Added an SRID_CACHE to GeoDjango db/models/fields/__init__.py so that we only hit the spatial_ref_sys table once per SRID per process

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10488 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 7 insertions, 1 deletions

diff --git a/django/contrib/gis/db/models/fields/__init__.py b/django/contrib/gis/db/models/fields/__init__.py
index d4ec8a2fc9..b108c16b00 100644
--- a/django/contrib/gis/db/models/fields/__init__.py
+++ b/django/contrib/gis/db/models/fields/__init__.py
@@ -13,6 +13,10 @@ def deprecated_property(func):
     warn('This attribute has been deprecated, please use "%s" instead.' % func.__name__[1:])
     return property(func)
 
+# Local cache of the spatial_ref_sys table, which holds static data.
+# This exists so that we don't have to hit the database each time.
+SRID_CACHE = {}
+
 class GeometryField(SpatialBackend.Field):
     "The base GIS field -- maps to the OpenGIS Specification Geometry type."
 
@@ -60,7 +64,9 @@ class GeometryField(SpatialBackend.Field):
         super(GeometryField, self).__init__(**kwargs) # Calling the parent initializtion function
 
     def _populate_srid_info(self):
-        self._units_cache, self._units_name_cache, self._spheroid_cache = get_srid_info(self.srid)
+        if self.srid not in SRID_CACHE:
+            SRID_CACHE[self.srid] = get_srid_info(self.srid)
+        self._units_cache, self._units_name_cache, self._spheroid_cache = SRID_CACHE[self.srid]
 
     def _get_units(self):
         if self._units_cache is None: