Class: Elephas::Backends::Hash

Inherits:
Base
  • Object
show all
Defined in:
lib/elephas/backends/hash.rb

Overview

This is a simple backend, which uses an hash for storing the values.

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Base

#now

Constructor Details

#initialize(data = nil) ⇒ Hash

Initialize the backend.

Parameters:

  • data (Hash) (defaults to: nil) —

    The initial data stored.



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# File 'lib/elephas/backends/hash.rb', line 19

def initialize(data = nil)
  @data = data.ensure_hash({}).with_indifferent_access
end

Instance Attribute Details

#data ⇒ HashWithIndifferentAccess

Returns The internal hash used by the backend.

Returns:

  • (HashWithIndifferentAccess) —

    The internal hash used by the backend.



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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

Instance Method Details

#delete(key) ⇒ Boolean

Deletes a value from the cache.

Parameters:

  • key (String) —

    The key to delete.

Returns:

  • (Boolean) —

    true if the key was in the cache, false otherwise.



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# File 'lib/elephas/backends/hash.rb', line 49

def delete(key)
  rv = @data.has_key?(key)
  @data.delete(key)
  rv
end

#exists?(key) ⇒ Boolean

Checks if a key exists in the cache.

Parameters:

  • key (String) —

    The key to lookup.

Returns:

  • (Boolean) —

    true if the key is in the cache, false otherwise.



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# File 'lib/elephas/backends/hash.rb', line 59

def exists?(key)
  @data.has_key?(key) && @data[key].valid?(self)
end

#read(key) ⇒ Entry|NilClass

Reads a value from the cache.

Parameters:

  • key (String) —

    The key to lookup.

Returns:

  • (Entry|NilClass) —

    The read value or nil.



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# File 'lib/elephas/backends/hash.rb', line 27

def read(key)
  exists?(key) ? @data[key] : nil
end

#write(key, value, options = {}) ⇒ Object

Writes a value to the cache.

Parameters:

  • key (String) —

    The key to associate the value with.

  • value (Object) —

    The value to write. Setting a value to nil doesn't mean deleting the value.

  • options (Hash) (defaults to: {}) —

    A list of options for writing.

Returns:

  • (Object) —

    The value itself.

See Also:

  • Cache.setup_options


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# File 'lib/elephas/backends/hash.rb', line 38

def write(key, value, options = {})
  entry = ::Elephas::Entry.ensure(value, key, options)
  entry.refresh
  @data[key] = entry
  entry
end