diff options
Diffstat (limited to 'django')
| -rw-r--r-- | django/contrib/gis/db/models/fields.py | 33 |
1 files changed, 17 insertions, 16 deletions
diff --git a/django/contrib/gis/db/models/fields.py b/django/contrib/gis/db/models/fields.py index 4ded5b1b4e..8dc272aaa4 100644 --- a/django/contrib/gis/db/models/fields.py +++ b/django/contrib/gis/db/models/fields.py @@ -1,8 +1,11 @@ +from collections import defaultdict + from django.contrib.gis import forms, gdal from django.contrib.gis.db.models.lookups import ( RasterBandTransform, gis_lookups, ) from django.contrib.gis.db.models.proxy import SpatialProxy +from django.contrib.gis.gdal import SpatialReference from django.contrib.gis.gdal.error import GDALException from django.contrib.gis.geometry.backend import Geometry, GeometryException from django.core.exceptions import ImproperlyConfigured @@ -14,7 +17,7 @@ from django.utils.translation import ugettext_lazy as _ # Local cache of the spatial_ref_sys table, which holds SRID data for each # spatial database alias. This cache exists so that the database isn't queried # for SRID info each time a distance query is constructed. -_srid_cache = {} +_srid_cache = defaultdict(dict) def get_srid_info(srid, connection): @@ -29,21 +32,21 @@ def get_srid_info(srid, connection): # The SpatialRefSys model for the spatial backend. SpatialRefSys = connection.ops.spatial_ref_sys() except NotImplementedError: - # No `spatial_ref_sys` table in spatial backend (e.g., MySQL). - return None, None, None - - if connection.alias not in _srid_cache: - # Initialize SRID dictionary for database if it doesn't exist. - _srid_cache[connection.alias] = {} + SpatialRefSys = None - if srid not in _srid_cache[connection.alias]: - # Use `SpatialRefSys` model to query for spatial reference info. - sr = SpatialRefSys.objects.using(connection.alias).get(srid=srid) - units, units_name = sr.units - spheroid = SpatialRefSys.get_spheroid(sr.wkt) - _srid_cache[connection.alias][srid] = (units, units_name, spheroid) + alias, get_srs = ( + (connection.alias, lambda srid: SpatialRefSys.objects.using(connection.alias).get(srid=srid).srs) + if SpatialRefSys else + (None, SpatialReference) + ) + if srid not in _srid_cache[alias]: + srs = get_srs(srid) + units, units_name = srs.units + sphere_name = srs['spheroid'] + spheroid = 'SPHEROID["%s",%s,%s]' % (sphere_name, srs.semi_major, srs.inverse_flattening) + _srid_cache[alias][srid] = (units, units_name, spheroid) - return _srid_cache[connection.alias][srid] + return _srid_cache[alias][srid] class GeoSelectFormatMixin(object): @@ -149,8 +152,6 @@ class BaseSpatialField(Field): system that uses non-projected units (e.g., latitude/longitude). """ units_name = self.units_name(connection) - # Some backends like MySQL cannot determine units name. In that case, - # test if srid is 4326 (WGS84), even if this is over-simplification. return units_name.lower() in self.geodetic_units if units_name else self.srid == 4326 def get_placeholder(self, value, compiler, connection): |