logger.rb in davidlee-state-fu-0.3.1

- old
+ new
@@ -1,10 +1,88 @@
 require 'logger'
-
 module StateFu
-  if Object.const_defined?( "RAILS_DEFAULT_LOGGER" )
-    Logger       = RAILS_DEFAULT_LOGGER
-  else
-    Logger       = ::Logger.new( STDOUT )
-    Logger.level = ::Logger.const_get( (ENV["ZEN_LOGLEVEL"] || 'WARN').upcase )
+  class Logger
+    cattr_accessor :prefix   # prefix for log messages
+    cattr_accessor :suppress # set true to send messages to /dev/null
+
+    DEBUG   = 0
+    INFO    = 1
+    WARN    = 2
+    ERROR   = 3
+    FATAL   = 4
+    UNKNOWN = 5
+
+    ENV_LOG_LEVEL = 'STATEFU_LOGLEVEL'
+    DEFAULT_LEVEL = INFO
+
+    DEFAULT_PREFIX    = nil
+    SHARED_LOG_PREFIX = 'StateFu: '
+
+    @@prefix   = DEFAULT_PREFIX
+    @@logger   = nil
+    @@suppress = false
+
+    def self.level=( new_level )
+      instance.level = case new_level
+                       when String, Symbol
+                         const_get( new_level )
+                       when Fixnum
+                         new_level
+                       else
+                         state_fu_log_level()
+                       end
+    end
+
+    def self.state_fu_log_level
+      if ENV[ ENV_LOG_LEVEL ]
+        const_get( ENV[ ENV_LOG_LEVEL ] )
+      else
+        DEFAULT_LEVEL
+      end
+    end
+
+    def self.new( log = $stdout, level = () )
+      self.instance = get_logger( log )
+    end
+
+    def self.instance=( logger )
+      @@logger ||= get_logger
+    end
+
+    def self.instance
+      @@logger ||= get_logger
+    end
+
+    def self.get_logger( log = $stdout )
+      if Object.const_defined?( "RAILS_DEFAULT_LOGGER" )
+        logger         = RAILS_DEFAULT_LOGGER
+        prefix         = SHARED_LOG_PREFIX
+      else
+        if Object.const_defined?( 'ActiveSupport' ) && ActiveSupport.const_defined?('BufferedLogger')
+          logger       = ActiveSupport::BufferedLogger.new( log )
+        else
+          logger       = ::Logger.new( log )
+          logger.level = state_fu_log_level()
+        end
+      end
+      logger
+    end
+
+    def self.suppress!
+      @@suppress = true
+    end
+
+    # method_missing is usually a last resort
+    # but i don't see it causing any headaches here.
+    def self.method_missing( method_id, *args )
+      return if @@suppress
+      if [:debug, :info, :warn, :error, :fatal].include?( method_id ) &&
+          args[0].is_a?(String) && @@prefix
+        args[0] = @@prefix + args[0]
+      end
+      instance.send( method_id, *args )
+    end
+
   end
 end
+
+# StateFu::Logger.info( StateFu::Logger.instance.inspect )