From 7b1dacffc794bc80866c097dad4a4042291078df Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Carlos=20Mart=C3=ADn=20Nieto?= <cmn@dwim.me>
Date: Thu, 23 May 2013 10:49:00 +0200
Subject: [PATCH] Convert geef_odb to a gen_server

---
 src/geef_odb.erl     | 103 ++++++++++++++++++++++++++++++++++++-------
 src/geef_records.hrl |   2 -
 src/geef_repo.erl    |   4 +-
 3 files changed, 88 insertions(+), 21 deletions(-)

diff --git a/src/geef_odb.erl b/src/geef_odb.erl
index 807b254..9803443 100644
--- a/src/geef_odb.erl
+++ b/src/geef_odb.erl
@@ -1,27 +1,96 @@
+%%%-------------------------------------------------------------------
+%%% @author Carlos Martin Nieto <cmn@dwim.me>
+%%% @copyright (C) 2013, Carlos Martin Nieto
+%%% @doc
+%%%
+%%% @end
+%%% Created : 23 May 2013 by Carlos Martin Nieto <cmn@dwim.me>
+%%%-------------------------------------------------------------------
 -module(geef_odb).
 
+-behaviour(gen_server).
+
+%% API
+-export([start_link/1, exists/2, write/3]).
+
+%% gen_server callbacks
+-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
+	 terminate/2, code_change/3]).
+
+-include("geef_records.hrl").
+
+-record(state, {handle}).
+
+%%%===================================================================
+%%% API
+%%%===================================================================
+
+%% @doc
+%% Starts the server
+-spec start_link(term()) -> {ok, pid()} | ignore | {error, term()}.
+start_link(Handle) ->
+    gen_server:start_link(?MODULE, Handle, []).
+
+%%%===================================================================
+%%% gen_server callbacks
+%%%===================================================================
+
+%% @private
+init(Handle) ->
+    {ok, #state{handle=Handle}}.
+
+%% @private
+handle_call({exists, Oid}, _From, State = #state{handle=Handle}) ->
+    Reply = geef_nif:odb_object_exists(Handle, Oid),
+    {reply, Reply, State};
+
+handle_call({write, Content, Type}, _From, State = #state{handle=Handle}) ->
+    Reply = case geef_nif:odb_write(Handle, Content, Type) of
+		{ok, Oid} ->
+		    {ok, #geef_oid{oid=Oid}};
+		Other ->
+		    Other
+	    end,
+    {reply, Reply, State};
+
+handle_call(stop, _From, State) ->
+    {stop, normal, ok, State}.
+
+%% @private
+handle_cast(_Msg, State) ->
+    {noreply, State}.
+
+%% @private
+handle_info(_Info, State) ->
+    {noreply, State}.
+
+
+%% @private
+terminate(_Reason, _State) ->
+    ok.
+
+%% @private
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.
+
+%%%===================================================================
+%%% Internal functions
+%%%===================================================================
+
 -ifdef(TEST).
 -include_lib("eunit/include/eunit.hrl").
 -endif.
 
--export([exists/2, write/3]).
+-spec exists(pid(), geef_oid() | iolist()) -> boolean().
+exists(Pid, #geef_oid{oid=Oid}) ->
+    gen_server:call(Pid, {exists, Oid});
+exists(Pid, Sha) ->
+    #geef_oid{oid=Oid} = geef_oid:parse(Sha),
+    gen_server:call(Pid, {exists, Oid}).
 
--include("geef_records.hrl").
-
--spec exists(geef_odb(), geef_oid() | iolist()) -> boolean().
-exists(#geef_odb{handle=Handle}, #geef_oid{oid=Oid}) ->
-    geef_nif:odb_object_exists(Handle, Oid);
-exists(Odb = #geef_odb{}, Sha) ->
-    exists(Odb, geef_oid:parse(Sha)).
-
--spec write(geef_odb(), iolist(), atom()) -> {ok, geef_oid()} | {error, term}.
-write(#geef_odb{handle=Handle}, Contents, Type) ->
-    case geef_nif:odb_write(Handle, Contents, Type) of
-	{ok, Oid} ->
-	    {ok, #geef_oid{oid=Oid}};
-	Other ->
-	    Other
-    end.
+-spec write(pid(), iolist(), atom()) -> {ok, geef_oid()} | {error, term}.
+write(Pid, Contents, Type) ->
+    gen_server:call(Pid, {write, Contents, Type}).
 
 -ifdef(TEST).
 
diff --git a/src/geef_records.hrl b/src/geef_records.hrl
index 748c5ec..954a5b8 100644
--- a/src/geef_records.hrl
+++ b/src/geef_records.hrl
@@ -1,11 +1,9 @@
 -record(geef_ref, {handle, name :: binary(), type :: atom(), target :: binary() | geef_oid()}).
--record(geef_odb, {handle}).
 -record(geef_oid, {oid}).
 -record(geef_object, {type :: atom(), handle}).
 -record(geef_index_entry, {mode, id :: geef_oid(), path :: iolist()}).
 
 -type geef_ref() :: #geef_ref{}.
--type geef_odb() :: #geef_odb{}.
 -type geef_oid() :: #geef_oid{}.
 -type geef_object() :: #geef_object{}.
 -type geef_index_entry() :: #geef_index_entry{}.
diff --git a/src/geef_repo.erl b/src/geef_repo.erl
index 591b9cd..817d072 100644
--- a/src/geef_repo.erl
+++ b/src/geef_repo.erl
@@ -64,7 +64,7 @@ workdir(Pid) ->
 
 %% @doc The repository's current object database. This encompasses all
 %% the configured backends.
--spec odb(pid()) -> {ok, geef_odb()} | {error, term}.
+-spec odb(pid()) -> {ok, pid()} | {error, term}.
 odb(Pid) ->
     gen_server:call(Pid, odb).
 
@@ -176,7 +176,7 @@ start_link(Handle) ->
 handle_odb(Handle) ->
     case geef_nif:repository_get_odb(Handle) of
 	{ok, OdbHandle} ->
-	    {ok, #geef_odb{handle=OdbHandle}};
+	    geef_odb:start_link(OdbHandle);
 	Other ->
 	    Other
     end.