Class: Mustermann::EqualityMap
- Defined in:
- lib/rubypitaya/app-template/vendor/bundle/ruby/3.1.0/gems/mustermann-3.0.0/lib/mustermann/equality_map.rb
Overview
A simple wrapper around ObjectSpace::WeakMap that allows matching keys by equality rather than identity. Used for caching. Note that ‘fetch` is not guaranteed to return the object, even if it has not been garbage collected yet, especially when used concurrently. Therefore, the block passed to `fetch` has to be idempotent.
Instance Attribute Summary collapse
-
#map ⇒ Object
readonly
Returns the value of attribute map.
Class Method Summary collapse
Instance Method Summary collapse
-
#fetch(key) { ... } ⇒ Object
Value stored in map or result of block.
-
#initialize ⇒ EqualityMap
constructor
A new instance of EqualityMap.
Constructor Details
#initialize ⇒ EqualityMap
Returns a new instance of EqualityMap.
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# File 'lib/rubypitaya/app-template/vendor/bundle/ruby/3.1.0/gems/mustermann-3.0.0/lib/mustermann/equality_map.rb', line 25 def initialize @keys = {} @map = ObjectSpace::WeakMap.new end |
Instance Attribute Details
#map ⇒ Object (readonly)
Returns the value of attribute map.
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# File 'lib/rubypitaya/app-template/vendor/bundle/ruby/3.1.0/gems/mustermann-3.0.0/lib/mustermann/equality_map.rb', line 19 def map @map end |
Class Method Details
.new ⇒ Object
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# File 'lib/rubypitaya/app-template/vendor/bundle/ruby/3.1.0/gems/mustermann-3.0.0/lib/mustermann/equality_map.rb', line 21 def self.new defined?(ObjectSpace::WeakMap) ? super : {} end |
Instance Method Details
#fetch(key) { ... } ⇒ Object
Returns value stored in map or result of block.
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# File 'lib/rubypitaya/app-template/vendor/bundle/ruby/3.1.0/gems/mustermann-3.0.0/lib/mustermann/equality_map.rb', line 33 def fetch(key) identity = @keys[key.hash] if identity == key key = identity elsif key.frozen? key = key.dup end # it is ok that this is not thread-safe, worst case it has double cost in # generating, object equality is not guaranteed anyways @map[key] ||= track(key, yield) end |