%%
%% %CopyrightBegin%
%% 
%% Copyright Ericsson AB 2002-2018. All Rights Reserved.
%% 
%% 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.
%% 
%% %CopyrightEnd%
%%
-module(observer_backend).

%% General
-export([vsn/0]).

%% observer stuff
-export([sys_info/0, get_port_list/0, procs_info/1,
	 get_table/3, get_table_list/2, fetch_stats/2]).

%% etop stuff
-export([etop_collect/1]).
-include("observer_backend.hrl").

%% ttb stuff
-export([ttb_init_node/3,
	 ttb_write_trace_info/3,
	 ttb_write_binary/2,
	 ttb_stop/1,
	 ttb_fetch/2,
	 ttb_fetch/3,
         ttb_resume_trace/0,
	 ttb_get_filenames/1]).
-define(CHUNKSIZE,8191). % 8 kbytes - 1 byte

vsn() ->
    case application:load(runtime_tools) of
	R when R=:=ok; R=:={error,{already_loaded,runtime_tools}} -> 
	    application:get_key(runtime_tools,vsn);
	Error -> Error
    end.

%%
%% observer backend
%%
sys_info() ->
    MemInfo = try erlang:memory() of
		  Mem -> Mem
	      catch _:_ -> []
	      end,

    SchedulersOnline = erlang:system_info(schedulers_online),
    SchedulersAvailable = case erlang:system_info(multi_scheduling) of
			      enabled -> SchedulersOnline;
			      _ -> 1
			  end,

    {{_,Input},{_,Output}} = erlang:statistics(io),
    [{uptime, element(1, erlang:statistics(wall_clock))},
     {run_queue, erlang:statistics(run_queue)},
     {io_input, Input},
     {io_output,  Output},

     {logical_processors, erlang:system_info(logical_processors)},
     {logical_processors_online, erlang:system_info(logical_processors_online)},
     {logical_processors_available, erlang:system_info(logical_processors_available)},
     {schedulers, erlang:system_info(schedulers)},
     {schedulers_online, SchedulersOnline},
     {schedulers_available, SchedulersAvailable},

     {otp_release, erlang:system_info(otp_release)},
     {version, erlang:system_info(version)},
     {system_architecture, erlang:system_info(system_architecture)},
     {kernel_poll, erlang:system_info(kernel_poll)},
     {smp_support, erlang:system_info(smp_support)},
     {threads, erlang:system_info(threads)},
     {thread_pool_size, erlang:system_info(thread_pool_size)},
     {wordsize_internal, erlang:system_info({wordsize, internal})},
     {wordsize_external, erlang:system_info({wordsize, external})},
     {alloc_info, alloc_info()},
     {process_count, erlang:system_info(process_count)},
     {atom_limit,  erlang:system_info(atom_limit)},
     {atom_count, erlang:system_info(atom_count)},
     {process_limit, erlang:system_info(process_limit)},
     {process_count, erlang:system_info(process_count)},
     {port_limit, erlang:system_info(port_limit)},
     {port_count, erlang:system_info(port_count)},
     {ets_limit,  erlang:system_info(ets_limit)},
     {ets_count, erlang:system_info(ets_count)},
     {dist_buf_busy_limit, erlang:system_info(dist_buf_busy_limit)}
     | MemInfo].

alloc_info() ->
    AlcuAllocs = erlang:system_info(alloc_util_allocators),
    try erlang:system_info({allocator_sizes, AlcuAllocs}) of
	Allocators -> Allocators
    catch _:_ -> []
    end.

get_table(Parent, Table, Module) ->
    spawn(fun() ->
		  link(Parent),
		  get_table2(Parent, Table, Module)
	  end).

get_table2(Parent, Table, Type) ->
    Size = case Type of
	       ets -> ets:info(Table, size);
	       mnesia -> mnesia:table_info(Table, size)
	   end,
    case Size =/= undefined andalso Size > 0 of
	false ->
	    Parent ! {self(), '$end_of_table'},
	    normal;
	true when Type =:= ets ->
	    Mem = ets:info(Table, memory),
	    Average = Mem div Size,
	    NoElements = max(10, 20000 div Average),
	    get_ets_loop(Parent, ets:match(Table, '$1', NoElements));
	true ->
	    Mem = mnesia:table_info(Table, memory),
	    Average = Mem div Size,
	    NoElements = max(10, 20000 div Average),
	    Ms = [{'$1', [], ['$1']}],
	    Get = fun() ->
			  get_mnesia_loop(Parent, mnesia:select(Table, Ms, NoElements, read))
		  end,
	    %% Not a transaction, we don't want to grab locks when inspecting the table
	    mnesia:async_dirty(Get)
    end.

