Programming: Caching

Invalidation

Tag Caching

Objects are assigned an auto-incrementing version number
When an object changes, the cache is updated with that version number
Caches that refer to multiple object-types, keep a reference to the versions of each object the cache refers to.

ex.

• User created user_v=0
• User renamed user_v=1
• ProjectUsers adds user proj_v=1
• ProjUserCache is tagged with user_v=1,proj_v=1

When a request is made to the cache, user/project versions stored in cache are verified as being up to date, and the cache entry is either used or expired.

NOTE:

this feels like it has an atomicity problem...