implemented rabbit_misc:plmerge/2 to merge property lists

Author: priviterag

src/rabbit_misc.erl

@@ -54,7 +54,7 @@
 -export([const/1]).
 -export([ntoa/1, ntoab/1]).
 -export([is_process_alive/1]).
--export([pget/2, pget/3, pget_or_die/2, pmerge/3, pset/3]).
+-export([pget/2, pget/3, pget_or_die/2, pmerge/3, pset/3, plmerge/2]).
 -export([format_message_queue/2]).
 -export([append_rpc_all_nodes/4]).
 -export([os_cmd/1]).
@@ -228,6 +228,7 @@
 -spec(pget/3 :: (term(), [term()], term()) -> term()).
 -spec(pget_or_die/2 :: (term(), [term()]) -> term() | no_return()).
 -spec(pmerge/3 :: (term(), term(), [term()]) -> term()).
+-spec(plmerge/2 :: ([term()], [term()]) -> term()).
 -spec(pset/3 :: (term(), term(), [term()]) -> term()).
 -spec(format_message_queue/2 :: (any(), priority_queue:q()) -> term()).
 -spec(append_rpc_all_nodes/4 :: ([node()], atom(), atom(), [any()]) -> [any()]).
@@ -883,12 +884,19 @@ pget_or_die(K, P) ->
         V         -> V
     end.
 
+%% property merge 
 pmerge(Key, Val, List) ->
       case proplists:is_defined(Key, List) of
               true -> List;
               _    -> [{Key, Val} | List]
       end.
 
+%% proplists merge
+plmerge(P1, P2) ->
+    K1 = proplists:get_keys(P1),
+    K2 = proplists:get_keys(P2),
+    P1 ++ [X || {K, _} = X <- P2, lists:member(K, K2 -- K1)].
+
 pset(Key, Value, List) -> [{Key, Value} | proplists:delete(Key, List)].
 
 format_message_queue(_Opt, MQ) ->

test/src/rabbit_tests.erl

@@ -56,6 +56,7 @@ all_tests0() ->
     passed = test_pg_local(),
     passed = test_unfold(),
     passed = test_pmerge(),
+    passed = test_plmerge(),
     passed = test_supervisor_delayed_restart(),
     passed = test_table_codec(),
     passed = test_content_framing(),
@@ -430,6 +431,12 @@ test_pmerge() ->
     [{c, 3} | P] = rabbit_misc:pmerge(c, 3, P),
     passed.
 
+test_plmerge() ->
+    P1 = [{a, 1}, {b, 2}, {c, 3}],
+    P2 = [{a, 2}, {d, 4}],
+    [{a, 1}, {b, 2}, {c, 3}, {d, 4}] = rabbit_misc:plmerge(P1, P2),
+    passed.
+
 test_table_codec() ->
     %% FIXME this does not test inexact numbers (double and float) yet,
     %% because they won't pass the equality assertions