Rev 129: Start some direct testing of the Proxy object. in http://bazaar.launchpad.net/~jameinel/meliae/mem-object-collection

[John Arbash Meinel]

At http://bazaar.launchpad.net/~jameinel/meliae/mem-object-collection

------------------------------------------------------------
revno: 129
revision-id: john at arbash-meinel.com-20091228005448-hm6ll74g7cw7slw2
parent: john at arbash-meinel.com-20091228003801-31hv17bjdpbmikv5
committer: John Arbash Meinel <john at arbash-meinel.com>
branch nick: mem-object-collection
timestamp: Sun 2009-12-27 18:54:48 -0600
message:
  Start some direct testing of the Proxy object.
-------------- next part --------------
=== modified file 'meliae/_loader.pyx'
--- a/meliae/_loader.pyx	2009-12-28 00:38:01 +0000
+++ b/meliae/_loader.pyx	2009-12-28 00:54:48 +0000
@@ -156,31 +156,20 @@
     these on-the-fly.
     """
 
-    # Note that it is possible for the table to be mutated while this object is
-    # live, which is why we don't hold a direct pointer to the _MemObject, and
-    # instead go through a table lookup for all attributes.  An alternative
-    # option would be to hold a copy-by-value, and only go back to the original
-    # object in __set__ functions.
-    # Alternatively, we could keep track of all proxy objects returned, and
-    # point them to the new locations when things move.
-    # We may want to keep track of them anyway, so that we don't create 20
-    # proxy objects for the same address. TBD
-
     cdef MemObjectCollection collection
     cdef public object address
+    cdef _MemObject *_obj
+    cdef object __weakref__
 
     def __init__(self, address, collection):
         self.address = address
         self.collection = collection
+        self._obj = NULL
 
     cdef _MemObject *_get_obj(self) except NULL:
-        cdef _MemObject **slot
-
-        slot = self.collection._lookup(self.address)
-        if slot[0] == NULL or slot[0] == _dummy:
-            raise RuntimeError('we failed to lookup the obj at address %d'
-                               % (self.address,))
-        return slot[0]
+        if self._obj is NULL:
+            raise RuntimeError('_MemObjectProxy was deleted underneath it.')
+        return self._obj
 
     property type_str:
         """The type of this object."""
@@ -318,21 +307,26 @@
 
     def __getitem__(self, at):
         cdef _MemObject **slot
+        cdef _MemObjectProxy proxy
 
         if isinstance(at, _MemObjectProxy):
             address = at.address
+            proxy = at
         else:
             address = at
+            proxy = None
 
         slot = self._lookup(address)
         if slot[0] == NULL or slot[0] == _dummy:
             raise KeyError('address %s not present' % (at,))
-        if at is address:
-            return _MemObjectProxy(address, self)
-        return at
+        if proxy is None:
+            proxy = _MemObjectProxy(address, self)
+            proxy._obj = slot[0]
+        return proxy
 
     def __delitem__(self, at):
         cdef _MemObject **slot
+        cdef _MemObjectProxy proxy
 
         if isinstance(at, _MemObjectProxy):
             address = at.address

=== modified file 'meliae/tests/test__loader.py'
--- a/meliae/tests/test__loader.py	2009-12-28 00:38:01 +0000
+++ b/meliae/tests/test__loader.py	2009-12-28 00:54:48 +0000
@@ -202,3 +202,24 @@
         mop = moc[1024]
         self.assertEqual(1024, mop.address)
         self.assertEqual(1124, mop.size)
+
+
+class Test_MemObjectProxy(tests.TestCase):
+
+    def setUp(self):
+        super(Test_MemObjectProxy, self).setUp()
+        self.moc = _loader.MemObjectCollection()
+        self.moc.add(1024, 'bar', 200)
+        self.moc.add(0, 'foo', 100)
+        self.moc.add(255, 'baz', 300)
+        del self.moc[1024]
+
+    def test_basic_proxy(self):
+        mop = self.moc[0]
+        self.assertEqual(0, mop.address)
+        self.assertEqual('foo', mop.type_str)
+        self.assertEqual(100, mop.size)
+        mop.size = 1024
+        self.assertEqual(1024, mop.size)
+        self.assertEqual(1024, self.moc[0].size)
+        self.assertEqual(0, len(mop))