File /tmp/svntemp/hscale/src/optivo/common/log4lua/logger.lua

Logging facility.
A logger consists of a category (to distinct different modules etc.) and an appender which actually writes the message (to console, file etc.)

Configuration

A sample configuration file looks like this:
local logger = require("optivo.common.log4lua.logger")
local console = require("optivo.common.log4lua.appenders.console")
local file = require("optivo.common.log4lua.appenders.file")
local config = {}

-- ROOT category must be configured.
config["ROOT"] = logger.Logger.new(console.new(), "ROOT", logger.FATAL)
config["foo"] = logger.Logger.new(file.new("foo-%s.log", "%Y-%m-%d"), "foo", logger.INFO)
config["bar"] = logger.Logger.new(file.new("bar.log", nil, "%LEVEL: %MESSAGE\n"), "bar", logger.INFO)

-- The config table must be returned.
return config
Then you can load this configuration file "by hand" calling loadConfig(fileName) or you can set a default configuration file using the environment variable LOG4LUA_CONFIG_FILE.

Patterns

Patterns may contain the following placeholders:
  • %DATE
  • %LEVEL
  • %MESSAGE
  • %FILE - the source filename w/o path
  • %PATH - the source filename including the path
  • %LINE - the position in the source file
  • %FUNCTION - the function name
  • %STACKTRACE - the complete stack trace
  • %ERROR - an exception string like the one you get using pcall(...)
Important performance note: Using one of %FILE, %PATH, %LINE, %FUNCTION, %STACKTRACE implies a quite huge performance hit because debug.traceback() has to be called for every message logged. Note that the default pattern uses these placeholders. Default pattern for all appenders is [%DATE] [%LEVEL] at %FILE:%LINE(%METHOD): %MESSAGE\n

Release: $Date: 2008-09-21 03:11:45 +0200 (So, 21 Sep 2008) $ $Rev: 87 $

Functions

Logger.new (appenders, category, level) Constructor.
Logger:debug (message, exception) Log message at DEBUG level.
Logger:error (message, exception) Log message at ERROR level.
Logger:fatal (message, exception) Log message at FATAL level.
Logger:info (message, exception) Log message at INFO level.
Logger:isLevel (level) Test whether the given level is enabled.
Logger:log (level, message, exception) Log the given message at the given level.
Logger:setLevel (level) Set the log level threshold.
Logger:warn (message, exception) Log message at WARN level.
getLogger (category) Main method that returns a fully configured logger for the given category.
The correct logger is found as follows:
  • If there is a configured logger with the exact category then use this.
  • Otherwise search for loggers with matching category.
loadConfig (fileName) Load a configuration file.


Functions

Logger.new (appenders, category, level)
Constructor.

Parameters

  • appenders: a single function or a table of functions taking a string as parameter that is responsible for writing the log message.
  • category: the category (== name) of this logger
  • level: the threshold level. Only messages for equal or higher levels will be logged.
Logger:debug (message, exception)
Log message at DEBUG level.

Parameters

  • message:
  • exception:
Logger:error (message, exception)
Log message at ERROR level.

Parameters

  • message:
  • exception:
Logger:fatal (message, exception)
Log message at FATAL level.

Parameters

  • message:
  • exception:
Logger:info (message, exception)
Log message at INFO level.

Parameters

  • message:
  • exception:
Logger:isLevel (level)
Test whether the given level is enabled.

Parameters

  • level:

Return value:

true if messages of the given level will be logged.
Logger:log (level, message, exception)
Log the given message at the given level.

Parameters

  • level:
  • message:
  • exception:
Logger:setLevel (level)
Set the log level threshold.

Parameters

  • level:
Logger:warn (message, exception)
Log message at WARN level.

Parameters

  • message:
  • exception:
getLogger (category)
Main method that returns a fully configured logger for the given category.
The correct logger is found as follows:
  • If there is a configured logger with the exact category then use this.
  • Otherwise search for loggers with matching category. Example: If there is a configured logger for category "test" then it is used for category "test.whatever", "testinger" etc.
  • Otherwise use the root category.

Parameters

  • category: the category of the desired logger.
loadConfig (fileName)
Load a configuration file.

Parameters

  • fileName: path to a configuration file written in lua. The lua code must return a map (table) with loggers configured for each category.

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