%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1999-2010. 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(odbc).
-behaviour(gen_server).
-include("odbc_internal.hrl").
%% API --------------------------------------------------------------------
-export([start/0, start/1, stop/0,
connect/2, disconnect/1, commit/2, commit/3, sql_query/2,
sql_query/3, select_count/2, select_count/3, first/1, first/2,
last/1, last/2, next/1, next/2, prev/1, prev/2, select/3,
select/4, param_query/3, param_query/4, describe_table/2,
describe_table/3]).
%%-------------------------------------------------------------------------
%% supervisor callbacks
-export([start_link_sup/1]).
%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
terminate/2, code_change/3]).
%%--------------------------------------------------------------------------
%% Internal state
-record(state, {erlang_port, % The port to the c-program
reply_to, % gen_server From parameter
owner, % Pid of the connection owner
result_set = undefined, % exists | undefined
auto_commit_mode = on, % on | off
%% Indicates if first, last and "select absolut"
%% is supported by the odbc driver.
absolute_pos, % true | false
%% Indicates if prev and "select relative"
%% is supported by the odbc driver.
relative_pos, % true | false
scrollable_cursors, % on | off
%% connecting | connected | disconnecting
state = connecting,
%% For timeout handling
pending_request,
num_timeouts = 0,
listen_sockets,
sup_socket,
odbc_socket
}).
%%--------------------------------------------------------------------------
%%%=========================================================================
%%% API
%%%=========================================================================
%%--------------------------------------------------------------------
%% Function: start([, Type]) -> ok
%%
%% Type = permanent | transient | temporary
%%
%% Description: Starts the inets application. Default type
%% is temporary. see application(3)
%%--------------------------------------------------------------------
start() ->
application:start(odbc).
start(Type) ->
application:start(odbc, Type).
%%--------------------------------------------------------------------
%% Function: stop() -> ok
%%
%% Description: Stops the odbc application.
%%--------------------------------------------------------------------
stop() ->
application:stop(odbc).
%%-------------------------------------------------------------------------
%% connect(ConnectionStr, Options) -> {ok, ConnectionReferense} |
%% {error, Reason}
%% Description: Spawns an erlang control process that will open a port
%% to a c-process that uses the ODBC API to open a connection
%% to the database.
%%-------------------------------------------------------------------------
connect(ConnectionStr, Options) when is_list(ConnectionStr), is_list(Options) ->
%% Spawn the erlang control process.
try supervisor:start_child(odbc_sup, [[{client, self()}]]) of
{ok, Pid} ->
connect(Pid, ConnectionStr, Options);
{error, Reason} ->
{error, Reason}
catch
exit:{noproc, _} ->
{error, odbc_not_started}
end.
%%--------------------------------------------------------------------------
%% disconnect(ConnectionReferense) -> ok | {error, Reason}
%%
%% Description: Disconnects from the database and terminates both the erlang
%% control process and the database handling c-process.
%%--------------------------------------------------------------------------
disconnect(ConnectionReference) when is_pid(ConnectionReference)->
ODBCCmd = [?CLOSE_CONNECTION],
case call(ConnectionReference, {disconnect, ODBCCmd}, 5000) of
{error, connection_closed} ->
%% If the connection has already been closed the effect of
%% disconnect has already been acomplished
ok;
%% Note a time out of this call will return ok, as disconnect
%% will always succeed, the time out is to make sure
%% the connection is killed brutaly if it will not be shut down
%% gracefully.
ok ->
ok;
%% However you may receive an error message as result if you try to
%% disconnect a connection started by another process.
Other ->
Other
end.
%%--------------------------------------------------------------------------
%% commit(ConnectionReference, CommitMode, <TimeOut>) -> ok | {error,Reason}
%%
%% Description: Commits or rollbacks a transaction. Needed on connections
%% where automatic commit is turned off.
%%--------------------------------------------------------------------------
commit(ConnectionReference, CommitMode) ->
commit(ConnectionReference, CommitMode, ?DEFAULT_TIMEOUT).
commit(ConnectionReference, commit, infinity)
when is_pid(ConnectionReference) ->
ODBCCmd = [?COMMIT_TRANSACTION, ?COMMIT],
call(ConnectionReference, {commit, ODBCCmd}, infinity);
commit(ConnectionReference, commit, TimeOut)
when is_pid(ConnectionReference), is_integer(TimeOut), TimeOut > 0 ->
ODBCCmd = [?COMMIT_TRANSACTION, ?COMMIT],
call(ConnectionReference, {commit, ODBCCmd}, TimeOut);
commit(ConnectionReference, rollback, infinity)
when is_pid(ConnectionReference) ->
ODBCCmd = [?COMMIT_TRANSACTION, ?ROLLBACK],
call(ConnectionReference, {commit, ODBCCmd}, infinity);
commit(ConnectionReference, rollback, TimeOut)
when is_pid(ConnectionReference), is_integer(TimeOut), TimeOut > 0 ->
ODBCCmd = [?COMMIT_TRANSACTION, ?ROLLBACK],
call(ConnectionReference, {commit, ODBCCmd}, TimeOut).
