diff options
Diffstat (limited to 'server')
| -rw-r--r-- | server/cldb.erl | 140 | ||||
| -rw-r--r-- | server/client.erl | 31 | ||||
| -rw-r--r-- | server/dispatcher.erl | 31 | ||||
| -rw-r--r-- | server/media.erl | 2 |
4 files changed, 156 insertions, 48 deletions
diff --git a/server/cldb.erl b/server/cldb.erl index d1daaa9..28815a6 100644 --- a/server/cldb.erl +++ b/server/cldb.erl @@ -1,8 +1,8 @@ % The clientdatabase -module(cldb). --export([init/0,all/0, ask/2, login/2, decVote/1, incVote/1, register/3, check_rights/1, give_votes/1]). --record(user, {name, passwd, votes, rights}). +-export([init/0, all/0, find/1, login/2, dec_vote/1, inc_vote/1, register/3, check_rights/1, update_votes/0, logout/1, set_client_pid/2]). +-record(user, {name, passwd, votes, logged_in, pid, rights}). init() -> mnesia:create_schema([node()]), @@ -10,44 +10,121 @@ init() -> mnesia:create_table(user, [{attributes, record_info(fields, user)}]), io:format("Userdb up and running \n"). -ask(User, Pwd) -> +find(User) when is_list(User) -> + find(User, '_'); +find(User) -> + find(User#user.name, '_'). + +find(User, Pwd) -> F = fun() -> - mnesia:match_object({user, User, Pwd, '_', '_'}) + mnesia:match_object({user, User, Pwd, '_', '_', '_', '_'}) end, mnesia:transaction(F). +find_logged_in_user() -> + F = fun() -> + mnesia:match_object({user, '_', '_', '_', true, '_', '_'}) + end, + case mnesia:transaction(F) of + {atomic, List} -> {ok, List}; + _ -> {error} + end. + +find_user_by_pid(Pid) -> + F = fun() -> + mnesia:match_object({user, '_', '_', '_', '_', Pid, '_'}) + end, + case mnesia:transaction(F) of + {atomic, List} -> {ok, List}; + _ -> {error} + end. + all() -> - F = fun() -> - mnesia:match_object({user, '_', '_', '_', '_'}) + F = fun() -> + mnesia:match_object({user, '_', '_', '_', '_', '_', '_'}) end, - {atomic, List} = mnesia:transaction(F), - List. - + case mnesia:transaction(F) of + {atomic, List} -> {ok, List}; + _ -> {error} + end. + +login(User, Pwd) when is_list(User) and is_list(Pwd) -> + case find(User, Pwd) of + {atomic, [UserRow|_]} -> + NewUserRow = UserRow#user{logged_in = true}, + F = fun() -> + mnesia:write(NewUserRow) + end, + case mnesia:transaction(F) of + {atomic, ok} -> + {ok, NewUserRow}; + {atomic, Why} -> + {error, Why} + end; -login(User, Pwd) -> - case ask(User, Pwd) of - {atomic, [UserRow|_]} -> {ok, UserRow}; _-> {error} + end; + +login(_, _) -> + {error}. + +set_client_pid(User, Pid) -> + case find(User) of + {atomic, [UserRow|_]} -> + NewUserRow = UserRow#user{pid = Pid}, + F = fun() -> + mnesia:write(NewUserRow) + end, + case mnesia:transaction(F) of + {atomic, ok} -> + {ok, pid_updated}; + {atomic, Why} -> + {error, Why} + end; + _ -> + {error, user_not_found} end. -register(User, Pwd, Root) -> - case ask(User, '_') of +logout(Pid) -> + case find_user_by_pid(Pid) of + {atomic, [UserRow|_]} -> + F = fun() -> + New = UserRow#user{logged_in = false}, + mnesia:write(New) + end, + case mnesia:transaction(F) of + {atomic, ok} -> + {ok, logged_out}; + {atomic, Why} -> + {error, Why} + end; + + _ -> + {error, invalid_user} + end. + +register(User, Pwd, Root) when is_list(User) and is_list(Pwd) -> + case find(User) of {atomic, []} -> F = fun() -> - mnesia:write(#user{name = User, passwd = Pwd, votes = 5, rights = Root}) + mnesia:write(#user{name = User, passwd = Pwd, votes = 5, logged_in = false, pid = undef, rights = Root}) end, case mnesia:transaction(F) of {atomic, ok} -> + io:format("User created: ~s~n", [User]), {ok, user_created}; {atomic, Why} -> {error, Why} end; _ -> {error, duplicated_user} - end. + end; + +register(_,_,_) -> + {error, invalid_username}. -decVote(User) when is_list(User) -> - {atomic, [Head|_]} = ask(User, '_'), +dec_vote(User) when is_list(User) -> + {atomic, [Head|_]} = find(User), if Head#user.votes > 0 -> F = fun() -> Votes = Head#user.votes - 1, @@ -58,12 +135,12 @@ decVote(User) when is_list(User) -> {ok}; true -> {error} end; -decVote(User) -> - decVote(User#user.name). +dec_vote(User) -> + dec_vote(User#user.name). -incVote(User) -> +inc_vote(User) -> F = fun() -> - {atomic, [Head|_]} = ask(User, '_'), + {atomic, [Head|_]} = find(User), Votes = Head#user.votes + 1, New = Head#user{votes = Votes}, mnesia:write(New) @@ -71,13 +148,18 @@ incVote(User) -> mnesia:transaction(F). check_rights(User) -> - {_, _, Rights} = ask(User, '_'), - Rights. + {atomic, [UserRow|_]} = find(User), + UserRow#user.rights. -% after a song every client gets on more vote -give_votes([Head|Rest]) -> - User = Head#user.name, - incVote(User), +update_votes() -> + %% after a song every logged_in client gets on more vote + case find_logged_in_user() of + {ok, List} -> + give_votes(List); + _ -> error + end. + +give_votes([User|Rest]) -> + inc_vote(User#user.name), give_votes(Rest); give_votes([]) -> ok. - diff --git a/server/client.erl b/server/client.erl index 7cee336..421280b 100644 --- a/server/client.erl +++ b/server/client.erl @@ -2,11 +2,19 @@ -export([start/2, loop/2, register/2, login/2]). start(Node, User) -> + %% start linked processes on client