Merge pull request #3392 from esl/wdbm-ejabberd_rdbms

Get rid of ejabberd_rdbms because all it did was compile mongoose_rdbms_type. In turn, all it did was get an option from the config.

The functionality is left as it was. From what I understand, one can (in theory) use ODBC with different databases, so maybe the rdbms_server_type option is needed, but it could at least be moved from the general section to the RDBMS pool options. This could be done after dynamically compiled modules are merged.

rebar.config

@@ -24,7 +24,7 @@
     mod_mam_cassandra_arch_params,
     mod_mam_cassandra_prefs_params, mod_mam_muc_cassandra_arch_params,
     mod_pubsub_db_backend, mod_revproxy_dynamic,
-    mod_shared_roster, mongoose_rdbms_type,
+    mod_shared_roster,
     %% Deprecated functions
     {crypto, rand_uniform, 2},
     {ranch, start_listener, 6},

src/ejabberd_app.erl

@@ -65,7 +65,6 @@ start(normal, _Args) ->
     %% ejabberd_sm is started separately because it may use one of the outgoing_pools
     %% but some outgoing_pools should be started only with ejabberd_sup already running
     ejabberd_sm:start(),
-    ejabberd_rdbms:start(),
     ejabberd_auth:start(),
     mongoose_cluster_id:start(),
     start_services(),

src/pubsub/mod_pubsub_db_rdbms.erl

@@ -256,7 +256,7 @@ stop() ->
 
 %% ------------------------ Queries execution --------------------
 prepare_select_nodes_by_owner() ->
-    case {mongoose_rdbms:db_engine(global), mongoose_rdbms_type:get()} of
+    case {mongoose_rdbms:db_engine(global), mongoose_rdbms:db_type()} of
         {mysql, _} ->
             mongoose_rdbms:prepare(pubsub_select_nodes_by_owner, pubsub_nodes, [owners],
                 <<"SELECT name, type FROM pubsub_nodes WHERE owners = convert(?, JSON);">>);

src/rdbms/mongoose_rdbms.erl

@@ -68,6 +68,7 @@
          sql_dirty/2,
          to_bool/1,
          db_engine/1,
+         db_type/0,
          print_state/1,
          use_escaped/1]).
 
@@ -734,6 +735,16 @@ db_engine(_HostType) ->
     try mongoose_backend:get_backend_name(global, ?MODULE)
     catch error:badarg -> undefined end.
 
+%% @doc Used to optimise queries for different databases.
+%% @todo Should be refactored to use host types with this module.
+%% Also, this parameter should not be global, but pool-name parameterized
+-spec db_type() -> mssql | generic.
+db_type() ->
+    case ejabberd_config:get_local_option(rdbms_server_type) of
+        mssql -> mssql;
+        _ -> generic
+    end.
+
 -spec connect(Settings :: term(), Retry :: non_neg_integer(), RetryAfter :: non_neg_integer(),
               MaxRetryDelay :: non_neg_integer()) -> {ok, term()} | {error, any()}.
 connect(Settings, Retry, RetryAfter, MaxRetryDelay) ->

src/rdbms/rdbms_queries.erl

@@ -45,7 +45,6 @@
          execute_upsert/5]).
 
 -ignore_xref([
-    {mongoose_rdbms_type, get, 0},
     count_records_where/3, get_db_specific_limits/1, get_db_specific_offset/2, get_db_type/0
 ]).
 
@@ -57,7 +56,7 @@
 -define(generic, true).
 -endif.
 
--define(RDBMS_TYPE, (mongoose_rdbms_type:get())).
+-define(RDBMS_TYPE, (mongoose_rdbms:db_type())).
 
 -include("mongoose.hrl").
 
@@ -82,7 +81,7 @@ get_db_type() ->
                      UpdateParams :: [any()],
                      UniqueKeyValues :: [any()]) -> mongoose_rdbms:query_result().
 execute_upsert(Host, Name, InsertParams, UpdateParams, UniqueKeyValues) ->
-    case {mongoose_rdbms:db_engine(Host), mongoose_rdbms_type:get()} of
+    case {mongoose_rdbms:db_engine(Host), mongoose_rdbms:db_type()} of
         {mysql, _} ->
             mongoose_rdbms:execute(Host, Name, InsertParams ++ UpdateParams);
         {pgsql, _} ->
@@ -111,14 +110,14 @@ prepare_upsert(Host, Name, Table, InsertFields, Updates, UniqueKeyFields) ->
 
 prepared_upsert_fields(InsertFields, Updates, UniqueKeyFields) ->
     UpdateFields = lists:filter(fun is_field/1, Updates),
-    case mongoose_rdbms_type:get() of
+    case mongoose_rdbms:db_type() of
         mssql ->
             UniqueKeyFields ++ InsertFields ++ UpdateFields;
         _ -> InsertFields ++ UpdateFields
     end.
 
 upsert_query(Host, Table, InsertFields, Updates, UniqueKeyFields) ->
-    case {mongoose_rdbms:db_engine(Host), mongoose_rdbms_type:get()} of
+    case {mongoose_rdbms:db_engine(Host), mongoose_rdbms:db_type()} of
         {mysql, _} ->
             upsert_mysql_query(Table, InsertFields, Updates, UniqueKeyFields);
         {pgsql, _} ->

src/vcard/mod_vcard_rdbms.erl

@@ -207,7 +207,7 @@ search(HostType, LServer, Data) ->
 limit_type(infinity) ->
     infinity;
 limit_type(_Limit) ->
-    case mongoose_rdbms_type:get() of
+    case mongoose_rdbms:db_type() of
         mssql -> top;
         _ -> limit
     end.