Initial commit. Still building up the env and some parsing code.

python/packages/sqlobject/include/hashcol.py

@@ -0,0 +1,62 @@
+__all__ = ['HashCol']
+
+import sqlobject.col
+
+class DbHash:
+    """ Presents a comparison object for hashes, allowing plain text to be
+    automagically compared with the base content. """
+
+    def __init__( self, hash, hashMethod ):
+        self.hash = hash
+        self.hashMethod = hashMethod
+
+    def __cmp__( self, other ):
+        if other is None:
+            if self.hash is None:
+                return 0
+            return True
+        if not isinstance( other, basestring ):
+            raise TypeError( "A hash may only be compared with a string, or None." )
+        return cmp( self.hashMethod( other ), self.hash )
+
+    def __repr__( self ):
+        return "<DbHash>"
+
+class HashValidator( sqlobject.col.StringValidator ):
+    """ Provides formal SQLObject validation services for the HashCol. """
+
+    def to_python( self, value, state ):
+        """ Passes out a hash object. """
+        if value is None:
+            return None
+        return DbHash( hash = value, hashMethod = self.hashMethod )
+
+    def from_python( self, value, state ):
+        """ Store the given value as a MD5 hash, or None if specified. """
+        if value is None:
+            return None
+        return self.hashMethod( value )
+
+class SOHashCol( sqlobject.col.SOStringCol ):
+    """ The internal HashCol definition. By default, enforces a md5 digest. """
+
+    def __init__( self, **kw ):
+        if 'hashMethod' not in kw:
+            from md5 import md5
+            self.hashMethod = lambda v: md5( v ).hexdigest()
+            if 'length' not in kw:
+                kw['length'] = 32
+        else:
+            self.hashMethod = kw['hashMethod']
+            del kw['hashMethod']
+        super( sqlobject.col.SOStringCol, self ).__init__( **kw )
+
+    def createValidators( self ):
+        return [HashValidator( name=self.name, hashMethod=self.hashMethod )] + \
+            super( SOHashCol, self ).createValidators()
+
+class HashCol( sqlobject.col.StringCol ):
+    """ End-user HashCol class. May be instantiated with 'hashMethod', a function
+    which returns the string hash of any other string (i.e. basestring). """
+
+    baseClass = SOHashCol