: AMI_STREAM::stream_len(): ftell(fp) failed ");
 +     perror(path);
 +     exit(1);
    }

 +  fseek(fp, 0, SEEK_END);
 +  st_size = ftell(fp);
 +  if(st_size == -1) {
 +     perror("ERROR: AMI_STREAM::stream_len(): ftell[SEEK_END] failed ");
 +     perror(path);
 +     exit(1);
 +  }
 +
 +  fseek(fp, posn_save, SEEK_SET);
 +
    //DEBUG:
    fprintf(stderr, "%s: length = %lld   sizeof(T)=%d\n",
 -         path, buf.st_size, sizeof(T));
 +         path, st_size, sizeof(T));

 -  return (buf.st_size / sizeof(T));
 +  return (st_size / sizeof(T));
  };


 }}}


 Hamish

-- 
Ticket URL: <https://trac.osgeo.org/grass/ticket/1006#comment:24>
GRASS GIS <http://grass.osgeo.org>