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-module(pg_async).
-define(DRV_CONNECT, $C).
-define(DRV_DISCONNECT, $D).
-define(DRV_SELECT, $S).
-export([connect/1, disconnect/1, select/2]).
connect(ConnectStr) ->
case erl_ddll:load_driver(".", "pg_async") of
ok -> ok;
{error, already_loaded} -> ok;
E -> exit(E)
end,
Port = open_port({spawn, ?MODULE}, [binary]),
port_control(Port, ?DRV_CONNECT, ConnectStr),
case return_port_data(Port) of
ok ->
{ok, Port};
Error ->
Error
end.
disconnect(Port) ->
port_control(Port, ?DRV_DISCONNECT, ""),
R = return_port_data(Port),
port_close(Port),
R.
select(Port, Query) ->
port_control(Port, ?DRV_SELECT, Query),
return_port_data(Port).
return_port_data(Port) ->
receive
{Port, {data, Data}} ->
binary_to_term(Data)
end.
|
