about summary refs log tree commit diff
path: root/users/wpcarro/assessments/semiprimes/server/lib/cache.ex
blob: cd064cc1ae4b7b0f79ef7ced5c67932ec76baf12 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
defmodule Cache do
  @moduledoc """
  Cache is an in-memory key-value store.
  """
  use Agent

  @doc """
  Inititalize the key-value store.
  """
  def start_link(_) do
    Agent.start_link(fn -> %{} end, name: __MODULE__)
  end

  @doc """
  Attempt to return the value stored at `key`
  """
  def get(key) do
    Agent.get(__MODULE__, &Map.get(&1, key))
  end

  @doc """
  Write the `value` under the `key`. Last writer wins.
  """
  def put(key, value) do
    Agent.update(__MODULE__, &Map.put(&1, key, value))
  end

  @doc """
  List the contents of the cache. Useful for debugging purposes.
  """
  def list() do
    Agent.get(__MODULE__, & &1)
  end

  @doc """
  Invalidate the entire cache.
  """
  def clear() do
    Agent.update(__MODULE__, fn _ -> %{} end)
  end
end