1 files changed, 31 insertions, 0 deletions
diff --git a/lib/irc/client/user_cache.ex b/lib/irc/client/user_cache.ex
new file mode 100644
index 0000000..2653630
--- /dev/null
+++ b/lib/irc/client/user_cache.ex
@@ -0,0 +1,31 @@
+defmodule Irc.Client.UserCache do
+
+  # tuple: {nick, user}
+
+  def init(args) do
+    opts = [{:read_concurrency, true}, :protected]
+    :ets.new(__MODULE__, opts)
+  end
+
+  def lookup(ets, nick) do
+    case :ets.lookup(ets, nick) do
+      [{^nick, user}] -> user
+      _ -> nil
+    end
+  end
+
+  def change(ets, nick, changes) do
+    initial = if user = lookup(ets, nick), do: user, else: %Irc.User{nick: nick}
+    user = User.change(initial, changes)
+    put(ets, nick, user)
+  end
+
+  defp put(ets, original_nick, user) do
+    tuple = {user.nick, user}
+    if original_nick != user.nick do
+      true = :ets.delete(ets, original_nick)
+    end
+    :ets.insert(ets, tuple)
+  end
+
+end