AshCache.Resource

Caches the read and generic actions you declare, each with its own lifetime.

defmodule MyApp.Shop.Product do
  use Ash.Resource,
    domain: MyApp.Shop,
    extensions: [AshCache.Resource]

  cache do
    read :get_by_sku, ttl: :timer.hours(1)
    action :exchange_rate, ttl: :timer.minutes(10)
    calculation :shipping_quote, ttl: :timer.hours(1)
  end
end

Each read is cached, keyed by the action, the whole query, the actor and the tenant (see AshCache.Key). A read lives as long as its own ttl, else the block's ttl (5 minutes by default); empty results are not cached unless you ask. Entries go in the shared :ash_cache store unless you set store. Every create, update or destroy clears the resource's cached reads after the transaction commits (see AshCache.Changes.InvalidateCache). So does a write to any resource listed in clear_when_changed.

Each action caches a generic action, keyed by the action, its arguments, the actor and the tenant, with the same ttl rules. On a hit its run is not called (see AshCache.Actions.RunThrough). Writes clear these entries too.

Each calculation caches a module calculation's result per record, keyed by its arguments, the actor, the tenant and every value it can read from the record (see AshCache.Calculations.CalculateThrough). It lives as long as its own ttl, else the block's. Writes do not clear these entries: a changed record gives a new key. Expression calculations are rejected; they already run in the database and cached reads hold them.

Actions and calculations without an entry are never cached.

cache

Which reads, generic actions and calculations to cache, where, and for how long.

Options

Name	Type	Default	Docs
`store`	`atom`	`:ash_cache`	Name of the cache store. Distinct stores isolate eviction and clearing. With `AshCache.Store.Adapters.Nebulex`, the Nebulex cache module.
`ttl`	`pos_integer \| :infinity`	`300000`	Milliseconds a cached entry lives before it expires, for every `read`, `action` and `calculation` that does not set its own `ttl`. `:infinity` never expires; it is never the default.
`clear_when_changed`	`list(atom)`	`[]`	Other resources whose create, update or destroy also clears this resource's cached reads and generic actions, e.g. `clear_when_changed [MyApp.Blog.Comment]`. Each one must use the `AshCache.Resource` extension, even if it caches nothing itself.

cache.read

read name

Cache this read action, with its own lifetime and settings.

Arguments

Name	Type	Default	Docs
`name`	`atom`		The read action to cache.

Options

Name	Type	Default	Docs
`ttl`	`pos_integer \| :infinity`		Milliseconds a cached entry of this read lives before it expires, or `:infinity` to never expire. Defaults to the `cache` block's `ttl`.
`cache_empty?`	`boolean`	`false`	Whether empty results ([] or nil) are cached. Off by default.
`store_options`	`keyword`	`[]`	Options passed verbatim to the store adapter's put/4. Couples the resource to that adapter.

Introspection

Target: AshCache.CachedRead

cache.action

action name

Cache this generic action, with its own lifetime and settings.

Arguments

Name	Type	Default	Docs
`name`	`atom`		The generic action to cache.

Options

Name	Type	Default	Docs
`ttl`	`pos_integer \| :infinity`		Milliseconds a cached entry of this read lives before it expires, or `:infinity` to never expire. Defaults to the `cache` block's `ttl`.
`cache_empty?`	`boolean`	`false`	Whether empty results ([] or nil) are cached. Off by default.
`store_options`	`keyword`	`[]`	Options passed verbatim to the store adapter's put/4. Couples the resource to that adapter.

Introspection

Target: AshCache.CachedAction

cache.calculation

calculation name

Cache this module calculation's result per record, with its own lifetime.

Arguments

Name	Type	Default	Docs
`name`	`atom`		The calculation to cache.

Options

Name	Type	Default	Docs
`ttl`	`pos_integer \| :infinity`		Milliseconds a cached entry of this read lives before it expires, or `:infinity` to never expire. Defaults to the `cache` block's `ttl`.
`store_options`	`keyword`	`[]`	Options passed verbatim to the store adapter's put/4. Couples the resource to that adapter.

Introspection

Target: AshCache.CachedCalculation

cache.refresh

refresh read

Re-run a read after every successful create/update so the fresh value is cached immediately (write-through), e.g. refresh :get_by_key, arguments: [key: :key].

Arguments

Name	Type	Default	Docs
`read`	`atom`		The cached read action to refresh.

Options

Name	Type	Default	Docs
`arguments`	`keyword`	`[]`	Read arguments as `argument_name: record_attribute` pairs.
`actor`	`nil \| mfa`		MFA returning the actor to refresh as. Refreshed entries are cached under this actor's key, so it must match how the read is normally called.

Introspection

Target: AshCache.Refresh

← Previous Page How to test with AshCache

Next Page → Changelog