exchange: add exchange info callback implementation

Provides to the User access to cache information (size and number of
entries).

Signed-off-by: Matteo Cafasso <[email protected]>

Author: noxdafox

lib/rabbit_message_deduplication_exchange.ex

@@ -154,11 +154,15 @@ defmodule RabbitMQ.MessageDeduplicationExchangeType do
     RabbitExchange.assert_args_equivalence(exchange, args)
   end
 
-  def info(_x) do
-    []
+  def info(exchange) do
+    info(exchange, [:cache_info])
+  end
+
+  def info(exchange(name: name), [:cache_info]) do
+    [cache_info: name |> cache_name() |> RabbitMQ.Cache.info()]
   end
 
-  def info(_x, _y) do
+  def info(_ex, _it) do
     []
   end