Class: Stupidedi::ThreadLocalHash

Inherits:
Object
  • Object
show all
Includes:
Inspect
Defined in:
lib/stupidedi/thread_local.rb

Overview

Examples:

class Counter
  delegate :current, :current=, :to => @threadlocal

  def counter(start)
    @threadlocal = ThreadLocalHash.new(:current => start)
  end
end

counter = Counter.new(50)

x = Thread.new { 200.times { counter.current += 1 }; counter.current }
y = Thread.new { 300.times { counter.current += 1 }; counter.current }

x.value         #=> 250
x.value         #=> 350
counter.current #=> 50

Instance Method Summary collapse

Methods included from Inspect

#inspect

Constructor Details

#initialize(defaults = {}) ⇒ ThreadLocalHash

Returns a new instance of ThreadLocalHash.



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# File 'lib/stupidedi/thread_local.rb', line 92

def initialize(defaults = {})
  @defaults = defaults.clone
  @threads  = Hash.new
  @cleaner  = lambda {|key| @threads.delete_if{|(t,_),_| t == key }}

  defaults.keys.each do |name|
    case defaults[name]
    when Numeric, Symbol, nil
      # These are immutable values and can't be cloned
      instance_eval <<-RUBY
        def #{name}
          @threads.fetch([key, :#{name}]) do
            @defaults[:#{name}]
          end
        end
      RUBY
    else
      instance_eval <<-RUBY
        def #{name}
          @threads.fetch([key, :#{name}]) do
            finalizer(Thread.current)
            @threads[[key, :#{name}]] =
              @defaults[:#{name}].clone
          end
        end
      RUBY
    end

    instance_eval <<-RUBY
      def #{name}=(value)
        unless @threads.include?(key)
          finalizer(Thread.current)
        end

        @threads[[key, :#{name}]] = value
      end
    RUBY
  end
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name, value = (getter = true)) ⇒ Object (private) 



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# File 'lib/stupidedi/thread_local.rb', line 164

def method_missing(name, value = (getter = true))
  if getter
    self[name]
  else
    if name.to_s =~ /^(.+)=$/
      self[$1.to_sym] = value
    else
      super
    end
  end
end

Instance Method Details

#[](name) ⇒ Object 



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# File 'lib/stupidedi/thread_local.rb', line 132

def [](name)
  @threads.fetch([Thread.current, name]) do
    case value = @defaults[name]
    when Numeric, Symbol, nil
      # These are immutable values and can't be cloned
      value
    else
      finalizer(Thread.current)
      @threads[[key, name]] = value.clone
    end
  end
end

#[]=(name, value) ⇒ Object 



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# File 'lib/stupidedi/thread_local.rb', line 145

def []=(name, value)
  unless @threads.include?(key)
    finalizer(Thread.current)
  end

  @threads[[key, name]] = value
end