Merge pull request #2 from ericbmerritt/rename-to-relx

Relup + rename support

1 files changed, 204 insertions, 0 deletions

diff --git a/src/rlx_log.erl b/src/rlx_log.erl
new file mode 100644
index 0000000..901ae7c
--- /dev/null
+++ b/src/rlx_log.erl
@@ -0,0 +1,204 @@
+%% -*- erlang-indent-level: 4; indent-tabs-mode: nil; fill-column: 80 -*-
+%%% Copyright 2012 Erlware, LLC. All Rights Reserved.
+%%%
+%%% This file is provided to you under the Apache License,
+%%% Version 2.0 (the "License"); you may not use this file
+%%% except in compliance with the License.  You may obtain
+%%% a copy of the License at
+%%%
+%%%   http://www.apache.org/licenses/LICENSE-2.0
+%%%
+%%% Unless required by applicable law or agreed to in writing,
+%%% software distributed under the License is distributed on an
+%%% "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+%%% KIND, either express or implied.  See the License for the
+%%% specific language governing permissions and limitations
+%%% under the License.
+%%%---------------------------------------------------------------------------
+%%% @author Eric Merritt <[email protected]>
+%%% @copyright (C) 2012 Erlware, LLC.
+%%%
+%%% @doc This provides simple output functions for relx. You should use this
+%%% to talk to the users if you are wrting code for the system
+-module(rlx_log).
+
+-export([new/1,
+         log/4,
+         should/2,
+         debug/2,
+         debug/3,
+         info/2,
+         info/3,
+         error/2,
+         error/3,
+         log_level/1,
+         atom_log_level/1,
+         format/1]).
+
+-export_type([int_log_level/0,
+              atom_log_level/0,
+              log_level/0,
+              log_fun/0,
+              t/0]).
+
+-include_lib("relx/include/relx.hrl").
+
+%%============================================================================
+%% types
+%%============================================================================
+
+-type log_level() :: int_log_level() | atom_log_level().
+
+-type int_log_level() :: 0..2.
+
+%% Why no warn? because for our purposes there is no difference between error
+%% and warn
+-type atom_log_level() :: error | info | debug.
+
+-opaque t() :: {?MODULE, int_log_level()}.
+
+-type log_fun() :: fun(() -> iolist()).
+
+%%============================================================================
+%% API
+%%============================================================================
+%% @doc Create a new 'log level' for the system
+-spec new(log_level()) -> t().
+new(LogLevel) when LogLevel >= 0, LogLevel =< 2 ->
+    {?MODULE, LogLevel};
+new(AtomLogLevel)
+  when AtomLogLevel =:= error;
+       AtomLogLevel =:= info;
+       AtomLogLevel =:= debug ->
+    LogLevel = case AtomLogLevel of
+                   error -> 0;
+                   info -> 1;
+                   debug -> 2
+               end,
+    new(LogLevel).
+
+
+%% @doc log at the debug level given the current log state with a string or
+%% function that returns a string
+-spec debug(t(), string() | log_fun()) -> ok.
+debug(LogState, Fun)
+  when erlang:is_function(Fun) ->
+    log(LogState, ?RLX_DEBUG, Fun);
+debug(LogState, String) ->
+    debug(LogState, "~s~n", [String]).
+
+%% @doc log at the debug level given the current log state with a format string
+%% and argements @see io:format/2
+-spec debug(t(), string(), [any()]) -> ok.
+debug(LogState, FormatString, Args) ->
+    log(LogState, ?RLX_DEBUG, FormatString, Args).
+
+%% @doc log at the info level given the current log state with a string or
+%% function that returns a string
+-spec info(t(), string() | log_fun()) -> ok.
+info(LogState, Fun)
+    when erlang:is_function(Fun) ->
+    log(LogState, ?RLX_INFO, Fun);
