mongodb:sharded/2 add multiple or just one mongos, will connect to ra…

…ndom mongos in the list

README.rdoc

@@ -29,6 +29,7 @@ mongodb:replicaPairs/3
 mongodb:replicaSets/2
 mongodb:masterSlave/3
 mongodb:connect/1
+mongodb:sharded/2
 
 Connection info is saved in an application variable (erlmongo,connections) and updated with every call to: singleServer, masterSlave, replicaPairs, masterMaster, replicaSets, and deleteConnection. If mongodb process crashes for some reason, connections will be restarted. Also if the application itself is stopped and started. You can add a connections variable to erlmongo.app file:
   % def is name of connection, types can be: masterSlave,masterMaster or replicaPairs. This is how singleServer info is saved:

src/mongoapi.erl

@@ -176,7 +176,7 @@ findOne(Query) when is_tuple(Query) ->
 		R ->
 			R
 	end.
-findOne(Col, [_|_] = Query, [_|_] = Selector) ->
+findOne(Col, Query, Selector) ->
 	case find(Col, Query, Selector, 0, 1) of
 		{ok, [Res]} -> {ok, Res};
 		{ok, []} -> {ok, []};

src/mongodb.erl

@@ -3,7 +3,7 @@
 		 handle_cast/2, handle_info/2, terminate/2, code_change/3]).
 % API
 -export([connect/1, connect/2, is_connected/1,deleteConnection/1, singleServer/2, singleServer/1, 
-		 masterSlave/3,masterMaster/3, replicaPairs/3, datetime_to_now/1,replicaSets/2]).
+		 masterSlave/3,masterMaster/3, replicaPairs/3, datetime_to_now/1,replicaSets/2,sharded/2]).
 % Internal
 -export([exec_cursor/3, exec_delete/3, exec_cmd/3, exec_insert/3, exec_find/3, exec_update/3, exec_getmore/3,  
          encoderec/1, encode_findrec/1, encoderec_selector/2, gen_keyname/2, gen_prop_keyname/2, rec/0, recoffset/1, recfields/1,
@@ -99,9 +99,15 @@ masterSlave(Pool,MasterAddr, SlaveAddr) ->
 	[IP2,Port2] = string:tokens(SlaveAddr,":"),
 	gen_server:cast(?MODULE, {conninfo,Pool, {masterSlave, {IP1,Port1}, {IP2,Port2}}}).
 masterMaster(Pool,Addr1,Addr2) ->
-	[IP1,Port1] = string:tokens(Addr1,":"),
-	[IP2,Port2] = string:tokens(Addr2,":"),
-	gen_server:cast(?MODULE, {conninfo,Pool, {masterMaster, {IP1,Port1}, {IP2,Port2}}}).
+	% [IP1,Port1] = string:tokens(Addr1,":"),
+	% [IP2,Port2] = string:tokens(Addr2,":"),
+	% gen_server:cast(?MODULE, {conninfo,Pool, {masterMaster, {IP1,Port1}, {IP2,Port2}}}).
+	sharded(Pool,[Addr1,Addr2]).
+sharded(Pool,[[_|_]|_] = L) ->
+	SL = [list_to_tuple(string:tokens(A,":")) || A <- L],
+	gen_server:cast(?MODULE, {conninfo,Pool, {multimaster, list_to_tuple(SL)}});
+sharded(Pool,[_|_] = L) ->
+	sharded(Pool,[L]).
 replicaPairs(Pool,Addr1,Addr2) ->
 	[IP1,Port1] = string:tokens(Addr1,":"),
 	[IP2,Port2] = string:tokens(Addr2,":"),
@@ -173,7 +179,7 @@ exec_find(Pool,Collection, Quer) ->
 			receive
 				{query_result, _Src, <<_:32,_CursorID:64/little, _From:32/little, _NDocs:32/little, Result/binary>>} ->
 					Result
-				after 20000 ->
+				after 200000 ->
 					not_connected
 			end;
 		X ->
@@ -269,7 +275,6 @@ startcon(Name, undefined, Type, Addr, Port) when is_list(Port) ->
 startcon(Name, undefined, Type, Addr, Port) ->
 	PID = spawn_link(fun() -> connection(true) end),
 	put(PID,Name),
-	% register(Name,PID),
 	PID ! {start, Name, self(), Type, Addr, Port};
 startcon(_,PID, _, _, _) ->
 	PID.
@@ -336,16 +341,27 @@ handle_cast({print_info}, P) ->
 handle_cast(_, P) ->
 	{noreply, P}.
 