get_ets_loop(Parent, '$end_of_table') ->
    Parent ! {self(), '$end_of_table'};
get_ets_loop(Parent, {Match, Cont}) ->
    Parent ! {self(), Match},
    get_ets_loop(Parent, ets:match(Cont)).

get_mnesia_loop(Parent, '$end_of_table') ->
    Parent ! {self(), '$end_of_table'};
get_mnesia_loop(Parent, {Match, Cont}) ->
    Parent ! {self(), Match},
    get_mnesia_loop(Parent, mnesia:select(Cont)).

get_port_list() ->
    ExtraItems = [monitors,monitored_by,parallelism,locking,queue_size,memory],
    [begin
	 [{port_id,P}|erlang:port_info(P)] ++
             port_info(P,ExtraItems) ++
             inet_port_extra(erlang:port_info(P, name), P)
     end || P <- erlang:ports()].

port_info(P,[Item|Items]) ->
    case erlang:port_info(P,Item) of
        undefined -> port_info(P,Items);
        Value -> [Value|port_info(P,Items)]
    end;
port_info(_,[]) ->
    [].

inet_port_extra({_,Type},Port) when Type =:= "udp_inet";
                                    Type =:= "tcp_inet";
                                    Type =:= "sctp_inet" ->
    Data =
        case inet:getstat(Port) of
            {ok, Stats} -> [{statistics, Stats}];
            _ -> []
        end ++
        case inet:peername(Port) of
            {ok, {RAddr,RPort}} when is_tuple(RAddr), is_integer(RPort) ->
                [{remote_address,RAddr},{remote_port,RPort}];
            {ok, RAddr} ->
                [{remote_address,RAddr}];
            {error, _} ->  []
        end ++
        case inet:sockname(Port) of
            {ok, {LAddr,LPort}} when is_tuple(LAddr), is_integer(LPort) ->
                [{local_address,LAddr},{local_port,LPort}];
            {ok, LAddr} ->
                [{local_address,LAddr}];
            {error, _} -> []
        end ++
        case inet:getopts(Port,
                          [active, broadcast, buffer, bind_to_device,
                           delay_send, deliver, dontroute, exit_on_close,
                           header, high_msgq_watermark, high_watermark,
                           ipv6_v6only, keepalive, linger, low_msgq_watermark,
                           low_watermark, mode, netns, nodelay, packet,
                           packet_size, priority, read_packets, recbuf,
                           reuseaddr, send_timeout, send_timeout_close,
                           show_econnreset, sndbuf, tos, tclass]) of
            {ok, Opts} -> [{options, Opts}];
            {error, _} -> []
        end,
    [{inet,Data}];
inet_port_extra(_,_) ->
    [].

get_table_list(ets, Opts) ->
    HideUnread = proplists:get_value(unread_hidden, Opts, true),
    HideSys = proplists:get_value(sys_hidden, Opts, true),
    Info = fun(Id, Acc) ->
		   try
		       TabId = case ets:info(Id, named_table) of
				   true -> ignore;
				   false -> Id
			       end,
		       Name = ets:info(Id, name),
		       Protection = ets:info(Id, protection),
		       ignore(HideUnread andalso Protection == private, unreadable),
		       Owner = ets:info(Id, owner),
		       RegName = case catch process_info(Owner, registered_name) of
				     [] -> ignore;
				     {registered_name, ProcName} -> ProcName
				 end,
		       ignore(HideSys andalso ordsets:is_element(RegName, sys_processes()), system_tab),
		       ignore(HideSys andalso ordsets:is_element(Name, sys_tables()), system_tab),
		       ignore((RegName == mnesia_monitor)
			      andalso Name /= schema
			      andalso is_atom((catch mnesia:table_info(Name, where_to_read))), mnesia_tab),
		       Memory = ets:info(Id, memory) * erlang:system_info(wordsize),
		       Tab = [{name,Name},
			      {id,TabId},
			      {protection,Protection},
			      {owner,Owner},
			      {size,ets:info(Id, size)},
			      {reg_name,RegName},
			      {type,ets:info(Id, type)},
			      {keypos,ets:info(Id, keypos)},
			      {heir,ets:info(Id, heir)},
			      {memory,Memory},
			      {compressed,ets:info(Id, compressed)},
			      {fixed,ets:info(Id, fixed)}
			     ],
		       [Tab|Acc]
		   catch _:_What ->
			   %% io:format("Skipped ~p: ~p ~n",[Id, _What]),
			   Acc
		   end
	   end,
    lists:foldl(Info, [], ets:all());

