The blob work requires zope.proxy.

src/zope/proxy/DEPENDENCIES.cfg

+zope.interface
+zope.testing

src/zope/proxy/SETUP.cfg

+# Packaging information for zpkg.
+
+header proxy.h
+
+<extension _zope_proxy_proxy>
+  source      _zope_proxy_proxy.c
+  depends-on  proxy.h
+</extension>

src/zope/proxy/__init__.py

+##############################################################################
+#
+# Copyright (c) 2003 Zope Corporation and Contributors.
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE.
+#
+##############################################################################
+"""More convenience functions for dealing with proxies.
+
+$Id$
+"""
+from zope.interface import moduleProvides
+from zope.proxy.interfaces import IProxyIntrospection
+from types import ClassType
+from zope.proxy._zope_proxy_proxy import *
+from zope.proxy._zope_proxy_proxy import _CAPI
+
+moduleProvides(IProxyIntrospection)
+__all__ = tuple(IProxyIntrospection)
+
+def ProxyIterator(p):
+    yield p
+    while isProxy(p):
+        p = getProxiedObject(p)
+        yield p

src/zope/proxy/interfaces.py

+##############################################################################
+#
+# Copyright (c) 2001, 2002 Zope Corporation and Contributors.
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE
+#
+##############################################################################
+"""Proxy-related interfaces.
+
+$Id$
+"""
+
+from zope.interface import Interface
+
+class IProxyIntrospection(Interface):
+    """Provides methods for indentifying proxies and extracting proxied objects
+    """
+
+    def isProxy(obj, proxytype=None):
+        """Check whether the given object is a proxy
+
+        If proxytype is not None, checkes whether the object is
+        proxied by the given proxytype.
+        """
+
+    def sameProxiedObjects(ob1, ob2):
+        """Check whether ob1 and ob2 are the same or proxies of the same object
+        """
+
+    def getProxiedObject(obj):
+        """Get the proxied Object
+
+        If the object isn't proxied, then just return the object.
+        """
+
+    def removeAllProxies(obj):
+        """Get the proxied object with no proxies
+
+        If obj is not a proxied object, return obj.
+
+        The returned object has no proxies.
+        """
+
+    def queryProxy(obj, proxytype, default=None):
+        """Look for a proxy of the given type around the object
+
+        If no such proxy can be found, return the default.
+        """
+
+    def queryInnerProxy(obj, proxytype, default=None):
+        """Look for the inner-most proxy of the given type around the object
+
+        If no such proxy can be found, return the default.
+
+        If there is such a proxy, return the inner-most one.
+        """

src/zope/proxy/proxy.h

+#ifndef _proxy_H_
+#define _proxy_H_ 1
+
+typedef struct {
+    PyObject_HEAD
+    PyObject *proxy_object;
+} ProxyObject;
+
+#define Proxy_GET_OBJECT(ob)   (((ProxyObject *)(ob))->proxy_object)
+
+typedef struct {
+    PyTypeObject *proxytype;
+    int (*check)(PyObject *obj);
+    PyObject *(*create)(PyObject *obj);
+    PyObject *(*getobject)(PyObject *proxy);
+} ProxyInterface;
+
+
+#ifndef PROXY_MODULE
+
+/* These are only defined in the public interface, and are not
+ * available within the module implementation.  There we use the
+ * classic Python/C API only.
+ */
+
+static ProxyInterface *_proxy_api = NULL;
+
+static int
+Proxy_Import(void)
+{
+    if (_proxy_api == NULL) {
+        PyObject *m = PyImport_ImportModule("zope.proxy");
+        if (m != NULL) {
+            PyObject *tmp = PyObject_GetAttrString(m, "_CAPI");
+            if (tmp != NULL) {
+                if (PyCObject_Check(tmp))
+                    _proxy_api = (ProxyInterface *)
+                        PyCObject_AsVoidPtr(tmp);
+                Py_DECREF(tmp);
+            }
+        }
+    }
+    return (_proxy_api == NULL) ? -1 : 0;
+}
+
+#define ProxyType               (*_proxy_api->proxytype)
+#define Proxy_Check(obj)        (_proxy_api->check((obj)))
+#define Proxy_CheckExact(obj)   ((obj)->ob_type == ProxyType)
+#define Proxy_New(obj)          (_proxy_api->create((obj)))
+#define Proxy_GetObject(proxy)  (_proxy_api->getobject((proxy)))
+
+#endif /* PROXY_MODULE */
+
+#endif /* _proxy_H_ */

src/zope/proxy/tests/__init__.py

+#
+# This file is necessary to make this directory a package.