Parent

Logging::Appender

The Appender class is provides methods for appending log events to a logging destination. The log events are formatted into strings using a Layout.

All other Appenders inherit from this class which provides stub methods. Each subclass should provide a write method that will write log messages to the logging destination.

A private sync method is provided for use by subclasses. It is used to synchronize writes to the logging destination, and can be used by subclasses to synchronize the closing or flushing of the logging destination.

Attributes

layout[R]
level[R]
name[R]

Public Class Methods

new( name ) click to toggle source
new( name, :layout => layout )

Creates a new appender using the given name. If no Layout is specified, then a Basic layout will be used. Any logging header supplied by the layout will be written to the logging destination when the Appender is created.

Options:

:layout   => the layout to use when formatting log events
:level    => the level at which to log
:encoding => encoding to use when writing messages (defaults to UTF-8)
# File lib/logging/appender.rb, line 36
def initialize( name, opts = {} )
  ::Logging.init unless ::Logging.initialized?

  @name = name.to_s
  @closed = false

  self.layout = opts.getopt(:layout, ::Logging::Layouts::Basic.new)
  self.level = opts.getopt(:level)
  self.encoding = opts.fetch(:encoding, self.encoding)

  @mutex = ReentrantMutex.new

  if opts.getopt(:header, true)
    header = @layout.header

    unless header.nil? || header.empty?
      begin
        write(header)
      rescue StandardError => err
        ::Logging.log_internal(-2) {err}
      end
    end
  end

  ::Logging::Appenders[@name] = self
end

Public Instance Methods

appender << string click to toggle source

Write the given string to the logging destination "as is" -- no layout formatting will be performed.

# File lib/logging/appender.rb, line 94
def <<( str )
  if @closed
    raise RuntimeError,
          "appender '<#{self.class.name}: #{@name}>' is closed"
  end

  unless @level >= ::Logging::LEVELS.length
    begin
      write(str)
    rescue StandardError => err
      ::Logging.log_internal(-2) {err}
    end
  end
  self
end
append( event ) click to toggle source

Write the given event to the logging destination. The log event will be processed through the Layout associated with the Appender.

# File lib/logging/appender.rb, line 69
def append( event )
  if @closed
    raise RuntimeError,
          "appender '<#{self.class.name}: #{@name}>' is closed"
  end

  # only append if the event level is less than or equal to the configured
  # appender level
  unless @level > event.level
    begin
      write(event)
    rescue StandardError => err
      ::Logging.log_internal(-2) {err}
    end
  end

  self
end
close( footer = true ) click to toggle source

Close the appender and writes the layout footer to the logging destination if the footer flag is set to true. Log events will no longer be written to the logging destination after the appender is closed.

# File lib/logging/appender.rb, line 173
def close( footer = true )
  return self if @closed
  ::Logging::Appenders.remove(@name)
  @closed = true

  flush

  if footer
    footer = @layout.footer
    unless footer.nil? || footer.empty?
      begin
        write(footer)
      rescue StandardError => err
        ::Logging.log_internal(-2) {err}
      end
    end
  end
  self
end
closed? click to toggle source

Returns true if the appender has been closed; returns false otherwise. When an appender is closed, no more log events can be written to the logging destination.

# File lib/logging/appender.rb, line 200
def closed?
  @closed
end
encoding() click to toggle source

Returns the current Encoding for the appender or nil if an encoding has not been set.

# File lib/logging/appender.rb, line 239
def encoding
  return @encoding if defined? @encoding
  @encoding = Object.const_defined?(:Encoding) ? Encoding.default_external : nil
end
encoding=( value ) click to toggle source

Set the appender encoding to the given value. The value can either be an Encoding instance or a String or Symbol referring to a valid encoding.

This method only applies to Ruby 1.9 or later. The encoding will always be nil for older Rubies.

value - The encoding as a String, Symbol, or Encoding instance.

Raises ArgumentError if the value is not a valid encoding.

# File lib/logging/appender.rb, line 254
def encoding=( value )
  if value.nil?
    @encoding = nil
  else
    @encoding = Object.const_defined?(:Encoding) ? Encoding.find(value.to_s) : nil
  end
end
flush click to toggle source

Call flush to force an appender to write out any buffered log events. Similar to IO#flush, so use in a similar fashion.

# File lib/logging/appender.rb, line 219
def flush
  self
end
inspect => string click to toggle source

Returns a string representation of the appender.

# File lib/logging/appender.rb, line 228
def inspect
  "<%s:0x%x name=\"%s\">" % [
      self.class.name.sub(/^Logging::/, ''),
      self.object_id,
      self.name
  ]
end
layout=( layout ) click to toggle source

call-seq

appender.layout = Logging::Layouts::Basic.new

Sets the layout to be used by this appender.

# File lib/logging/appender.rb, line 157
def layout=( layout )
  unless layout.kind_of? ::Logging::Layout
    raise TypeError,
          "#{layout.inspect} is not a kind of 'Logging::Layout'"
  end
  @layout = layout
end
level = :all click to toggle source

Set the level for this appender; log events below this level will be ignored by this appender. The level can be either a String, a Symbol, or a Fixnum. An ArgumentError is raised if this is not the case.

There are two special levels -- "all" and "off". The former will enable recording of all log events. The latter will disable the recording of all events.

Example:

appender.level = :debug
appender.level = "INFO"
appender.level = 4
appender.level = 'off'
appender.level = :all

These produce an ArgumentError

appender.level = Object
appender.level = -1
appender.level = 1_000_000_000_000
# File lib/logging/appender.rb, line 136
def level=( level )
  lvl = case level
        when String, Symbol; ::Logging::level_num(level)
        when Fixnum; level
        when nil; 0
        else
          raise ArgumentError,
                "level must be a String, Symbol, or Integer"
        end
  if lvl.nil? or lvl < 0 or lvl > ::Logging::LEVELS.length
    raise ArgumentError, "unknown level was given '#{level}'"
  end

  @level = lvl
end
reopen() click to toggle source

Reopen the connection to the underlying logging destination. If the connection is currently closed then it will be opened. If the connection is currently open then it will be closed and immediately opened.

# File lib/logging/appender.rb, line 208
def reopen
  @closed = false
  self
end

[Validate]

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