Here's how you use this thing without using any macro help:
dinerl:setup("AWS_ACCESS_KEY_ID", "AWS_SECRET_ACCESS_KEY", "us-east-1b").
or (use a specific endpoint by specifying the zone, and obtain security tokens from the local instance metadata server):
dinerl:setup("us-east-1b").
or (obtain security tokens from the local instance metadata server, and use the zone returned from the instance metadata server to determine the endpoint):
dinerl:setup().
then:
dinerl:create_table(<<"TestTable">>, [{<<"HashKeyElement">>, [{<<"AttributeName">>, <<"Key">>}, {<<"AttributeType">>, <<"S">>}]}], 50, 50).
dinerl:list_tables().
dinerl:put_item(<<"TestTable">>, [{<<"Key">>, [{<<"S">>, <<"jello">>}]}], []).
dinerl:get_item(<<"TestTable">>, [{<<"HashKeyElement">>, [{<<"S">>, <<"jello">>}]}], []).
put(Key, Value, TTL, Now) ->
dinerl:put_item(<<"Attributions">>, [{<<"UserKey">>, [{<<"S">>, Key}]},
{<<"Updated">>, [{<<"N">>, list_to_binary(integer_to_list(Now))}]},
{<<"TTL">>, [{<<"N">>, list_to_binary(integer_to_list(TTL))}]},
{<<"Value">>, [{<<"S">>, Value}]}], []).
get(Key, Now, Default) ->
case dinerl:get_item(<<"Attributions">>, [{<<"HashKeyElement">>, [{<<"S">>, Key}]}], [{attrs, [<<"TTL">>, <<"Updated">>, <<"Value">>, <<"Visited">>]}]) of
{ok, Element} ->
ParsedResult = parsejson(Element),
return_if_not_expired(Key, ParsedResult, Now, Default);
{error, Short, Long} ->
io:format("~p", [Long]),
Default
end.
add(Key, Value, TTL, Now) ->
dinerl:update_item(<<"Attributions">>,
[{<<"HashKeyElement">>, [{<<"S">>, Key}]}],
[{update, [{<<"Visited">>, [{value, [{<<"SS">>, [Value]}]},
{action, add}]},
{<<"Updated">>, [{value, [{<<"N">>, list_to_binary(integer_to_list(Now))}]},
{action, put}]},
{<<"TTL">>, [{value, [{<<"N">>, list_to_binary(integer_to_list(TTL))}]},
{action, put}]}]}]).
parsejson([]) ->
[];
parsejson({struct, L}) ->
parsejson(L);
parsejson([{<<"Item">>, {struct, Fields}}|_Rest]) ->
parsejsonfields(Fields, []);
parsejson([_H|T]) ->
parsejson(T).
parsejsonfields([], Acc) ->
Acc;
parsejsonfields([{Name, {struct, [{<<"N">>, Value}]}}|Rest], Acc) ->
parsejsonfields(Rest, [{Name, list_to_integer(binary_to_list(Value))}|Acc]);
parsejsonfields([{Name, {struct, [{<<"S">>, Value}]}}|Rest], Acc) ->
parsejsonfields(Rest, [{Name, Value}|Acc]);
parsejsonfields([{Name, {struct, [{<<"NS">>, Value}]}}|Rest], Acc) ->
parsejsonfields(Rest, [{Name, all_to_int(Value)}|Acc]);
parsejsonfields([{Name, {struct, [{<<"SS">>, Value}]}}|Rest], Acc) ->
parsejsonfields(Rest, [{Name, Value}|Acc]).
return_if_not_expired(_, [], _, Default) ->
Default;
return_if_not_expired(Key, ParsedResult, Now, Default) ->
Updated = proplists:get_value(<<"Updated">>, ParsedResult),
TTL = proplists:get_value(<<"TTL">>, ParsedResult),
case (Updated+TTL) > Now of
true ->
ParsedResult;
false ->
dinerl:delete_item(<<"Attributions">>, [{<<"HashKeyElement">>, [{<<"S">>, Key}]}], []),
Default
end.
all_to_int(L) ->
all_to_int(L, []).
all_to_int([], Acc) ->
lists:reverse(Acc);
all_to_int([H|T], Acc) ->
all_to_int(T, [list_to_integer(binary_to_list(H))|Acc]).
pytime() ->
pytime(erlang:now()).
pytime({MegaSecs, Secs, MicroSecs}) ->
erlang:trunc((1.0e+6 * MegaSecs) + Secs + (1.0e-6 * MicroSecs)).