Ticket #5440: geos_wkb_support.patch

django/contrib/gis/geos/base.py

@@ -6 +6 @@
 from ctypes import \
      byref, string_at, create_string_buffer, pointer, \
      c_char_p, c_double, c_int, c_size_t
-from types import StringType, UnicodeType, IntType, FloatType
+from types import StringType, UnicodeType, IntType, FloatType, BufferType
 
 # Python and GEOS-related dependencies.
 import re
@@ -30 +30 @@
     #### Python 'magic' routines ####
     def __init__(self, geo_input, srid=None):
         """
-        The base constructor for GEOS geometry objects, and may take the following
-         string inputs: WKT and HEXEWKB (a PostGIS-specific canonical form).
-
+        The base constructor for GEOS geometry objects, and may take the 
+         following inputs:
+         
+         * string: WKT
+         * string: HEXEWKB (a PostGIS-specific canonical form)
+         * buffer: WKB
+        
         The `srid` keyword is used to specify the Source Reference Identifier
          (SRID) number for this Geometry.  If not set, the SRID will be None.
         """
@@ -55 +59 @@
             # When the input is either a memory address (an integer), or a 
             #  GEOSPointer object.
             g = geo_input
+        elif isinstance(geo_input, BufferType):
+            # When the input is a buffer (WKB).
+            s_geo_input = str(geo_input)
+            sz = c_size_t(len(s_geo_input))
+            g = lgeos.GEOSGeomFromWKB_buf(s_geo_input, sz)
+                        
         else:
             # Invalid geometry type.
             raise TypeError, 'Improper geometry input type: %s' % str(type(geo_input))
@@ -414 +424 @@
         return string_at(h, sz.value)
 
     @property
+    def wkb(self):
+        "Returns the WKB of the Geometry as a buffer."
+        sz = c_size_t()
+        h = lgeos.GEOSGeomToWKB_buf(self._ptr(), byref(sz))
+        return buffer(string_at(h, sz.value))
+
+    @property
     def kml(self):
         "Returns the KML representation of this Geometry."
         gtype = self.geom_type

django/contrib/gis/tests/geometries.py

@@ -49 +49 @@
           TestGeom('POINT (5, 23)', bad=True, hex=False),
           TestGeom('AAABBBDDDAAD##@#1113511111-098111111111111111533333333333333', bad=True, hex=True),
           TestGeom('FFFFFFFFFFFFFFFFF1355555555555555555565111', bad=True, hex=True),
+          TestGeom('', bad=True, hex=False),
           )
 
 # Polygons

django/contrib/gis/tests/test_geos.py

@@ -31 +31 @@
 
     def test01d_errors(self):
         "Testing the Error handlers."
+        # string-based
         print "\nBEGIN - expecting GEOS_ERROR; safe to ignore.\n"
         for err in errors:
-            if err.hex:
-                self.assertRaises(GEOSException, fromstr, err.wkt)
-            else:
-                self.assertRaises(GEOSException, fromstr, err.wkt)
+            self.assertRaises(GEOSException, fromstr, err.wkt)
         print "\nEND - expecting GEOS_ERROR; safe to ignore.\n"
+        
+        class NotAGeometry(object):
+            pass
+        
+        # Some other object
+        self.assertRaises(TypeError, GEOSGeometry, NotAGeometry())
+        # None
+        self.assertRaises(TypeError, GEOSGeometry, None)
+        # Bad WKB
+        self.assertRaises(GEOSException, GEOSGeometry, buffer('0'))
                 
+    def test01e_wkb(self):
+        "Testing WKB output."
+        from binascii import b2a_hex
+        for g in hex_wkt:
+            geom = fromstr(g.wkt)
+            wkb = geom.wkb
+            self.assertEqual(b2a_hex(wkb).upper(), g.hex)
+
+    def test01f_create_hex(self):
+        "Testing creation from HEX."
+        for g in hex_wkt:
+            geom_h = GEOSGeometry(g.hex)
+            # we need to do this so decimal places get normalised
+            geom_t = fromstr(g.wkt)
+            self.assertEqual(geom_t.wkt, geom_h.wkt)
+
+    def test01g_create_wkb(self):
+        "Testing creation from WKB."
+        from binascii import a2b_hex
+        for g in hex_wkt:
+            wkb = buffer(a2b_hex(g.hex))
+            geom_h = GEOSGeometry(wkb)
+            # we need to do this so decimal places get normalised
+            geom_t = fromstr(g.wkt)
+            self.assertEqual(geom_t.wkt, geom_h.wkt)
+    
     def test02a_points(self):
         "Testing Point objects."
         prev = fromstr('POINT(0 0)')