-start_connection(Name, #conn{conninfo = {masterMaster, {A1,P1},{A2,P2}}} = P) ->
+% start_connection(Name, #conn{conninfo = {masterMaster, {A1,P1},{A2,P2}}} = P) ->
+% 	case P#conn.pid of
+% 		undefined ->
+% 			Timer = P#conn.timer,
+% 			case random:uniform(2) of
+% 				1 ->
+% 					startcon(Name,P#conn.pid,readwrite,A1,P1);
+% 				2 ->
+% 					startcon(Name,P#conn.pid,readwrite,A2,P2)
+% 			end;
+% 		_ ->
+% 			Timer = ctimer(P#conn.timer)
+% 	end,
+% 	put(Name,P#conn{timer = Timer});
+start_connection(Name, #conn{conninfo = {multimaster, Srvrs}} = P) ->
 	case P#conn.pid of
 		undefined ->
 			Timer = P#conn.timer,
-			case random:uniform(2) of
-				1 ->
-					startcon(Name,P#conn.pid,readwrite,A1,P1);
-				2 ->
-					startcon(Name,P#conn.pid,readwrite,A2,P2)
-			end;
+			Index = random:uniform(tuple_size(Srvrs)),
+			{Adr,Port} = element(Index,Srvrs),
+			startcon(Name,P#conn.pid,readwrite,Adr,Port);
 		_ ->
 			Timer = ctimer(P#conn.timer)
 	end,
@@ -519,6 +535,8 @@ init([]) ->
 	{ok, HN} = inet:gethostname(),
 	<<HashedHN:3/binary,_/binary>> = erlang:md5(HN),
 	process_flag(trap_exit, true),
+	{A1,A2,A3} = now(),
+    random:seed(A1, A2, A3),
 	{ok, #mngd{indexes = ets:new(mongoIndexes, [set, private]), hashed_hostn = HashedHN}}.
 
 
@@ -717,11 +735,19 @@ connection(#con{} = P,Index,Buf) ->
 		{tcp, _, Bin} ->
 			% io:format("~p~n", [{byte_size(Bin), Buf}]),
 			connection(P,Index,readpacket(<<Buf/binary,Bin/binary>>));
+		{ping} ->
+			erlang:send_after(1000,self(),{ping}),
+			Collection = <<"admin.$cmd">>, 
+			Query = #search{nskip = 0, ndocs = 1, criteria = mongodb:encode([{<<"ping">>, 1}])},
+			QBin = constr_query(Query,Index, Collection),
+			ok = gen_tcp:send(P#con.sock, QBin),
+			connection(P,Index+1,Buf);
 		{stop} ->
 			true;
 		{start, Pool, Source, Type, IP, Port} ->
 			{A1,A2,A3} = now(),
 		    random:seed(A1, A2, A3),
+			% io:format("MDB ~p~n", [{Pool,IP,Port}]),
 			{ok, Sock} = gen_tcp:connect(IP, Port, [binary, {packet, 0}, {active, true}, {keepalive, true}]),
 			case Type of
 				ifmaster ->
@@ -737,6 +763,7 @@ connection(#con{} = P,Index,Buf) ->
 					register(Pool,self()),
 					Source ! {conn_established, Pool, Type, self()}
 			end,
+			erlang:send_after(1000,self(),{ping}),
 			connection(#con{sock = Sock},1, <<>>);
 		{tcp_closed, _} ->
 			exit(stop)