Packages
mmath
0.2.23
0.2.26
0.2.25
0.2.24
0.2.23
0.2.22
0.2.21
0.2.20
0.2.19
0.2.18
0.2.17
0.2.16
0.2.15
0.2.14
0.2.13
0.2.12
0.2.11
0.2.10
0.2.9
0.2.8
0.2.7
0.2.6
0.2.5
0.2.4
0.2.3
0.2.2
0.2.1
0.2.0
0.2.0-alpha9
0.2.0-alpha8
0.2.0-alpha7
0.2.0-alpha6
0.2.0-alpha5
0.2.0-alpha4
0.2.0-alpha3
0.2.0-alpha2
0.2.0-alpha10
0.2.0-alpha1
0.2.0-alpha
0.1.17-alpha
0.1.16
0.1.15
0.1.14
0.1.13
0.1.11
0.1.10
0.1.9
0.1.8
0.1.7
0.1.6
math library for metric sequences and binary arrays.
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src/mmath_hpts.erl
%%%-------------------------------------------------------------------
%%% @author Heinz Nikolaus Gies <heinz@licenser.net>
%%% @copyright (C) 2014, Heinz Nikolaus Gies
%%% @doc
%%% Binary manipulation functions.
%%% @end
%%% Created : 8 Jun 2014 by Heinz Nikolaus Gies <heinz@licenser.net>
%%%-------------------------------------------------------------------
-module(mmath_hpts).
-ifdef(TEST).
-include_lib("eunit/include/eunit.hrl").
-endif.
-include("mmath.hrl").
-export([from_list/1, to_list/1, empty/1, length/1, values/1, timestamps/1]).
-define(APPNAME, mmath).
-define(LIBNAME, hpts_nif).
-on_load(load_nif/0).
load_nif() ->
SoName = case code:priv_dir(?APPNAME) of
{error, bad_name} ->
case filelib:is_dir(filename:join(["..", priv])) of
true ->
filename:join(["..", priv, ?LIBNAME]);
_ ->
filename:join([priv, ?LIBNAME])
end;
Dir ->
filename:join(Dir, ?LIBNAME)
end,
erlang:load_nif(SoName, 0).
%%--------------------------------------------------------------------
%% @doc
%% Converts a list of values to it's binary representation.
%% @end
%%--------------------------------------------------------------------
-spec from_list([{non_neg_integer(), number()}]) -> binary().
from_list(L) ->
from_list(L, <<>>).
from_list([], Acc) ->
Acc;
from_list([{T, V} | R], Acc) ->
from_list(R, <<Acc/binary, (mmath_bin:from_list([V]))/binary, T:64/unsigned-integer>>).
%%--------------------------------------------------------------------
%% @doc
%% Converts a the binary repesentation back to a list of values.
%% @end
%%--------------------------------------------------------------------
-spec to_list(binary()) -> [{non_neg_integer(), number()}].
to_list(B) ->
to_list(B, []).
to_list(<<>>, Acc) ->
lists:reverse(Acc);
to_list(<<VB:8/binary, T:64/unsigned-integer, R/binary>>, Acc) ->
[V] = mmath_bin:to_list(VB),
to_list(R, [{T, V} | Acc]).
%%--------------------------------------------------------------------
%% @doc
%% Extracts values
%% @end
%%--------------------------------------------------------------------
values(_Data) ->
erlang:nif_error(nif_library_not_loaded).
%%--------------------------------------------------------------------
%% @doc
%% Extracts timestamps
%% @end
%%--------------------------------------------------------------------
timestamps(_Data) ->
erlang:nif_error(nif_library_not_loaded).
%%--------------------------------------------------------------------
%% @doc
%% Calculates the number of values in a binary representation.
%% @end
%%--------------------------------------------------------------------
length(B) ->
mmath_bin:length(B) div 2.
%%--------------------------------------------------------------------
%% @doc
%% Creates an empty binary representaton if a given list
%% representation.
%% @end
%%--------------------------------------------------------------------
empty(C) ->
mmath_bin:empty(C * 2).
-ifdef(TEST).
values_test() ->
?assertEqual(<<0:64, 2:64>>, values(<<0:64, 1:64, 2:64, 3:64>>)).
timestamps_test() ->
?assertEqual(<<1:64, 3:64>>, timestamps(<<0:64, 1:64, 2:64, 3:64>>)).
one_test() ->
?assertEqual([{0, 1}], to_list(from_list([{0, 1}]))),
?assertEqual([{0, 1.0}], to_list(from_list([{0, 1.0}]))),
?assertEqual([{0, 1}, {0, 1.0}, {0, 1}], to_list(from_list([{0,1}, {0, 1.0}, {0, 1}]))).
-endif.