%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2002-2016. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
%%
%%-----------------------------------------------------------------
%% Purpose: Functions for handling statistic counters
%%-----------------------------------------------------------------
-module(megaco_stats).
%%-----------------------------------------------------------------
%% Application internal exports
%%-----------------------------------------------------------------
-export([init/1, init/2]).
-export([inc/2, inc/3, inc/4]).
-export([get_stats/1, get_stats/2, get_stats/3,
reset_stats/1, reset_stats/2]).
%% -include_lib("megaco/include/megaco.hrl").
%%-----------------------------------------------------------------
%% Func: init/1, init/2
%% Description: Initiate the statistics. Creates the stats table
%% and the global counters.
%%-----------------------------------------------------------------
init(Name) ->
init(Name, []).
init(Name, GlobalCounters) ->
ets:new(Name, [public, named_table, {keypos, 1}]),
ets:insert(Name, {global_counters, GlobalCounters}),
create_global_snmp_counters(Name, GlobalCounters).
create_global_snmp_counters(_Name, []) ->
ok;
create_global_snmp_counters(Name, [Counter|Counters]) ->
ets:insert(Name, {Counter, 0}),
create_global_snmp_counters(Name, Counters).
%%-----------------------------------------------------------------
%% Func: inc/2, inc/3, inc/4
%% Description: Increment counter value. Default increment is one
%% (1).
%%-----------------------------------------------------------------
inc(Tab, GlobalCnt) when is_atom(GlobalCnt) ->
inc(Tab, GlobalCnt, 1).
inc(Tab, GlobalCnt, Incr)
when is_atom(GlobalCnt) andalso (is_integer(Incr) andalso (Incr > 0)) ->
do_inc(Tab, GlobalCnt, Incr);
inc(Tab, Handle, Cnt)
when is_atom(Cnt) ->
inc(Tab, Handle, Cnt, 1).
inc(Tab, Handle, Cnt, Incr)
when is_atom(Cnt) andalso (is_integer(Incr) andalso (Incr > 0)) ->
Key = {Handle, Cnt},
do_inc(Tab, Key, Incr).
do_inc(Tab, Key, Incr) ->
case (catch ets:update_counter(Tab, Key, Incr)) of
{'EXIT', {badarg, _Reason}} ->
ets:insert(Tab, {Key, Incr}),
Incr;
Val ->
Val
end.
%%-----------------------------------------------------------------
%% Func: get_stats/1, get_stats/2, get_stats/3
%% Description: Get statistics
%%-----------------------------------------------------------------
get_stats(Ets) ->
Handles = get_handles_and_global_counters(Ets),
(catch do_get_stats(Ets, Handles, [])).
do_get_stats(_Ets, [], Acc) ->
{ok, lists:reverse(Acc)};
do_get_stats(Ets, [Handle|Handles], Acc) ->
case get_stats(Ets, Handle) of
{ok, Stats} ->
do_get_stats(Ets, Handles, [{Handle, Stats}|Acc]);
{error, Reason} ->
throw({error, Reason})
end.
get_stats(Ets, GlobalCounter) when is_atom(GlobalCounter) ->
case (catch ets:lookup(Ets, GlobalCounter)) of
[{GlobalCounter, Val}] ->
{ok, Val};
[] ->
{error, {no_such_counter, GlobalCounter}}
end;
get_stats(Ets, Handle) ->
case (catch ets:match(Ets, {{Handle, '$1'},'$2'})) of
CounterVals when is_list(CounterVals) ->
{ok, [{Counter, Val} || [Counter, Val] <- CounterVals]};
Other ->
{error, {unexpected_result, Other}}
end.
get_stats(Ets, Handle, Counter) when is_atom(Counter) ->
Key = {Handle, Counter},
case (catch ets:lookup(Ets, Key)) of
[{Key, Val}] ->
{ok, Val};
_ ->
{error, {undefined_counter, Counter}}
end.
%%-----------------------------------------------------------------
%% Funcs: reset_stats/1, reset_stats/2
%% Description: Reset statistics
%%-----------------------------------------------------------------
reset_stats(Ets) ->
Handles = get_handles_and_global_counters(Ets),
(catch do_reset_stats(Ets, Handles, [])).
do_reset_stats(_Ets, [], Acc) ->
{ok, lists:reverse(Acc)};
do_reset_stats(Ets, [Handle|Handles], Acc) ->
case reset_stats(Ets, Handle) of
{ok, OldStats} ->
do_reset_stats(Ets, Handles, [{Handle, OldStats}|Acc]);
{error, Reason} ->
throw({error, Reason})
end.
reset_stats(Ets, GlobalCounter) when is_atom(GlobalCounter) ->
%% First get the current value of the counter
case (catch ets:lookup(Ets, GlobalCounter)) of
[{GlobalCounter, Val}] ->
ets:insert(Ets, {GlobalCounter, 0}),
{ok, Val};
[] -> %% Oooups
{error, {no_such_counter, GlobalCounter}}
end;
reset_stats(Ets, Handle) ->
case (catch ets:match(Ets, {{Handle, '$1'},'$2'})) of
CounterVals when is_list(CounterVals) ->
CVs = [{Counter, Val} || [Counter, Val] <- CounterVals],
reset_stats(Ets, Handle, CVs),
{ok, CVs};
Other ->
{error, {unexpected_result, Other}}
end.
reset_stats(_Ets, _Handle, []) ->
ok;
reset_stats(Ets, Handle, [{Counter, _}|CVs]) ->
ets:insert(Ets, {{Handle, Counter}, 0}),
reset_stats(Ets, Handle, CVs).
%%-----------------------------------------------------------------
%% Internal functions
%%-----------------------------------------------------------------
get_handles_and_global_counters(Ets) ->
GlobalCounters =
case ets:lookup(Ets, global_counters) of
[{global_counters, GC}] ->
GC;
[] ->
[]
end,
L1 = ets:match(Ets, {{'$1', '_'}, '_'}),
GlobalCounters ++
lists:sort([Handle || [Handle] <- remove_duplicates(L1, [])]).
remove_duplicates([], L) ->
L;
remove_duplicates([H|T], L) ->
case lists:member(H,T) of
true ->
remove_duplicates(T, L);
false ->
remove_duplicates(T, [H|L])
end.
