From 70ab6cdd988091207c983f68206417157ed72ad6 Mon Sep 17 00:00:00 2001
From: Fabio Salvini <salvini.fabio001@gmail.com>
Date: Sun, 2 Jul 2017 13:35:56 +0200
Subject: [PATCH] Managed problem of infinite consecutive errors

---
 TODO.md                           |  1 -
 apps/log_monitor/src/gatherer.erl | 23 +++++++++++++++++------
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/TODO.md b/TODO.md
index bac07dc..0ab8bed 100644
--- a/TODO.md
+++ b/TODO.md
@@ -1,4 +1,3 @@
 TODO
 =====
-  - Fix problem of infinite consecutive errors.
   - Limit number of emails that can be sent in a period of time.
diff --git a/apps/log_monitor/src/gatherer.erl b/apps/log_monitor/src/gatherer.erl
index 1fa3a68..2134b67 100644
--- a/apps/log_monitor/src/gatherer.erl
+++ b/apps/log_monitor/src/gatherer.erl
@@ -24,7 +24,7 @@
 
 -record(log, {file, error_regex}).
 -record(state_off, {log}).
--record(state_on, {log, error, until}).
+-record(state_on, {log, error, until, max_until}).
 
 %%%===================================================================
 %%% API
@@ -81,9 +81,14 @@ state_off({log_line, Text}, State = #state_off{log = Log}) ->
     case isError(Text, Log#log.error_regex) of
         true ->
             Timeout = timer_time(),
+            MaxTimeout = safe_timer_time(),
             Now = to_milliseconds(os:timestamp()),
             Until = Now + Timeout,
-            {next_state, state_on, #state_on{log = Log, error = Text, until = Until}, Timeout};
+            MaxUntil = Now + MaxTimeout,
+            {next_state,
+             state_on,
+             #state_on{log = Log, error = Text, until = Until, max_until = MaxUntil},
+             Timeout};
         false -> {next_state, state_off, State}
     end.
 
@@ -102,17 +107,23 @@ state_off({log_line, Text}, State = #state_off{log = Log}) ->
 %%                   {stop, Reason, NewState}
 %% @end
 %%--------------------------------------------------------------------
-state_on({log_line, Text}, #state_on{log = Log, error = Error, until = Until}) ->
+state_on({log_line, Text}, #state_on{log = Log, error = Error, until = Until, max_until = MaxUntil}) ->
     case isError(Text, Log#log.error_regex) of
         true ->
             Timeout = timer_time(),
             Now = to_milliseconds(os:timestamp()),
-            Until = Now + Timeout,
-            {next_state, state_on, #state_on{log = Log, error = Error ++ Text, until = Until}, Timeout};
+            NewUntil = min(Now + Timeout, MaxUntil),
+            {next_state,
+             state_on,
+             #state_on{log = Log, error = Error ++ Text, until = NewUntil, max_until = MaxUntil},
+             if MaxUntil > Now -> Timeout; true -> 0 end};
         false ->
             Now = to_milliseconds(os:timestamp()),
             Timeout = Until - Now,
-            {next_state, state_on, #state_on{log = Log, error = Error ++ Text, until = Until}, Timeout}
+            {next_state,
+             state_on,
+             #state_on{log = Log, error = Error ++ Text, until = Until, max_until = MaxUntil},
+             Timeout}
     end;
 state_on(timeout, #state_on{log = Log, error = Error, until = _}) ->
     mailer ! {error, Log#log.file, Error},