Starting to work on the DB implementation.

9 files changed, 284 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index f7f311c..1ac3973 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 ################################################################################
 ## CONFIG ######################################################################
 ################################################################################
-MODULES ?= battlemap
+MODULES ?= battlemap db
 MODULES_DIR ?= ${CURDIR}/src
 
 YAWS_CONFIG_TEMPLATE ?= ${CURDIR}/conf/yaws.conf.m4
diff --git a/src/db/Makefile b/src/db/Makefile
new file mode 100644
index 0000000..d7b6eed
--- /dev/null
+++ b/src/db/Makefile
@@ -0,0 +1,63 @@
+################################################################################
+## CONFIG ######################################################################
+################################################################################
+MODULE_NAME ?= $ $(shell basename ${CURDIR})
+MODULE_PORT ?= 8002
+
+DIALYZER_PLT_FILE ?= tacticians-server.plt
+
+## Main Directories
+SRC_DIR ?= ${CURDIR}/src
+CONF_DIR ?= ${CURDIR}/conf
+
+#### Optional Dirs
+BIN_DIR ?= ${CURDIR}/ebin
+INCLUDE_DIR ?= ${CURDIR}/include
+
+## Binaries
+ERLC ?= erlc
+ERLC_OPTS ?=
+DIALYZER ?= dialyzer
+
+################################################################################
+## MAKEFILE MAGIC ##############################################################
+################################################################################
+OPTIONAL_DIRS = $(BIN_DIR) $(INCLUDE_DIR)
+
+################################################################################
+## SANITY CHECKS ###############################################################
+################################################################################
+DIALYZER_PLT_FILE ?= tacticians-server.plt
+
+## Main Directories
+SRC_DIR ?= src
+CONF_DIR ?= conf
+
+################################################################################
+## INCLUDES ####################################################################
+################################################################################
+main_target: all
+
+include ${CURDIR}/mk/debug.mk
+include ${CURDIR}/mk/erlang.mk
+include ${CURDIR}/mk/preprocessor.mk
+
+################################################################################
+## TARGET RULES ################################################################
+################################################################################
+all: build
+
+debug: debug_run
+
+build: $(REQUIRED_HEADERS) $(PREPROCESSOR_RESULT) $(ERLANG_RESULT)
+
+run:
+
+clean:
+	rm -rf $(PREPROCESSOR_RESULT) $(ERLANG_RESULT)
+
+################################################################################
+## INTERNAL RULES ##############################################################
+################################################################################
+$(OPTIONAL_DIRS): %:
+	mkdir -p $@
diff --git a/src/db/include/db_query.hrl b/src/db/include/db_query.hrl
new file mode 100644
index 0000000..bdd9dc1
--- /dev/null
+++ b/src/db/include/db_query.hrl
@@ -0,0 +1,34 @@
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% TYPES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-record
+(
+   set_field,
+   {
+      field :: non_neg_integer(),
+      value :: any()
+   }
+).
+
+-record
+(
+   add_to_field,
+   {
+      field :: non_neg_integer(),
+      values :: list(any()),
+      head :: boolean()
+   }
+).
+
+-record
+(
+   update_indexed,
+   {
+      field :: non_neg_integer(),
+      ix :: non_neg_integer(),
+      update :: list(db_query())
+   }
+).
+
+-type db_query() :: (#set_field{} | #add_to_field{} | #update_indexed{}).
