Purge Queues

This module provides extra Purge queue plugins, and solves the Duplicate Queued Items problem.

While a general solution that works for all Purge queue implementations
is hard to implement, a specific change to the database plugin in order
to reject duplicate items is feasible.

Two database plugins are provided:

• database_alt: extends the database plugin provided by Purge. It works the same, but provides an extended schema to store the invalidation type and expression in database columns. Queue item data is not altered at all.
• database_unique: based on database_alt, avoids the enqueuing of duplicated items.

Usage

1. Download and enable purge_queues
2. Change the queue engine to "Database unique" at admin/config/development/performance/purge