From 223acaf58b87c3a6bfe6f2fa0a91da0f71d7536b Mon Sep 17 00:00:00 2001
From: Petrovsky Alexander <petrovsky@aboutecho.com>
Date: Tue, 9 Oct 2012 18:25:32 +0400
Subject: [PATCH] Add ewma for day suport, add tests

---
 src/folsom_ewma.erl           | 13 +++++++++----
 src/folsom_metrics_meter.erl  | 19 +++++++++++++++----
 test/folsom_erlang_checks.erl |  8 +++++++-
 3 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/src/folsom_ewma.erl b/src/folsom_ewma.erl
index fc82781..77b2413 100644
--- a/src/folsom_ewma.erl
+++ b/src/folsom_ewma.erl
@@ -29,9 +29,10 @@
 
 -module(folsom_ewma).
 
--define(M1_ALPHA, 1 - math:exp(-5 / 60.0)).
--define(M5_ALPHA, 1 - math:exp(-5 / 60.0 / 5)).
--define(M15_ALPHA, 1 - math:exp(-5 / 60.0 / 15)).
+-define(M1_ALPHA,   1 - math:exp(-5 / 60.0)).
+-define(M5_ALPHA,   1 - math:exp(-5 / 60.0 / 5)).
+-define(M15_ALPHA,  1 - math:exp(-5 / 60.0 / 15)).
+-define(D1_ALPHA,   1 - math:exp(-5 / 60.0 / 1440)).
 
 -record(ewma, {
           alpha,
@@ -47,7 +48,8 @@
          tick/1,
          one_minute_ewma/0,
          five_minute_ewma/0,
-         fifteen_minute_ewma/0]).
+         fifteen_minute_ewma/0,
+         one_day_ewma/0]).
 
 
 % API
@@ -61,6 +63,9 @@ five_minute_ewma() ->
 fifteen_minute_ewma() ->
     new(?M15_ALPHA, 5).
 
+one_day_ewma() ->
+    new(?D1_ALPHA, 5).
+
 new(Alpha, Interval) ->
     #ewma{alpha = Alpha, interval = Interval}.
 
diff --git a/src/folsom_metrics_meter.erl b/src/folsom_metrics_meter.erl
index 5f8236b..7646b0d 100644
--- a/src/folsom_metrics_meter.erl
+++ b/src/folsom_metrics_meter.erl
@@ -37,6 +37,7 @@
           one,
           five,
           fifteen,
+          day,
           count = 0,
           start_time
          }).
@@ -47,26 +48,31 @@ new(Name) ->
     OneMin = folsom_ewma:one_minute_ewma(),
     FiveMin = folsom_ewma:five_minute_ewma(),
     FifteenMin = folsom_ewma:fifteen_minute_ewma(),
+    OneDay = folsom_ewma:one_day_ewma(),
 
     ets:insert(?METER_TABLE,
                {Name, #meter{one = OneMin,
                              five = FiveMin,
                              fifteen = FifteenMin,
+                             day = OneDay,
                              start_time = folsom_utils:now_epoch_micro()}}).
 
 tick(Name) ->
     #meter{one = OneMin,
            five = FiveMin,
-           fifteen = FifteenMin} = Meter = get_value(Name),
+           fifteen = FifteenMin,
+           day = OneDay} = Meter = get_value(Name),
 
     OneMin1 = folsom_ewma:tick(OneMin),
     FiveMin1 = folsom_ewma:tick(FiveMin),
     FifteenMin1 = folsom_ewma:tick(FifteenMin),
+    OneDay1 = folsom_ewma:tick(OneDay),
 
     ets:insert(?METER_TABLE,
                {Name, Meter#meter{one = OneMin1,
                                   five = FiveMin1,
-                                  fifteen = FifteenMin1}}).
+                                  fifteen = FifteenMin1,
+                                  day = OneDay1}}).
 
 mark(Name) ->
     mark(Name, 1).
@@ -75,21 +81,25 @@ mark(Name, Value) ->
     #meter{count = Count,
            one = OneMin,
            five = FiveMin,
-           fifteen = FifteenMin} = Meter = get_value(Name),
+           fifteen = FifteenMin,
+           day = OneDay} = Meter = get_value(Name),
 
     OneMin1 = folsom_ewma:update(OneMin, Value),
     FiveMin1 = folsom_ewma:update(FiveMin, Value),
     FifteenMin1 = folsom_ewma:update(FifteenMin, Value),
+    OneDay1 = folsom_ewma:update(OneDay, Value),
 
     ets:insert(?METER_TABLE, {Name, Meter#meter{count = Count + Value,
                                                 one = OneMin1,
                                                 five = FiveMin1,
-                                                fifteen = FifteenMin1}}).
+                                                fifteen = FifteenMin1,
+                                                day = OneDay1}}).
 
 get_values(Name) ->
     #meter{one = OneMin,
            five = FiveMin,
            fifteen = FifteenMin,
+           day = OneDay,
            count = Count} = Meter = get_value(Name),
 
     L = [
@@ -97,6 +107,7 @@ get_values(Name) ->
          {one, get_rate(OneMin)},
          {five, get_rate(FiveMin)},
          {fifteen, get_rate(FifteenMin)},
+         {day, get_rate(OneDay)},
          {mean, get_mean_rate(Meter)},
          {acceleration, get_acceleration(Name)}
         ],
diff --git a/test/folsom_erlang_checks.erl b/test/folsom_erlang_checks.erl
index 80271d1..c35d27a 100644
--- a/test/folsom_erlang_checks.erl
+++ b/test/folsom_erlang_checks.erl
@@ -183,12 +183,18 @@ check_metrics() ->
              _ ->
                  error
          end,
+    ok = case proplists:get_value(day, Meter) of
+             Value1 when Value1 > 0.005 ->
+                 ok;
+             _ ->
+                 error
+         end,
 
     ?debugFmt("checking meter reader~n", []),
     MeterReader = folsom_metrics:get_metric_value(meter_reader),
     ?debugFmt("~p~n", [MeterReader]),
     ok = case proplists:get_value(one, MeterReader) of
-             Value1 when Value1 > 1 ->
+             Value2 when Value2 > 1 ->
                  ok;
              _ ->
                  error