keysearch_microbench.erl

-module(keysearch_microbench).
-compile(export_all).

test(ListLength, NumberOfReps) ->
    crypto:start(),
    Data = make_data(ListLength),

    % TestId = key(), % worst-case, missing key
    TestId = element(1,lists:nth(4,Data)), % some key in the list

    Counter = lists:seq(1,NumberOfReps),
    T0 = now(),
    [get_value(TestId, Data) || _I <- Counter],
    T1 = now(),
    [proplists:get_value(TestId, Data) || _I <- Counter],
    T2 = now(),
    {timer:now_diff(T1, T0), timer:now_diff(T2, T1)}.


% proplists:get_value API wrapper around keysearch
get_value(Key, List) ->
    get_value(Key, List, undefined).

get_value(Key, List, Default) ->
    case lists:keysearch(Key, 1, List) of
    {value, {Key,Value}} ->
        Value;
    false ->
        Default
    end.

make_data(0) ->
    [];
make_data(N) ->
    [{key(), random:uniform()}|make_data(N-1)].

key() ->
    list_to_binary(to_hex(crypto:rand_bytes(16))).

to_hex([]) ->
    [];
to_hex(Bin) when is_binary(Bin) ->
    to_hex(binary_to_list(Bin));
to_hex([H|T]) ->
    [to_digit(H div 16), to_digit(H rem 16) | to_hex(T)].

to_digit(N) when N < 10 -> $0 + N;
to_digit(N)             -> $a + N-10.

Hi Adam,

I first got an error trying to run the benchmark, before I had figured out that the crypto server needs to be started.
Consequently, I'd suggest to insert a "crypto:start()," into the first line of test/2. (In the case the crypto server is already running, it at least will not harm.)

With kind regards,
Klaus

Klaus, thanks! I certainly should have added that in the beginning.