+info(LogState, String) ->
+    info(LogState, "~s~n", [String]).
+
+%% @doc log at the info level given the current log state with a format string
+%% and argements @see io:format/2
+-spec info(t(), string(), [any()]) -> ok.
+info(LogState, FormatString, Args) ->
+    log(LogState, ?RLX_INFO, FormatString, Args).
+
+%% @doc log at the error level given the current log state with a string or
+%% format string that returns a function
+-spec error(t(), string() | log_fun()) -> ok.
+error(LogState, Fun)
+    when erlang:is_function(Fun) ->
+    log(LogState, ?RLX_ERROR, Fun);
+error(LogState, String) ->
+    error(LogState, "~s~n", [String]).
+
+%% @doc log at the error level given the current log state with a format string
+%% and argements @see io:format/2
+-spec error(t(), string(), [any()]) -> ok.
+error(LogState, FormatString, Args) ->
+    log(LogState, ?RLX_ERROR, FormatString, Args).
+
+%% @doc Execute the fun passed in if log level is as expected.
+-spec log(t(), int_log_level(), log_fun()) -> ok.
+log({?MODULE, DetailLogLevel}, LogLevel, Fun)
+    when DetailLogLevel >= LogLevel ->
+    io:format("~s~n", [Fun()]);
+log(_, _, _) ->
+    ok.
+
+
+%% @doc when the module log level is less then or equal to the log level for the
+%% call then write the log info out. When its not then ignore the call.
+-spec log(t(), int_log_level(), string(), [any()]) -> ok.
+log({?MODULE, DetailLogLevel}, LogLevel, FormatString, Args)
+  when DetailLogLevel >= LogLevel,
+       erlang:is_list(Args) ->
+    io:format(FormatString, Args);
+log(_, _, _, _) ->
+    ok.
+
+%% @doc return a boolean indicating if the system should log for the specified
+%% levelg
+-spec should(t(), int_log_level() | any()) -> boolean().
+should({?MODULE, DetailLogLevel}, LogLevel)
+  when DetailLogLevel >= LogLevel ->
+    true;
+should(_, _) ->
+    false.
+
+%% @doc get the current log level as an integer
+-spec log_level(t()) -> int_log_level().
+log_level({?MODULE, DetailLogLevel}) ->
+    DetailLogLevel.
+
+%% @doc get the current log level as an atom
+-spec atom_log_level(t()) -> atom_log_level().
+atom_log_level({?MODULE, ?RLX_ERROR}) ->
+    error;
+atom_log_level({?MODULE, ?RLX_INFO}) ->
+    info;
+atom_log_level({?MODULE, ?RLX_DEBUG}) ->
+    debug.
+
+-spec format(t()) -> iolist().
+format(Log) ->
+    [<<"(">>,
+     erlang:integer_to_list(log_level(Log)), <<":">>,
+     erlang:atom_to_list(atom_log_level(Log)),
+     <<")">>].
+
+%%%===================================================================
+%%% Test Functions
+%%%===================================================================
+
+-ifndef(NOTEST).
+-include_lib("eunit/include/eunit.hrl").
+
+should_test() ->
+    ErrorLogState = new(error),
+    ?assertMatch(true, should(ErrorLogState, ?RLX_ERROR)),
+    ?assertMatch(true, not should(ErrorLogState, ?RLX_INFO)),
+    ?assertMatch(true, not should(ErrorLogState, ?RLX_DEBUG)),
+    ?assertEqual(?RLX_ERROR, log_level(ErrorLogState)),
+    ?assertEqual(error, atom_log_level(ErrorLogState)),
+
+    InfoLogState = new(info),
+    ?assertMatch(true, should(InfoLogState, ?RLX_ERROR)),
+    ?assertMatch(true, should(InfoLogState, ?RLX_INFO)),
+    ?assertMatch(true, not should(InfoLogState, ?RLX_DEBUG)),
+    ?assertEqual(?RLX_INFO, log_level(InfoLogState)),
+    ?assertEqual(info, atom_log_level(InfoLogState)),
+
+    DebugLogState = new(debug),
+    ?assertMatch(true, should(DebugLogState, ?RLX_ERROR)),
+    ?assertMatch(true, should(DebugLogState, ?RLX_INFO)),
+    ?assertMatch(true, should(DebugLogState, ?RLX_DEBUG)),
+    ?assertEqual(?RLX_DEBUG, log_level(DebugLogState)),
+    ?assertEqual(debug, atom_log_level(DebugLogState)).
+
+-endif.