[geoconcept driver] open gtx file with polyline containing thousands (>5000) coordinates

[ndavid]

The geoconcept drivers can't handle gtx file with object containing huge coordinats list due to the size of the char buffer used for reading line.

struct _GCExportFileH {
  char                  cache[kCacheSize_GCIO+1];
  char*                 path;
  ....
}

#define  kCacheSize_GCIO          65535

if you change this buffer size :

#define  kCacheSize_GCIO          262143

It compile fine and at the execution time the geoemtry line is readed but it leads to strange error on "OGRGeoconceptDataSource::LoadFile" method. More precisely on ligne 184 of ogrgeoconceptdatasource.cpp

    if( (_hGXT= Open_GCIO(_pszName,_pszExt,pszMode,_pszGCT))==NULL )
    {
      return FALSE;
    }

    /* Collect layers : */
    GCExportFileMetadata* Meta= GetGCMeta_GCIO(_hGXT);
    if( Meta )
    {
      int nC, iC, nS, iS;

      if( (nC= CountMetaTypes_GCIO(Meta))>0 )
      {

the "Open_GCIO(_pszName,_pszExt,pszMode,_pszGCT)" method works and all internal values seems ok, but after the return assigment the hGXT member are no longer correct ( memory seems corrupt). Even with a gtx file with "normal" line size.

[ndavid]

file working with normal char buffer size

[ndavid]

file not working with normal char buffer size

[dgrichard]

I have made the change and run ogrinfo on both files :

$ ogrinfo  -ro test_polyline_2865_coord.gxt
GEOCONCEPT: filename 'test_polyline_2865_coord.gxt' - 'gxt' - mode 'rt' - config path '???'        
GEOCONCEPT: Type 'Stereopolis#-1' added.                                                           
GEOCONCEPT: SubType 'Stereopolis.Trajectoire#-1' added.                                            
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@Identifier#-1' added.                                  
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@Class#-1' added.                                       
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@Subclass#-1' added.                                    
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@Name#-1' added.                                        
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@NbFields#-1' added.                                    
GEOCONCEPT: Field 'Stereopolis.Trajectoire@IDSEL#-1' added.                                        
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@X#-1' added.                                           
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@Y#-1' added.                                           
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@XP#-1' added.                                          
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@YP#-1' added.                                          
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@Graphics#-1' added.                                    
GEOCONCEPT: This SysCoord value: -1:-1 was translated to :                                         
GEOCONCEPT: Feature Type [Trajectoire] starts at #317, line 8                                      

GEOCONCEPT: Metadata = (
  nb Types : 1          
  Charset : ANSI        
  Delimiter : 0x9       
  Unit : m              
  Resolution : 0.1      
  Quoted-Text : no      
  Format : absolute     
  CoordSystemID : -1; TimeZoneValue : -1
)                                       
GEOCONCEPT: Export =(                   
  Path : .                              
  Basename : test_polyline_2865_coord   
  Extension : gxt                       
  Mode : READ                           
  Status : NONE                         
)                                       
GEOCONCEPT: nLayers=1 - last=[Stereopolis.Trajectoire]
OGR: OGROpen(test_polyline_2865_coord.gxt/0x839f600) succeeded as Geoconcept.
INFO: Open of `test_polyline_2865_coord.gxt'                                 
      using driver `Geoconcept' successful.                                  
OGR: GetLayerCount() = 1                                                     

1: Stereopolis.Trajectoire (Line String)
GEOCONCEPT: 1 features on layer Stereopolis.Trajectoire.

then :

ogrinfo -ro test_polyline_5427_coord.gxt
GEOCONCEPT: filename 'test_polyline_5427_coord.gxt' - 'gxt' - mode 'rt' - config path '???'        
GEOCONCEPT: Type 'Stereopolis#-1' added.
GEOCONCEPT: SubType 'Stereopolis.Trajectoire#-1' added.
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@Identifier#-1' added.
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@Class#-1' added.
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@Subclass#-1' added.
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@Name#-1' added.
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@NbFields#-1' added.
GEOCONCEPT: Field 'Stereopolis.Trajectoire@IDSEL#-1' added.
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@X#-1' added.
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@Y#-1' added.
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@XP#-1' added.
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@YP#-1' added.
GEOCONCEPT: Field 'Stereopolis.Trajectoire@@Graphics#-1' added.
GEOCONCEPT: This SysCoord value: -1:-1 was translated to :
GEOCONCEPT: Feature Type [Trajectoire] starts at #317, line 8

GEOCONCEPT: Metadata = (
  nb Types : 1
  Charset : ANSI
  Delimiter : 0x9
  Unit : m
  Resolution : 0.1
  Quoted-Text : no
  Format : absolute
  CoordSystemID : -1; TimeZoneValue : -1
)
GEOCONCEPT: Export =(
  Path : .
  Basename : test_polyline_5427_coord
  Extension : gxt
  Mode : READ
  Status : NONE
)
GEOCONCEPT: nLayers=1 - last=[Stereopolis.Trajectoire]
OGR: OGROpen(test_polyline_5427_coord.gxt/0x82fb600) succeeded as Geoconcept.
INFO: Open of `test_polyline_5427_coord.gxt'
      using driver `Geoconcept' successful.
OGR: GetLayerCount() = 1

1: Stereopolis.Trajectoire (Line String)
GEOCONCEPT: 1 features on layer Stereopolis.Trajectoire.

So, for me everything seems ok.

The driver is also working if you add -al to ogrinfo : the Geoconcept file are correctly dumped.

Could you check on your side what is the ogrinfo's behavior ?

[ndavid]

i've checked on my side. everything is ok. I've just need to make clean and remarke all gdal, and not only re-make only the geoconcept drivers. So error is mine.

[Jukka Rahkonen]

Notices 4 years ago that it was not a bug at all.