%%--------------------------------------------------------------------------
%% sql_query(ConnectionReference, SQLQuery, <TimeOut>) -> {updated, NRows} |
%% {selected, ColNames, Rows} | {error, Reason}
%%
%% Description: Executes a SQL query. If it is a SELECT query the
%% result set is returned, otherwise the number of affected
%% rows are returned.
%%--------------------------------------------------------------------------
sql_query(ConnectionReference, SQLQuery) ->
sql_query(ConnectionReference, SQLQuery, ?DEFAULT_TIMEOUT).
sql_query(ConnectionReference, SQLQuery, infinity) when
is_pid(ConnectionReference), is_list(SQLQuery) ->
ODBCCmd = [?QUERY, SQLQuery],
call(ConnectionReference, {sql_query, ODBCCmd}, infinity);
sql_query(ConnectionReference, SQLQuery, TimeOut)
when is_pid(ConnectionReference),is_list(SQLQuery),is_integer(TimeOut),TimeOut>0 ->
ODBCCmd = [?QUERY, SQLQuery],
call(ConnectionReference, {sql_query, ODBCCmd}, TimeOut).
%%--------------------------------------------------------------------------
%% select_count(ConnectionReference, SQLQuery, <TimeOut>) -> {ok, NrRows} |
%% {error, Reason}
%%
%% Description: Executes a SQL SELECT query and associates the result set
%% with the connection. A cursor is positioned before
%% the first row in the result set and the number of
%% rows in the result set is returned.
%%--------------------------------------------------------------------------
select_count(ConnectionReference, SQLQuery) ->
select_count(ConnectionReference, SQLQuery, ?DEFAULT_TIMEOUT).
select_count(ConnectionReference, SQLQuery, infinity) when
is_pid(ConnectionReference), is_list(SQLQuery) ->
ODBCCmd = [?SELECT_COUNT, SQLQuery],
call(ConnectionReference, {select_count, ODBCCmd}, infinity);
select_count(ConnectionReference, SQLQuery, TimeOut) when
is_pid(ConnectionReference), is_list(SQLQuery), is_integer(TimeOut), TimeOut > 0 ->
ODBCCmd = [?SELECT_COUNT, SQLQuery],
call(ConnectionReference, {select_count, ODBCCmd}, TimeOut).
%%--------------------------------------------------------------------------
%% first(ConnectionReference, <TimeOut>) -> {selected, ColNames, Rows} |
%% {error, Reason}
%%
%% Description: Selects the first row in the current result set. The cursor
%% : is positioned at this row.
%%--------------------------------------------------------------------------
first(ConnectionReference) ->
first(ConnectionReference, ?DEFAULT_TIMEOUT).
first(ConnectionReference, infinity) when is_pid(ConnectionReference) ->
ODBCCmd = [?SELECT, ?SELECT_FIRST],
call(ConnectionReference, {select_cmd, absolute, ODBCCmd}, infinity);
first(ConnectionReference, TimeOut)
when is_pid(ConnectionReference), is_integer(TimeOut), TimeOut > 0 ->
ODBCCmd = [?SELECT, ?SELECT_FIRST],
call(ConnectionReference, {select_cmd, absolute, ODBCCmd}, TimeOut).
%%--------------------------------------------------------------------------
%% last(ConnectionReference, <TimeOut>) -> {selected, ColNames, Rows} |
%% {error, Reason}
%%
%% Description: Selects the last row in the current result set. The cursor
%% : is positioned at this row.
%%--------------------------------------------------------------------------
last(ConnectionReference) ->
last(ConnectionReference, ?DEFAULT_TIMEOUT).
last(ConnectionReference, infinity) when is_pid(ConnectionReference) ->
ODBCCmd = [?SELECT, ?SELECT_LAST],
call(ConnectionReference, {select_cmd, absolute, ODBCCmd}, infinity);
last(ConnectionReference, TimeOut)
when is_pid(ConnectionReference), is_integer(TimeOut), TimeOut > 0 ->
ODBCCmd = [?SELECT, ?SELECT_LAST],
call(ConnectionReference, {select_cmd, absolute, ODBCCmd}, TimeOut).
%%--------------------------------------------------------------------------
%% next(ConnectionReference, <TimeOut>) -> {selected, ColNames, Rows} |
%% {error, Reason}
%%
%% Description: Selects the next row relative the current cursor position
%% : in the current result set. The cursor is positioned at
%% : this row.
