added BTreeFolder2

CHANGES.txt

@@ -0,0 +1,21 @@
+Version 1.0.1
+
+  - ConflictError was swallowed by _delObject. This could break code
+    expecting to do cleanups before deletion.
+
+  - Renamed hasObject() to has_key().  hasObject() conflicted with
+    another product.
+
+  - You can now visit objects whose names have a trailing space.
+
+Version 1.0
+
+  - BTreeFolder2s now use an icon contributed by Chris Withers.
+
+  - Since recent ZODB releases have caused minor corruption in BTrees,
+    there is now a manage_cleanup method for fixing damaged BTrees
+    contained in BTreeFolders.
+
+Version 0.5.1
+
+  - Fixed the CMFBTreeFolder constructor.

CMFBTreeFolder.py

@@ -0,0 +1,68 @@
+##############################################################################
+#
+# Copyright (c) 2001, 2002 Zope Corporation and Contributors.
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.0 (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
+#
+##############################################################################
+"""CMFBTreeFolder
+
+$Id: CMFBTreeFolder.py,v 1.2 2002/10/30 14:54:18 shane Exp $
+"""
+
+import Globals
+from BTreeFolder2 import BTreeFolder2Base
+from Products.CMFCore.PortalFolder import PortalFolder
+import Products.CMFCore.PortalFolder
+
+
+_actions = Products.CMFCore.PortalFolder.factory_type_information[0]['actions']
+
+factory_type_information = ( { 'id'             : 'CMF BTree Folder',
+                               'meta_type'      : 'CMF BTree Folder',
+                               'description'    : """\
+CMF folder designed to hold a lot of objects.""",
+                               'icon'           : 'folder_icon.gif',
+                               'product'        : 'BTreeFolder2',
+                               'factory'        : 'manage_addCMFBTreeFolder',
+                               'filter_content_types' : 0,
+                               'immediate_view' : 'folder_edit_form',
+                               'actions'        : _actions,
+                               },
+                           )
+
+
+def manage_addCMFBTreeFolder(dispatcher, id, title='', REQUEST=None):
+    """Adds a new BTreeFolder object with id *id*.
+    """
+    id = str(id)
+    ob = CMFBTreeFolder(id)
+    ob.title = str(title)
+    dispatcher._setObject(id, ob)
+    ob = dispatcher._getOb(id)
+    if REQUEST is not None:
+        REQUEST['RESPONSE'].redirect(ob.absolute_url() + '/manage_main' )
+
+
+class CMFBTreeFolder(BTreeFolder2Base, PortalFolder):
+    """BTree folder for CMF sites.
+    """
+    meta_type = 'CMF BTree Folder'
+
+    def __init__(self, id, title=''):
+        PortalFolder.__init__(self, id, title)
+        BTreeFolder2Base.__init__(self, id)
+
+    def _checkId(self, id, allow_dup=0):
+        PortalFolder._checkId(self, id, allow_dup)
+        BTreeFolder2Base._checkId(self, id, allow_dup)
+
+
+Globals.InitializeClass(CMFBTreeFolder)
+

