| %%% |
| %%% Copyright 2011, Boundary |
| %%% |
| %%% 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. |
| %%% |
| |
| |
| %%%------------------------------------------------------------------- |
| %%% File: folsom_meter_timer_server.erl |
| %%% @author joe williams <j@boundary.com> |
| %%% @doc |
| %%% gen_server for registering meter ticks |
| %%% @end |
| %%%----------------------------------------------------------------- |
| |
| -module(folsom_meter_timer_server). |
| |
| -behaviour(gen_server). |
| |
| %% API |
| -export([start_link/0, register/2, dump/0]). |
| |
| %% gen_server callbacks |
| -export([init/1, handle_call/3, handle_cast/2, handle_info/2, |
| terminate/2, code_change/3]). |
| |
| -define(SERVER, ?MODULE). |
| |
| -include("folsom.hrl"). |
| |
| -record(state, { |
| registered_timers = [] |
| }). |
| |
| %%%=================================================================== |
| %%% API |
| %%%=================================================================== |
| |
| %%-------------------------------------------------------------------- |
| %% @doc |
| %% Starts the server |
| %% |
| %% @spec start_link() -> {ok, Pid} | ignore | {error, Error} |
| %% @end |
| %%-------------------------------------------------------------------- |
| start_link() -> |
| gen_server:start_link({local, ?SERVER}, ?MODULE, [], []). |
| |
| %%%=================================================================== |
| %%% gen_server callbacks |
| %%%=================================================================== |
| |
| %%-------------------------------------------------------------------- |
| %% @private |
| %% @doc |
| %% Initializes the server |
| %% |
| %% @spec init(Args) -> {ok, State} | |
| %% {ok, State, Timeout} | |
| %% ignore | |
| %% {stop, Reason} |
| %% @end |
| %%-------------------------------------------------------------------- |
| init([]) -> |
| {ok, #state{}}. |
| |
| %%-------------------------------------------------------------------- |
| %% @private |
| %% @doc |
| %% Handling call messages |
| %% |
| %% @spec handle_call(Request, From, State) -> |
| %% {reply, Reply, State} | |
| %% {reply, Reply, State, Timeout} | |
| %% {noreply, State} | |
| %% {noreply, State, Timeout} | |
| %% {stop, Reason, Reply, State} | |
| %% {stop, Reason, State} |
| %% @end |
| %%-------------------------------------------------------------------- |
| handle_call({register, Name, Module}, _From, State) -> |
| NewState = case proplists:is_defined(Name, State#state.registered_timers) of |
| true -> |
| State; |
| false -> |
| {ok, Ref} = timer:apply_interval(?DEFAULT_INTERVAL, Module, tick, [Name]), |
| NewList = [{Name, Ref} | State#state.registered_timers], |
| #state{registered_timers = NewList} |
| end, |
| {reply, ok, NewState}; |
| handle_call(dump, _From, State) -> |
| {reply, State, State}. |
| |
| %%-------------------------------------------------------------------- |
| %% @private |
| %% @doc |
| %% Handling cast messages |
| %% |
| %% @spec handle_cast(Msg, State) -> {noreply, State} | |
| %% {noreply, State, Timeout} | |
| %% {stop, Reason, State} |
| %% @end |
| %%-------------------------------------------------------------------- |
| handle_cast(_Msg, State) -> |
| {noreply, State}. |
| |
| %%-------------------------------------------------------------------- |
| %% @private |
| %% @doc |
| %% Handling all non call/cast messages |
| %% |
| %% @spec handle_info(Info, State) -> {noreply, State} | |
| %% {noreply, State, Timeout} | |
| %% {stop, Reason, State} |
| %% @end |
| %%-------------------------------------------------------------------- |
| handle_info(_Info, State) -> |
| {noreply, State}. |
| |
| %%-------------------------------------------------------------------- |
| %% @private |
| %% @doc |
| %% This function is called by a gen_server when it is about to |
| %% terminate. It should be the opposite of Module:init/1 and do any |
| %% necessary cleaning up. When it returns, the gen_server terminates |
| %% with Reason. The return value is ignored. |
| %% |
| %% @spec terminate(Reason, State) -> void() |
| %% @end |
| %%-------------------------------------------------------------------- |
| terminate(_Reason, _State) -> |
| ok. |
| |
| %%-------------------------------------------------------------------- |
| %% @private |
| %% @doc |
| %% Convert process state when code is changed |
| %% |
| %% @spec code_change(OldVsn, State, Extra) -> {ok, NewState} |
| %% @end |
| %%-------------------------------------------------------------------- |
| code_change(_OldVsn, State, _Extra) -> |
| {ok, State}. |
| |
| %%%=================================================================== |
| %%% Internal functions |
| %%%=================================================================== |
| |
| %% Name of the metric and name of the module used to tick said metric |
| register(Name, Module) -> |
| gen_server:call(?SERVER, {register, Name, Module}). |
| |
| dump() -> |
| gen_server:call(?SERVER, dump). |