diff options
Diffstat (limited to 'apps/dreki/src/dreki_dets_store.erl')
-rw-r--r-- | apps/dreki/src/dreki_dets_store.erl | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/apps/dreki/src/dreki_dets_store.erl b/apps/dreki/src/dreki_dets_store.erl new file mode 100644 index 0000000..05cf9fb --- /dev/null +++ b/apps/dreki/src/dreki_dets_store.erl @@ -0,0 +1,74 @@ +-module(dreki_dets_store). + +-include("dreki.hrl"). + +-behaviour(dreki_store_backend). + +-export([start/0, start/4, checkout/1, checkin/1, stop/0, stop/1]). +-export([valid_store/5]). +-export([list/1, count/1, exists/2, get/2, create/2, update/2, delete/2]). + +-record(?MODULE, {tab, file}). + +start() -> ok. + +valid_store(_Namespace, _Location, _Name, _NSMod, _Args) -> ok. + +start(Namespace, Name, _XUrn, Args) -> + StoreName = {?MODULE, Namespace, Name}, + File = maps:get(file_name, Args, <<Namespace/binary, ".", Name/binary, ".dets">>), + FileName = binary:bin_to_list(File), + case dets:open_file(StoreName, [{file, FileName}, {keypos, 2}]) of + {ok, Tab} -> {ok, #?MODULE{tab = Tab, file = FileName}}; + {error, Error} -> {error, {dets_open_failed, Error}} + end. + +checkout(#?MODULE{tab = Tab, file = FileName}) -> + case dets:open_file(Tab, [{file, FileName}, {keypos, 2}]) of + {ok, Tab} -> {ok, {dreki_dets_store_ref, Tab}}; + {error, Error} -> {error, {dets_open_failed, Error}} + end. + +checkin({dreki_dets_store_ref, Tab}) -> + dets:close(Tab). + +stop() -> ok. + +stop(#?MODULE{tab = Tab}) -> + dets:close(Tab). + +list({dreki_dets_store_ref, Tab}) -> + dets:foldl(fun (T, {ok, Ts}) -> {ok, [T | Ts]} end, {ok, []}, Tab). + +count({dreki_dets_store_ref, Tab}) -> + dets:foldl(fun (_T, {ok, Ct}) -> {ok, Ct + 1} end, {ok, 0}, Tab). + +exists({dreki_dets_store_ref, Tab}, Id) -> + dets:member(Tab, Id). + +get({dreki_dets_store_ref, Tab}, Id) -> + case dets:lookup(Tab, Id) of + [] -> {error, {task_not_found, Id}}; + [Task] -> {ok, Task} + end. + +delete({dreki_dets_store_ref, Tab}, Id) -> + dets:delete(Tab, Id). + +create({dreki_dets_store_ref, Tab}, Task = #dreki_task{persisted=false}) -> + case dets:insert_new(Tab, Task#dreki_task{persisted=true, dirty=false}) of + true -> {ok, Task#dreki_task{persisted=true, dirty=false}}; + false -> {error, {task_exists, Task#dreki_task.id}}; + {error, Error} -> {error, Error} + end. + +update(_Tab, Task = #dreki_task{persisted=false}) -> + {error, {task_not_created, Task#dreki_task.id}}; +update(_Tab, Task = #dreki_task{dirty=false}) -> + {ok, Task}; +update({dreki_dets_store_ref, Tab}, Task = #dreki_task{persisted=true, dirty=true}) -> + case dets:insert(Tab, Task#dreki_task{dirty=false}) of + ok -> {ok, Task#dreki_task{dirty=false}}; + {error, Error} -> {error, Error} + end. + |