Cleanup, bug fixes, and new tests for the GEOS I/O objects and GEOSBase object.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10177 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/gis/geos/base.py

@@ -41,9 +41,7 @@ class GEOSBase(object):
     def _set_ptr(self, ptr):
         # Only allow the pointer to be set with pointers of the
         # compatible type or None (NULL).
-        if isinstance(ptr, int):
+        if isinstance(ptr, (self.ptr_type, NoneType)):
-            self._ptr = self.ptr_type(ptr)
-        elif isinstance(ptr, (self.ptr_type, NoneType)):
             self._ptr = ptr
         else:
             raise TypeError('Incompatible pointer type')

django/contrib/gis/geos/geometry.py

@@ -20,7 +20,6 @@ from django.contrib.gis.geos.mutable_list import ListMixin
 # prototypes module -- which handles all interaction with
 # the underlying GEOS library.
 from django.contrib.gis.geos import prototypes as capi
-from django.contrib.gis.geos import io
 
 # Regular expression for recognizing HEXEWKB and WKT.  A prophylactic measure
 # to prevent potentially malicious input from reaching the underlying C
@@ -62,13 +61,13 @@ class GEOSGeometry(GEOSBase, ListMixin):
             if wkt_m:
                 # Handling WKT input.
                 if wkt_m.group('srid'): srid = int(wkt_m.group('srid'))
-                g = io.wkt_r.read(wkt_m.group('wkt'))
+                g = wkt_r.read(wkt_m.group('wkt'))
             elif hex_regex.match(geo_input):
                 # Handling HEXEWKB input.
-                g = io.wkb_r.read(geo_input)
+                g = wkb_r.read(geo_input)
             elif gdal.GEOJSON and gdal.geometries.json_regex.match(geo_input):
                 # Handling GeoJSON input.
-                g = io.wkb_r.read(gdal.OGRGeometry(geo_input).wkb)
+                g = wkb_r.read(gdal.OGRGeometry(geo_input).wkb)
             else:
                 raise ValueError('String or unicode input unrecognized as WKT EWKT, and HEXEWKB.')
         elif isinstance(geo_input, GEOM_PTR):
@@ -76,7 +75,7 @@ class GEOSGeometry(GEOSBase, ListMixin):
             g = geo_input
         elif isinstance(geo_input, buffer):
             # When the input is a buffer (WKB).
-            g = io.wkb_r.read(geo_input)
+            g = wkb_r.read(geo_input)
         elif isinstance(geo_input, GEOSGeometry):
             g = capi.geom_clone(geo_input.ptr)
         else:
@@ -366,7 +365,7 @@ class GEOSGeometry(GEOSBase, ListMixin):
     @property
     def wkt(self):
         "Returns the WKT (Well-Known Text) of the Geometry."
-        return io.wkt_w.write(self.ptr)
+        return wkt_w.write(self)
 
     @property
     def hex(self):
@@ -377,7 +376,7 @@ class GEOSGeometry(GEOSBase, ListMixin):
         """
         # A possible faster, all-python, implementation:
         #  str(self.wkb).encode('hex')
-        return io.wkb_w.write_hex(self.ptr)
+        return wkb_w.write_hex(self)
 
     @property
     def json(self):
@@ -394,7 +393,7 @@ class GEOSGeometry(GEOSBase, ListMixin):
     @property
     def wkb(self):
         "Returns the WKB of the Geometry as a buffer."
-        return io.wkb_w.write(self.ptr)
+        return wkb_w.write(self)
 
     @property
     def kml(self):
@@ -456,7 +455,7 @@ class GEOSGeometry(GEOSBase, ListMixin):
             g = gdal.OGRGeometry(self.wkb, srid)
             g.transform(ct)
             # Getting a new GEOS pointer
-            ptr = io.wkb_r.read(g.wkb)
+            ptr = wkb_r.read(g.wkb)
             if clone:
                 # User wants a cloned transformed geometry returned.
                 return GEOSGeometry(ptr, srid=g.srid)
@@ -618,6 +617,9 @@ GEOS_CLASSES = {0 : Point,
                 7 : GeometryCollection,
                 }
 