+
diff --git a/src/db/mk/debug.mk b/src/db/mk/debug.mk
new file mode 100644
index 0000000..bd93669
--- /dev/null
+++ b/src/db/mk/debug.mk
@@ -0,0 +1,40 @@
+################################################################################
+## CONFIG ######################################################################
+################################################################################
+DIALYZER_PLT_FILE ?= tacticians-server.plt
+DIALYZER ?= dialyzer
+
+################################################################################
+## MAKEFILE MAGIC ##############################################################
+################################################################################
+SRC_FILES ?= $(wildcard $(SRC_DIR)/*.erl $(SRC_DIR)/*/*.erl)
+
+################################################################################
+## SANITY CHECKS ###############################################################
+################################################################################
+
+################################################################################
+## TARGET RULES ################################################################
+################################################################################
+DEBUG_RESULT = $(DIALYZER_PLT_FILE)
+
+debug_rebuild:
+	$(MAKE) clean
+	$(MAKE) ERLC_OPTS=+debug_info
+
+################################################################################
+## INTERNAL RULES ##############################################################
+################################################################################
+ifeq ($(wildcard $(DIALYZER_PLT_FILE)),)
+debug_run:
+	$(DIALYZER) --build_plt --apps erts kernel stdlib --output_plt \
+		$(DIALYZER_PLT_FILE)
+	$(MAKE) debug_rebuild
+	$(DIALYZER) --add_to_plt --plt $(DIALYZER_PLT_FILE) -r $(BIN_DIR)
+else
+debug_run:
+	$(MAKE) debug_rebuild
+	$(DIALYZER) --check_plt --plt $(DIALYZER_PLT_FILE)
+	$(DIALYZER) --get_warnings $(SRC_DIR)/*.erl $(SRC_DIR)/*/*.erl \
+		--src --plt $(DIALYZER_PLT_FILE)
+endif
diff --git a/src/db/mk/erlang.mk b/src/db/mk/erlang.mk
new file mode 100644
index 0000000..9150f63
--- /dev/null
+++ b/src/db/mk/erlang.mk
@@ -0,0 +1,28 @@
+################################################################################
+## CONFIG ######################################################################
+################################################################################
+ERLC ?= erlc
+ERLC_OPTS ?=
+
+################################################################################
+## MAKEFILE MAGIC ##############################################################
+################################################################################
+SRC_FILES ?= $(wildcard $(SRC_DIR)/*.erl $(SRC_DIR)/*/*.erl)
+BIN_FILES = \
+	$(patsubst %.erl,$(BIN_DIR)/%.beam,$(notdir $(SRC_FILES)))
+
+################################################################################
+## SANITY CHECKS ###############################################################
+################################################################################
+
+################################################################################
+## TARGET RULES ################################################################
+################################################################################
+ERLANG_RESULT = $(BIN_DIR) $(BIN_FILES)
+
+################################################################################
+## INTERNAL RULES ##############################################################
+################################################################################
+.SECONDEXPANSION:
+$(BIN_FILES): $(BIN_DIR)/%.beam : $$(wildcard $(SRC_DIR)/*/%.erl $(SRC_DIR)/%.erl)
+	$(ERLC) $(ERLC_OPTS) -o $(BIN_DIR) $<
diff --git a/src/db/mk/preprocessor.mk b/src/db/mk/preprocessor.mk
new file mode 100644
index 0000000..74f66ba
--- /dev/null
+++ b/src/db/mk/preprocessor.mk
@@ -0,0 +1,34 @@
+################################################################################
+## CONFIG ######################################################################
+################################################################################
+CONFIG_FILE ?= ${CURDIR}/module.conf
+
+################################################################################
+## MAKEFILE MAGIC ##############################################################
+################################################################################
+PREPROCESSOR_FILES = $(shell find ${CURDIR} -name "*.m4")
+PREPROCESSED_FILES = $(patsubst %.m4,%,$(PREPROCESSOR_FILES))
+
+MAKEFILE_TO_M4 = \
+	--define=__MAKEFILE_MODULE_NAME=$(MODULE_NAME) \
+	--define=__MAKEFILE_MODULE_PORT=$(MODULE_PORT) \
+	--define=__MAKEFILE_BIN_DIR=$(BIN_DIR) \
+	--define=__MAKEFILE_INCLUDE_DIR=$(INCLUDE_DIR)
+
+################################################################################
+## SANITY CHECKS ###############################################################
+################################################################################
+ifeq ($(wildcard $(CONFIG_FILE)),)
+$(error "Missing CONFIG_FILE ($(CONFIG_FILE)).")
