Class: Volt::GenericPool

Inherits:
Object show all
Defined in:
lib/volt/utils/generic_pool.rb

Overview

GenericPool is a base class you can inherit from to cache items based on a lookup.

GenericPool assumes either a block is passed to lookup, or a #create method, that takes the path arguments and reutrns a new instance.

GenericPool can handle as deep of paths as needed. You can also lookup all of the items at a sub-path with #lookup_all

TODO: make the lookup/create threadsafe

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ GenericPool

Returns a new instance of GenericPool.



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# File 'lib/volt/utils/generic_pool.rb', line 15

def initialize
  @pool = {}
end

Instance Attribute Details

#pool ⇒ Object (readonly)

Returns the value of attribute pool.



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# File 'lib/volt/utils/generic_pool.rb', line 13

def pool
  @pool
end

Instance Method Details

#create_new_item(*args) ⇒ Object

Does the actual creating, if a block is not passed in, it calls #create on the class.



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# File 'lib/volt/utils/generic_pool.rb', line 43

def create_new_item(*args)
  if block_given?
    new_item = yield(*args)
  else
    new_item = create(*args)
  end

  transform_item(new_item)
end

#lookup(*args, &block) ⇒ Object Also known as: __lookup 



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# File 'lib/volt/utils/generic_pool.rb', line 19

def lookup(*args, &block)
  section = @pool

  # TODO: This is to work around opal issue #500
  if RUBY_PLATFORM == 'opal'
    args.pop if args.last.nil?
  end

  args.each_with_index do |arg, index|
    last = (args.size - 1) == index

    if last
      # return, creating if needed
      return(section[arg] ||= create_new_item(*args, &block))
    else
      next_section = section[arg]
      next_section ||= (section[arg] = {})
      section      = next_section
    end
  end
end

#lookup_all(*args) ⇒ Object 



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# File 'lib/volt/utils/generic_pool.rb', line 62

def lookup_all(*args)
  result = __lookup(*args) { nil }

  if result
    return result.values
  else
    return []
  end
end

#remove(*args) ⇒ Object 



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# File 'lib/volt/utils/generic_pool.rb', line 72

def remove(*args)
  stack   = []
  section = @pool

  args.each_with_index do |arg, index|
    stack << section

    if args.size - 1 == index
      section.delete(arg)
    else
      section = section[arg]
    end
  end

  (stack.size - 1).downto(1) do |index|
    node   = stack[index]
    parent = stack[index - 1]

    if node.size == 0
      parent.delete(args[index - 1])
    end
  end
end

#transform_item(item) ⇒ Object

Allow other pools to override how the created item gets stored.



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# File 'lib/volt/utils/generic_pool.rb', line 54

def transform_item(item)
  item
end