%%--------------------------------------------------------------------------
next(ConnectionReference) ->
next(ConnectionReference, ?DEFAULT_TIMEOUT).
next(ConnectionReference, infinity) when is_pid(ConnectionReference) ->
ODBCCmd = [?SELECT, ?SELECT_NEXT],
call(ConnectionReference, {select_cmd, next, ODBCCmd}, infinity);
next(ConnectionReference, TimeOut)
when is_pid(ConnectionReference), is_integer(TimeOut), TimeOut > 0 ->
ODBCCmd = [?SELECT, ?SELECT_NEXT],
call(ConnectionReference, {select_cmd, next, ODBCCmd}, TimeOut).
%%--------------------------------------------------------------------------
%% prev(ConnectionReference, <TimeOut>) -> {selected, ColNames, Rows} |
%% {error, Reason}
%%
%% Description: Selects the previous row relative the current cursor
%% : position in the current result set. The cursor is
%% : positioned at this row.
%%--------------------------------------------------------------------------
prev(ConnectionReference) ->
prev(ConnectionReference, ?DEFAULT_TIMEOUT).
prev(ConnectionReference, infinity) when is_pid(ConnectionReference) ->
ODBCCmd = [?SELECT, ?SELECT_PREV],
call(ConnectionReference, {select_cmd, relative, ODBCCmd}, infinity);
prev(ConnectionReference, TimeOut)
when is_pid(ConnectionReference), is_integer(TimeOut), TimeOut > 0 ->
ODBCCmd = [?SELECT, ?SELECT_PREV],
call(ConnectionReference, {select_cmd, relative, ODBCCmd}, TimeOut).
%%--------------------------------------------------------------------------
%% select(ConnectionReference, <Timeout>) -> {selected, ColNames, Rows} |
%% {error, Reason}
%%
%% Description: Selects <N> rows. If <Position> is next it is
%% semanticly eqvivivalent of calling next/[1,2] <N>
%% times. If <Position> is {relative, Pos} <Pos> will be
%% used as an offset from the current cursor position to
%% determine the first selected row. If <Position> is
%% {absolute, Pos}, <Pos> will be the number of the first
%% row selected. After this function has returned the
%% cursor is positioned at the last selected row.
%%--------------------------------------------------------------------------
select(ConnectionReference, Position, N) ->
select(ConnectionReference, Position, N, ?DEFAULT_TIMEOUT).
select(ConnectionReference, next, N, infinity)
when is_pid(ConnectionReference), is_integer(N), N > 0 ->
ODBCCmd = [?SELECT, ?SELECT_N_NEXT,
integer_to_list(?DUMMY_OFFSET), ";",
integer_to_list(N), ";"],
call(ConnectionReference, {select_cmd, next, ODBCCmd},
infinity);
select(ConnectionReference, next, N, TimeOut)
when is_pid(ConnectionReference), is_integer(N), N > 0,
is_integer(TimeOut), TimeOut > 0 ->
ODBCCmd = [?SELECT, ?SELECT_N_NEXT,
integer_to_list(?DUMMY_OFFSET), ";",
integer_to_list(N), ";"],
call(ConnectionReference, {select_cmd, next, ODBCCmd},
TimeOut);
select(ConnectionReference, {relative, Pos} , N, infinity)
when is_pid(ConnectionReference), is_integer(Pos), Pos > 0, is_integer(N), N > 0 ->
ODBCCmd = [?SELECT, ?SELECT_RELATIVE,
integer_to_list(Pos), ";", integer_to_list(N), ";"],
call(ConnectionReference, {select_cmd, relative, ODBCCmd},
infinity);
select(ConnectionReference, {relative, Pos} , N, TimeOut)
when is_pid(ConnectionReference), is_integer(Pos), Pos >0, is_integer(N), N > 0,
is_integer(TimeOut), TimeOut > 0 ->
ODBCCmd = [?SELECT,?SELECT_RELATIVE,
integer_to_list(Pos), ";", integer_to_list(N), ";"],
call(ConnectionReference, {select_cmd, relative, ODBCCmd},
TimeOut);
select(ConnectionReference, {absolute, Pos} , N, infinity)
when is_pid(ConnectionReference), is_integer(Pos), Pos > 0, is_integer(N), N > 0 ->
ODBCCmd = [?SELECT, ?SELECT_ABSOLUTE,
integer_to_list(Pos), ";", integer_to_list(N), ";"],
call(ConnectionReference, {select_cmd, absolute, ODBCCmd},
infinity);
select(ConnectionReference, {absolute, Pos} , N, TimeOut)
when is_pid(ConnectionReference), is_integer(Pos), Pos > 0, is_integer(N), N > 0,
is_integer(TimeOut), TimeOut > 0 ->
ODBCCmd = [?SELECT, ?SELECT_ABSOLUTE,
integer_to_list(Pos), ";", integer_to_list(N), ";"],
call(ConnectionReference, {select_cmd, absolute, ODBCCmd},
TimeOut).
