util/logger.lua

   1 -- Prosody IM
   2 -- Copyright (C) 2008-2010 Matthew Wild
   3 -- Copyright (C) 2008-2010 Waqas Hussain
   4 --
   5 -- This project is MIT/X11 licensed. Please see the
   6 -- COPYING file in the source package for more information.
   7 --
   8 -- luacheck: ignore 213/level
   9
  10 local pairs = pairs;
  11 local ipairs = ipairs;
  12 local require = require;
  13
  14 local _ENV = nil;
  15 -- luacheck: std none
  16
  17 local level_sinks = {};
  18
  19 local make_logger;
  20
  21 local function init(name)
  22         local log_debug = make_logger(name, "debug");
  23         local log_info = make_logger(name, "info");
  24         local log_warn = make_logger(name, "warn");
  25         local log_error = make_logger(name, "error");
  26
  27         return function (level, message, ...)
  28                         if level == "debug" then
  29                                 return log_debug(message, ...);
  30                         elseif level == "info" then
  31                                 return log_info(message, ...);
  32                         elseif level == "warn" then
  33                                 return log_warn(message, ...);
  34                         elseif level == "error" then
  35                                 return log_error(message, ...);
  36                         end
  37                 end
  38 end
  39
  40 function make_logger(source_name, level)
  41         local level_handlers = level_sinks[level];
  42         if not level_handlers then
  43                 level_handlers = {};
  44                 level_sinks[level] = level_handlers;
  45         end
  46
  47         local logger = function (message, ...)
  48                 for i = 1,#level_handlers do
  49                         level_handlers[i](source_name, level, message, ...);
  50                 end
  51         end
  52
  53         return logger;
  54 end
  55
  56 local function reset()
  57         for level, handler_list in pairs(level_sinks) do
  58                 -- Clear all handlers for this level
  59                 for i = 1, #handler_list do
  60                         handler_list[i] = nil;
  61                 end
  62         end
  63 end
  64
  65 local function add_level_sink(level, sink_function)
  66         if not level_sinks[level] then
  67                 level_sinks[level] = { sink_function };
  68         else
  69                 level_sinks[level][#level_sinks[level] + 1 ] = sink_function;
  70         end
  71 end
  72
  73 local function add_simple_sink(simple_sink_function, levels)
  74         local format = require "util.format".format;
  75         local function sink_function(name, level, msg, ...)
  76                 return simple_sink_function(name, level, format(msg, ...));
  77         end
  78         for _, level in ipairs(levels or {"debug", "info", "warn", "error"}) do
  79                 add_level_sink(level, sink_function);
  80         end
  81 end
  82
  83 return {
  84         init = init;
  85         make_logger = make_logger;
  86         reset = reset;
  87         add_level_sink = add_level_sink;
  88         add_simple_sink = add_simple_sink;
  89         new = make_logger;
  90 };