Class: AmplitudeExperiment::LRUCache

Inherits:
Object
  • Object
show all
Defined in:
lib/experiment/util/lru_cache.rb

Overview

Cache

Instance Method Summary collapse

Constructor Details

#initialize(capacity, ttl_millis) ⇒ LRUCache

Returns a new instance of LRUCache.



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# File 'lib/experiment/util/lru_cache.rb', line 26

def initialize(capacity, ttl_millis)
  @capacity = capacity
  @ttl_millis = ttl_millis
  @cache = {}
  @head = nil
  @tail = nil
end

Instance Method Details

#clear ⇒ Object 



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# File 'lib/experiment/util/lru_cache.rb', line 67

def clear
  @cache.clear
  @head = nil
  @tail = nil
end

#get(key) ⇒ Object 



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# File 'lib/experiment/util/lru_cache.rb', line 47

def get(key)
  node = @cache[key]
  return nil unless node

  time_elapsed = (Time.now.to_f * 1000).to_i - node.data.created_at
  if time_elapsed > @ttl_millis
    remove(key)
    return nil
  end

  remove_from_list(key)
  insert_to_list(node)
  node.data.value
end

#put(key, value) ⇒ Object 



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# File 'lib/experiment/util/lru_cache.rb', line 34

def put(key, value)
  if @cache.key?(key)
    remove_from_list(key)
  elsif @cache.size >= @capacity
    evict_lru
  end

  cache_item = CacheItem.new(key, value)
  node = ListNode.new(cache_item)
  @cache[key] = node
  insert_to_list(node)
end

#remove(key) ⇒ Object 



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# File 'lib/experiment/util/lru_cache.rb', line 62

def remove(key)
  remove_from_list(key)
  @cache.delete(key)
end