%%--------------------------------------------------------------------------
%% param_query(ConnectionReference, SQLQuery, Params, <TimeOut>) ->
%% ok | {error, Reason}
%%
%% Description: Executes a parameterized update/delete/insert-query.
%%--------------------------------------------------------------------------
param_query(ConnectionReference, SQLQuery, Params) ->
param_query(ConnectionReference, SQLQuery, Params, ?DEFAULT_TIMEOUT).
param_query(ConnectionReference, SQLQuery, Params, infinity)
when is_pid(ConnectionReference), is_list(SQLQuery), is_list(Params) ->
Values = param_values(Params),
NoRows = length(Values),
NewParams = lists:map(fun fix_params/1, Params),
ODBCCmd = [?PARAM_QUERY, term_to_binary({SQLQuery ++ [?STR_TERMINATOR],
NoRows, NewParams})],
call(ConnectionReference, {param_query, ODBCCmd}, infinity);
param_query(ConnectionReference, SQLQuery, Params, TimeOut)
when is_pid(ConnectionReference), is_list(SQLQuery), is_list(Params),
is_integer(TimeOut), TimeOut > 0 ->
Values = param_values(Params),
NoRows = length(Values),
NewParams = lists:map(fun fix_params/1, Params),
ODBCCmd = [?PARAM_QUERY, term_to_binary({SQLQuery ++ [?STR_TERMINATOR],
NoRows, NewParams})],
call(ConnectionReference, {param_query, ODBCCmd}, TimeOut).
%%--------------------------------------------------------------------------
%% describe_table(ConnectionReference, Table, <TimeOut>) -> {ok, Desc}
%%
%% Desc - [{ColName, Datatype}]
%% ColName - atom()
%% Datatype - atom()
%% Description: Queries the database to find out the datatypes of the
%% table <Table>
%%--------------------------------------------------------------------------
describe_table(ConnectionReference, Table) ->
describe_table(ConnectionReference, Table, ?DEFAULT_TIMEOUT).
describe_table(ConnectionReference, Table, infinity) when
is_pid(ConnectionReference), is_list(Table) ->
ODBCCmd = [?DESCRIBE, "SELECT * FROM " ++ Table],
call(ConnectionReference, {describe_table, ODBCCmd}, infinity);
describe_table(ConnectionReference, Table, TimeOut)
when is_pid(ConnectionReference),is_list(Table),is_integer(TimeOut),TimeOut>0 ->
ODBCCmd = [?DESCRIBE, "SELECT * FROM " ++ Table],
call(ConnectionReference, {describe_table, ODBCCmd}, TimeOut).
%%%=========================================================================
%%% Start/stop
%%%=========================================================================
%%--------------------------------------------------------------------------
%% start_link_sup(Args) -> {ok, Pid} | {error, Reason}
%%
%% Description: Callback function for the odbc supervisor. It is called
%% : when connect/2 calls supervisor:start_child/2 to start an
%% : instance of the erlang odbc control process.
%%--------------------------------------------------------------------------
start_link_sup(Args) ->
gen_server:start_link(?MODULE, Args, []).
%%% Stop functionality is handled by disconnect/1
%%%========================================================================
%%% Callback functions from gen_server
%%%========================================================================
%%-------------------------------------------------------------------------
%% init(Args) -> {ok, State} | {ok, State, Timeout} | {stop, Reason}
%% Description: Initiates the erlang process that manages the connection
%% and starts the port-program that use the odbc driver
%% to communicate with the database.
%%-------------------------------------------------------------------------
init(Args) ->
process_flag(trap_exit, true),
{value, {client, ClientPid}} = lists:keysearch(client, 1, Args),
erlang:monitor(process, ClientPid),
Inet = case gen_tcp:listen(0, [inet6]) of
{ok, Dummyport} ->
gen_tcp:close(Dummyport),
inet6;
_ ->
inet
end,
{ok, ListenSocketSup} =
gen_tcp:listen(0, [Inet, binary, {packet, ?LENGTH_INDICATOR_SIZE},
{active, false}, {nodelay, true}]),
{ok, ListenSocketOdbc} =
gen_tcp:listen(0, [Inet, binary, {packet, ?LENGTH_INDICATOR_SIZE},
{active, false}, {nodelay, true}]),
%% Start the port program (a c program) that utilizes the odbc driver
case os:find_executable(?SERVERPROG, ?SERVERDIR) of
FileName when is_list(FileName)->
Port = open_port({spawn, FileName},
[{packet, ?LENGTH_INDICATOR_SIZE}, binary,
exit_status]),
State = #state{listen_sockets =
[ListenSocketSup, ListenSocketOdbc],
erlang_port = Port, owner = ClientPid},
{ok, State};
false ->
{stop, port_program_executable_not_found}
end.
