Django-cacheops

- support and test against Python 3.9 and Django 3.1/3.2
- added custom serializers support (thx to Arcady Usov)
- support callable extra in cached_as() and friends
- made simple cache obey prefix
- skip JSONFields for purposes of invalidation
- configure skipped fields by internal types, classes still supported
- handle `DatabaseError` on transaction cleanup (Roman Gorbil)
- do not query old object if cacheops is disabled
- do not fetch deferred fields during invalidation, fixes 387
Backwards incompatible changes:
- callable `extra` param, including type, now behaves differently
- simple cache now uses prefix

- support subqueries in annotations (Jeremy Stretch)
- included tests into distro (John Vandenberg)
- fixed .invalidated_update(), if updated QuerySet had related fields selected (M1hacka)
- fixed possible deadlock in .invalidated_update() (M1hacka)
- fixed filtering with expressions
- fixed queries filtering in Exists (thx to Axel Wegener)
- updated min redis-py to 3.0.0

- fixed reverse o2o invalidation (thx to John Anderson)
- fixed unstable cache key when field validors are used
- guard against non-integer timeouts

- support Python 3.8 and Django 3.0 (thx to Misha Kalyna)
- improve model fields stamping (Alex Lokhman)
- disabled postponed invalidation when no_invalidation is applied (Vladimir)
- fixed custom manager derived from BaseManager (Eric Plaster)
Backwards incompatible changes:
- dropped Python 2.7 and Djangos before 2.1
- Redis 4.0+ required

- support Django 2.1 and 2.2
- added keep_fresh option to cached_as (George Lee)
- pass CACHEOPS_SENTINEL options through (David Fuentes Baldomir)
- made SKIP_FIELDS and LONG_DISJUCTION configurable (Nic Wolff)
- fixed .aggregate() over .annotate() fields in Django 2.2
- fixed .bulk_create() in Django 2.2 (Grzegorz Szczepanczyk)
- fixed test database to work in environments without /dev/shm (George Lee)
- fixed proxy/abstract model bug
- added test case for issue 312 (Andy Tzeng)
- some warnings and doc-strings improvements

- use UNLINK instead of DEL when available, use Redis 4.0+ for that
- request m2m objects for invalidation using correct db
- fixed caching counts, aggregates and exists in writes,
dirty transactions and while cacheops is disabled
- fixed various multidb/invalidation issues (Svan70)
- fixed db in .invalidated_update()
- fixed possible key disrepancy in cache_on_save with multidb
- fixed jinja2 support in Python 3
- documented CACHEOPS_CLIENT_CLASS