Behaviour for pluggable key-value storage adapters.

Provides the minimal contract shared by every store used in the Orchid ecosystem: write a value, read it back. Domain-specific extensions (existence checks, deletion, garbage collection, bulk export) are defined as separate optional behaviours under Orchid.Repo.*.

Store Reference

Every callback receives an opaque store_ref as its first argument. The concrete type is determined by the adapter (an ETS tid, a map of connection options, a PID, etc.). Callers obtain the reference from the adapter's own init/1 or equivalent.

Composition with Extension Behaviours

Adapters declare the capabilities they support:

defmodule MyApp.BlobStore do
  @behaviour Orchid.Repo
  @behaviour Orchid.Repo.ContentAddressable
  # implements get/2, put/3, exists?/2
end

defmodule MyApp.MetaStore do
  @behaviour Orchid.Repo
  @behaviour Orchid.Repo.Deletable
  @behaviour Orchid.Repo.GC
  # implements get/2, put/3, delete/2, garbage_collect/2
end