get_table_list(mnesia, Opts) ->
    HideSys = proplists:get_value(sys_hidden, Opts, true),
    Owner = ets:info(schema, owner),
    Owner /= undefined orelse
	throw({error, "Mnesia is not running on: " ++ atom_to_list(node())}),
    {registered_name, RegName} = process_info(Owner, registered_name),
    Info = fun(Id, Acc) ->
		   try
		       Name = Id,
		       ignore(HideSys andalso ordsets:is_element(Name, mnesia_tables()), system_tab),
		       ignore(Name =:= schema, mnesia_tab),
		       Storage = mnesia:table_info(Id, storage_type),
		       Tab0 = [{name,Name},
			       {owner,Owner},
			       {size,mnesia:table_info(Id, size)},
			       {reg_name,RegName},
			       {type,mnesia:table_info(Id, type)},
			       {keypos,2},
			       {memory,mnesia:table_info(Id, memory) * erlang:system_info(wordsize)},
			       {storage,Storage},
			       {index,mnesia:table_info(Id, index)}
			      ],
		       Tab = if Storage == disc_only_copies ->
				     [{fixed, dets:info(Id, safe_fixed)}|Tab0];
				(Storage == ram_copies) orelse
				(Storage == disc_copies) ->
				     [{fixed, ets:info(Id, fixed)},
				      {compressed, ets:info(Id, compressed)}|Tab0];
				true -> Tab0
			     end,
		       [Tab|Acc]
		   catch _:_What ->
			   %% io:format("Skipped ~p: ~p ~p ~n",[Id, _What, Stacktrace]),
			   Acc
		   end
	   end,
    lists:foldl(Info, [], mnesia:system_info(tables)).

fetch_stats(Parent, Time) ->
    process_flag(trap_exit, true),
    fetch_stats_loop(Parent, Time).

fetch_stats_loop(Parent, Time) ->
    erlang:system_flag(scheduler_wall_time, true),
    receive
	_Msg ->
	    erlang:system_flag(scheduler_wall_time, false),
	    ok
    after Time ->
	    _M = Parent ! {stats, 1,
			   erlang:statistics(scheduler_wall_time),
			   erlang:statistics(io),
			   try erlang:memory() catch _:_ -> [] end},
	    fetch_stats_loop(Parent, Time)
    end.

%%
%% Chunk sending process info to etop/observer
%%
procs_info(Collector) ->
    All = processes(),
    Send = fun Send (Pids) ->
                   try lists:split(10000, Pids) of
                       {First, Rest} ->
                           Collector ! {procs_info, self(), etop_collect(First, [])},
                           Send(Rest)
                   catch _:_ ->
                           Collector ! {procs_info, self(), etop_collect(Pids, [])}
                   end
           end,
    Send(All).

%%
%% etop backend
%%
etop_collect(Collector) ->
    %% If this is the first time and the scheduler_wall_time flag is
    %% false, SchedulerWallTime will be 'undefined' (and show 0 cpu
    %% utilization in etop). Next time the flag will be true and then
    %% there will be a measurement.
    SchedulerWallTime = erlang:statistics(scheduler_wall_time),
    ProcInfo = etop_collect(processes(), []),

    Collector ! {self(),#etop_info{now = erlang:timestamp(),
				   n_procs = length(ProcInfo),
				   run_queue = erlang:statistics(run_queue),
				   runtime = SchedulerWallTime,
				   memi = etop_memi(),
				   procinfo = ProcInfo
				  }},

    case SchedulerWallTime of
	undefined ->
            spawn(fun() -> flag_holder_proc(Collector) end),
            ok;
	_ ->
	    ok
    end.

flag_holder_proc(Collector) ->
    erlang:system_flag(scheduler_wall_time,true),
    Ref = erlang:monitor(process,Collector),
    receive
	{'DOWN',Ref,_,_,_} ->
	    erlang:system_flag(scheduler_wall_time,false),
	    ok
    end.

