%%%------------------------------------------------------------------- %%% @author danny %%% @copyright (C) 2018, danny %%% @doc %%% %%% @end %%% Created : 2018-08-08 10:26:55.093338 %%%------------------------------------------------------------------- -module(tivan_schema). -behaviour(gen_server). %% API -export([start_link/0 ,create/1 ,create/2 ,drop/1 ,clear/1 ,is_local/1 ,info/0 ,info/1 ,info/2]). %% gen_server callbacks -export([init/1 ,handle_call/3 ,handle_cast/2 ,handle_info/2 ,terminate/2 ,code_change/3]). %%%=================================================================== %%% API %%%=================================================================== %%-------------------------------------------------------------------- %% @doc %% Starts the server %% %% @spec start_link() -> {ok, Pid} | ignore | {error, Error} %% @end %%-------------------------------------------------------------------- start_link() -> gen_server:start_link({local, ?MODULE}, ?MODULE, [], []). create(Table) -> create(Table, #{memory => true, persist => true}). create(Table, Options) when is_atom(Table), is_map(Options) -> gen_server:call(?MODULE, {create, Table, Options}, 60000). drop(Table) when is_atom(Table) -> gen_server:cast(?MODULE, {drop, Table}). clear(Table) when is_atom(Table) -> gen_server:call(?MODULE, {clear, Table}). is_local(Table) -> lists:member(Table, mnesia:system_info(local_tables)). info() -> mnesia:info(). info(Table) -> mnesia:table_info(Table, all). info(Table, ItemList) when is_list(ItemList) -> [ {Item, info(Table, Item)} || Item <- ItemList ]; info(Table, Item) -> mnesia:table_info(Table, Item). %%%=================================================================== %%% gen_server callbacks %%%=================================================================== %%-------------------------------------------------------------------- %% @private %% @doc %% Initializes the server %% %% @spec init(Args) -> {ok, State} | %% {ok, State, Timeout} | %% ignore | %% {stop, Reason} %% @end %%-------------------------------------------------------------------- init([]) -> init_schema(), {ok, #{}}. %%-------------------------------------------------------------------- %% @private %% @doc %% Handling call messages %% %% @spec handle_call(Request, From, State) -> %% {reply, Reply, State} | %% {reply, Reply, State, Timeout} | %% {noreply, State} | %% {noreply, State, Timeout} | %% {stop, Reason, Reply, State} | %% {stop, Reason, State} %% @end %%-------------------------------------------------------------------- handle_call({create, Table, Options}, _From, State) -> Reply = do_create(Table, Options), {reply, Reply, State}; handle_call({clear, Table}, _From, State) -> Reply = handle_clear(Table), {reply, Reply, State}; handle_call(_Request, _From, State) -> Reply = ok, {reply, Reply, State}. %%-------------------------------------------------------------------- %% @private %% @doc %% Handling cast messages %% %% @spec handle_cast(Msg, State) -> {noreply, State} | %% {noreply, State, Timeout} | %% {stop, Reason, State} %% @end %%-------------------------------------------------------------------- handle_cast({drop, Table}, State) -> handle_drop(Table), {noreply, State}; handle_cast(_Msg, State) -> {noreply, State}. %%-------------------------------------------------------------------- %% @private %% @doc %% Handling all non call/cast messages %% %% @spec handle_info(Info, State) -> {noreply, State} | %% {noreply, State, Timeout} | %% {stop, Reason, State} %% @end %%-------------------------------------------------------------------- handle_info(_Info, State) -> {noreply, State}. %%-------------------------------------------------------------------- %% @private %% @doc %% This function is called by a gen_server when it is about to %% terminate. It should be the opposite of Module:init/1 and do any %% necessary cleaning up. When it returns, the gen_server terminates %% with Reason. The return value is ignored. %% %% @spec terminate(Reason, State) -> void() %% @end %%-------------------------------------------------------------------- terminate(_Reason, _State) -> ok. %%-------------------------------------------------------------------- %% @private %% @doc %% Convert process state when code is changed %% %% @spec code_change(OldVsn, State, Extra) -> {ok, NewState} %% @end %%-------------------------------------------------------------------- code_change(_OldVsn, State, _Extra) -> {ok, State}. %%%=================================================================== %%% Internal functions %%%=================================================================== init_schema() -> case application:get_env(tivan, remote_node, undefined) of undefined -> init_standalone_schema(); RemoteNode -> case net_adm:ping(RemoteNode) of pang -> init_standalone_schema(); pong -> init_cluster_schema(RemoteNode) end end. init_cluster_schema(RemoteNode) -> MnesiaNodes = mnesia:system_info(running_db_nodes), case lists:member(RemoteNode, MnesiaNodes) of true -> init_standalone_schema(); false -> rpc:call(RemoteNode, mnesia, change_config, [extra_db_nodes, [node()]]), init_standalone_schema() end. init_standalone_schema() -> PersistFlag = application:get_env(tivan, persist_db, true), case mnesia:table_info(schema, storage_type) of disc_copies when not PersistFlag -> vaporize(); ram_copies when PersistFlag -> persist(); _ -> ok end. vaporize() -> LocalTables = mnesia:system_info(local_tables) -- [schema], Vaporize = fun(Table) -> case mnesia:table_info(Table, storage_type) of disc_copies -> catch mnesia:change_table_copy_type(Table, node(), ram_copies); _ -> ok end end, lists:map(Vaporize, LocalTables), mnesia:change_table_copy_type(schema, node(), ram_copies). persist() -> mnesia:change_table_copy_type(schema, node(), disc_copies). do_create(Table, Options) -> SchemaPersistFlag = application:get_env(tivan, persist_db, true), MnesiaOptions = maps:get(mnesia_options, Options, []), {Attributes, Indexes} = get_attributes_indexes(Options), Memory = maps:get(memory, Options, true), Persist = maps:get(persist, Options, true), Type = maps:get(type, Options, set), StorageType = if Memory, Persist, SchemaPersistFlag -> disc_copies; Persist, SchemaPersistFlag -> rocksdb_copies; Memory -> ram_copies end, case catch mnesia:table_info(Table, storage_type) of {'EXIT', _Reason} -> case mnesia:create_table(Table, [{attributes, Attributes}, {index, Indexes}, {type, Type}, {StorageType, [node()]}|MnesiaOptions]) of {atomic, ok} -> ok; Error -> Error end; unknown -> case mnesia:add_table_copy(Table, node(), StorageType) of {atomic, ok} -> ok; Error -> Error end; StorageType -> ok; _Other -> case mnesia:change_table_copy_type(Table, node(), StorageType) of {atomic, ok} -> ok; Error -> Error end end, wait_for_tables([Table], 50000), transform_if_needed(Table, Attributes, Indexes, Options). get_attributes_indexes(#{columns := AttributesIndexes}) -> lists:foldr( fun({Attribute}, {AttributesAcc, IndexesAcc}) -> {[Attribute|AttributesAcc], [Attribute|IndexesAcc]}; (Attribute, {AttributesAcc, IndexesAcc}) -> {[Attribute|AttributesAcc], IndexesAcc} end, {[], []}, AttributesIndexes ); get_attributes_indexes(_Other) -> {[key, value], []}. wait_for_tables(Tables, Time) -> lager:info("Waiting for tables ~p for ~p milliseconds", [Tables, Time]), case mnesia:wait_for_tables(Tables, Time) of {timeout, TablesToLoad} -> lager:info("Tables still loading ~p", [TablesToLoad]), TimeToWait = if Time > 5000 -> Time div 2; true -> Time end, wait_for_tables(TablesToLoad, TimeToWait); {error, Reason} -> lager:error("Failed to load ~p", [Reason]); ok -> lager:info("Completed loading tables.") end. transform_if_needed(Table, Attributes, Indexes, Options) -> lager:info("Transform if needed for ~p", [{Table, Attributes, Indexes, Options}]), TransformFlag = maps:get(transform, Options, true), case mnesia:table_info(Table, attributes) of Attributes -> lager:info("The attributes are the same so no need to transform ~p", [Attributes]), IndexesExisting = [ lists:nth(X-1, Attributes) || X <- mnesia:table_info(Table, index) ], IndexesToDelete = IndexesExisting -- Indexes, IDRes = [ mnesia:del_table_index(Table, Index) || Index <- IndexesToDelete ], lager:info("Deleting ~p indexes and response is ~p", [IndexesToDelete, IDRes]), IndexesToAdd = Indexes -- IndexesExisting, IARes = [ mnesia:add_table_index(Table, Index) || Index <- IndexesToAdd ], lager:info("Adding ~p Indexes and response is ~p", [IndexesToAdd, IARes]); AttributesExisting when not TransformFlag -> lager:error("The attributes are different ~p vs ~p.BUT transform flag not set." ,[AttributesExisting, Attributes]); AttributesExisting -> lager:info("The attributes are different ~p vs ~p.Thus initiating table transform" ,[AttributesExisting, Attributes]), IndexesExisting = [ lists:nth(X-1, AttributesExisting) || X <- mnesia:table_info(Table, index) ], lager:info("First dropping all additional indexes ~p", [IndexesExisting]), IDRes = [ mnesia:del_table_index(Table, Index) || Index <- IndexesExisting ], lager:info("All additional indexes drop response ~p", [IDRes]), Defaults = maps:get(defaults, Options, #{}), TransformFun = transform_function(Table, AttributesExisting, Attributes, Defaults), TRes = mnesia:transform_table(Table, TransformFun, Attributes), lager:info("Transform table response ~p", [TRes]), IARes = [ mnesia:add_table_index(Table, Index) || Index <- Indexes ], lager:info("Creating ~p Indexes and response is ~p", [Indexes, IARes]) end. transform_function(Table, AttributesExisting, Attributes, Defaults) -> fun(Row) -> list_to_tuple([Table|lists:map( fun(Field) -> case string:str(AttributesExisting, [Field]) of 0 -> maps:get(Field, Defaults, undefined); P -> element(P + 1, Row) end end, Attributes )]) end. handle_drop(Table) -> mnesia:delete_table(Table). handle_clear(Table) -> mnesia:clear_table(Table).