common: small cleanup

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

Author: noxdafox

lib/cache.ex

@@ -102,7 +102,7 @@ defmodule RabbitMQ.MessageDeduplicationPlugin.Cache do
   end
 
   # Inserts the entry if it doesn't exist.
-  # If the cache is full, remove an element to make space.
+  # If the cache is full, it removes an element to make space.
   def handle_call({:insert, cache, entry, ttl}, _from, state) do
     function = fn ->
       if cache_member?(cache, entry) do

lib/common.ex

@@ -58,8 +58,9 @@ defmodule RabbitMQ.MessageDeduplicationPlugin.Common do
   Retrieve the given header from the message.
   """
   @spec message_header(basic_message, String.t) :: String.t | nil
-  def message_header(basic_message(content:
-      content(properties: properties)), header) do
+  def message_header(message, header) do
+    basic_message(content: content(properties: properties)) = message
+
     case properties do
       basic_properties(headers: headers) when is_list(headers) ->
         rabbit_keyfind(headers, header)