etop_memi() ->
    try
	[{total, c:memory(total)},
	 {processes, c:memory(processes)}, 
	 {ets, c:memory(ets)},
	 {atom, c:memory(atom)},
	 {code, c:memory(code)},
	 {binary, c:memory(binary)}]
    catch
	error:notsup ->
	    undefined
    end.

etop_collect([P|Ps], Acc) when P =:= self() ->
    etop_collect(Ps, Acc);
etop_collect([P|Ps], Acc) ->
    Fs = [registered_name,initial_call,memory,reductions,current_function,message_queue_len],
    case process_info(P, Fs) of
	undefined ->
	    etop_collect(Ps, Acc);
	[{registered_name,Reg},{initial_call,Initial},{memory,Mem},
	 {reductions,Reds},{current_function,Current},{message_queue_len,Qlen}] ->
	    Name = case Reg of
		       [] -> initial_call(Initial, P);
		       _ -> Reg
		   end,
	    Info = #etop_proc_info{pid=P,mem=Mem,reds=Reds,name=Name,
				   cf=Current,mq=Qlen},
	    etop_collect(Ps, [Info|Acc])
    end;
etop_collect([], Acc) -> Acc.

initial_call({proc_lib, init_p, _}, Pid) ->
    proc_lib:translate_initial_call(Pid);
initial_call(Initial, _Pid) ->
    Initial.

%%
%% ttb backend
%%
ttb_init_node(MetaFile_0,PI,Traci) ->
    if
	is_list(MetaFile_0);
	is_atom(MetaFile_0) ->
	    {ok, Cwd} = file:get_cwd(),
	    MetaFile = filename:join(Cwd, MetaFile_0),
	    file:delete(MetaFile);
	true -> 				% {local,_,_}
	    MetaFile = MetaFile_0
    end,
    case proplists:get_value(resume, Traci) of
        {true, _} -> (autostart_module()):write_config(Traci);
        _    -> ok
    end,
    Self = self(),
    MetaPid = spawn(fun() -> ttb_meta_tracer(MetaFile,PI,Self,Traci) end),
    receive {MetaPid,started} -> ok end,
    MetaPid ! {metadata,Traci},
    case PI of
	true ->
	    MetaPid ! {metadata,pnames()},
            ok;
	false ->
	    ok
    end,
    {ok,MetaFile,MetaPid}.

ttb_write_trace_info(MetaPid,Key,What) ->
    MetaPid ! {metadata,Key,What},
    ok.

ttb_meta_tracer(MetaFile,PI,Parent,SessionData) ->
    erlang:monitor(process, proplists:get_value(ttb_control, SessionData)),
    case PI of
	true ->
	    ReturnMS = [{'_',[],[{return_trace}]}],
	    erlang:trace_pattern({erlang,spawn,3},ReturnMS,[meta]),
	    erlang:trace_pattern({erlang,spawn_link,3},ReturnMS,[meta]),
	    erlang:trace_pattern({erlang,spawn_opt,1},ReturnMS,[meta]),
	    erlang:trace_pattern({erlang,register,2},[],[meta]),
	    erlang:trace_pattern({global,register_name,2},[],[meta]),
            ok;
	false ->
	    ok
    end,
    Parent ! {self(),started},
    case proplists:get_value(overload_check, SessionData) of
        {Ms, M, F} ->
            catch M:F(init),
            erlang:send_after(Ms, self(), overload_check),
            ok;
        _ ->
            ok
    end,
    ttb_meta_tracer_loop(MetaFile,PI,dict:new(),SessionData).