and server to get noticed if + %% client disconnects and properly handle the logged in status process_flag(trap_exit, true), Client = server:start_on_node(Node, client, undef), link(Client), + %% store the client pid in the client database to find the correct + %% user on the exit message from the client + cldb:set_client_pid(User, Client), Server = spawn_link(client, loop, [Client, User]), + %% update the server process_id in the state of the client process, + %% so that the client process know directly its counterpart on the + %% server case server:rpc(Client, {change_state, Server}) of {ok} -> {ok, Client}; @@ -26,12 +34,12 @@ execute(Client, F) -> end. loop(Client, User) -> - %% mainloop for client modul in server + %% mainloop for client modul in server, handle the commands form + %% the logged_in client receive {register, Name, Password} -> - case User of - {user, _, _, _, admin} -> - execute(Client, fun() -> cldb:register(Name, Password, none) end); + case cldb:check_rights(User) of + admin -> execute(Client, fun() -> cldb:register(Name, Password, none) end); _ -> Client ! {error, {no_rights}} end; @@ -42,21 +50,30 @@ loop(Client, User) -> execute(Client, fun() -> media:getVotes(Client) end); {vote, Artist, Title} -> - case cldb:decVote(User) of + %% only allow vote if user has vote to give away + case cldb:dec_vote(User) of {ok} -> execute(Client, fun() -> media:vote(Artist, Title) end); _ -> Client ! {error, no_votes_available} - end; + end; {devote, Artist, Title} -> - execute(Client, fun() -> media:devote(Artist, Title) end); + %% only allow devote if user has vote to give away + case cldb:dec_vote(User) of + {ok} -> execute(Client, fun() -> media:devote(Artist, Title) end); + _ -> Client ! {error, no_votes_available} + end; Cmd -> + %% fallback for error messages Client ! {error, {unknown_command, Cmd}} end, loop(Client, User). register(Client, {Name, Password}) -> + %% forward the register messages to the dispatcher (if user is not + %% logged in) dis ! {Client, {register, {Name, Password}}}. login(Client, {Node, Name, Password}) -> + %% forward the login messages to the dispatcher dis ! {Client, {login, {Node, Name, Password}}}. diff --git a/server/dispatcher.erl b/server/dispatcher.erl index 3806ef7..27c2d4c 100644 --- a/server/dispatcher.erl +++ b/server/dispatcher.erl @@ -1,7 +1,8 @@ -module(dispatcher). --export([start/0, handle/2, checkUserExists/1]). +-export([start/0, handle/2]). checkUserExists([_|_]) -> + %% helper function to check if given array contains at least one element false; checkUserExists(_) -> true. @@ -12,6 +13,7 @@ start() -> code:purge(server), code:load_abs("../common/server"), + %% initalize database cldb:init(), %% spawn media backend in seperat process @@ -24,13 +26,15 @@ start() -> exit(1) end, - %% start server (registered as dis) - %% server-module will call handle if message arrives and init to - %% initialize the status - UserExists = checkUserExists(cldb:ask('_', '_')), + %% start server (registered as dis, arriving messages will call + %% the handle function to get the result) + %% The state of the server is true if register is allowed (no user + %% exists) -> first created user is admit and after the first + %% registration only the admit could register the other user + UserExists = checkUserExists(cldb:all()), try server:start(dis, dispatcher, UserExists) of true -> - io:format("Server started: ~w!~n", [UserExists]), + io:format("Server started!~n"), true catch _ -> @@ -39,14 +43,16 @@ start() -> end. handle({register, {User, Password}}, true) -> - io:format("User created: ~s~n", [User]), - cldb:register(User, Password, admin), - {{ok, user_created}, false}; + %% first registration + {cldb:register(User, Password, admin), false}; handle({register, _}, false) -> + %% if state of the server is false, no registration allowed, + %% because the admin user allready exists {{error, no_rights}, false}; handle({login, {Node, User, Password}}, State) -> + %% login user if Password match case cldb:login(User, Password) of {ok, UserRow} -> case client:start(Node, UserRow) of @@ -59,9 +65,12 @@ handle({login, {Node, User, Password}}, State) -> {{error, {user_or_password_invalid, Why}}, State} end; -handle({'EXIT', _, _}, State) -> +handle({'EXIT', From, _}, State) -> + %% handle the exit messages from the client, so that the client + %% logouts if the connection between server and client breaks + cldb:logout(From), State; handle(Cmd, State) -> - %% standard command, to find transmission errors + %% standard command, to find invalid commands and emit an error {{error, {unknown_command, Cmd}}, State}. diff --git a/server/media.erl b/server/media.erl index 5148edc..14aa53e 100644 --- a/server/media.erl +++ b/server/media.erl @@ -112,7 +112,7 @@ play(Artist, Title) -> io:format("playing: ~s, Artist: ~s~n", [Title, Artist]), receive - {Port, {exit_status, 0}} -> cldb:give_votes(cldb:all()), start_playing(); + {Port, {exit_status, 0}} -> cldb:update_votes(), start_playing(); {Port, {exit_status, S}} -> throw({commandfailed, S}) end. |