Operate cache specification.

A cache is responsible for storing and retrieving tapes and ops from a cache, and if necessary instructing an adapter to fetch items from a data source.

Operate comes bundled with a ConCache ETS cache, although by default runs without any caching.

Creating a cache

A cache must implement both of the following callbacks:

• fetch_tx/3 - function that takes a txid and returns a Operate.BPU.Transaction.t/0
• fetch_ops/3 - function that takes a list of Op references and returns a list of Operate.Op.t/0 functions.

The third argument in both functions is a tuple containing the adapter module and a keyword list of options to pass to the adapter.

defmodule MyCache do
  use Operate.Cache

  def fetch_tx(txid, opts, {adapter, adapter_opts}) do
    ttl = Keyword.get(opts, :ttl, 3600)
    Cache.fetch_or_store(txid, ttl: ttl, fn ->
      adapter.fetch_tx(txid, adapter_opts)
    end)
  end
end

Using the above example, Operate can be configured with:

{Operate, [
  cache: {MyCache, [ttl: 3600]}
]}