%%--------------------------------------------------------------------------
%% handle_call(Request, From, State) -> {reply, Reply, State} |
%% {reply, Reply, State, Timeout} |
%% {noreply, State} |
%% {noreply, State, Timeout} |
%% {stop, Reason, Reply, State} |
%% {stop, Reason, Reply, State}
%% Description: Handle incoming requests. Only requests from the process
%% that created the connection are allowed in order to preserve
%% the semantics of result sets.
%% Note: The order of the function clauses is significant.
%%--------------------------------------------------------------------------
handle_call({Client, Msg, Timeout}, From, State =
#state{owner = Client, reply_to = undefined}) ->
handle_msg(Msg, Timeout, State#state{reply_to = From});
%% The client has caught the timeout and is sending a new request, but
%% we must preserve a synchronous communication with the port. This
%% request will be handled when we have received the answer to the
%% timed out request and thrown it away, if it has not already been
%% timed out itself in which case the request is thrown away.
handle_call(Request = {Client, _, Timeout}, From,
State = #state{owner = Client, reply_to = skip,
num_timeouts = N}) when N < ?MAX_SEQ_TIMEOUTS ->
{noreply, State#state{pending_request = {Request, From}}, Timeout};
%% The client has sent so many sequential requests that has timed out that
%% there might be something radically wrong causing the ODBC-driver to
%% hang. So we give up and close the connection.
handle_call({Client, _, _}, From,
State = #state{owner = Client,
num_timeouts = N}) when N >= ?MAX_SEQ_TIMEOUTS ->
gen_server:reply(From, {error, connection_closed}),
{stop, too_many_sequential_timeouts, State#state{reply_to = undefined}};
handle_call(_, _, State) ->
{reply, {error, process_not_owner_of_odbc_connection},
State#state{reply_to = undefined}}.
%%--------------------------------------------------------------------------
%% Func: handle_msg(Msg, Timeout, State) -> same as handle_call/3.
%% Description: Sends requests to the port-program.
%% Note: The order of the function clauses is significant.
%%--------------------------------------------------------------------------
handle_msg({connect, ODBCCmd, AutoCommitMode, SrollableCursors},
Timeout, State) ->
[ListenSocketSup, ListenSocketOdbc] = State#state.listen_sockets,
%% Inform c-client so it knows where to send answers
{ok, InetPortSup} = inet:port(ListenSocketSup),
{ok, InetPortOdbc} = inet:port(ListenSocketOdbc),
port_command(State#state.erlang_port,
[integer_to_list(InetPortSup), ";",
integer_to_list(InetPortOdbc) , ?STR_TERMINATOR]),
NewState = State#state{auto_commit_mode = AutoCommitMode,
scrollable_cursors = SrollableCursors},
case gen_tcp:accept(ListenSocketSup, 5000) of
{ok, SupSocket} ->
gen_tcp:close(ListenSocketSup),
case gen_tcp:accept(ListenSocketOdbc, 5000) of
{ok, OdbcSocket} ->
gen_tcp:close(ListenSocketOdbc),
odbc_send(OdbcSocket, ODBCCmd),
{noreply, NewState#state{odbc_socket = OdbcSocket,
sup_socket = SupSocket},
Timeout};
{error, Reason} ->
{stop, Reason, {error, connection_closed}, NewState}
end;
{error, Reason} ->
{stop, Reason, {error, connection_closed}, NewState}
end;
handle_msg({disconnect, ODBCCmd}, Timeout, State) ->
odbc_send(State#state.odbc_socket, ODBCCmd),
{noreply, State#state{state = disconnecting}, Timeout};
handle_msg({commit, _ODBCCmd}, Timeout,
State = #state{auto_commit_mode = on}) ->
{reply, {error, not_an_explicit_commit_connection},
State#state{reply_to = undefined}, Timeout};
handle_msg({commit, ODBCCmd}, Timeout,
State = #state{auto_commit_mode = off}) ->
odbc_send(State#state.odbc_socket, ODBCCmd),
{noreply, State, Timeout};
handle_msg({sql_query, ODBCCmd}, Timeout, State) ->
odbc_send(State#state.odbc_socket, ODBCCmd),
{noreply, State#state{result_set = undefined}, Timeout};
handle_msg({param_query, ODBCCmd}, Timeout, State) ->
odbc_send(State#state.odbc_socket, ODBCCmd),
{noreply, State#state{result_set = undefined}, Timeout};
handle_msg({describe_table, ODBCCmd}, Timeout, State) ->
odbc_send(State#state.odbc_socket, ODBCCmd),
{noreply, State#state{result_set = undefined}, Timeout};
handle_msg({select_count, ODBCCmd}, Timeout, State) ->
odbc_send(State#state.odbc_socket, ODBCCmd),
{noreply, State#state{result_set = exists}, Timeout};
handle_msg({select_cmd, absolute, ODBCCmd}, Timeout,
State = #state{result_set = exists, absolute_pos = true}) ->
odbc_send(State#state.odbc_socket, ODBCCmd),
{noreply, State, Timeout};
handle_msg({select_cmd, relative, ODBCCmd}, Timeout,
State = #state{result_set = exists, relative_pos = true}) ->
odbc_send(State#state.odbc_socket, ODBCCmd),
{noreply, State, Timeout};
handle_msg({select_cmd, next, ODBCCmd}, Timeout,
State = #state{result_set = exists}) ->
odbc_send(State#state.odbc_socket, ODBCCmd),
{noreply, State, Timeout};
handle_msg({select_cmd, _Type, _ODBCCmd}, _Timeout,
State = #state{result_set = undefined}) ->
{reply, {error, result_set_does_not_exist},
State#state{reply_to = undefined}};
handle_msg({select_cmd, _Type, _ODBCCmd}, _Timeout, State) ->
Reply = case State#state.scrollable_cursors of
on ->
{error, driver_does_not_support_function};
off ->
{error, scrollable_cursors_disabled}
end,
{reply, Reply, State#state{reply_to = undefined}};
%---------------------------------------------------------------------------
%% Catch all - This can oly happen if the application programmer writes
%% really bad code that violates the API.
