experimental.catalogmoveopt

Plone add-on that optimizes catalog operations when content is moved or renamed, preserving Record IDs (RIDs) and reindexing only the indexes that actually change.

The problem

When an object is moved or renamed in stock Plone, Products.CMFCore fires a full catalog cycle: unindex at the old path, reindex everything at the new path. For large content trees this is expensive because every index is recomputed even though most of them (title, description, content body, …) have not changed at all. It also assigns a new RID to the object, which can invalidate in-flight catalog references.

How it works

The add-on monkey-patches Products.CMFCore at Zope startup (via an IProcessStarting subscriber) to replace the stock handleContentishEvent with an optimized version.

On a true object move (old parent ≠ new parent, i.e. cut-paste):

1. IObjectWillBeMovedEvent — instead of calling unindexObject(), the object's current physical path is saved in the transaction-local registry keyed by its ZODB _p_oid. The catalog entry is left untouched.
2. IObjectMovedEvent — the saved old path is retrieved, and CatalogTool.moveObject() (injected by this add-on) is called. It remaps old_path → same RID → new_path in the catalog's internal BTree structures, then calls reindexObject() with only the context-aware indexes.

The net result: the RID is preserved, only the path-dependent and security-dependent indexes are recomputed, and the full reindex of expensive text/metadata indexes is skipped entirely.

For renames (same parent, new id) the same path is followed — the object stays in the same container, only its path and id change.

For all other event types (add, copy, delete) the behaviour is identical to stock CMFCore.

Transaction-local path registry

The old path is stored via transaction.set_data() / transaction.data(), keyed by a stable module-level singleton object. This avoids the _v_ volatile attribute pattern, which is vulnerable to ZODB cache ghostification: for large subtrees, objects can be evicted from the ZODB cache between the WillBeMoved and Moved event phases, causing silent fallback to a full reindex. Transaction-attached data lives outside the ZODB object graph and is discarded automatically on commit or abort.

Context-aware indexes

Only indexes whose values change when an object moves need to be reindexed. This add-on ships with two built-in providers:

Third-party packages can contribute additional indexes by registering a named utility providing IContextAwareIndexProvider:

<!-- my.package/configure.zcml -->
<utility
    provides="experimental.catalogmoveopt.interfaces.IContextAwareIndexProvider"
    name="my.package.myindex"
    component=".providers.MyIndexProvider"
    />

# my.package/providers.py
from zope.interface import implementer
from experimental.catalogmoveopt.interfaces import IContextAwareIndexProvider

@implementer(IContextAwareIndexProvider)
class MyIndexProvider:
    def getIndexNames(self):
        return ("my_custom_index",)

If no providers are registered the optimization is disabled and the stock full-reindex path is used as a safe fallback.

Installation

Add experimental.catalogmoveopt to your Plone backend's dependencies:

# pyproject.toml
dependencies = [
    ...
    "experimental.catalogmoveopt",
]

No further configuration is required. The add-on uses z3c.autoinclude.plugin so its ZCML is loaded automatically when installed in a Plone site.

Compatibility

Development

git clone git@github.com:RedTurtle/experimental.catalogmoveopt.git
cd experimental.catalogmoveopt
make install
make test

Prior art and upstream discussion

This add-on exists as a monkey-patch package while the optimization makes its way into the Plone/CMFCore ecosystem proper. Key references:

• 4teamwork/ftw.copymovepatches — the original proof-of-concept for Plone 4.3 that demonstrated the approach. A real-world benchmark reported an 80-second move of a folder with ~300 files dropping to ~8 seconds (~10× speedup).

• plone/Products.CMFPlone#3834 — David Glick's draft experiment bringing the same optimization to Plone 6, using ftw.copymovepatches as the starting point. The linked comment explicitly requests that the fix land in CMFCore rather than as a monkey-patch in CMFPlone.

• zopefoundation/Products.CMFCore#161 — the upstream CMFCore pull request (by the author of this package) that proposes adding CatalogTool.moveObject() and the IContextAwareIndexProvider interface directly to CMFCore. Once merged, this add-on will become unnecessary.

Contribute

• Issue tracker
• Source code

License

The project is licensed under GPLv2.