%%%----------------------------------------------------------------------
%%% File : ejabberd_odbc.erl
%%% Author : Alexey Shchepin <alexey@process-one.net>
%%% Purpose : Serve ODBC connection
%%% Created : 8 Dec 2004 by Alexey Shchepin <alexey@process-one.net>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2013 ProcessOne
%%%
%%% This program is free software; you can redistribute it and/or
%%% modify it under the terms of the GNU General Public License as
%%% published by the Free Software Foundation; either version 2 of the
%%% License, or (at your option) any later version.
%%%
%%% This program is distributed in the hope that it will be useful,
%%% but WITHOUT ANY WARRANTY; without even the implied warranty of
%%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
%%% General Public License for more details.
%%%
%%% You should have received a copy of the GNU General Public License
%%% along with this program; if not, write to the Free Software
%%% Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
%%% 02111-1307 USA
%%%
%%%----------------------------------------------------------------------
-module(ejabberd_odbc).
-author('alexey@process-one.net').
-define(GEN_FSM, p1_fsm).
-behaviour(?GEN_FSM).
%% External exports
-export([start/1, start_link/2,
sql_query/2,
sql_query_t/1,
sql_transaction/2,
sql_bloc/2,
escape/1,
escape_like/1,
to_bool/1,
encode_term/1,
decode_term/1,
keep_alive/1]).
%% gen_fsm callbacks
-export([init/1, handle_event/3, handle_sync_event/4,
handle_info/3, terminate/3, print_state/1,
code_change/4]).
%% gen_fsm states
-export([connecting/2, connecting/3,
session_established/2, session_established/3]).
-include("ejabberd.hrl").
-include("logger.hrl").
-record(state,
{db_ref = self() :: pid(),
db_type = odbc :: pgsql | mysql | odbc,
start_interval = 0 :: non_neg_integer(),
host = <<"">> :: binary(),
max_pending_requests_len :: non_neg_integer(),
pending_requests = {0, queue:new()} :: {non_neg_integer(), queue()}}).
-define(STATE_KEY, ejabberd_odbc_state).
-define(NESTING_KEY, ejabberd_odbc_nesting_level).
-define(TOP_LEVEL_TXN, 0).
-define(PGSQL_PORT, 5432).
-define(MYSQL_PORT, 3306).
-define(MAX_TRANSACTION_RESTARTS, 10).
-define(TRANSACTION_TIMEOUT, 60000).
-define(KEEPALIVE_TIMEOUT, 60000).
-define(KEEPALIVE_QUERY, <<"SELECT 1;">>).
%%-define(DBGFSM, true).
-ifdef(DBGFSM).
-define(FSMOPTS, [{debug, [trace]}]).
-else.
-define(FSMOPTS, []).
-endif.
%%%----------------------------------------------------------------------
%%% API
%%%----------------------------------------------------------------------
start(Host) ->
(?GEN_FSM):start(ejabberd_odbc, [Host],
fsm_limit_opts() ++ (?FSMOPTS)).
start_link(Host, StartInterval) ->
(?GEN_FSM):start_link(ejabberd_odbc,
[Host, StartInterval],
fsm_limit_opts() ++ (?FSMOPTS)).
-type sql_query() :: [sql_query() | binary()].
-type sql_query_result() :: {updated, non_neg_integer()} |
{error, binary()} |
{selected, [binary()],
[[binary()]]}.
-spec sql_query(binary(), sql_query()) -> sql_query_result().
sql_query(Host, Query) ->
sql_call(Host, {sql_query, Query}).
%% SQL transaction based on a list of queries
%% This function automatically
-spec sql_transaction(binary(), [sql_query()] | fun(() -> any())) ->
{atomic, any()} |
{aborted, any()}.
sql_transaction(Host, Queries)
when is_list(Queries) ->
F = fun () ->
lists:foreach(fun (Query) -> sql_query_t(Query) end,
Queries)
end,
sql_transaction(Host, F);
%% SQL transaction, based on a erlang anonymous function (F = fun)
sql_transaction(Host, F) when is_function(F) ->
sql_call(Host, {sql_transaction, F}).
%% SQL bloc, based on a erlang anonymous function (F = fun)
sql_bloc(Host, F) -> sql_call(Host, {sql_bloc, F}).
sql_call(Host, Msg) ->
case get(?STATE_KEY) of
undefined ->
(?GEN_FSM):sync_send_event(ejabberd_odbc_sup:get_random_pid(Host),
{sql_cmd, Msg, now()},
?TRANSACTION_TIMEOUT);
_State -> nested_op(Msg)
end.
keep_alive(PID) ->
(?GEN_FSM):sync_send_event(PID,
{sql_cmd, {sql_query, ?KEEPALIVE_QUERY}, now()},
?KEEPALIVE_TIMEOUT).
