Module: Mize::CacheMethods

Included in:
Memoize
Defined in:
lib/mize/cache_methods.rb

Overview

Per-object memoization bookkeeping.

Mixed into any module that calls memoize. Each object gets its own lazily-created cache instance (a copy of Mize.default_cache), and the key-building helpers below produce stable, argument-sensitive cache keys.

State is deliberately kept per-object: two instances of the same memoized class do not share a cache, which is the expected semantics for instance methods.

Instance Method Summary collapse

Instance Method Details

#__mize_cache__ ⇒ Mize::CacheProtocol (private)

Return the cache object, creating one on first use.

The first access makes a fresh copy of Mize.default_cache (via prototype / "dup") so that each object holds an independent store.

Returns:



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# File 'lib/mize/cache_methods.rb', line 50

def __mize_cache__
  if defined?(@__mize_cache__)
    @__mize_cache__
  else
    self.__mize_cache__ = Mize.default_cache.prototype
  end
end

#__mize_cache__=(cache) ⇒ Mize::CacheProtocol (private)

Set the cache object to cache.

Parameters:

Returns:



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# File 'lib/mize/cache_methods.rb', line 40

def __mize_cache__=(cache)
  @__mize_cache__ = cache
end

#build_key(name, *args) ⇒ String (private)

Build a name prefixed key for the arguments args.

The argument list is +Marshal#+d so structurally-identical arguments always collide on the same key regardless of object identity.

Parameters:

  • name (String, Symbol) —

    The method/function name.

  • args (Array) —

    The arguments to key on (positional, then splatted keywords).

Returns:

  • (String) —

    The full cache key.



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# File 'lib/mize/cache_methods.rb', line 75

def build_key(name, *args)
  "#{build_key_prefix(name)}/#{Marshal.dump(args)}"
end

#build_key_prefix(name) ⇒ String (private)

Build a key prefix for name.

Parameters:

  • name (String, Symbol) —

    The method/function name.

Returns:

  • (String) —

    The namespaced prefix, e.g. "mize/foo".



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# File 'lib/mize/cache_methods.rb', line 62

def build_key_prefix(name)
  "mize/#{name}"
end

#memoize_apply_visibility(id) { ... } ⇒ Object (private)

Apply the visibility of method id to the wrapper method of this method.

The block is expected to (re)define id as public; afterwards the original visibility is re-applied in the ensure clause so a memoized private method stays private.

Parameters:

  • id (String, Symbol) —

    The name of the method whose visibility to mirror.

Yields:

  • The block that performs the define_method of id.



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# File 'lib/mize/cache_methods.rb', line 88

def memoize_apply_visibility(id)
  visibility = instance_eval do
    case
    when private_method_defined?(id)
      :private
    when protected_method_defined?(id)
      :protected
    end
  end
  yield
ensure
  visibility and __send__(visibility, id)
end

#mize_cache_clear ⇒ self

Clear cached values for all methods/functions of this object.

Returns:

  • (self) —

    The receiver, for chaining.



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# File 'lib/mize/cache_methods.rb', line 17

def mize_cache_clear
  __mize_cache__.clear
  self
end

#mize_cache_clear_name(name) ⇒ self

Clear all cached results for the method/function name.

Parameters:

  • name (String, Symbol) —

    The name of the memoized method/function.

Returns:

  • (self) —

    The receiver, for chaining.



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# File 'lib/mize/cache_methods.rb', line 26

def mize_cache_clear_name(name)
  name = build_key_prefix(name)
  __mize_cache__.each_name do |n|
    n =~ %r{\A#{Regexp.quote(name)}/} and __mize_cache__.delete(n)
  end
  self
end