+# Similarly, import the GEOS I/O instances here to avoid conflicts.
+from django.contrib.gis.geos.io import wkt_r, wkt_w, wkb_r, wkb_w
+
 # If supported, import the PreparedGeometry class.
 if GEOS_PREPARE:
     from django.contrib.gis.geos.prepared import PreparedGeometry

django/contrib/gis/geos/io.py

@@ -6,11 +6,12 @@ reader and writer classes.
 from ctypes import byref, c_size_t
 from django.contrib.gis.geos.base import GEOSBase
 from django.contrib.gis.geos.error import GEOSException
+from django.contrib.gis.geos.geometry import GEOSGeometry
 from django.contrib.gis.geos.libgeos import GEOM_PTR
 from django.contrib.gis.geos.prototypes import io as capi
 
 class IOBase(GEOSBase):
-    "Base class for IO objects that that have `destroy` method."
+    "Base class for GEOS I/O objects."
     def __init__(self):
         # Getting the pointer with the constructor.
         self.ptr = self.constructor()
@@ -19,36 +20,43 @@ class IOBase(GEOSBase):
         # Cleaning up with the appropriate destructor.
         if self._ptr: self.destructor(self._ptr)
 
-    def _get_geom_ptr(self, geom):
-        if hasattr(geom, 'ptr'): geom = geom.ptr
-        if not isinstance(geom, GEOM_PTR): raise TypeError
-        return geom
-
 ### WKT Reading and Writing objects ###
-class WKTReader(IOBase):
+
+# Non-public class for internal use because its `read` method returns
+# _pointers_ instead of a GEOSGeometry object.
+class _WKTReader(IOBase):
     constructor = capi.wkt_reader_create
     destructor = capi.wkt_reader_destroy
     ptr_type = capi.WKT_READ_PTR
 
-    def read(self, wkt, ptr=False):
+    def read(self, wkt):
         if not isinstance(wkt, basestring): raise TypeError
         return capi.wkt_reader_read(self.ptr, wkt)
 
+class WKTReader(_WKTReader):
+    def read(self, wkt):
+        "Returns a GEOSGeometry for the given WKT string."
+        return GEOSGeometry(super(WKTReader, self).read(wkt))
+
 class WKTWriter(IOBase):
     constructor = capi.wkt_writer_create
     destructor = capi.wkt_writer_destroy
     ptr_type = capi.WKT_WRITE_PTR
 
     def write(self, geom):
-        return capi.wkt_writer_write(self.ptr, self._get_geom_ptr(geom))
+        "Returns the WKT representation of the given geometry."
+        return capi.wkt_writer_write(self.ptr, geom.ptr)
 
 ### WKB Reading and Writing objects ###
-class WKBReader(IOBase):
+
+# Non-public class for the same reason as _WKTReader above.
+class _WKBReader(IOBase):
     constructor = capi.wkb_reader_create
     destructor = capi.wkb_reader_destroy
     ptr_type = capi.WKB_READ_PTR
 
     def read(self, wkb):
+        "Returns a _pointer_ to C GEOS Geometry object from the given WKB."
         if isinstance(wkb, buffer):
             wkb_s = str(wkb)
             return capi.wkb_reader_read(self.ptr, wkb_s, len(wkb_s))
@@ -57,16 +65,23 @@ class WKBReader(IOBase):
         else:
             raise TypeError
 
+class WKBReader(_WKBReader):
+    def read(self, wkb):
+        "Returns a GEOSGeometry for the given WKB buffer."
+        return GEOSGeometry(super(WKBReader, self).read(wkb))
+
 class WKBWriter(IOBase):
     constructor = capi.wkb_writer_create
     destructor = capi.wkb_writer_destroy
-    ptr_type = capi.WKB_READ_PTR
+    ptr_type = capi.WKB_WRITE_PTR
 
     def write(self, geom):
-        return buffer(capi.wkb_writer_write(self.ptr, self._get_geom_ptr(geom), byref(c_size_t())))
+        "Returns the WKB representation of the given geometry."
+        return buffer(capi.wkb_writer_write(self.ptr, geom.ptr, byref(c_size_t())))
 
     def write_hex(self, geom):
-        return capi.wkb_writer_write_hex(self.ptr, self._get_geom_ptr(geom), byref(c_size_t()))
+        "Returns the HEXEWKB representation of the given geometry."
+        return capi.wkb_writer_write_hex(self.ptr, geom.ptr, byref(c_size_t()))
 
     ### WKBWriter Properties ###
 
@@ -102,8 +117,7 @@ class WKBWriter(IOBase):
     srid = property(_get_include_srid, _set_include_srid)
 
