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% 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).
-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]).
-define(TIMEOUT, 5000).
-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) ->
gen_server:call(Pid, {execute, JsonReq}).
% Gen Server Handlers
init([Name, Command]) ->
?LOG_INFO("Starting process for: ~s", [Name]),
{ok, Pid} = couch_os_process:start_link(Command),
{ok, {Name, Command, Pid}}.
terminate(_Reason, {Name, _Command, Pid}) ->
?LOG_INFO("External Process Terminating: ~p: ~p", [Name, 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({'EXIT', Pid, Reason}, {Name, Command, Pid}) ->
?LOG_INFO("EXTERNAL: Restarting process for ~s (reason: ~w)", [Name, Reason]),
{ok, Pid} = couch_os_process:start_link(Command),
{noreply, {Name, Command, Pid}}.
handle_cast(stop, State) ->
{stop, normal, State};
handle_cast(_Whatever, State) ->
{noreply, State}.
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
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