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Diffstat (limited to 'lib/odbc/src/odbc.erl')
| -rw-r--r-- | lib/odbc/src/odbc.erl | 943 |
1 files changed, 943 insertions, 0 deletions
diff --git a/lib/odbc/src/odbc.erl b/lib/odbc/src/odbc.erl new file mode 100644 index 0000000000..8178accf6d --- /dev/null +++ b/lib/odbc/src/odbc.erl @@ -0,0 +1,943 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 1999-2009. 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(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),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),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), + ODBCCmd = + [?OPEN_CONNECTION, C_AutoCommitMode, C_TraceDriver, + C_SrollableCursors, C_TupleRow, 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}. + +%%------------------------------------------------------------------------- +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 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 = + case (catch + lists:map(fun(Str) -> Str ++ [?STR_TERMINATOR] end, Values)) of + Result -> + Result + end, + {?USER_CHAR, Max, fix_inout(InOut), NewValues}; +fix_params({{sql_varchar, Max}, InOut, Values}) -> + NewValues = + case (catch + lists:map(fun(Str) -> Str ++ [?STR_TERMINATOR] end, Values)) of + Result -> + Result + end, + {?USER_VARCHAR, 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. |