handle_msg(Request, _Timeout, State) ->
{stop, {'API_violation_connection_colsed', Request},
{error, connection_closed}, State#state{reply_to = undefined}}.
%%--------------------------------------------------------------------------
%% handle_cast(Request, State) -> {noreply, State} |
%% {noreply, State, Timeout} |
%% {stop, Reason, State}
%% Description: Handles cast messages.
%% Note: The order of the function clauses is significant.
%%-------------------------------------------------------------------------
%% Catch all - This can only happen if the application programmer writes
%% really bad code that violates the API.
handle_cast(Msg, State) ->
{stop, {'API_violation_connection_colsed', Msg}, State}.
%%--------------------------------------------------------------------------
%% handle_info(Msg, State) -> {noreply, State} | {noreply, State, Timeout} |
%% {stop, Reason, State}
%% Description: Handles timouts, replys from the port-program and EXIT and
%% down messages.
%% Note: The order of the function clauses is significant.
%%--------------------------------------------------------------------------
handle_info({tcp, Socket, BinData}, State = #state{state = connecting,
reply_to = From,
odbc_socket = Socket}) ->
case binary_to_term(BinData) of
{ok, AbsolutSupport, RelativeSupport} ->
NewState = State#state{absolute_pos = AbsolutSupport,
relative_pos = RelativeSupport},
gen_server:reply(From, ok),
{noreply, NewState#state{state = connected,
reply_to = undefined}};
Error ->
gen_server:reply(From, Error),
{stop, normal, State#state{reply_to = undefined}}
end;
handle_info({tcp, Socket, _},
State = #state{state = connected,
odbc_socket = Socket,
reply_to = skip,
pending_request = undefined}) ->
%% Disregard this message as it is a answer to a query that has timed
%% out.
{noreply, State#state{reply_to = undefined}};
handle_info({tcp, Socket, _},
State = #state{state = connected, odbc_socket = Socket,
reply_to = skip}) ->
%% Disregard this message as it is a answer to a query that has timed
%% out and process the pending request.
{{_, Msg, Timeout}, From} = State#state.pending_request,
handle_msg(Msg, Timeout, State#state{pending_request=undefined,
reply_to = From});
handle_info({tcp, Socket, BinData}, State = #state{state = connected,
reply_to = From,
odbc_socket = Socket}) ->
%% Send the reply from the database (received by the erlang control
%% process from the port program) to the waiting client.
