Rewrite ordering functions for maintainability

3 files changed, 29 insertions, 25 deletions

diff --git a/lib/snmp/src/agent/snmp_framework_mib.erl b/lib/snmp/src/agent/snmp_framework_mib.erl
index 6589ace949..43c91bbbc8 100644
--- a/lib/snmp/src/agent/snmp_framework_mib.erl
+++ b/lib/snmp/src/agent/snmp_framework_mib.erl
@@ -222,15 +222,9 @@ check_agent(X) ->
     error({invalid_agent_attribute, X}).
 
 %% Ordering function to sort intAgentTransportDomain first
-%% hence before intAgentIpAddress
-order_agent({Name, _}, {Name, _}) ->
-    true; %% Less than or equal
-order_agent({_, _}, {intAgentTransportDomain, _}) ->
-    false; %% Greater than
-order_agent({intAgentTransportDomain, _}, {_, _}) ->
-    true; %% Less than or equal
-order_agent({A, _}, {B, _}) ->
-    A =< B.
+%% hence before intAgentIpAddress.  Sort other entries on the key.
+order_agent(EntryA, EntryB) ->
+    snmp_conf:keyorder(1, EntryA, EntryB, [intAgentTransportDomain | sort]).
 
 
 
diff --git a/lib/snmp/src/manager/snmpm_config.erl b/lib/snmp/src/manager/snmpm_config.erl
index 69a6b4a3a9..36c7b914ac 100644
--- a/lib/snmp/src/manager/snmpm_config.erl
+++ b/lib/snmp/src/manager/snmpm_config.erl
@@ -1783,21 +1783,10 @@ init_agent_config({UserId, TargetName, Config}) ->
 
 
 
-%% Sort tdomain first then port to ensure both comes before taddress
-order_agent({Item1, _}, {Item2, _}) ->
-    if  Item1 == Item2 ->
-	    true; % Item1 == Item2
-	Item2 =:= tdomain ->
-	    false; % Item1 > tdomain
-	Item2 =:= port ->
-	    if  Item1 =:= tdomain ->
-		    true; % tdomain < port
-		true ->
-		    false % Item1 > port
-	    end;
-	true ->
-	    true % Item1 < Item 2
-    end.
+%% Sort 'tdomain' first then 'port' to ensure both
+%% sorts before 'taddress'.  Keep the order of other items.
+order_agent(ItemA, ItemB) ->
+    snmp_conf:keyorder(1, ItemA, ItemB, [tdomain, port]).
 
 fix_agent_config(Conf) ->
     ?vdebug("fix_agent_config -> entry with~n~n"
diff --git a/lib/snmp/src/misc/snmp_conf.erl b/lib/snmp/src/misc/snmp_conf.erl
index eb71c55cf4..0c9c755bf4 100644
--- a/lib/snmp/src/misc/snmp_conf.erl
+++ b/lib/snmp/src/misc/snmp_conf.erl
@@ -25,7 +25,7 @@
 %% External exports
 %% Avoid warning for local function error/1 clashing with autoimported BIF.
 -compile({no_auto_import,[error/1]}).
--export([read_files/2, no_gen/2, no_order/2, no_filter/1]).
+-export([read_files/2, no_gen/2, no_order/2, no_filter/1, keyorder/4]).
 -export([read/2, read/3]).
 
 %% Basic (type) check functions
@@ -158,6 +158,27 @@ no_gen(_Dir, _R) -> [].
 no_order(_, _) -> true.
 no_filter(X) -> X.
 
+%% Order tuples on element N with Keys first in appearence order.
+%%
+%% An ordering function (A, B) shall return true iff
+%% A is less than or equal to B i.e shall return
+%% false iff A is to be ordered after B.
+keyorder(N, A, B, _) when element(N, A) == element(N, B) ->
+    true;
+keyorder(N, A, B, [Key | _])
+  when tuple_size(A) >= 1, element(N, B) == Key ->
+    false;
+keyorder(N, A, B, [Key | _])
+  when element(N, A) == Key, tuple_size(B) >= 1 ->
+    true;
+keyorder(N, A, B, [_ | Keys]) ->
+    keyorder(N, A, B, Keys);
+keyorder(_, A, B, []) when tuple_size(A) >= 1, tuple_size(B) >= 1 ->
+    %% Do not order other keys
+    true;
+keyorder(N, A, B, sort) ->
+    %% Order other keys according to standard sort order
+    element(N, A) =< element(N, B).
 
 
 read(File, Verify) ->