From ee9c2ac044cc77b80f30420c8f0788cad4281084 Mon Sep 17 00:00:00 2001 From: nsensfel Date: Wed, 6 Jun 2018 15:54:18 +0200 Subject: Figuring out how to organize the src folder(s)... --- src/db/logic/storage_access.erl | 54 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 src/db/logic/storage_access.erl (limited to 'src/db/logic/storage_access.erl') diff --git a/src/db/logic/storage_access.erl b/src/db/logic/storage_access.erl new file mode 100644 index 0000000..437294f --- /dev/null +++ b/src/db/logic/storage_access.erl @@ -0,0 +1,54 @@ +-module(storage_access). + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%% TYPES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%% EXPORTS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +-export +( + [ + read/2, + insert/4, + query/1 + ] +). +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%% LOCAL FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +get_value ([]) -> not_found; +get_value ([Regval]) -> {ok, db_item:get_value(Regval)}. + +read_transaction (DB, ID) -> + get_value(mnesia:read(DB, ID)). + +insert_transaction (DB, ID, Perm, Value) -> + StoredItem = db_item:new(ID, Perm, Value), + % FIXME: handle return value, mnesia:write -> (transaction abort | ok). + % FIXME: is this an atomic OP? Is the lock freed afterwards? + mnesia:write(DB, StoredItem, sticky_write), + ok. + +query_transaction (Query) -> + DB = db_query:get_database(Query), + ID = db_query:get_entry_id(Query), + [Item] = mnesia:read(DB, ID), + {ok, UpdatedItem} = db_query:apply_to(Query, Item), + % FIXME: handle return value, mnesia:write -> (transaction abort | ok). + % FIXME: is this an atomic OP? Is the lock freed afterwards? + mnesia:write(DB, UpdatedItem, sticky_write), + ok. + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%% EXPORTED FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +read (DB, ID) -> + mnesia:transaction(fun read_transaction/2, [DB, ID]). + +insert (DB, ID, Perm, Value) -> + mnesia:transaction(fun insert_transaction/4, [DB, ID, Perm, Value]). + +query (Query) -> + mnesia:transaction(fun query_transaction/1, [Query]). -- cgit v1.2.3-70-g09d2