gen_server:reply(From, BinData),
{noreply, State#state{reply_to = undefined,
num_timeouts = 0}};
handle_info({tcp, Socket, BinData}, State = #state{state = disconnecting,
reply_to = From,
odbc_socket = Socket}) ->
%% The connection will always be closed
gen_server:reply(From, ok),
case binary_to_term(BinData) of
ok ->
ok;
{error, Reason} ->
Report =
io_lib:format("ODBC could not end connection "
"gracefully due to ~p~n", [Reason]),
error_logger:error_report(Report)
end,
{stop, normal, State#state{reply_to = undefined}};
handle_info(timeout,
State = #state{state = disconnecting,
reply_to = From}) when From /= undefined ->
gen_server:reply(From, ok),
{stop, {timeout, "Port program is not responding to disconnect, "
"will be killed"}, State};
handle_info(timeout,
State = #state{state = connecting,
reply_to = From}) when From /= undefined ->
gen_server:reply(From, timeout),
{stop, normal, State#state{reply_to = undefined}};
handle_info(timeout,
State = #state{state = connected,
pending_request = undefined,
reply_to = From}) when From /= undefined ->
gen_server:reply(From, timeout),
{noreply, State#state{reply_to = skip,
num_timeouts = State#state.num_timeouts + 1}};
handle_info(timeout, State =
#state{state = connected,
pending_request = {{_, {disconnect, _}, _},
PendingFrom}}) ->
gen_server:reply(PendingFrom, ok),
{stop, {timeout, "Port-program busy when trying to disconnect, "
"will be killed"},
State#state{pending_request = undefined, reply_to = undefined,
num_timeouts = State#state.num_timeouts + 1}};
handle_info(timeout, State =
#state{state = connected,
pending_request = {_, PendingFrom}}) ->
gen_server:reply(PendingFrom, timeout),
%% The state variable reply_to should continue to have the value skip
{noreply, State#state{pending_request = undefined,
num_timeouts = State#state.num_timeouts + 1}};
handle_info({Port, {exit_status, ?EXIT_SUCCESS}},
State = #state{erlang_port = Port, state = disconnecting}) ->
{noreply, State}; % Ignore as this is perfectly normal in this case
handle_info({Port, {exit_status, Status}},
State = #state{erlang_port = Port}) ->
{stop, {port_exit, ?PORT_EXIT_REASON(Status)}, State};
handle_info({'EXIT', Port, _}, State = #state{erlang_port = Port,
state = disconnecting}) ->
{noreply, State}; % Ignore as this is perfectly normal in this case
handle_info({'EXIT', Port, Reason}, State = #state{erlang_port = Port}) ->
{stop, Reason, State};
%%% If the owning process dies there is no reson to go on
handle_info({'DOWN', _Ref, _Type, _Process, normal}, State) ->
{stop, normal, State#state{reply_to = undefined}};
handle_info({'DOWN', _Ref, _Type, _Process, timeout}, State) ->
{stop, normal, State#state{reply_to = undefined}};
handle_info({'DOWN', _Ref, _Type, Process, Reason}, State) ->
{stop, {stopped, {'EXIT', Process, Reason}},
State#state{reply_to = undefined}};
%---------------------------------------------------------------------------
%% Catch all - throws away unknown messages (This could happen by "accident"
%% so we do not want to crash, but we make a log entry as it is an
%% unwanted behaviour.)
handle_info(Info, State) ->
Report = io_lib:format("ODBC: received unexpected info: ~p~n", [Info]),
error_logger:error_report(Report),
{noreply, State}.
%%-------------------------------------------------------------------------
%% terminate/2 and code_change/3
%%--------------------------------------------------------------------------
terminate({port_exit, _Reason}, State = #state{reply_to = undefined}) ->
%% Port program crashed
gen_tcp:close(State#state.odbc_socket),
gen_tcp:close(State#state.sup_socket),
ok;
terminate(_Reason, State = #state{reply_to = undefined}) ->
catch gen_tcp:send(State#state.sup_socket,
[?SHUTDOWN, ?STR_TERMINATOR]),
catch gen_tcp:close(State#state.odbc_socket),
catch gen_tcp:close(State#state.sup_socket),
catch port_close(State#state.erlang_port),
ok;
terminate(Reason, State = #state{reply_to = From}) ->
gen_server:reply(From, {error, connection_closed}),
terminate(Reason, State#state{reply_to = undefined}).
%---------------------------------------------------------------------------
code_change(_Vsn, State, _Extra) ->
{ok, State}.
%%%========================================================================
%%% Internal functions
%%%========================================================================
connect(ConnectionReferense, ConnectionStr, Options) ->
{C_AutoCommitMode, ERL_AutoCommitMode} =
connection_config(auto_commit, Options),
TimeOut = connection_config(timeout, Options),
{C_TraceDriver, _} = connection_config(trace_driver, Options),
{C_SrollableCursors, ERL_SrollableCursors} =
connection_config(scrollable_cursors, Options),
{C_TupleRow, _} =
connection_config(tuple_row, Options),
{BinaryStrings, _} = connection_config(binary_strings, Options),
ODBCCmd =
[?OPEN_CONNECTION, C_AutoCommitMode, C_TraceDriver,
C_SrollableCursors, C_TupleRow, BinaryStrings, ConnectionStr],
%% Send request, to open a database connection, to the control process.
case call(ConnectionReferense,
{connect, ODBCCmd, ERL_AutoCommitMode, ERL_SrollableCursors},
TimeOut) of
ok ->
{ok, ConnectionReferense};
Error ->
Error
end.
%%-------------------------------------------------------------------------
odbc_send(Socket, Msg) -> %% Note currently all allowed messages are lists
NewMsg = Msg ++ [?STR_TERMINATOR],
ok = gen_tcp:send(Socket, NewMsg),
inet:setopts(Socket, [{active, once}]).
