use different opt config strategy (#218)

* use different opt config strategy

* log different message when no adapter is used

Makefile

@@ -11,7 +11,6 @@ bench-results:
 
 compile:
 	${REBAR} as test compile
-	escript -s scripts/populate_fmke.escript
 
 console: rel
 	./_build/default/rel/fmke/bin/env console

config/fmke.config

@@ -14,15 +14,15 @@
 %% (3): "8080 8081"
 %% If you're connecting to multiple nodes on the same address but on different ports, you can list all of the different
 %% ports here and leave a single entry in the database_addresses option (e.g. ["127.0.0.1"]).
-{database_ports, [9042]}.
+{database_ports, [8087]}.
 
 %% Target back end data store. This is required in order for FMKe to load the
 %% correct drivers to connect to your desired data store.
 %% Currently FMKe supports the following data stores:
 %% antidote, riak, redis
 %% Please select one of the previous values in the form of an erlang atom
 %% (e.g. riak) or string (e.g. "riak")
-{target_database, cassandra}.
+{target_database, antidote}.
 
 %% Uses an optimized driver that implements the entire FMKe API (only if implemented).
 %% Currently these are available for antidote, riak and redis. You're welcome to implement a new one and submit a

src/fmke.erl

@@ -44,6 +44,9 @@
 start_link(Args) ->
     gen_server:start_link({local, ?SERVER}, ?MODULE, Args, []).
 
+init([none]) ->
+    lager:info("~p is booting in passthrough mode (no adapter)", [?MODULE]),
+    {ok, undefined};
 init([Adapter]) ->
     lager:info("~p will use the ~p adapter~n", [?MODULE, Adapter]),
     {ok, Adapter}.

src/fmke_driver_config.erl

@@ -91,7 +91,7 @@ driver_adapter(Driver) ->
         false ->
             ?KV_ADAPTER;
         true ->
-            Driver
+            none
     end.
 
 db_from_driver(fmke_driver_ets) -> ets;

src/fmke_sup.erl

@@ -18,6 +18,13 @@
 %% Supervisor callbacks
 -export([init/1]).
 
+%% useful config funs
+-import(fmke_driver_config, [
+    driver_adapter/1,
+    default_driver/1,
+    db_from_driver/1
+]).
+
 -define(SERVER, ?MODULE).
 
 -define(KV_ADAPTER, fmke_kv_adapter).
@@ -118,40 +125,65 @@ config(Config) ->
     Ports = get_option(database_ports, Config),
     HttpPort = get_option(http_port, Config),
     Model = get_option(data_model, Config),
-    config(driver, {Driver, Database}),
-    config(adapter, {driver, Driver}),
-    config(target_database, fmke_driver_config:db_from_driver(Driver)),
-    config(pool_size, PoolSize),
-    config(database_addresses, Addresses),
-    config(database_ports, Ports),
-    config(http_port, HttpPort),
-    config(data_model, Model).
+    set_opts([
+        {driver, Driver},
+        {target_database, Database},
+        {connection_pool_size, PoolSize},
+        {database_addresses, Addresses},
+        {database_ports, Ports},
+        {http_port, HttpPort},
+        {data_model, Model}
+    ]).
+
+set_opts([]) ->
+    ok;
+
+set_opts([{_Opt, undefined} | Rest]) ->
+    set_opts(Rest);
+
+set_opts([{Opt, Val} | Rest]) ->
+    config(Opt, Val),
+    set_opts(Rest).
 
 config(data_model, Model) ->
     maybe_config(data_model, Model);
 config(http_port, HttpPort) ->
     maybe_config(http_port, HttpPort);
 config(target_database, Database) ->
-    maybe_config(target_database, Database);
+    maybe_config(target_database, Database),
+    Driver = default_driver(Database),
+    maybe_config(driver, Driver),
+    case driver_adapter(Driver) of
+        none ->
+            ok;
+        Adapter ->
+            maybe_config(adapter, Adapter)
+    end;
 config(database_ports, Ports) ->
     maybe_config(database_ports, Ports);
 config(database_addresses, Addresses) ->
     maybe_config(database_addresses, Addresses);
-config(pool_size, Size) ->
+config(connection_pool_size, Size) ->
     maybe_config(connection_pool_size, Size);
-config(adapter, {driver, Driver}) ->
-    maybe_config(adapter, fmke_driver_config:driver_adapter(Driver));
-config(driver, {undefined, Database}) ->
-    maybe_config(driver, fmke_driver_config:default_driver(Database));
-config(driver, {Driver, _Database}) ->
-    maybe_config(driver, Driver).
-
-maybe_config(Key, undefined) ->
-    lager:info("Unable to set ~p (value undefined)~n", [Key]),
-    ok;
+config(driver, Driver) ->
+    maybe_config(driver, Driver),
+    case driver_adapter(Driver) of
+        none ->
+            ok;
+        Adapter ->
+            maybe_config(adapter, Adapter)
+    end,
+    maybe_config(target_database, db_from_driver(Driver)).
+
 maybe_config(Key, Val) ->
-    lager:info("Setting FMKe option ~p = ~p~n", [Key, Val]),
-    ok = application:set_env(?APP, Key, Val).
+    case application:get_env(?APP, Key) of
+        undefined ->
+            lager:info("Setting FMKe option ~p = ~p~n", [Key, Val]),
+            ok = application:set_env(?APP, Key, Val);
+        {ok, Predefined} ->
+            lager:info("Setting FMKe option ~p failed (already defined as ~p)~n", [Key, Predefined]),
+            already_defined
+    end.
 
 get_option(Opt, Config) ->
     {_Source, Val} = get_value(os:getenv(atom_to_list(Opt)),