%% Author: blaxter
%% Created: 13/07/2008
%% Description: Benchmark is a module for helping you to do benchmark stuff
-module(benchmark).

-export([do/1, do_silent/1]).

-import(timer, [now_diff/2]).

%%
%% Executes a function an evaluates the time it costs
%%
do(F) ->
   Time_in_ms = do_silent(F),
   benchmark_message(Time_in_ms).

%%
%% Executes a function an returns the time it costs
%%
do_silent(F) ->
   Before = erlang:now(),
   F(),   
   timer:now_diff(erlang:now(), Before).

%%
%% Private functions
%%
benchmark_message(N) when N < 1000 ->
   io:format("Execute time: ~p microseconds~n", [ N ]);
benchmark_message(N) when N < 1000000 ->
   io:format("Execute time: ~p ms~n", [ N/1000 ]);
benchmark_message(N) when N < 60000000 ->
   io:format("Execute time: ~p s~n", [ N / 1000000 ]);
benchmark_message(N) ->
   io:format("Execute time: ~p min ~p seg~n", [ N div 60000000, (N rem 60000000) div 1000000 ]).