ttb_meta_tracer_loop(MetaFile,PI,Acc,State) ->
    receive
	{trace_ts,_,call,{erlang,register,[Name,Pid]},_} ->
	    ok = ttb_store_meta({pid,{Pid,Name}},MetaFile),
	    ttb_meta_tracer_loop(MetaFile,PI,Acc,State);
	{trace_ts,_,call,{global,register_name,[Name,Pid]},_} ->
	    ok = ttb_store_meta({pid,{Pid,{global,Name}}},MetaFile),
	    ttb_meta_tracer_loop(MetaFile,PI,Acc,State);
	{trace_ts,CallingPid,call,{erlang,spawn_opt,[{M,F,Args,_}]},_} ->
	    MFA = {M,F,length(Args)},
	    NewAcc = dict:update(CallingPid,
				 fun(Old) -> [MFA|Old] end, [MFA], 
				 Acc),
	    ttb_meta_tracer_loop(MetaFile,PI,NewAcc,State);
	{trace_ts,CallingPid,return_from,{erlang,spawn_opt,_Arity},Ret,_} ->
	    case Ret of
		{NewPid,_Mref} when is_pid(NewPid) -> ok;
		NewPid when is_pid(NewPid) -> ok
	    end,
	    NewAcc = 
		dict:update(CallingPid,
			    fun([H|T]) -> 
				    ok = ttb_store_meta({pid,{NewPid,H}},MetaFile),
				    T 
			    end,
			    Acc),
	    ttb_meta_tracer_loop(MetaFile,PI,NewAcc,State);
	{trace_ts,CallingPid,call,{erlang,Spawn,[M,F,Args]},_} 
	when Spawn==spawn;Spawn==spawn_link ->
	    MFA = {M,F,length(Args)},
	    NewAcc = dict:update(CallingPid,
				 fun(Old) -> [MFA|Old] end, [MFA], 
				 Acc),
	    ttb_meta_tracer_loop(MetaFile,PI,NewAcc,State);

	{trace_ts,CallingPid,return_from,{erlang,Spawn,_Arity},NewPid,_} 
	when Spawn==spawn;Spawn==spawn_link ->
	    NewAcc = 
		dict:update(CallingPid,
			    fun([H|T]) -> 
				    ok = ttb_store_meta({pid,{NewPid,H}},MetaFile),
				    T
			    end,
			    Acc),
	    ttb_meta_tracer_loop(MetaFile,PI,NewAcc,State);

	{metadata,Data} when is_list(Data) ->
	    ok = ttb_store_meta(Data,MetaFile),
	    ttb_meta_tracer_loop(MetaFile,PI,Acc,State);

	{metadata,Key,Fun} when is_function(Fun) ->
	    ok = ttb_store_meta([{Key,Fun()}],MetaFile),
	    ttb_meta_tracer_loop(MetaFile,PI,Acc,State);

	{metadata,Key,What} ->
	    ok = ttb_store_meta([{Key,What}],MetaFile),
	    ttb_meta_tracer_loop(MetaFile,PI,Acc,State);
        overload_check ->
            {Ms, M, F} = proplists:get_value(overload_check, State),
            case catch M:F(check) of
                true ->
                    erlang:trace(all, false, [all]),
                    ControlPid = proplists:get_value(ttb_control, State),
                    ControlPid ! {node_overloaded, node()},
                    catch M:F(stop),
                    ttb_meta_tracer_loop(MetaFile,PI,Acc,lists:keydelete(overload_check, 1, State));
                _ ->
                    erlang:send_after(Ms, self(), overload_check),
                    ttb_meta_tracer_loop(MetaFile,PI,Acc, State)
            end;
     {'DOWN', _, _, _, _} ->
            _ = stop_seq_trace(),
            self() ! stop,
            ttb_meta_tracer_loop(MetaFile,PI,Acc, State);
     stop when PI=:=true ->
            try_stop_resume(State),
            try_stop_overload_check(State),
            erlang:trace_pattern({erlang,spawn,3},false,[meta]),
	    erlang:trace_pattern({erlang,spawn_link,3},false,[meta]),
	    erlang:trace_pattern({erlang,spawn_opt,1},false,[meta]),
	    erlang:trace_pattern({erlang,register,2},false,[meta]),
	    erlang:trace_pattern({global,register_name,2},false,[meta]);
	stop ->
            try_stop_resume(State),
            try_stop_overload_check(State)
    end.

try_stop_overload_check(State) ->
    case proplists:get_value(overload, State) of
        undefined -> ok;
        {_, M, F} -> catch M:F(stop)
    end.

pnames() ->
    Processes = processes(),
    Globals = lists:map(fun(G) -> {global:whereis_name(G),G} end, 
			global:registered_names()),
    lists:flatten(lists:foldl(fun(Pid,Acc) -> [pinfo(Pid,Globals)|Acc] end, 
			      [], Processes)).

