| % 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. |
| |
| -module(couch_external_server). |
| -behaviour(gen_server). |
| -vsn(1). |
| -behaviour(config_listener). |
| |
| -export([start_link/2, stop/1, execute/2]). |
| -export([init/1, terminate/2, handle_call/3, handle_cast/2, handle_info/2, code_change/3]). |
| |
| % config_listener api |
| -export([handle_config_change/5]). |
| |
| -include_lib("couch/include/couch_db.hrl"). |
| |
| % External API |
| |
| start_link(Name, Command) -> |
| gen_server:start_link(couch_external_server, [Name, Command], []). |
| |
| stop(Pid) -> |
| gen_server:cast(Pid, stop). |
| |
| execute(Pid, JsonReq) -> |
| {json, Json} = gen_server:call(Pid, {execute, JsonReq}, infinity), |
| ?JSON_DECODE(Json). |
| |
| % Gen Server Handlers |
| |
| init([Name, Command]) -> |
| ?LOG_INFO("EXTERNAL: Starting process for: ~s", [Name]), |
| ?LOG_INFO("COMMAND: ~s", [Command]), |
| process_flag(trap_exit, true), |
| Timeout = list_to_integer(config:get("couchdb", "os_process_timeout", |
| "5000")), |
| {ok, Pid} = couch_os_process:start_link(Command, [{timeout, Timeout}]), |
| ok = config:listen_for_changes(?MODULE, Pid), |
| {ok, {Name, Command, Pid}}. |
| |
| terminate(_Reason, {_Name, _Command, Pid}) -> |
| couch_os_process:stop(Pid), |
| ok. |
| |
| handle_call({execute, JsonReq}, _From, {Name, Command, Pid}) -> |
| {reply, couch_os_process:prompt(Pid, JsonReq), {Name, Command, Pid}}. |
| |
| handle_info({gen_event_EXIT, {config_listener, ?MODULE}, _Reason}, State) -> |
| erlang:send_after(5000, self(), restart_config_listener), |
| {noreply, State}; |
| handle_info(restart_config_listener, State) -> |
| ok = config:listen_for_changes(?MODULE, State), |
| {noreply, State}; |
| handle_info({'EXIT', _Pid, normal}, State) -> |
| {noreply, State}; |
| handle_info({'EXIT', Pid, Reason}, {Name, Command, Pid}) -> |
| ?LOG_INFO("EXTERNAL: Process for ~s exiting. (reason: ~w)", [Name, Reason]), |
| {stop, Reason, {Name, Command, Pid}}. |
| |
| handle_cast(stop, {Name, Command, Pid}) -> |
| ?LOG_INFO("EXTERNAL: Shutting down ~s", [Name]), |
| exit(Pid, normal), |
| {stop, normal, {Name, Command, Pid}}; |
| handle_cast(_Whatever, State) -> |
| {noreply, State}. |
| |
| code_change(_OldVsn, State, _Extra) -> |
| {ok, State}. |
| |
| |
| handle_config_change("couchdb", "os_process_timeout", NewTimeout, _, Pid) -> |
| couch_os_process:set_timeout(Pid, list_to_integer(NewTimeout)), |
| {ok, Pid}; |
| handle_config_change(_, _, _, _, Pid) -> |
| {ok, Pid}. |
| |