Has the DB run as a separate node.

I am still figuring out how Erlang handles node connections... It would
seem that spawn(NODE, ...) automatically initiates the connection to
NODE (i.e. no need to use net_kernel:connect_node before).

3 files changed, 110 insertions, 0 deletions

diff --git a/src/db/Makefile b/src/db/Makefile
index d7b6eed..206a332 100644
--- a/src/db/Makefile
+++ b/src/db/Makefile
@@ -17,6 +17,13 @@ INCLUDE_DIR ?= ${CURDIR}/include
 ## Binaries
 ERLC ?= erlc
 ERLC_OPTS ?=
+ERL ?= erl
+ERL_OPTS ?= \
+	-connect_all false \
+	-name db_node \
+	-pa $(BIN_DIR) \
+	-run db_node start
+
 DIALYZER ?= dialyzer
 
 ################################################################################
@@ -52,6 +59,7 @@ debug: debug_run
 build: $(REQUIRED_HEADERS) $(PREPROCESSOR_RESULT) $(ERLANG_RESULT)
 
 run:
+	$(ERL) $(ERL_OPTS)
 
 clean:
 	rm -rf $(PREPROCESSOR_RESULT) $(ERLANG_RESULT)
diff --git a/src/db/src/db_node.erl b/src/db/src/db_node.erl
new file mode 100644
index 0000000..be295c6
--- /dev/null
+++ b/src/db/src/db_node.erl
@@ -0,0 +1,31 @@
+-module(db_node).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% TYPES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% EXPORTS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-export([start/0]).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% LOCAL FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-spec wait_for_stop () -> 'ok'.
+wait_for_stop () ->
+   receive
+      stop -> ok;
+      {ping, Pid} -> Pid ! pong;
+      _ -> wait_for_stop()
+   end.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% EXPORTED FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-spec start () -> 'ok'.
+start () ->
+   DB = db_model:new(battle_db, "/tmp/battle_db.mnesia", []),
+   db_model:start(DB),
+   wait_for_stop(),
+   ok.
diff --git a/src/db/src/struct/db_model.erl b/src/db/src/struct/db_model.erl
new file mode 100644
index 0000000..0f8c872
--- /dev/null
+++ b/src/db/src/struct/db_model.erl
@@ -0,0 +1,71 @@
+-module(db_model).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% TYPES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-include("../../include/db_item.hrl").
+
+-record
+(
+   db_model,
+   {
+      name :: atom(),
+      store_file :: string(),
+      neighbors :: list(node())
+   }
+).
+
+-type type() :: #db_model{}.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% EXPORTS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-export_type([type/0]).
+
+-export
+(
+   [
+      new/3,
+      start/1
+   ]
+).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% LOCAL FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% EXPORTED FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-spec new (atom(), string(), list(node())) -> type().
+new (DBName, StorageFile, Neighbors) ->
+   #db_model
+   {
+      name = DBName,
+      store_file = StorageFile,
+      neighbors = Neighbors
+   }.
+
+start (Model) ->
+   DBName = Model#db_model.name,
+   StorageFile = Model#db_model.store_file,
+   Neighbors = Model#db_model.neighbors,
+
+   ok = application:set_env(mnesia, dir, StorageFile),
+   case mnesia:create_schema([node()|Neighbors]) of
+      {error, {Name, {already_exists, Name}}} -> ok;
+      ok -> ok
+   end,
+   ok = mnesia:start(),
+   mnesia:create_table
+   (
+      DBName,
+      [
+         {attributes, record_info(fields, db_item)},
+         {disc_copies, [node()|Neighbors]},
+         {disc_only_copies, []},
+         {ram_copies, []},
+         {type, ordered_set},
+         {local_content, false}
+      ]
+   ).