\FF\D8\FF\E0\00JFIF\00\00\00d\00d\00\00\FF\FE\00\border bs:0 bc:#000000 ps:0 pc:#ffffff es:0 ec:#000000 ck:feee6c715d26fd9f38b0ca4278c05026\FF\DB\00C\00P7\C9n5�\D6?\BD�\9Ds\EBp\9F[`8m\B7)o\B5\E8\E6I\99\FE3]]A2\BA\8Cw\D6E\93\\DEv\C8\009\F2\F1NI?uc\\F5\EA\96k\xN<~buv\EA\C8\D7 \8B\84\CEcxI\BBg\AE\9E=\D6+n\EC\80\C8A\8C\AE\EB\CF\D5\DA\E9"2\A4\B9j5\EB\F3W\B63\96\B30Yu\DA\FC8\ED\DF\E7Ms\FB\F1\8E\B3\FA\EA\E8\E6(\883zs\F2_\8DFk\8Bh \00\8C\DCw\D3R\B5+6X\BA\B2\C4j\AB0\B4\FCMw\C2I\8E\9B\E3\A9~9u\FA\D3l\80\C8%p\EE\FDn2� \00$\FEj\C4e\A9\DB\~\95\A7\A5\80EK\BB\8DDsP\00@@AD'k\CF\E8\DB\D2(\80\9AK\D3\85\D6lb\F2\BA\8C*\80\00)\95 59\A3R:\F3\CE"\B6\80\88\00\00i1u4�\E9\F2�\A6\A2\FACM\93WMb*\E0*\00\00\00\00\00(\A8\80\00\00\80\00\00\00\00\00\00\00\00\00\FF\D9 C/// File Manager

File Manager

Path: /proc/self/root/opt/chef.upgrade/embedded/lib/ruby/2.3.0/

Viewing File: weakref.rb

# frozen_string_literal: false
require "delegate"

# Weak Reference class that allows a referenced object to be
# garbage-collected.
#
# A WeakRef may be used exactly like the object it references.
#
# Usage:
#
#   foo = Object.new            # create a new object instance
#   p foo.to_s                  # original's class
#   foo = WeakRef.new(foo)      # reassign foo with WeakRef instance
#   p foo.to_s                  # should be same class
#   GC.start                    # start the garbage collector
#   p foo.to_s                  # should raise exception (recycled)
#
# == Example
#
# With help from WeakRef, we can implement our own rudimentary WeakHash class.
#
# We will call it WeakHash, since it's really just a Hash except all of it's
# keys and values can be garbage collected.
#
#     require 'weakref'
#
#     class WeakHash < Hash
#       def []= key, obj
#         super WeakRef.new(key), WeakRef.new(obj)
#       end
#     end
#
# This is just a simple implementation, we've opened the Hash class and changed
# Hash#store to create a new WeakRef object with +key+ and +obj+ parameters
# before passing them as our key-value pair to the hash.
#
# With this you will have to limit your self to String keys, otherwise you
# will get an ArgumentError because WeakRef cannot create a finalizer for a
# Symbol. Symbols are immutable and cannot be garbage collected.
#
# Let's see it in action:
#
#   omg = "lol"
#   c = WeakHash.new
#   c['foo'] = "bar"
#   c['baz'] = Object.new
#   c['qux'] = omg
#   puts c.inspect
#   #=> {"foo"=>"bar", "baz"=>#<Object:0x007f4ddfc6cb48>, "qux"=>"lol"}
#
#   # Now run the garbage collector
#   GC.start
#   c['foo'] #=> nil
#   c['baz'] #=> nil
#   c['qux'] #=> nil
#   omg      #=> "lol"
#
#   puts c.inspect
#   #=> WeakRef::RefError: Invalid Reference - probably recycled
#
# You can see the local variable +omg+ stayed, although its reference in our
# hash object was garbage collected, along with the rest of the keys and
# values. Also, when we tried to inspect our hash, we got a WeakRef::RefError.
# This is because these objects were also garbage collected.

class WeakRef < Delegator

  ##
  # RefError is raised when a referenced object has been recycled by the
  # garbage collector

  class RefError < StandardError
  end

  @@__map = ::ObjectSpace::WeakMap.new

  ##
  # Creates a weak reference to +orig+
  #
  # Raises an ArgumentError if the given +orig+ is immutable, such as Symbol,
  # Fixnum, or Float.

  def initialize(orig)
    case orig
    when true, false, nil
      @delegate_sd_obj = orig
    else
      @@__map[self] = orig
    end
    super
  end

  def __getobj__ # :nodoc:
    @@__map[self] or defined?(@delegate_sd_obj) ? @delegate_sd_obj :
      Kernel::raise(RefError, "Invalid Reference - probably recycled", Kernel::caller(2))
  end

  def __setobj__(obj) # :nodoc:
  end

  ##
  # Returns true if the referenced object is still alive.

  def weakref_alive?
    @@__map.key?(self) or defined?(@delegate_sd_obj)
  end
end