-spec sql_query_t(sql_query()) -> sql_query_result().
%% This function is intended to be used from inside an sql_transaction:
sql_query_t(Query) ->
QRes = sql_query_internal(Query),
case QRes of
{error, Reason} -> throw({aborted, Reason});
Rs when is_list(Rs) ->
case lists:keysearch(error, 1, Rs) of
{value, {error, Reason}} -> throw({aborted, Reason});
_ -> QRes
end;
_ -> QRes
end.
%% Escape character that will confuse an SQL engine
escape(S) ->
<< <<(odbc_queries:escape(Char))/binary>> || <<Char>> <= S >>.
%% Escape character that will confuse an SQL engine
%% Percent and underscore only need to be escaped for pattern matching like
%% statement
escape_like(S) when is_binary(S) ->
<< <<(escape_like(C))/binary>> || <<C>> <= S >>;
escape_like($%) -> <<"\\%">>;
escape_like($_) -> <<"\\_">>;
escape_like(C) when is_integer(C), C >= 0, C =< 255 -> odbc_queries:escape(C).
to_bool(<<"t">>) -> true;
to_bool(<<"true">>) -> true;
to_bool(<<"1">>) -> true;
to_bool(true) -> true;
to_bool(1) -> true;
to_bool(_) -> false.
encode_term(Term) ->
escape(list_to_binary(
erl_prettypr:format(erl_syntax:abstract(Term)))).
decode_term(Bin) ->
Str = binary_to_list(<<Bin/binary, ".">>),
{ok, Tokens, _} = erl_scan:string(Str),
{ok, Term} = erl_parse:parse_term(Tokens),
Term.
%%%----------------------------------------------------------------------
%%% Callback functions from gen_fsm
%%%----------------------------------------------------------------------
init([Host, StartInterval]) ->
case ejabberd_config:get_option(
{keepalive_interval, Host},
fun(I) when is_integer(I), I>0 -> I end) of
undefined ->
ok;
KeepaliveInterval ->
timer:apply_interval(KeepaliveInterval * 1000, ?MODULE,
keep_alive, [self()])
end,
[DBType | _] = db_opts(Host),
(?GEN_FSM):send_event(self(), connect),
ejabberd_odbc_sup:add_pid(Host, self()),
{ok, connecting,
#state{db_type = DBType, host = Host,
max_pending_requests_len = max_fsm_queue(),
pending_requests = {0, queue:new()},
start_interval = StartInterval}}.
connecting(connect, #state{host = Host} = State) ->
ConnectRes = case db_opts(Host) of
[mysql | Args] -> apply(fun mysql_connect/5, Args);
[pgsql | Args] -> apply(fun pgsql_connect/5, Args);
[odbc | Args] -> apply(fun odbc_connect/1, Args)
end,
{_, PendingRequests} = State#state.pending_requests,
case ConnectRes of
{ok, Ref} ->
erlang:monitor(process, Ref),
lists:foreach(fun (Req) ->
(?GEN_FSM):send_event(self(), Req)
end,
queue:to_list(PendingRequests)),
{next_state, session_established,
State#state{db_ref = Ref,
pending_requests = {0, queue:new()}}};
{error, Reason} ->
?INFO_MSG("~p connection failed:~n** Reason: ~p~n** "
"Retry after: ~p seconds",
[State#state.db_type, Reason,
State#state.start_interval div 1000]),
(?GEN_FSM):send_event_after(State#state.start_interval,
connect),
{next_state, connecting, State}
end;
connecting(Event, State) ->
?WARNING_MSG("unexpected event in 'connecting': ~p",
[Event]),
{next_state, connecting, State}.
