Class: Elephas::Backends::Hash

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# File 'lib/elephas/backends/hash.rb', line 13

class Hash < Base
  attr_accessor :data

  # Initialize the backend.
  #
  # @param data [Hash] The initial data stored.
  def initialize(data = nil)
    @data = data.ensure_hash({}).with_indifferent_access
  end

  # Reads a value from the cache.
  #
  # @param key [String] The key to lookup.
  # @return [Entry|NilClass] The read value or `nil`.
  def read(key)
    exists?(key) ? @data[key] : nil
  end

  # Writes a value to the cache.
  #
  # @param key [String] The key to associate the value with.
  # @param value [Object] The value to write. Setting a value to `nil` **doesn't** mean *deleting* the value.
  # @param options [Hash] A list of options for writing.
  # @see Elephas::Cache.setup_options
  # @return [Object] The value itself.
  def write(key, value, options = {})
    entry = ::Elephas::Entry.ensure(value, key, options)
    entry.refresh
    @data[key] = entry
    entry
  end

  # Deletes a value from the cache.
  #
  # @param key [String] The key to delete.
  # @return [Boolean] `true` if the key was in the cache, `false` otherwise.
  def delete(key)
    rv = @data.has_key?(key)
    @data.delete(key)
    rv
  end

  # Checks if a key exists in the cache.
  #
  # @param key [String] The key to lookup.
  # @return [Boolean] `true` if the key is in the cache, `false` otherwise.
  def exists?(key)
    @data.has_key?(key) && @data[key].valid?(self)
  end
end