Class: Memorb::KeyValueStore

Inherits:
Object
  • Object
show all
Defined in:
lib/memorb/key_value_store.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ KeyValueStore

Returns a new instance of KeyValueStore.



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# File 'lib/memorb/key_value_store.rb', line 8

def initialize
  @data = ::Hash.new
  @lock = ::Concurrent::ReentrantReadWriteLock.new
end

Instance Attribute Details

#lock ⇒ Object (readonly)

Returns the value of attribute lock.



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# File 'lib/memorb/key_value_store.rb', line 13

def lock
  @lock
end

Instance Method Details

#fetch(key, &fallback) ⇒ Object 



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# File 'lib/memorb/key_value_store.rb', line 27

def fetch(key, &fallback)
  @lock.with_read_lock do
    return _read(key) if _has?(key)
  end
  # Concurrent readers could all see no entry if none were able to
  # write before the others checked for the key, so they need to be
  # synchronized below to ensure that only one of them actually
  # executes the fallback block and writes the resulting value.
  @lock.with_write_lock do
    # The first thread to acquire the write lock will write the value
    # for the key causing the other aforementioned threads that may
    # also want to write to now see the key and return it.
    _has?(key) ? _read(key) : _write(key, fallback.call)
  end
end

#forget(key) ⇒ Object 



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# File 'lib/memorb/key_value_store.rb', line 43

def forget(key)
  @lock.with_write_lock { _forget(key) }
end

#has?(key) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/memorb/key_value_store.rb', line 23

def has?(key)
  @lock.with_read_lock { _has?(key) }
end

#inspect ⇒ Object 



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# File 'lib/memorb/key_value_store.rb', line 55

def inspect
  "#<#{ self.class.name } keys=#{ keys.inspect }>"
end

#keys ⇒ Object 



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# File 'lib/memorb/key_value_store.rb', line 51

def keys
  @lock.with_read_lock { _keys }
end

#read(key) ⇒ Object 



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# File 'lib/memorb/key_value_store.rb', line 19

def read(key)
  @lock.with_read_lock { _read(key) }
end

#reset! ⇒ Object 



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# File 'lib/memorb/key_value_store.rb', line 47

def reset!
  @lock.with_write_lock { _reset! }
end

#write(key, value) ⇒ Object 



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# File 'lib/memorb/key_value_store.rb', line 15

def write(key, value)
  @lock.with_write_lock { _write(key, value) }
end