From 84adefa331c4159d432d22840663c38f155cd4c1 Mon Sep 17 00:00:00 2001 From: Erlang/OTP Date: Fri, 20 Nov 2009 14:54:40 +0000 Subject: The R13B03 release. --- erts/example/pg_async.erl | 57 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 erts/example/pg_async.erl (limited to 'erts/example/pg_async.erl') diff --git a/erts/example/pg_async.erl b/erts/example/pg_async.erl new file mode 100644 index 0000000000..10506bfe9f --- /dev/null +++ b/erts/example/pg_async.erl @@ -0,0 +1,57 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2006-2009. All Rights Reserved. +%% +%% The contents of this file are subject to the Erlang Public License, +%% Version 1.1, (the "License"); you may not use this file except in +%% compliance with the License. You should have received a copy of the +%% Erlang Public License along with this software. If not, it can be +%% retrieved online at http://www.erlang.org/. +%% +%% Software distributed under the License is distributed on an "AS IS" +%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See +%% the License for the specific language governing rights and limitations +%% under the License. +%% +%% %CopyrightEnd% +%% +-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. + -- cgit v1.2.3