+endif
+
+################################################################################
+## TARGET RULES ################################################################
+################################################################################
+PREPROCESSOR_RESULT = $(PREPROCESSED_FILES)
+
+################################################################################
+## INTERNAL RULES ##############################################################
+################################################################################
+$(PREPROCESSED_FILES): %: $(CONFIG_FILE) %.m4
+	m4 -P $^ > $@
diff --git a/src/db/module.conf b/src/db/module.conf
new file mode 100644
index 0000000..08714a1
--- /dev/null
+++ b/src/db/module.conf
@@ -0,0 +1,6 @@
+m4_define(`__MODULE_NAME', `__MAKEFILE_MODULE_NAME')m4_dnl
+m4_define(`__MODULE_PORT', `__MAKEFILE_MODULE_PORT')m4_dnl
+m4_dnl
+m4_define(`__MODULE_BIN_DIR', `__MAKEFILE_BIN_DIR')m4_dnl
+m4_define(`__MODULE_INCLUDE_DIR', `__MAKEFILE_INCLUDE_DIR')m4_dnl
+m4_dnl
diff --git a/src/db/src/storage_access.erl b/src/db/src/storage_access.erl
new file mode 100644
index 0000000..be481ee
--- /dev/null
+++ b/src/db/src/storage_access.erl
@@ -0,0 +1,42 @@
+-module(storage_access).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% TYPES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-record(regval, {id, owner, val}).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% EXPORTS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-export
+(
+   [
+      read/2,
+      insert/4,
+      update/3
+   ]
+).
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% LOCAL FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+get_value([]) -> [];
+get_value([#regval{ val = Val }]) -> [Val].
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% EXPORTED FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+read (DB, ID) ->
+   get_value(mnesia:read(DB, ID)).
+
+insert (DB, ID, Owner, Value) ->
+   StoredItem = #regval{ id = ID, owner = Owner, val = Value },
+   % FIXME: handle return value, mnesia:write -> (transaction abort | ok).
+   % FIXME: is this an atomic OP? Is the lock freed afterwards?
+   mnesia:write(DB, StoredItem, sticky_write).
+
+update (DB, ID, Update) ->
+   % FIXME: handle return value, mnesia:write -> (transaction abort | ok).
+   case mnesia:read(DB, ID) of
+      [] -> error;
+      _ -> unimplemented
+   end.
diff --git a/src/db/src/storage_update.erl b/src/db/src/storage_update.erl
new file mode 100644
index 0000000..c3a53e4
--- /dev/null
+++ b/src/db/src/storage_update.erl
@@ -0,0 +1,36 @@
+-module(storage_update).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% TYPES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-include("../include/db_query.hrl").
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% EXPORTS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-export([apply_to/2]).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% LOCAL FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% EXPORTED FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+apply_to (#set_field{ field = Field, value = Value }, Elem) ->
+   setelement(Field, Elem, Value);
+apply_to (#add_to_field{ field = Field, values = Values, head = Head }, Elem) ->
+   CurrentValues = element(Field, Elem),
+   UpdatedValues =
+      case Head of
+         true -> (Values ++ CurrentValues);
+         _ -> (CurrentValues ++ Values)
+      end,
+   setelement(Field, Elem, UpdatedValues);
+apply_to (#update_indexed{ field = Field, ix = IX, update = Update}, Elem) ->
+   IndexedFieldValue = element(Field, Elem),
+   ArrayValue = array:get(IX, IndexedFieldValue),
+   UpdatedArrayValue = lists:foldl(fun apply_to/2, ArrayValue, Update),
+   UpdatedIndexedFieldValue = array:set(IX, UpdatedArrayValue),
+   setelement(Field, Elem, UpdatedIndexedFieldValue).