connecting({sql_cmd, {sql_query, ?KEEPALIVE_QUERY},
_Timestamp},
From, State) ->
(?GEN_FSM):reply(From,
{error, <<"SQL connection failed">>}),
{next_state, connecting, State};
connecting({sql_cmd, Command, Timestamp} = Req, From,
State) ->
?DEBUG("queuing pending request while connecting:~n\t~p",
[Req]),
{Len, PendingRequests} = State#state.pending_requests,
NewPendingRequests = if Len <
State#state.max_pending_requests_len ->
{Len + 1,
queue:in({sql_cmd, Command, From, Timestamp},
PendingRequests)};
true ->
lists:foreach(fun ({sql_cmd, _, To,
_Timestamp}) ->
(?GEN_FSM):reply(To,
{error,
<<"SQL connection failed">>})
end,
queue:to_list(PendingRequests)),
{1,
queue:from_list([{sql_cmd, Command, From,
Timestamp}])}
end,
{next_state, connecting,
State#state{pending_requests = NewPendingRequests}};
connecting(Request, {Who, _Ref}, State) ->
?WARNING_MSG("unexpected call ~p from ~p in 'connecting'",
[Request, Who]),
{reply, {error, badarg}, connecting, State}.
session_established({sql_cmd, Command, Timestamp}, From,
State) ->
run_sql_cmd(Command, From, State, Timestamp);
session_established(Request, {Who, _Ref}, State) ->
?WARNING_MSG("unexpected call ~p from ~p in 'session_establ"
"ished'",
[Request, Who]),
{reply, {error, badarg}, session_established, State}.
session_established({sql_cmd, Command, From, Timestamp},
State) ->
run_sql_cmd(Command, From, State, Timestamp);
session_established(Event, State) ->
?WARNING_MSG("unexpected event in 'session_established': ~p",
[Event]),
{next_state, session_established, State}.
handle_event(_Event, StateName, State) ->
{next_state, StateName, State}.
handle_sync_event(_Event, _From, StateName, State) ->
{reply, {error, badarg}, StateName, State}.
code_change(_OldVsn, StateName, State, _Extra) ->
{ok, StateName, State}.
%% We receive the down signal when we loose the MySQL connection (we are
%% monitoring the connection)
handle_info({'DOWN', _MonitorRef, process, _Pid, _Info},
_StateName, State) ->
(?GEN_FSM):send_event(self(), connect),
{next_state, connecting, State};
handle_info(Info, StateName, State) ->
?WARNING_MSG("unexpected info in ~p: ~p",
[StateName, Info]),
{next_state, StateName, State}.
terminate(_Reason, _StateName, State) ->
ejabberd_odbc_sup:remove_pid(State#state.host, self()),
case State#state.db_type of
mysql -> catch p1_mysql_conn:stop(State#state.db_ref);
_ -> ok
end,
ok.
%%----------------------------------------------------------------------
%% Func: print_state/1
%% Purpose: Prepare the state to be printed on error log
%% Returns: State to print
%%----------------------------------------------------------------------
print_state(State) -> State.
%%%----------------------------------------------------------------------
%%% Internal functions
%%%----------------------------------------------------------------------
run_sql_cmd(Command, From, State, Timestamp) ->
case timer:now_diff(now(), Timestamp) div 1000 of
Age when Age < (?TRANSACTION_TIMEOUT) ->
put(?NESTING_KEY, ?TOP_LEVEL_TXN),
put(?STATE_KEY, State),
abort_on_driver_error(outer_op(Command), From);
Age ->
?ERROR_MSG("Database was not available or too slow, "
"discarding ~p milliseconds old request~n~p~n",
[Age, Command]),
{next_state, session_established, State}
end.
%% Only called by handle_call, only handles top level operations.
%% @spec outer_op(Op) -> {error, Reason} | {aborted, Reason} | {atomic, Result}
outer_op({sql_query, Query}) ->
sql_query_internal(Query);
outer_op({sql_transaction, F}) ->
outer_transaction(F, ?MAX_TRANSACTION_RESTARTS, <<"">>);
outer_op({sql_bloc, F}) -> execute_bloc(F).
%% Called via sql_query/transaction/bloc from client code when inside a
%% nested operation
nested_op({sql_query, Query}) ->
sql_query_internal(Query);
nested_op({sql_transaction, F}) ->
NestingLevel = get(?NESTING_KEY),
if NestingLevel =:= (?TOP_LEVEL_TXN) ->
outer_transaction(F, ?MAX_TRANSACTION_RESTARTS, <<"">>);
true -> inner_transaction(F)
end;
nested_op({sql_bloc, F}) -> execute_bloc(F).
