Module serenity::cache [−][src]
Expand description
A cache containing data received from Shards.
Using the cache allows to avoid REST API requests via the http module
where possible. Issuing too many requests will lead to ratelimits.
Following a policy to never hand out locks, the cache will clone all values when calling its methods.
Use by Models
Most models of Discord objects, such as the Message, GuildChannel,
or Emoji, have methods for interacting with that single instance. This
feature is only compiled if the methods feature is enabled. An example of
this is Guild::edit, which performs a check to ensure that the current
user is the owner of the guild, prior to actually performing the HTTP
request. The cache is involved due to the function’s use of unlocking the
cache and retrieving the Id of the current user, and comparing it to the Id
of the user that owns the guild. This is an inexpensive method of being able
to access data required by these sugary methods.
Do I need the Cache?
If you’re asking this, the answer is likely “definitely yes” or “definitely no”; any in-between tends to be “yes”. If you are low on RAM, and need to run on only a couple MB, then the answer is “definitely no”. If you do not care about RAM and want your bot to be able to access data while needing to hit the REST API as little as possible, then the answer is “yes”.
Structs
Iterator given to the selector closure in Cache::channel_messages_field.
Settings for the cache.