the external process handler

git-svn-id: https://svn.apache.org/repos/asf/couchdb/trunk@727136 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 80 insertions, 0 deletions

diff --git a/src/couchdb/couch_external_server.erl b/src/couchdb/couch_external_server.erl
new file mode 100644
index 00000000..afbb729e
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+++ b/src/couchdb/couch_external_server.erl
@@ -0,0 +1,80 @@
+% 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/8]).
+-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, Db, Verb, Path, Query, Body, Post, Cookie) ->
+    gen_server:call(Pid, {execute, Db, Verb, Path, Query, Body, Post, Cookie}).
+
+% 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, Db, Verb, Path, Query, Body, Post, Cookie}, _From, {Name, Command, Pid}) ->
+    ?LOG_DEBUG("Query Params ~p",[Query]),
+    {ok, Info} = couch_db:get_db_info(Db),
+    Json = {[
+        {<<"info">>, {Info}},
+        {<<"verb">>, Verb},
+        {<<"path">>, Path},
+        {<<"query">>, to_json_terms(Query)},
+        {<<"body">>, Body},
+        {<<"form">>, to_json_terms(Post)},
+        {<<"cookie">>, to_json_terms(Cookie)}]},
+    {reply, couch_os_process:prompt(Pid, Json), {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}.
+
+% Internal API
+
+to_json_terms(Data) ->
+    to_json_terms(Data, []).
+to_json_terms([], Acc) ->
+    {lists:reverse(Acc)};
+to_json_terms([{Key, Value} | Rest], Acc) ->
+    to_json_terms(Rest, [{list_to_binary(Key), list_to_binary(Value)} | Acc]).
+