%% Never retry nested transactions - only outer transactions
inner_transaction(F) ->
PreviousNestingLevel = get(?NESTING_KEY),
case get(?NESTING_KEY) of
?TOP_LEVEL_TXN ->
{backtrace, T} = process_info(self(), backtrace),
?ERROR_MSG("inner transaction called at outer txn "
"level. Trace: ~s",
[T]),
erlang:exit(implementation_faulty);
_N -> ok
end,
put(?NESTING_KEY, PreviousNestingLevel + 1),
Result = (catch F()),
put(?NESTING_KEY, PreviousNestingLevel),
case Result of
{aborted, Reason} -> {aborted, Reason};
{'EXIT', Reason} -> {'EXIT', Reason};
{atomic, Res} -> {atomic, Res};
Res -> {atomic, Res}
end.
outer_transaction(F, NRestarts, _Reason) ->
PreviousNestingLevel = get(?NESTING_KEY),
case get(?NESTING_KEY) of
?TOP_LEVEL_TXN -> ok;
_N ->
{backtrace, T} = process_info(self(), backtrace),
?ERROR_MSG("outer transaction called at inner txn "
"level. Trace: ~s",
[T]),
erlang:exit(implementation_faulty)
end,
sql_query_internal(<<"begin;">>),
put(?NESTING_KEY, PreviousNestingLevel + 1),
Result = (catch F()),
put(?NESTING_KEY, PreviousNestingLevel),
case Result of
{aborted, Reason} when NRestarts > 0 ->
sql_query_internal(<<"rollback;">>),
outer_transaction(F, NRestarts - 1, Reason);
{aborted, Reason} when NRestarts =:= 0 ->
?ERROR_MSG("SQL transaction restarts exceeded~n** "
"Restarts: ~p~n** Last abort reason: "
"~p~n** Stacktrace: ~p~n** When State "
"== ~p",
[?MAX_TRANSACTION_RESTARTS, Reason,
erlang:get_stacktrace(), get(?STATE_KEY)]),
sql_query_internal(<<"rollback;">>),
{aborted, Reason};
{'EXIT', Reason} ->
sql_query_internal(<<"rollback;">>), {aborted, Reason};
Res -> sql_query_internal(<<"commit;">>), {atomic, Res}
end.
execute_bloc(F) ->
case catch F() of
{aborted, Reason} -> {aborted, Reason};
{'EXIT', Reason} -> {aborted, Reason};
Res -> {atomic, Res}
end.
sql_query_internal(Query) ->
State = get(?STATE_KEY),
Res = case State#state.db_type of
odbc ->
to_odbc(odbc:sql_query(State#state.db_ref, Query,
(?TRANSACTION_TIMEOUT) - 1000));
pgsql ->
pgsql_to_odbc(pgsql:squery(State#state.db_ref, Query));
mysql ->
?DEBUG("MySQL, Send query~n~p~n", [Query]),
%%squery to be able to specify result_type = binary
%%[Query] because p1_mysql_conn expect query to be a list (elements can be binaries, or iolist)
%% but doesn't accept just a binary
R = mysql_to_odbc(p1_mysql_conn:squery(State#state.db_ref,
[Query], self(),
[{timeout, (?TRANSACTION_TIMEOUT) - 1000},
{result_type, binary}])),
%% ?INFO_MSG("MySQL, Received result~n~p~n", [R]),
R
end,
case Res of
{error, <<"No SQL-driver information available.">>} ->
{updated, 0};
_Else -> Res
end.
%% Generate the OTP callback return tuple depending on the driver result.
abort_on_driver_error({error, <<"query timed out">>} =
Reply,
From) ->
(?GEN_FSM):reply(From, Reply),
{stop, timeout, get(?STATE_KEY)};
abort_on_driver_error({error,
<<"Failed sending data on socket", _/binary>>} =
Reply,
From) ->
(?GEN_FSM):reply(From, Reply),
{stop, closed, get(?STATE_KEY)};
abort_on_driver_error(Reply, From) ->
(?GEN_FSM):reply(From, Reply),
{next_state, session_established, get(?STATE_KEY)}.
%% == pure ODBC code
%% part of init/1
%% Open an ODBC database connection
odbc_connect(SQLServer) ->
ejabberd:start_app(odbc),
odbc:connect(binary_to_list(SQLServer), [{scrollable_cursors, off}]).
%% == Native PostgreSQL code
%% part of init/1
%% Open a database connection to PostgreSQL
pgsql_connect(Server, Port, DB, Username, Password) ->
case pgsql:connect([{host, Server},
{database, DB},
{user, Username},
{password, Password},
{port, Port},
{as_binary, true}]) of
{ok, Ref} ->
pgsql:squery(Ref, [<<"alter database ">>, DB, <<" set ">>,
<<"standard_conforming_strings='off';">>]),
{ok, Ref};
Err ->
Err
end.
