From e1d84dd4fb3b53905e8bbc92a8233b9b65b7a0bd Mon Sep 17 00:00:00 2001
From: Justin Bronn <jbronn@gmail.com>
Date: Mon, 7 Apr 2008 22:20:58 +0000
Subject: [PATCH] gis: Applied DRY to Oracle and MySQL geometry adaptors; the
 `PostGISAdaptor` now stores WKB in raw string form to support pickling; added
 an equivalence method to all adaptors.

git-svn-id: http://code.djangoproject.com/svn/django/branches/gis@7407 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
 django/contrib/gis/db/backend/__init__.py        |  6 ++----
 django/contrib/gis/db/backend/adaptor.py         | 13 +++++++++++++
 django/contrib/gis/db/backend/mysql/adaptor.py   | 10 ----------
 django/contrib/gis/db/backend/oracle/adaptor.py  | 11 -----------
 django/contrib/gis/db/backend/postgis/adaptor.py | 10 +++++++---
 django/contrib/gis/db/models/query.py            |  2 +-
 6 files changed, 23 insertions(+), 29 deletions(-)
 create mode 100644 django/contrib/gis/db/backend/adaptor.py
 delete mode 100644 django/contrib/gis/db/backend/mysql/adaptor.py
 delete mode 100644 django/contrib/gis/db/backend/oracle/adaptor.py

diff --git a/django/contrib/gis/db/backend/__init__.py b/django/contrib/gis/db/backend/__init__.py
index e797942c0e..9b4bc20ae8 100644
--- a/django/contrib/gis/db/backend/__init__.py
+++ b/django/contrib/gis/db/backend/__init__.py
@@ -47,8 +47,7 @@ if settings.DATABASE_ENGINE == 'postgresql_psycopg2':
     VERSION = (MAJOR_VERSION, MINOR_VERSION1, MINOR_VERSION2)
     SPATIAL_BACKEND = 'postgis'
 elif settings.DATABASE_ENGINE == 'oracle':
-    from django.contrib.gis.db.backend.oracle.adaptor import \
-        OracleSpatialAdaptor as GeoAdaptor
+    from django.contrib.gis.db.backend.adaptor import WKTAdaptor as GeoAdaptor
     from django.contrib.gis.db.backend.oracle.field import \
         OracleSpatialField as GeoBackendField
     from django.contrib.gis.db.backend.oracle.creation import create_spatial_db
@@ -58,8 +57,7 @@ elif settings.DATABASE_ENGINE == 'oracle':
     SPATIAL_BACKEND = 'oracle'
     LIMITED_WHERE = ['relate']
 elif settings.DATABASE_ENGINE == 'mysql':
-    from django.contrib.gis.db.backend.mysql.adaptor import \
-        MySQLAdaptor as GeoAdaptor
+    from django.contrib.gis.db.backend.adaptor import WKTAdaptor as GeoAdaptor
     from django.contrib.gis.db.backend.mysql.field import \
         MySQLGeoField as GeoBackendField
     from django.contrib.gis.db.backend.mysql.creation import create_spatial_db
diff --git a/django/contrib/gis/db/backend/adaptor.py b/django/contrib/gis/db/backend/adaptor.py
new file mode 100644
index 0000000000..1f01cb01e2
--- /dev/null
+++ b/django/contrib/gis/db/backend/adaptor.py
@@ -0,0 +1,13 @@
+class WKTAdaptor(object):
+    """
+    This provides an adaptor for Geometries sent to the
+    MySQL and Oracle database backends.
+    """
+    def __init__(self, geom):
+        self.wkt = geom.wkt
+
+    def __eq__(self, other):
+        return self.wkt == other.wkt
+
+    def __str__(self):
+        return self.wkt
diff --git a/django/contrib/gis/db/backend/mysql/adaptor.py b/django/contrib/gis/db/backend/mysql/adaptor.py
deleted file mode 100644
index 9a702d3fdf..0000000000
--- a/django/contrib/gis/db/backend/mysql/adaptor.py
+++ /dev/null
@@ -1,10 +0,0 @@
-"""
- This object provides quoting for GEOS geometries into MySQL.
-"""
-class MySQLAdaptor(object):
-    def __init__(self, geom):
-        self.wkt = geom.wkt
-
-    def __str__(self):
-        "WKT is used as for the substitution value for the geometry."
-        return self.wkt
diff --git a/django/contrib/gis/db/backend/oracle/adaptor.py b/django/contrib/gis/db/backend/oracle/adaptor.py
deleted file mode 100644
index 7b1caa2ad9..0000000000
--- a/django/contrib/gis/db/backend/oracle/adaptor.py
+++ /dev/null
@@ -1,11 +0,0 @@
-"""
- This object provides the database adaptor for Oracle geometries.
-"""
-class OracleSpatialAdaptor(object):
-    def __init__(self, geom):
-        "Initializes only on the geometry object."
-        self.wkt = geom.wkt
-
-    def __str__(self):
-        "WKT is used for the substitution value of the geometry."
-        return self.wkt
diff --git a/django/contrib/gis/db/backend/postgis/adaptor.py b/django/contrib/gis/db/backend/postgis/adaptor.py
index e91834722b..c094a9825a 100644
--- a/django/contrib/gis/db/backend/postgis/adaptor.py
+++ b/django/contrib/gis/db/backend/postgis/adaptor.py
@@ -8,9 +8,10 @@ from psycopg2.extensions import ISQLQuote
 
 class PostGISAdaptor(object):
     def __init__(self, geom):
-        "Initializes on the geometry and the SRID."
-        # Getting the WKB and the SRID
-        self.wkb = geom.wkb
+        "Initializes on the geometry."
+        # Getting the WKB (in string form, to allow easy pickling of
+        # the adaptor) and the SRID from the geometry.
+        self.wkb = str(geom.wkb)
         self.srid = geom.srid
 
     def __conform__(self, proto):
@@ -20,6 +21,9 @@ class PostGISAdaptor(object):
         else:
             raise Exception('Error implementing psycopg2 protocol. Is psycopg2 installed?')
 
+    def __eq__(self, other):
+        return (self.wkb == other.wkb) and (self.srid == other.srid)
+
     def __str__(self):
         return self.getquoted()
 
diff --git a/django/contrib/gis/db/models/query.py b/django/contrib/gis/db/models/query.py
index f2cbcd15de..6550f0b6e4 100644
--- a/django/contrib/gis/db/models/query.py
+++ b/django/contrib/gis/db/models/query.py
@@ -291,7 +291,7 @@ class GeoQuerySet(QuerySet):
                 # some error checking is required.
                 if not isinstance(geo_field, PointField): 
                     raise TypeError('Spherical distance calculation only supported on PointFields.')
-                if not isinstance(GEOSGeometry(params[0].wkb), Point):
+                if not isinstance(GEOSGeometry(buffer(params[0].wkb)), Point):
                     raise TypeError('Spherical distance calculation only supported with Point Geometry parameters')
 
                 # Call to distance_spheroid() requires the spheroid as well.