from ctypes import c_void_p from django.contrib.gis.gdal.base import GDALBase from django.contrib.gis.gdal.error import GDALException from django.contrib.gis.gdal.prototypes import ds as vcapi, raster as rcapi from django.utils.encoding import force_bytes, force_text class Driver(GDALBase): """ Wrap a GDAL/OGR Data Source Driver. For more information, see the C API source code: http://www.gdal.org/gdal_8h.html - http://www.gdal.org/ogr__api_8h.html """ # Case-insensitive aliases for some GDAL/OGR Drivers. # For a complete list of original driver names see # http://www.gdal.org/ogr_formats.html (vector) # http://www.gdal.org/formats_list.html (raster) _alias = { # vector 'esri': 'ESRI Shapefile', 'shp': 'ESRI Shapefile', 'shape': 'ESRI Shapefile', 'tiger': 'TIGER', 'tiger/line': 'TIGER', # raster 'tiff': 'GTiff', 'tif': 'GTiff', 'jpeg': 'JPEG', 'jpg': 'JPEG', } def __init__(self, dr_input): """ Initialize an GDAL/OGR driver on either a string or integer input. """ if isinstance(dr_input, str): # If a string name of the driver was passed in self.ensure_registered() # Checking the alias dictionary (case-insensitive) to see if an # alias exists for the given driver. if dr_input.lower() in self._alias: name = self._alias[dr_input.lower()] else: name = dr_input # Attempting to get the GDAL/OGR driver by the string name. for iface in (vcapi, rcapi): driver = c_void_p(iface.get_driver_by_name(force_bytes(name))) if driver: break elif isinstance(dr_input, int): self.ensure_registered() for iface in (vcapi, rcapi): driver = iface.get_driver(dr_input) if driver: break elif isinstance(dr_input, c_void_p): driver = dr_input else: raise GDALException('Unrecognized input type for GDAL/OGR Driver: %s' % type(dr_input)) # Making sure we get a valid pointer to the OGR Driver if not driver: raise GDALException('Could not initialize GDAL/OGR Driver on input: %s' % dr_input) self.ptr = driver def __str__(self): return self.name @classmethod def ensure_registered(cls): """ Attempt to register all the data source drivers. """ # Only register all if the driver counts are 0 (or else all drivers # will be registered over and over again) if not vcapi.get_driver_count(): vcapi.register_all() if not rcapi.get_driver_count(): rcapi.register_all() @classmethod def driver_count(cls): """ Return the number of GDAL/OGR data source drivers registered. """ return vcapi.get_driver_count() + rcapi.get_driver_count() @property def name(self): """ Return description/name string for this driver. """ return force_text(rcapi.get_driver_description(self.ptr))