%% Convert PostgreSQL query result to Erlang ODBC result formalism
pgsql_to_odbc({ok, PGSQLResult}) ->
case PGSQLResult of
[Item] -> pgsql_item_to_odbc(Item);
Items -> [pgsql_item_to_odbc(Item) || Item <- Items]
end.
pgsql_item_to_odbc({<<"SELECT", _/binary>>, Rows,
Recs}) ->
{selected, [element(1, Row) || Row <- Rows], Recs};
pgsql_item_to_odbc({<<"FETCH", _/binary>>, Rows,
Recs}) ->
{selected, [element(1, Row) || Row <- Rows], Recs};
pgsql_item_to_odbc(<<"INSERT ", OIDN/binary>>) ->
[_OID, N] = str:tokens(OIDN, <<" ">>),
{updated, jlib:binary_to_integer(N)};
pgsql_item_to_odbc(<<"DELETE ", N/binary>>) ->
{updated, jlib:binary_to_integer(N)};
pgsql_item_to_odbc(<<"UPDATE ", N/binary>>) ->
{updated, jlib:binary_to_integer(N)};
pgsql_item_to_odbc({error, Error}) -> {error, Error};
pgsql_item_to_odbc(_) -> {updated, undefined}.
%% == Native MySQL code
%% part of init/1
%% Open a database connection to MySQL
mysql_connect(Server, Port, DB, Username, Password) ->
case p1_mysql_conn:start(binary_to_list(Server), Port,
binary_to_list(Username), binary_to_list(Password),
binary_to_list(DB), fun log/3)
of
{ok, Ref} ->
p1_mysql_conn:fetch(Ref, [<<"set names 'utf8';">>],
self()),
{ok, Ref};
Err -> Err
end.
%% Convert MySQL query result to Erlang ODBC result formalism
mysql_to_odbc({updated, MySQLRes}) ->
{updated, p1_mysql:get_result_affected_rows(MySQLRes)};
mysql_to_odbc({data, MySQLRes}) ->
mysql_item_to_odbc(p1_mysql:get_result_field_info(MySQLRes),
p1_mysql:get_result_rows(MySQLRes));
mysql_to_odbc({error, MySQLRes})
when is_binary(MySQLRes) ->
{error, MySQLRes};
mysql_to_odbc({error, MySQLRes}) ->
{error, p1_mysql:get_result_reason(MySQLRes)}.
%% When tabular data is returned, convert it to the ODBC formalism
mysql_item_to_odbc(Columns, Recs) ->
{selected, [element(2, Column) || Column <- Columns], Recs}.
to_odbc({selected, Columns, Recs}) ->
{selected, Columns, [tuple_to_list(Rec) || Rec <- Recs]};
to_odbc(Res) ->
Res.
log(Level, Format, Args) ->
case Level of
debug -> ?DEBUG(Format, Args);
normal -> ?INFO_MSG(Format, Args);
error -> ?ERROR_MSG(Format, Args)
end.
db_opts(Host) ->
Type = ejabberd_config:get_option({odbc_type, Host},
fun(mysql) -> mysql;
(pgsql) -> pgsql;
(odbc) -> odbc
end, odbc),
Server = ejabberd_config:get_option({odbc_server, Host},
fun iolist_to_binary/1,
<<"localhost">>),
case Type of
odbc ->
[odbc, Server];
_ ->
Port = ejabberd_config:get_option(
{port, Host},
fun(P) when is_integer(P), P > 0, P < 65536 -> P end,
case Type of
mysql -> ?MYSQL_PORT;
pgsql -> ?PGSQL_PORT
end),
DB = ejabberd_config:get_option({odbc_database, Host},
fun iolist_to_binary/1,
<<"ejabberd">>),
User = ejabberd_config:get_option({odbc_username, Host},
fun iolist_to_binary/1,
<<"ejabberd">>),
Pass = ejabberd_config:get_option({odbc_password, Host},
fun iolist_to_binary/1,
<<"">>),
[Type, Server, Port, DB, User, Pass]
end.
max_fsm_queue() ->
ejabberd_config:get_option(
max_fsm_queue,
fun(N) when is_integer(N), N > 0 -> N end).
fsm_limit_opts() ->
case max_fsm_queue() of
N when is_integer(N) -> [{max_queue, N}];
_ -> []
end.