README.txt

@@ -0,0 +1,124 @@
+
+Contact
+=======
+
+Shane Hathaway
+Zope Corporation
+shane at zope dot com
+
+
+BTreeFolder2 Product
+====================
+
+BTreeFolder2 is a Zope product that acts like a Zope folder but can
+store many more items.
+
+When you fill a Zope folder with too many items, both Zope and your
+browser get overwhelmed.  Zope has to load and store a large folder
+object, and the browser has to render large HTML tables repeatedly.
+Zope can store a lot of objects, but it has trouble storing a lot of
+objects in a single standard folder.
+
+Zope Corporation once had an extensive discussion on the subject.  It
+was decided that we would expand standard folders to handle large
+numbers of objects gracefully.  Unfortunately, Zope folders are used
+and extended in so many ways today that it would be difficult to
+modify standard folders in a way that would be compatible with all
+Zope products.
+
+So the BTreeFolder product was born.  It stored all subobjects in a
+ZODB BTree, a structure designed to allow many items without loading
+them all into memory.  It also rendered the contents of the folder as
+a simple select list rather than a table.  Most browsers have no
+trouble rendering large select lists.
+
+But there was still one issue remaining.  BTreeFolders still stored
+the ID of all subobjects in a single database record.  If you put tens
+of thousands of items in a single BTreeFolder, you would still be
+loading and storing a multi-megabyte folder object.  Zope can do this,
+but not quickly, and not without bloating the database.
+
+BTreeFolder2 solves this issue.  It stores not only the subobjects but
+also the IDs of the subobjects in a BTree.  It also batches the list
+of items in the UI, showing only 1000 items at a time.  So if you
+write your application carefully, you can use a BTreeFolder2 to store
+as many items as will fit in physical storage.
+
+There are products that depend on the internal structure of the
+original BTreeFolder, however.  So rather than risk breaking those
+products, the product has been renamed.  You can have both products
+installed at the same time.  If you're developing new applications,
+you should use BTreeFolder2.
+
+
+Installation
+============
+
+Untar BTreeFolder2 in your Products directory and restart Zope.
+BTreeFolder2 will now be available in your "Add" drop-down.
+
+Additionally, if you have CMF installed, the BTreeFolder2 product also
+provides the "CMF BTree Folder" addable type.
+
+
+Usage
+=====
+
+The BTreeFolder2 user interface shows a list of items rather than a
+series of checkboxes.  To visit an item, select it in the list and
+click the "edit" button.
+
+BTreeFolder2 objects provide Python dictionary-like methods to make them
+easier to use in Python code than standard folders::
+
+    has_key(key)
+    keys()
+    values()
+    items()
+    get(key, default=None)
+    __len__()
+
+keys(), values(), and items() return sequences, but not necessarily
+tuples or lists.  Use len(folder) to call the __len__() method.  The
+objects returned by values() and items() have acquisition wrappers.
+
+BTreeFolder2 also provides a method for generating unique,
+non-overlapping IDs::
+
+    generateId(prefix='item', suffix='', rand_ceiling=999999999)
+
+The ID returned by this method is guaranteed to not clash with any
+other ID in the folder.  Use the returned value as the ID for new
+objects.  The generated IDs tend to be sequential so that objects that
+are likely related in some way get loaded together.
+
+BTreeFolder2 implements the full Folder interface, with the exception
+that the superValues() method does not return any items.  To implement
+the method in the way the Zope codebase expects would undermine the
+performance benefits gained by using BTreeFolder2.
+
+
+Repairing BTree Damage
+======================
+
+Certain ZODB bugs in the past have caused minor corruption in BTrees.
+Fortunately, the damage is apparently easy to repair.  As of version
+1.0, BTreeFolder2 provides a 'manage_cleanup' method that will check
+the internal structure of existing BTreeFolder2 instances and repair
+them if necessary.  Many thanks to Tim Peters, who fixed the BTrees
+code and provided a function for checking a BTree.
+
+Visit a BTreeFolder2 instance through the web as a manager.  Add
+"manage_cleanup" to the end of the URL and request that URL.  It may
+take some time to load and fix the entire structure.  If problems are
+detected, information will be added to the event log.
+
+
+Future
+======
+
+BTreeFolder2 will be maintained for Zope 2.  Zope 3, however, is not
+likely to require BTreeFolder, since the intention is to make Zope 3
+folders gracefully expand to support many items.
+
+

__init__.py

@@ -0,0 +1,51 @@
+##############################################################################
+#
+# Copyright (c) 2001, 2002 Zope Corporation and Contributors.
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.0 (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
+#
+##############################################################################
+__doc__='''BTreeFolder2 Product Initialization
+$Id: __init__.py,v 1.4 2003/08/21 17:03:52 shane Exp $'''
+__version__='$Revision: 1.4 $'[11:-2]
+
+import BTreeFolder2
+
+def initialize(context):
+
+    context.registerClass(
+        BTreeFolder2.BTreeFolder2,
+        constructors=(BTreeFolder2.manage_addBTreeFolderForm,
+                      BTreeFolder2.manage_addBTreeFolder),
+        icon='btreefolder2.gif',
+        )
+
+    #context.registerHelp()
+    #context.registerHelpTitle('Zope Help')
+
+    context.registerBaseClass(BTreeFolder2.BTreeFolder2)
+
+    try:
+        from Products.CMFCore import utils
+    except ImportError:
+        # CMF not installed
+        pass
+    else:
+        # CMF installed; make available a special folder type.
+        import CMFBTreeFolder
+        ADD_FOLDERS_PERMISSION = 'Add portal folders'
+
+        utils.ContentInit(
+            'CMF BTree Folder',
+            content_types=(CMFBTreeFolder.CMFBTreeFolder,),
+            permission=ADD_FOLDERS_PERMISSION,
+            extra_constructors=(CMFBTreeFolder.manage_addCMFBTreeFolder,),
+            fti=CMFBTreeFolder.factory_type_information
+            ).initialize(context)
+