Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

973 lines (840 sloc) 39.904 kb
%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1999-2011. 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()}] ++ Options]) 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, {ip, loopback}]) 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},
{ip, loopback}]),
{ok, ListenSocketOdbc} =
gen_tcp:listen(0, [Inet, binary, {packet, ?LENGTH_INDICATOR_SIZE},
{active, false}, {nodelay, true},
{ip, loopback}]),
Dir = proplists:get_value(driver_dir, Args, ?SERVERDIR),
%% Start the port program (a c program) that utilizes the odbc driver
case os:find_executable(?SERVERPROG, Dir) 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_wlongvarchar, Max}, InOut, Values}) ->
NewValues = string_terminate(Values),
{?USER_WLONGVARCHAR, 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};
fix_params({'sql_timestamp', InOut, Values}) ->
NewValues =
case (catch
lists:map(fun({{Year,Month,Day},{Hour,Minute,Second}}) ->
{Year,Month,Day,Hour,Minute,Second}
end, Values)) of
Result ->
Result
end,
{?USER_TIMESTAMP, fix_inout(InOut), NewValues};
%% 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.
Jump to Line
Something went wrong with that request. Please try again.