couch_index: don't try to get the config each time in the indexer
Rather than fetching the threshold and refresh interval settings each
time we need them, register the process to couch_config events so we can
update the config only when needed.
diff --git a/src/couch_index_indexer.erl b/src/couch_index_indexer.erl
index 4af85cf..727c8dd 100644
--- a/src/couch_index_indexer.erl
+++ b/src/couch_index_indexer.erl
@@ -19,6 +19,8 @@
-record(state, {index,
dbname,
+ threshold,
+ refresh_interval,
db_updates=0,
tref=nil,
notifier=nil,
@@ -30,10 +32,25 @@
init({Index, DbName}) ->
process_flag(trap_exit, true),
+ %% register to config events
+ Self = self(),
+ ok = couch_config:register(fun
+ ("couch_index", "threshold") ->
+ gen_server:cast(Self, config_threshold);
+ ("couch_index", "refresh_interval") ->
+ gen_server:cast(Self, config_refresh)
+ end),
+
+ %% get defaults
+ Threshold = get_db_threshold(),
+ Refresh = get_refresh_interval(),
+
%% delay background index indexing
self() ! start_indexing,
{ok, #state{index=Index,
dbname=DbName,
+ threshold=Threshold,
+ refresh_interval=Refresh,
locks=dict:new()}}.
handle_call({acquire, Pid}, _From, #state{locks=Locks}=State) ->
@@ -66,9 +83,24 @@
handle_call(stop, _From, State) ->
{stop, normal, ok, State}.
-handle_cast(updated, #state{index=Index, dbname=DbName,
- db_updates=Updates}=State) ->
+
+handle_cast(config_threshold, State) ->
Threshold = get_db_threshold(),
+ {noreply, State#state{threshold=Threshold}};
+handle_cast(config_refresh, #state{tref=TRef}=State) ->
+ R = get_refresh_interval(),
+ %% stop the old timee
+ if TRef /= nil ->
+ erlang:cancel_timer(TRef);
+ true -> ok
+ end,
+ %% start the new timer
+ NTRef = erlang:start_timer(R, self(), refresh_index),
+ {noreply, State#state{refresh_interval=R, tref=NTRef}};
+
+handle_cast(updated, #state{index=Index, dbname=DbName,
+ threshold=Threshold,
+ db_updates=Updates}=State) ->
NUpdates = Updates + 1,
%% we only update if the number of updates is greater than the
@@ -85,12 +117,12 @@
handle_cast(_Msg, State) ->
{noreply, State}.
-handle_info(start_indexing, #state{dbname=DbName}=State) ->
+handle_info(start_indexing, #state{dbname=DbName,
+ refresh_interval=R}=State) ->
%% start the db notifier to watch db update events
{ok, NotifierPid} = start_db_notifier(DbName),
%% start the timer
- R = get_refresh_interval(),
TRef = erlang:start_timer(R, self(), refresh_index),
{noreply, State#state{tref=TRef, notifier=NotifierPid}};
