merle.erl

<snip>

set(Key, Value) ->
    Flag = random:uniform(65000),
    set(Key, Flag, "0", Value).

set(Key, Flag, ExpTime, Value) when is_integer(Flag) ->
    set(Key, integer_to_list(Flag), ExpTime, Value);
set(Key, Flag, ExpTime, Value) when is_integer(ExpTime) ->
    set(Key, Flag, integer_to_list(ExpTime), Value);
set(Key, Flag, ExpTime, Value) when is_integer(Value) ->
    set(Key, Flag, ExpTime, integer_to_list(Value));
set(Key, Flag, ExpTime, Value) when is_atom(Value) ->
    set(Key, Flag, ExpTime, atom_to_list(Value));
set(Key, Flag, ExpTime, Value) ->
	case gen_server:call(?SERVER, {set, {Key, Flag, ExpTime, Value}}) of
	    ["STORED"] -> ok;
	    [X] -> X
	end.

<snip>

%% @doc Increment already existing value.
increment(Key, Value) when is_integer(Value) ->
	increment(Key, integer_to_list(Value));
increment(Key, Value) ->
	gen_server:call(?SERVER, {increment, {Key, Value}}).

%% @doc Decrement already existing value.
decrement(Key, Value) when is_integer(Value) ->
	decrement(Key, integer_to_list(Value));
decrement(Key, Value) ->
	gen_server:call(?SERVER, {decrement, {Key, Value}}).
<snip>

handle_call({set, {Key, Flag, ExpTime, Value}}, _From, Socket) ->
	Bytes = length(Value),
	BytesStr = integer_to_list(Bytes),
    Reply = send_storage_cmd(
        Socket,
        iolist_to_binary([
            <<"set ">>, Key, <<" ">>, Flag, <<" ">>, ExpTime, <<" ">>, BytesStr
        ]),
        Value
    ),
    {reply, Reply, Socket};

<snip>

handle_call({increment, {Key, Value}}, _From, Socket) ->
    Reply = send_incr_decr_cmd(
        Socket,
        "incr " ++ " " ++ Key ++ " " ++ Value),
    {reply, Reply, Socket};

handle_call({decrement, {Key, Value}}, _From, Socket) ->
    Reply = send_incr_decr_cmd(
        Socket,
        "decr " ++ " " ++ Key ++ " " ++ Value),
    {reply, Reply, Socket}.

<snip>

%% @private
%% @doc send_generic_cmd/2 function for simple informational and deletion commands
send_generic_cmd(Socket, Cmd) ->
    gen_tcp:send(Socket, <<Cmd/binary, "\r\n">>),
	Reply = recv_simple_reply(),
	Reply.

%% @private
%% @doc send_storage_cmd/3 funtion for storage commands
send_storage_cmd(Socket, Cmd, Value) ->
    gen_tcp:send(Socket, <<Cmd/binary, "\r\n">>),
    gen_tcp:send(Socket, Value ++ "\r\n"),
    Reply = recv_simple_reply(),
   	Reply.

<snip>

%% @private
%% @doc send_incr_decr_cmd/2 function for simple informational and deletion commands
send_incr_decr_cmd(Socket, Cmd) ->
    gen_tcp:send(Socket, Cmd ++ "\r\n"),
	Reply = recv_incr_decr_reply(),
	Reply.

%% @private
%% @doc recv_incr_decr_reply/0 function for increment and decrement responses
recv_incr_decr_reply() ->
	receive
	  	{tcp,_,Data} ->
        	Parse = io_lib:fread("~s\r\n", binary_to_list(Data)),
        	{ok,[Reply], _} = Parse,
			Reply;
        {error, closed} ->
  			connection_closed
    after ?TIMEOUT ->
   		timeout
    end.

<snip>

%% @private
%% @doc receive function for respones containing VALUEs
recv_complex_reply(Socket) ->
	receive
		%% For receiving get responses where the key does not exist
		{tcp, Socket, <<"END\r\n">>} -> ["END"];
		%% For receiving get responses containing data
		{tcp, Socket, Data} ->
			%% Reply format <<"VALUE SOMEKEY FLAG BYTES\r\nSOMEVALUE\r\nEND\r\n">>
  			Parse = io_lib:fread("~s ~s ~u ~u\r\n", binary_to_list(Data)),
  			{ok,[_,_,_,Bytes], ListBin} = Parse,
  			Bin = list_to_binary(ListBin),
  			Reply = get_data(Socket, Bin, Bytes, length(ListBin)),
  			Reply;
  		{error, closed} ->
  			connection_closed
    after ?TIMEOUT -> timeout
    end.

%% @private
%% @doc recieve loop to get all data
%% @todo
get_data(Socket, Bin, Bytes, Len) when Len < Bytes + 7->
    receive
        {tcp, Socket, Data} ->
            Combined = <<Bin/binary, Data/binary>>,
            get_data(Socket, Combined, Bytes, size(Combined));
     	{error, closed} ->
  			connection_closed
        after ?TIMEOUT -> timeout
    end;
get_data(_, Data, Bytes, _) ->
	Parse = io_lib:fread("~s\r\n", binary_to_list(Data)),
    {ok,[Reply], _} = Parse,
	[Reply].