pinfo(P,Globals) ->
    case process_info(P,registered_name) of
	[] ->
	    case lists:keysearch(P,1,Globals) of
		{value,{P,G}} -> {pid,{P,{global,G}}};
		false -> 
		    case process_info(P,initial_call) of
			{_,I} -> {pid,{P,I}};
			undefined -> [] % the process has terminated
		    end
	    end;
	{_,R} -> {pid,{P,R}};
	undefined -> [] % the process has terminated
    end.

autostart_module() ->
    element(2, application:get_env(runtime_tools, ttb_autostart_module)).

try_stop_resume(State) ->
    case proplists:get_value(resume, State) of
        true -> (autostart_module()):delete_config();
        _    -> ok
    end.

ttb_resume_trace() ->
    case (autostart_module()):read_config() of
        {error, _} ->
            ok;
        {ok, Data} ->
            Pid = proplists:get_value(ttb_control, Data),
            {_, Timeout} = proplists:get_value(resume, Data),
            case rpc:call(node(Pid), erlang, whereis, [ttb]) of
                Pid ->
                    Pid ! {noderesumed, node(), self()},
                    wait_for_fetch_ready(Timeout);
                _ ->
                    ok
            end,
            (autostart_module()):delete_config(),
            ok
    end.

wait_for_fetch_ready(Timeout) ->
    receive
        trace_resumed ->
            ok
    after Timeout ->
            ok
    end.

ttb_store_meta(Data,{local,MetaFile,Port}) when is_list(Data) ->
    ttb_send_to_port(Port,MetaFile,Data);
ttb_store_meta(Data,MetaFile) when is_list(Data) ->
    {ok,Fd} = file:open(MetaFile,[raw,append]),
    ttb_write_binary(Fd,Data),
    file:close(Fd);
ttb_store_meta(Data,MetaFile) ->
    ttb_store_meta([Data],MetaFile).

ttb_write_binary(Fd,[H|T]) ->
    ok = file:write(Fd,ttb_make_binary(H)),
    ttb_write_binary(Fd,T);
ttb_write_binary(_Fd,[]) ->
    ok.

ttb_send_to_port(Port,MetaFile,[H|T]) ->
    B1 = ttb_make_binary(H),
    B2 = term_to_binary({metadata,MetaFile,B1}),
    erlang:port_command(Port,B2),
    ttb_send_to_port(Port,MetaFile,T);
ttb_send_to_port(_Port,_MetaFile,[]) ->
    ok.

ttb_make_binary(Term) ->
    B = term_to_binary(Term),
    SizeB = byte_size(B),
    if SizeB > 255 ->
	    %% size is bigger than 8 bits, must therefore add an extra
	    %% size field
	    SB = term_to_binary({'$size',SizeB}),
	    <<(byte_size(SB)):8, SB/binary, B/binary>>;
        true ->
	    <<SizeB:8, B/binary>>
    end.

    
%% Stop ttb
ttb_stop(MetaPid) ->
    Delivered = erlang:trace_delivered(all),
    receive
	{trace_delivered,all,Delivered} -> ok
    end,
    Ref = erlang:monitor(process,MetaPid),
    MetaPid ! stop,

    %% Must wait for the process to terminate there
    %% because dbg will be stopped when this function
    %% returns, and then the Port (in {local,MetaFile,Port})
    %% cannot be accessed any more.
    receive {'DOWN', Ref, process, MetaPid, _Info} -> ok end,
    stop_seq_trace().

stop_seq_trace() ->
    seq_trace:reset_trace(),
    seq_trace:set_system_tracer(false).

%% Fetch ttb logs from remote node
ttb_fetch(MetaFile,{Port,Host}) ->
    ttb_fetch(MetaFile,{Port,Host},undefined).
ttb_fetch(MetaFile,{Port,Host},MasterEnc) ->
    erlang:process_flag(priority,low),
    Files = ttb_get_filenames(MetaFile),
    {ok, Sock} = gen_tcp:connect(Host, Port, [binary, {packet, 2}]),
    send_files({Sock,Host},Files,MasterEnc,file:native_name_encoding()),
    ok = gen_tcp:close(Sock).


send_files({Sock,Host},[File|Files],MasterEnc,MyEnc) ->
    {ok,Fd} = file:open(File,[raw,read,binary]),
    Basename = filename:basename(File),
    {Code,FilenameBin} = encode_filename(Basename,MasterEnc,MyEnc),
    ok = gen_tcp:send(Sock,<<Code,FilenameBin/binary>>),
    send_chunks(Sock,Fd),
    ok = file:delete(File),
    send_files({Sock,Host},Files,MasterEnc,MyEnc);
send_files({_Sock,_Host},[],_MasterEnc,_MyEnc) ->
    done.

