documentation for media.erl

2 files changed, 84 insertions, 11 deletions

diff --git a/server/cldb.erl b/server/cldb.erl
index 0f9f407..982aafc 100644
--- a/server/cldb.erl
+++ b/server/cldb.erl
@@ -1,12 +1,53 @@
 % The clientdatabase
 
 -module(cldb).
--export([init/0]).
--record(user, {name, passwd, votes}).
+-export([init/0, ask/2, login/2, decVote/2, incVote/2, register/3, check_rights/2]).
+-record(user, {name, passwd, votes, rights}).
 
 init() ->
     mnesia:create_schema([node()]),
     mnesia:start(),
-    mnesia:create_table(track, [{attributes, record_info(fields, track)}]),
+    mnesia:create_table(user, [{attributes, record_info(fields, user)}]),
     io:format("Userdb up and running \n").
     
+ask(User, Pwd) ->
+    F = fun() ->
+                mnesia:match_object({user, User, Pwd, '_'})
+        end,
+    mnesia:transaction(F).
+    
+                
+    
+login(User, Pwd) ->
+    {_, Reason} = ask(User, Pwd),
+    Reason.
+
+register(User, Pwd, Root) ->
+    F = fun() ->
+                mnesia:write(#user{name = User, passwd = Pwd, votes = 5, rights = Root})
+        end,
+    {_, Reason} = mnesia:transaction(F),
+    Reason.
+
+decVote(User, Pwd) ->
+    F = fun() ->
+                [Head|_] = ask(User, Pwd),
+                Votes = Head#user.votes - 1,
+                New = Head#user{votes = Votes},
+                mnesia:write(New)
+        end,
+    mnesia:transaction(F).
+
+incVote(User, Pwd) ->
+    F = fun() ->
+                [Head|_] = ask(User, Pwd),
+                Votes = Head#user.votes + 1,
+                New = Head#user{votes = Votes},
+                mnesia:write(New)
+        end,
+    mnesia:transaction(F).
+
+check_rights(User, Name) ->
+    {_, _, Rights} = ask(User, Name),
+    Rights.
+                
diff --git a/server/media.erl b/server/media.erl
index 0ef5a44..d6adc5b 100644
--- a/server/media.erl
+++ b/server/media.erl
@@ -1,5 +1,5 @@
 -module(media).
--export([init/0,insert/3, ask/2, all/0, play/3, vote/2, devote/2, lock_process/2]).
+-export([init/0,insert/3, ask/2, all/0, play/2, vote/2, devote/2, lock_process/2]).
 -define(TESTPATTERN, "../ac/*.mp3").
 -define(TIMEOUT, 100000000).
 
@@ -59,7 +59,11 @@ insert(Artist, Title, Filepath) ->
         end,
     mnesia:transaction(F).
 
-% search the track with the highest votes and return {Artist, Title}
+% Of course we need a query to find out whats actually the most wished for track.
+% We will do it by requesting all the records from the database and then iteramte over just taking a look at the vote
+% variable, so it is like list of integers. In case no tracks were voted for we just take the first track we find and play it. 
+% Of course it is locked afterwards so another will be choosen.
+
 
 search_best([Head|Rest], Max_Votes, Track) -> 
 	if 
@@ -72,7 +76,7 @@ search_best([], _, Track) -> {Track#track.artist, Track#track.title}.
 
 % if nothing is playable anymore (because all songs are locked) just reset all songs and start playing again...
 
-reset_all([Head|Rest) ->
+reset_all([Head|Rest]) ->
 	unlock(Head#track.artist, Head#track.title),
 	reset_all(Rest);
 reset_all([]) -> ok.
@@ -104,18 +108,22 @@ play(Artist, Title) ->
     {_, Title, Artist, _, _, Fp} = Head,
     Port = erlang:open_port({spawn_executable, "/usr/bin/mplayer"}, [{args, [Fp]}, exit_status]),
     reset_votes(Artist, Title),
-    lock_process(Artist, Title),
+    spawn(media, lock_process, [Artist, Title]),
     
     io:format("playing: ~s, Artist: ~s~n", [Title, Artist]),
     receive
 		{Port, {exit_status, 0}} -> start_playing();
 		{Port, {exit_status, S}} -> throw({commandfailed, S})
     end.
+<<<<<<< HEAD
 
 
 % Of course we need a query to find out what the highest voted track is.
 % We accomplish this by requesting all the records from the database and then iterate over them, just taking a look at the vote
 % variable, so it is like a list of integers. In case no tracks were voted for we just take the first track we found and play it. Of course this song is locked afterwards so a different one will be chosen.
+=======
+%Increase the vote in the database so it will hopefully be played in the future
+>>>>>>> 3ab5da8355e114953c154114aa4c0c36b719e92e
 
 %votes for a track, i.e. increases its vote count by one.
 vote(Artist, Title) ->
@@ -127,7 +135,12 @@ vote(Artist, Title) ->
         end,
     mnesia:transaction(F).
 
+<<<<<<< HEAD
 %votes against a track, i.e. decreases its vote count by one.
+=======
+% decrease votes in database
+
+>>>>>>> 3ab5da8355e114953c154114aa4c0c36b719e92e
 devote(Artist, Title) ->
     F = fun() ->
                 [Head|_] = ask(Artist, Title),
@@ -137,7 +150,12 @@ devote(Artist, Title) ->
         end,
     mnesia:transaction(F).
 
+<<<<<<< HEAD
 %resets the vote count of selected track to 0 (this is called when the song is played).
+=======
+% Reset votes to zero in database
+
+>>>>>>> 3ab5da8355e114953c154114aa4c0c36b719e92e
 reset_votes(Artist, Title) ->
     F = fun() ->
                 [Head|_] = ask(Artist, Title),
@@ -146,28 +164,42 @@ reset_votes(Artist, Title) ->
         end,
     mnesia:transaction(F).
     
+<<<<<<< HEAD
 %locks a song so it can't be played again or voted for for that time.
+=======
+% Lock a song
+
+>>>>>>> 3ab5da8355e114953c154114aa4c0c36b719e92e
 lock(Artist, Title) ->
     F = fun() ->
                 [Head|_] = ask(Artist, Title),
-                Votes = Head#track.lock = true,
-                New = Head#track{lock = Votes},
+                New = Head#track{locked = true},
                 mnesia:write(New)
         end,
     mnesia:transaction(F).
 
+<<<<<<< HEAD
 %unlocks a song so it can be played and voted for again.
+=======
+% Unlock a song...
+
+>>>>>>> 3ab5da8355e114953c154114aa4c0c36b719e92e
 unlock(Artist, Title) ->
     F = fun() ->
                 [Head|_] = ask(Artist, Title),
-                Votes = Head#track.lock = false,
-                New = Head#track{lock = Votes},
+                New = Head#track{locked = false},
                 mnesia:write(New)
         end,
     mnesia:transaction(F).
 
+<<<<<<< HEAD
 %locks a song and then waits for a specified amount of time before unlocking it again.
 %this is called when the song is played.
+=======
+% Lock a song if it was just played, after a Timeout it will be unlocked automaticly
+% If all songs are locked, all will be unlocked.
+
+>>>>>>> 3ab5da8355e114953c154114aa4c0c36b719e92e
 lock_process(Artist, Title) ->
     lock(Artist, Title),
     receive