%%--------------------------------------------------------------------------
connection_config(Key, Options) ->
case lists:keysearch(Key, 1, Options) of
{value,{Key, on}} ->
{?ON, on};
{value,{Key, off}} ->
{?OFF, off};
{value,{Key, Value}} ->
Value;
_ ->
connection_default(Key)
end.
%%--------------------------------------------------------------------------
connection_default(auto_commit) ->
{?ON, on};
connection_default(timeout) ->
?DEFAULT_TIMEOUT;
connection_default(tuple_row) ->
{?ON, on};
connection_default(trace_driver) ->
{?OFF, off};
connection_default(scrollable_cursors) ->
{?ON, on};
connection_default(binary_strings) ->
{?OFF, off}.
%%-------------------------------------------------------------------------
call(ConnectionReference, Msg, Timeout) ->
Result = (catch gen_server:call(ConnectionReference,
{self(), Msg, Timeout}, infinity)),
case Result of
%% Normal case, the result from the port-program has directly
%% been forwarded to the client
Binary when is_binary(Binary) ->
decode(Binary);
timeout ->
exit(timeout);
{'EXIT', _} ->
{error, connection_closed};
%% At some occasions the erlang control process will have an
%% answer that was not directly received from the port-program.
Term ->
Term
end.
%%-------------------------------------------------------------------------
decode(Binary) ->
case binary_to_term(Binary) of
[ResultSet | []] ->
ResultSet;
param_badarg ->
exit({badarg, odbc, param_query, 'Params'});
MultipleResultSets_or_Other ->
MultipleResultSets_or_Other
end.
%%-------------------------------------------------------------------------
param_values(Params) ->
case Params of
[{_, Values} | _] ->
Values;
[{_, _, Values} | _] ->
Values
end.
%%-------------------------------------------------------------------------
fix_params({sql_integer, InOut, Values}) ->
{?USER_INT, fix_inout(InOut), [256 | Values]};
fix_params({sql_smallint, InOut, Values}) ->
{?USER_SMALL_INT, fix_inout(InOut), [256 | Values]};
fix_params({sql_tinyint, InOut, Values}) ->
{?USER_TINY_INT, fix_inout(InOut), [256 | Values]};
fix_params({{sql_decimal, Precision, 0}, InOut,
Values}) when Precision >= 0, Precision =< 9 ->
{?USER_DECIMAL, Precision, 0, fix_inout(InOut), [256 | Values]};
fix_params({{sql_decimal, Precision, Scale}, InOut, Values}) ->
{?USER_DECIMAL, Precision, Scale, fix_inout(InOut), Values};
fix_params({{sql_numeric, Precision, 0}, InOut,
Values}) when Precision >= 0, Precision =< 9 ->
{?USER_NUMERIC, Precision, 0, fix_inout(InOut), [256 | Values]};
fix_params({{sql_numeric, Precision, Scale}, InOut, Values}) ->
{?USER_NUMERIC, Precision, Scale, fix_inout(InOut), Values};
fix_params({{sql_char, Max}, InOut, Values}) ->
NewValues = string_terminate(Values),
{?USER_CHAR, Max, fix_inout(InOut), NewValues};
fix_params({{sql_varchar, Max}, InOut, Values}) ->
NewValues = string_terminate(Values),
{?USER_VARCHAR, Max, fix_inout(InOut), NewValues};
fix_params({{sql_wchar, Max}, InOut, Values}) ->
NewValues = string_terminate(Values),
{?USER_WCHAR, Max, fix_inout(InOut), NewValues};
fix_params({{sql_wvarchar, Max}, InOut, Values}) ->
NewValues = string_terminate(Values),
{?USER_WVARCHAR, Max, fix_inout(InOut), NewValues};
fix_params({{sql_float, Precision}, InOut, Values}) ->
{?USER_FLOAT, Precision, fix_inout(InOut), Values};
fix_params({sql_real, InOut, Values}) ->
{?USER_REAL, fix_inout(InOut), Values};
fix_params({sql_double, InOut, Values}) ->
{?USER_DOUBLE, fix_inout(InOut), Values};
fix_params({sql_bit, InOut, Values}) ->
{?USER_BOOLEAN, fix_inout(InOut), Values};
%% default is IN %%%
fix_params({Type, Values}) ->
fix_params({Type, in, Values}).
fix_inout(in) ->
?IN;
fix_inout(out) ->
?OUT;
fix_inout(inout) ->
?INOUT.
string_terminate([Value| _ ] = Values) when is_list(Value)->
case (catch
lists:map(fun(Str) -> Str ++ [?STR_TERMINATOR] end, Values)) of
Result ->
Result
end;
string_terminate([Value| _ ] = Values) when is_binary(Value)->
case (catch
lists:map(fun(B) -> <<B/binary,0:16>> end, Values)) of
Result ->
Result
end.