 # Instances of the WKT and WKB reader/writer objects.
-wkt_r = WKTReader()
+wkt_r = _WKTReader()
 wkt_w = WKTWriter()
-wkb_r = WKBReader()
+wkb_r = _WKBReader()
 wkb_w = WKBWriter()
-

django/contrib/gis/geos/tests/__init__.py

@@ -2,10 +2,11 @@
 GEOS Testing module.
 """
 from unittest import TestSuite, TextTestRunner
-import test_geos, test_geos_mutation, test_mutable_list
+import test_geos, test_io, test_geos_mutation, test_mutable_list
 
 test_suites = [
     test_geos.suite(),
+    test_io.suite(),
     test_geos_mutation.suite(),
     test_mutable_list.suite(),
     ]

django/contrib/gis/geos/tests/test_geos.py

@@ -1,7 +1,6 @@
-import random, unittest, sys
+import ctypes, random, unittest, sys
-from ctypes import ArgumentError
 from django.contrib.gis.geos import *
-from django.contrib.gis.geos.base import gdal, numpy
+from django.contrib.gis.geos.base import gdal, numpy, GEOSBase
 from django.contrib.gis.tests.geometries import *
 
 class GEOSTest(unittest.TestCase):
@@ -18,6 +17,48 @@ class GEOSTest(unittest.TestCase):
         else:
             return None
 
+    def test00_base(self):
+        "Tests out the GEOSBase class."
+        # Testing out GEOSBase class, which provides a `ptr` property
+        # that abstracts out access to underlying C pointers.
+        class FakeGeom1(GEOSBase):
+            pass
+
+        # This one only accepts pointers to floats
+        c_float_p = ctypes.POINTER(ctypes.c_float)
+        class FakeGeom2(GEOSBase):
+            ptr_type = c_float_p
+
+        # Default ptr_type is `c_void_p`.
+        fg1 = FakeGeom1()
+        # Default ptr_type is C float pointer
+        fg2 = FakeGeom2()
+
+        # These assignments are OK -- None is allowed because
+        # it's equivalent to the NULL pointer.
+        fg1.ptr = ctypes.c_void_p()
+        fg1.ptr = None
+        fg2.ptr = c_float_p(ctypes.c_float(5.23))
+        fg2.ptr = None
+
+        # Because pointers have been set to NULL, an exception should be
+        # raised when we try to access it.  Raising an exception is
+        # preferrable to a segmentation fault that commonly occurs when
+        # a C method is given a NULL memory reference.
+        for fg in (fg1, fg2):
+            # Equivalent to `fg.ptr`
+            self.assertRaises(GEOSException, fg._get_ptr)
+
+        # Anything that is either not None or the acceptable pointer type will
+        # result in a TypeError when trying to assign it to the `ptr` property.
+        # Thus, memmory addresses (integers) and pointers of the incorrect type
+        # (in `bad_ptrs`) will not be allowed.
+        bad_ptrs = (5, ctypes.c_char_p('foobar'))
+        for bad_ptr in bad_ptrs:
+            # Equivalent to `fg.ptr = bad_ptr`
+            self.assertRaises(TypeError, fg1._set_ptr, bad_ptr)
+            self.assertRaises(TypeError, fg2._set_ptr, bad_ptr)
+
     def test01a_wkt(self):
         "Testing WKT output."
         for g in wkt_out:
@@ -494,7 +535,7 @@ class GEOSTest(unittest.TestCase):
             exp_buf = fromstr(g_tup[1].wkt)
 
             # Can't use a floating-point for the number of quadsegs.
-            self.assertRaises(ArgumentError, g.buffer, g_tup[2], float(g_tup[3]))
+            self.assertRaises(ctypes.ArgumentError, g.buffer, g_tup[2], float(g_tup[3]))
 
             # Constructing our buffer
             buf = g.buffer(g_tup[2], g_tup[3])
@@ -518,7 +559,7 @@ class GEOSTest(unittest.TestCase):
         self.assertEqual(4326, pnt.srid)
         pnt.srid = 3084
         self.assertEqual(3084, pnt.srid)
-        self.assertRaises(ArgumentError, pnt.set_srid, '4326')
+        self.assertRaises(ctypes.ArgumentError, pnt.set_srid, '4326')
 
         # Testing SRID keyword on fromstr(), and on Polygon rings.
         poly = fromstr(polygons[1].wkt, srid=4269)
@@ -824,7 +865,7 @@ class GEOSTest(unittest.TestCase):
             self.assertEqual(mpoly.intersects(pnt), prep.intersects(pnt))
             self.assertEqual(c, prep.covers(pnt))
 
-    def test26_line_merge(self): 
+    def test26_line_merge(self):
         "Testing line merge support"
         ref_geoms = (fromstr('LINESTRING(1 1, 1 1, 3 3)'),
                      fromstr('MULTILINESTRING((1 1, 3 3), (3 3, 4 2))'),

