--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/lib/django/contrib/gis/geos/io.py	Wed Jan 20 00:34:04 2010 +0100
@@ -0,0 +1,123 @@
+"""
+Module that holds classes for performing I/O operations on GEOS geometry
+objects.  Specifically, this has Python implementations of WKB/WKT
+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 GEOS I/O objects."
+    def __init__(self):
+        # Getting the pointer with the constructor.
+        self.ptr = self.constructor()
+
+    def __del__(self):
+        # Cleaning up with the appropriate destructor.
+        if self._ptr: self.destructor(self._ptr)
+
+### WKT Reading and Writing objects ###
+
+# 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):
+        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):
+        "Returns the WKT representation of the given geometry."
+        return capi.wkt_writer_write(self.ptr, geom.ptr)
+
+### WKB Reading and Writing objects ###
+
+# 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))
+        elif isinstance(wkb, basestring):
+            return capi.wkb_reader_read_hex(self.ptr, wkb, len(wkb))
+        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_WRITE_PTR
+
+    def write(self, geom):
+        "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):
+        "Returns the HEXEWKB representation of the given geometry."
+        return capi.wkb_writer_write_hex(self.ptr, geom.ptr, byref(c_size_t()))
+
+    ### WKBWriter Properties ###
+
+    # Property for getting/setting the byteorder.
+    def _get_byteorder(self):
+        return capi.wkb_writer_get_byteorder(self.ptr)
+
+    def _set_byteorder(self, order):
+        if not order in (0, 1): raise ValueError('Byte order parameter must be 0 (Big Endian) or 1 (Little Endian).')
+        capi.wkb_writer_set_byteorder(self.ptr, order)
+
+    byteorder = property(_get_byteorder, _set_byteorder)
+
+    # Property for getting/setting the output dimension.
+    def _get_outdim(self):
+        return capi.wkb_writer_get_outdim(self.ptr)
+
+    def _set_outdim(self, new_dim):
+        if not new_dim in (2, 3): raise ValueError('WKB output dimension must be 2 or 3')
+        capi.wkb_writer_set_outdim(self.ptr, new_dim)
+
+    outdim = property(_get_outdim, _set_outdim)
+
+    # Property for getting/setting the include srid flag.
+    def _get_include_srid(self):
+        return bool(ord(capi.wkb_writer_get_include_srid(self.ptr)))
+
+    def _set_include_srid(self, include):
+        if bool(include): flag = chr(1)
+        else: flag = chr(0)
+        capi.wkb_writer_set_include_srid(self.ptr, flag)
+
+    srid = property(_get_include_srid, _set_include_srid)
+
+# Instances of the WKT and WKB reader/writer objects.
+wkt_r = _WKTReader()
+wkt_w = WKTWriter()
+wkb_r = _WKBReader()
+wkb_w = WKBWriter()