--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/lib/django/contrib/gis/db/backends/util.py	Tue May 25 02:43:45 2010 +0200
@@ -0,0 +1,70 @@
+"""
+A collection of utility routines and classes used by the spatial
+backends.
+"""
+
+def getstatusoutput(cmd):
+    """
+    Executes a shell command on the platform using subprocess.Popen and
+    return a tuple of the status and stdout output.
+    """
+    from subprocess import Popen, PIPE
+    # Set stdout and stderr to PIPE because we want to capture stdout and
+    # prevent stderr from displaying.
+    p = Popen(cmd, shell=True, stdout=PIPE, stderr=PIPE)
+    # We use p.communicate() instead of p.wait() to avoid deadlocks if the
+    # output buffers exceed POSIX buffer size.
+    stdout, stderr = p.communicate()
+    return p.returncode, stdout.strip()
+
+def gqn(val):
+    """
+    The geographic quote name function; used for quoting tables and
+    geometries (they use single rather than the double quotes of the
+    backend quotename function).
+    """
+    if isinstance(val, basestring):
+        if isinstance(val, unicode): val = val.encode('ascii')
+        return "'%s'" % val
+    else:
+        return str(val)
+
+class SpatialOperation(object):
+    """
+    Base class for generating spatial SQL.
+    """
+    sql_template = '%(geo_col)s %(operator)s %(geometry)s'
+
+    def __init__(self, function='', operator='', result='', **kwargs):
+        self.function = function
+        self.operator = operator
+        self.result = result
+        self.extra = kwargs
+
+    def as_sql(self, geo_col, geometry='%s'):
+        return self.sql_template % self.params(geo_col, geometry)
+
+    def params(self, geo_col, geometry):
+        params = {'function' : self.function,
+                  'geo_col' : geo_col,
+                  'geometry' : geometry,
+                  'operator' : self.operator,
+                  'result' : self.result,
+                  }
+        params.update(self.extra)
+        return params
+
+class SpatialFunction(SpatialOperation):
+    """
+    Base class for generating spatial SQL related to a function.
+    """
+    sql_template = '%(function)s(%(geo_col)s, %(geometry)s)'
+
+    def __init__(self, func, result='', operator='', **kwargs):
+        # Getting the function prefix.
+        default = {'function' : func,
+                   'operator' : operator,
+                   'result' : result
+                   }
+        kwargs.update(default)
+        super(SpatialFunction, self).__init__(**kwargs)