django/contrib/gis/geos/tests/test_io.py

@@ -0,0 +1,112 @@
+import binascii, ctypes, unittest
+from django.contrib.gis.geos import GEOSGeometry, WKTReader, WKTWriter, WKBReader, WKBWriter, geos_version_info
+
+class GEOSIOTest(unittest.TestCase):
+
+    def test01_wktreader(self):
+        # Creating a WKTReader instance
+        wkt_r = WKTReader()
+        wkt = 'POINT (5 23)'
+
+        # read() should return a GEOSGeometry
+        ref = GEOSGeometry(wkt)
+        g1 = wkt_r.read(wkt)
+        g2 = wkt_r.read(unicode(wkt))
+
+        for geom in (g1, g2):
+            self.assertEqual(ref, geom)
+
+        # Should only accept basestring objects.
+        self.assertRaises(TypeError, wkt_r.read, 1)
+        self.assertRaises(TypeError, wkt_r.read, buffer('foo'))
+
+    def test02_wktwriter(self):
+        # Creating a WKTWriter instance, testing its ptr property.
+        wkt_w = WKTWriter()
+        self.assertRaises(TypeError, wkt_w._set_ptr, WKTReader.ptr_type())
+
+        ref = GEOSGeometry('POINT (5 23)')
+        ref_wkt = 'POINT (5.0000000000000000 23.0000000000000000)'
+        self.assertEqual(ref_wkt, wkt_w.write(ref))
+
+    def test03_wkbreader(self):
+        # Creating a WKBReader instance
+        wkb_r = WKBReader()
+
+        hex = '000000000140140000000000004037000000000000'
+        wkb = buffer(binascii.a2b_hex(hex))
+        ref = GEOSGeometry(hex)
+
+        # read() should return a GEOSGeometry on either a hex string or
+        # a WKB buffer.
+        g1 = wkb_r.read(wkb)
+        g2 = wkb_r.read(hex)
+        for geom in (g1, g2):
+            self.assertEqual(ref, geom)
+
+        bad_input = (1, 5.23, None, False)
+        for bad_wkb in bad_input:
+            self.assertRaises(TypeError, wkb_r.read, bad_wkb)
+        
+    def test04_wkbwriter(self):
+        wkb_w = WKBWriter()
+
+        # Representations of 'POINT (5 23)' in hex -- one normal and
+        # the other with the byte order changed.
+        g = GEOSGeometry('POINT (5 23)')
+        hex1 = '010100000000000000000014400000000000003740'
+        wkb1 = buffer(binascii.a2b_hex(hex1))
+        hex2 = '000000000140140000000000004037000000000000'
+        wkb2 = buffer(binascii.a2b_hex(hex2))
+
+        self.assertEqual(hex1, wkb_w.write_hex(g))
+        self.assertEqual(wkb1, wkb_w.write(g))
+
+        # Ensuring bad byteorders are not accepted.
+        for bad_byteorder in (-1, 2, 523, 'foo', None):
+            # Equivalent of `wkb_w.byteorder = bad_byteorder`
+            self.assertRaises(ValueError, wkb_w._set_byteorder, bad_byteorder)
+            
+        # Setting the byteorder to 0 (for Big Endian)
+        wkb_w.byteorder = 0
+        self.assertEqual(hex2, wkb_w.write_hex(g))
+        self.assertEqual(wkb2, wkb_w.write(g))
+
+        # Back to Little Endian
+        wkb_w.byteorder = 1
+
+        # Now, trying out the 3D and SRID flags.
+        g = GEOSGeometry('POINT (5 23 17)')
+        g.srid = 4326
+        
+        hex3d = '0101000080000000000000144000000000000037400000000000003140'
+        wkb3d = buffer(binascii.a2b_hex(hex3d))
+        hex3d_srid = '01010000A0E6100000000000000000144000000000000037400000000000003140'
+        wkb3d_srid = buffer(binascii.a2b_hex(hex3d_srid))
+
+        # Ensuring bad output dimensions are not accepted
+        for bad_outdim in (-1, 0, 1, 4, 423, 'foo', None):
+            # Equivalent of `wkb_w.outdim = bad_outdim`
+            self.assertRaises(ValueError, wkb_w._set_outdim, bad_outdim)
+
+        # These tests will fail on 3.0.0 because of a bug that was fixed in 3.1:
+        # http://trac.osgeo.org/geos/ticket/216
+        if not geos_version_info()['version'] == '3.0.0':
+            # Now setting the output dimensions to be 3
+            wkb_w.outdim = 3
+
+            self.assertEqual(hex3d, wkb_w.write_hex(g))
+            self.assertEqual(wkb3d, wkb_w.write(g))
+
+            # Telling the WKBWriter to inlcude the srid in the representation.
+            wkb_w.srid = True
+            self.assertEqual(hex3d_srid, wkb_w.write_hex(g))
+            self.assertEqual(wkb3d_srid, wkb_w.write(g))
+
+def suite():
+    s = unittest.TestSuite()
+    s.addTest(unittest.makeSuite(GEOSIOTest))
+    return s
+
+def run(verbosity=2):
+    unittest.TextTestRunner(verbosity=verbosity).run(suite())