59 lines
1.4 KiB
Ruby
59 lines
1.4 KiB
Ruby
# frozen_string_literal: true
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require "delegate"
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# Weak Reference class that allows a referenced object to be
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# garbage-collected.
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#
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# A WeakRef may be used exactly like the object it references.
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#
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# Usage:
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#
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# foo = Object.new # create a new object instance
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# p foo.to_s # original's class
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# foo = WeakRef.new(foo) # reassign foo with WeakRef instance
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# p foo.to_s # should be same class
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# GC.start # start the garbage collector
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# p foo.to_s # should raise exception (recycled)
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#
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class WeakRef < Delegator
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VERSION = "0.1.1"
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##
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# RefError is raised when a referenced object has been recycled by the
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# garbage collector
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class RefError < StandardError
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end
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@@__map = ::ObjectSpace::WeakMap.new
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##
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# Creates a weak reference to +orig+
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def initialize(orig)
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case orig
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when true, false, nil
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@delegate_sd_obj = orig
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else
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@@__map[self] = orig
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end
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super
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end
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def __getobj__ # :nodoc:
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@@__map[self] or defined?(@delegate_sd_obj) ? @delegate_sd_obj :
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Kernel::raise(RefError, "Invalid Reference - probably recycled", Kernel::caller(2))
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end
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def __setobj__(obj) # :nodoc:
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end
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##
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# Returns true if the referenced object is still alive.
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def weakref_alive?
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@@__map.key?(self) or defined?(@delegate_sd_obj)
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end
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end
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