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|
-module(timed_cache_manager).
-export(
[
new/2,
start/1,
fetch/2
]
).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% LOCAL %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%% Manager %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
manager_core_loop (DB) ->
receive
terminate -> ets:delete(DB)
end.
new_database (DB) ->
ets:new(
DB,
[
set,
public,
{keypos, 1},
{read_concurrency, true}
]
).
%%%% Timer %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
timer_cleanup (DB, ObjectID) ->
ets:delete(DB, ObjectID).
timer_core_loop (DB, ObjectID, Timeout) ->
receive
ok -> timer_core_loop(DB, ObjectID, Timeout);
terminate -> ok
after Timeout ->
timer_cleanup(DB, ObjectID)
end.
add_timer (DB, ObjectID, Timeout) ->
spawn(timed_cache_manager, timer_core_loop, [DB, ObjectID, Timeout]).
add_to_cache (DB, ObjectID) ->
TimerPID = add_timer(DB, ObjectID, 60000),
Data = nothing, %% Do the actual NoSQL Fetch here.
ets:insert(DB, {ObjectID, TimerPID, Data}),
Data.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% EXPORTED %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
new (Manager, DB) ->
register(
Manager,
spawn(
timed_cache_manager,
start,
[DB]
)
).
start (DB) ->
new_database(DB),
manager_core_loop(DB).
fetch (DB, ObjectID) ->
case ets:lookup(DB, ObjectID) of
[] ->
add_to_cache(DB, ObjectID);
[{_, TimerPID, Data}] ->
TimerPID ! ok,
Data
end.
|