encode_filename(Basename,undefined,MyEnc) ->
    %% Compatible with old version of ttb.erl, but no longer crashing
    %% for code points > 255.
    {1,unicode:characters_to_binary(Basename,MyEnc,MyEnc)};
encode_filename(Basename,MasterEnc,MyEnc) ->
    case unicode:characters_to_binary(Basename,MyEnc,MasterEnc) of
        Bin when is_binary(Bin) ->
            %% Encoding succeeded
            {2,Bin};
        _ ->
            %% Can't convert Basename from my encoding to the master
            %% node's encoding. Doing my best and hoping that master
            %% node can fix it...
            {3,unicode:characters_to_binary(Basename,MyEnc,MyEnc)}
    end.

send_chunks(Sock,Fd) ->
    case file:read(Fd,?CHUNKSIZE) of
	{ok,Bin} -> 
	    ok = gen_tcp:send(Sock, <<0,Bin/binary>>),
	    send_chunks(Sock,Fd);
	eof ->
	    ok;
	{error,Reason} ->
	    ok = gen_tcp:send(Sock, <<2,(term_to_binary(Reason))/binary>>)
    end.

ttb_get_filenames(MetaFile) ->
    Dir = filename:dirname(MetaFile),
    Root = filename:rootname(filename:basename(MetaFile)),
    {ok,List} = file:list_dir(Dir),
    match_filenames(Dir,Root,List,[]).

match_filenames(Dir,MetaFile,[H|T],Files) ->
    case lists:prefix(MetaFile,H) of
	true -> match_filenames(Dir,MetaFile,T,[filename:join(Dir,H)|Files]);
	false -> match_filenames(Dir,MetaFile,T,Files)
    end;
match_filenames(_Dir,_MetaFile,[],Files) ->
    Files.


%%%%%%%%%%%%%%%%%

sys_tables() ->
    [ac_tab,  asn1,
     cdv_dump_index_table,  cdv_menu_table,  cdv_decode_heap_table,
     cell_id,  cell_pos,  clist,
     cover_internal_data_table,   cover_collected_remote_data_table, cover_binary_code_table,
     code, code_names,  cookies,
     corba_policy,  corba_policy_associations,
     dets, dets_owners, dets_registry,
     disk_log_names, disk_log_pids,
     eprof,  erl_atom_cache, erl_epmd_nodes,
     etop_accum_tab,  etop_tr,
     ets_coverage_data,
     file_io_servers,
     gs_mapping, gs_names,  gstk_db,
     gstk_grid_cellid, gstk_grid_cellpos, gstk_grid_id,
     httpd,
     id,
     ign_req_index, ign_requests,
     index,
     inet_cache, inet_db, inet_hosts,
     'InitialReferences',
     int_db,
     interpreter_includedirs_macros,
     ir_WstringDef,
     lmcounter,  locks,
						%     mnesia_decision,
     mnesia_gvar, mnesia_stats,
						%     mnesia_transient_decision,
     pg2_table,
     queue,
     schema,
     shell_records,
     snmp_agent_table, snmp_local_db2, snmp_mib_data, snmp_note_store, snmp_symbolic_ets,
     tkFun, tkLink, tkPriv,
     ttb, ttb_history_table,
     udp_fds, udp_pids
    ].

sys_processes() ->
    [auth, code_server, global_name_server, inet_db,
     mnesia_recover, net_kernel, timer_server, wxe_master].

mnesia_tables() ->
    [ir_AliasDef, ir_ArrayDef, ir_AttributeDef, ir_ConstantDef,
     ir_Contained, ir_Container, ir_EnumDef, ir_ExceptionDef,
     ir_IDLType, ir_IRObject, ir_InterfaceDef, ir_ModuleDef,
     ir_ORB, ir_OperationDef, ir_PrimitiveDef, ir_Repository,
     ir_SequenceDef, ir_StringDef, ir_StructDef, ir_TypedefDef,
     ir_UnionDef, logTable, logTransferTable, mesh_meas,
     mesh_type, mnesia_clist, orber_CosNaming,
     orber_objkeys, user
    ].

ignore(true, Reason) -> throw(Reason);
ignore(_,_ ) -> ok.
