Class: ActiveSupport::Cache::Entry

Inherits:
Object
  • Object
show all
Defined in:
lib/active_support/cache.rb

Overview

This class is used to represent cache entries. Cache entries have a value, an optional expiration time, and an optional version. The expiration time is used to support the :race_condition_ttl option on the cache. The version is used to support the :version option on the cache for rejecting mismatches.

Since cache entries in most instances will be serialized, the internals of this class are highly optimized using short instance variable names that are lazily defined.

Constant Summary collapse

DEFAULT_COMPRESS_LIMIT = 
1.kilobyte

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(value, compress: true, compress_threshold: DEFAULT_COMPRESS_LIMIT, version: nil, expires_in: nil) ⇒ Entry

Creates a new cache entry for the specified value. Options supported are :compress, :compress_threshold, :version and :expires_in.



739
740
741
742
743
744
745
746
 
# File 'lib/active_support/cache.rb', line 739

def initialize(value, compress: true, compress_threshold: DEFAULT_COMPRESS_LIMIT, version: nil, expires_in: nil, **)
  @value      = value
  @version    = version
  @created_at = Time.now.to_f
  @expires_in = expires_in && expires_in.to_f

  compress!(compress_threshold) if compress
end

Instance Attribute Details

#version ⇒ Object (readonly)

:nodoc:



733
734
735
 
# File 'lib/active_support/cache.rb', line 733

def version
  @version
end

Instance Method Details

#dup_value! ⇒ Object

Duplicates the value in a class. This is used by cache implementations that don’t natively serialize entries to protect against accidental cache modifications.



789
790
791
792
793
794
795
796
797
 
# File 'lib/active_support/cache.rb', line 789

def dup_value!
  if @value && !compressed? && !(@value.is_a?(Numeric) || @value == true || @value == false)
    if @value.is_a?(String)
      @value = @value.dup
    else
      @value = Marshal.load(Marshal.dump(@value))
    end
  end
end

#expired? ⇒ Boolean

Checks if the entry is expired. The expires_in parameter can override the value set when the entry was created.

Returns:

  • (Boolean) 


758
759
760
 
# File 'lib/active_support/cache.rb', line 758

def expired?
  @expires_in && @created_at + @expires_in <= Time.now.to_f
end

#expires_at ⇒ Object 



762
763
764
 
# File 'lib/active_support/cache.rb', line 762

def expires_at
  @expires_in ? @created_at + @expires_in : nil
end

#expires_at=(value) ⇒ Object 



766
767
768
769
770
771
772
 
# File 'lib/active_support/cache.rb', line 766

def expires_at=(value)
  if value
    @expires_in = value.to_f - @created_at
  else
    @expires_in = nil
  end
end

#mismatched?(version) ⇒ Boolean

Returns:

  • (Boolean) 


752
753
754
 
# File 'lib/active_support/cache.rb', line 752

def mismatched?(version)
  @version && version && @version != version
end

#size ⇒ Object

Returns the size of the cached value. This could be less than value.size if the data is compressed.



776
777
778
779
780
781
782
783
784
785
 
# File 'lib/active_support/cache.rb', line 776

def size
  case value
  when NilClass
    0
  when String
    @value.bytesize
  else
    @s ||= Marshal.dump(@value).bytesize
  end
end

#value ⇒ Object 



748
749
750
 
# File 'lib/active_support/cache.rb', line 748

def value
  compressed? ? uncompress(@value) : @value
end