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.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(value, compressed: false, version: nil, expires_in: nil, expires_at: nil) ⇒ Entry

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



919
920
921
922
923
924
925
 
# File 'lib/active_support/cache.rb', line 919

def initialize(value, compressed: false, version: nil, expires_in: nil, expires_at: nil, **)
  @value      = value
  @version    = version
  @created_at = 0.0
  @expires_in = expires_at&.to_f || expires_in && (expires_in.to_f + Time.now.to_f)
  @compressed = true if compressed
end

Instance Attribute Details

#version ⇒ Object (readonly)

Returns the value of attribute version.



915
916
917
 
# File 'lib/active_support/cache.rb', line 915

def version
  @version
end

Class Method Details

.unpack(members) ⇒ Object 



910
911
912
 
# File 'lib/active_support/cache.rb', line 910

def unpack(members)
  new(members[0], expires_at: members[1], version: members[2])
end

Instance Method Details

#bytesize ⇒ Object

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



955
956
957
958
959
960
961
962
963
964
 
# File 'lib/active_support/cache.rb', line 955

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

#compressed(compress_threshold) ⇒ Object 



970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
 
# File 'lib/active_support/cache.rb', line 970

def compressed(compress_threshold)
  return self if compressed?

  case @value
  when nil, true, false, Numeric
    uncompressed_size = 0
  when String
    uncompressed_size = @value.bytesize
  else
    serialized = Marshal.dump(@value)
    uncompressed_size = serialized.bytesize
  end

  if uncompressed_size >= compress_threshold
    serialized ||= Marshal.dump(@value)
    compressed = Zlib::Deflate.deflate(serialized)

    if compressed.bytesize < uncompressed_size
      return Entry.new(compressed, compressed: true, expires_at: expires_at, version: version)
    end
  end
  self
end

#compressed? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


966
967
968
 
# File 'lib/active_support/cache.rb', line 966

def compressed? # :nodoc:
  defined?(@compressed)
end

#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.



1000
1001
1002
1003
1004
1005
1006
1007
1008
 
# File 'lib/active_support/cache.rb', line 1000

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) 


937
938
939
 
# File 'lib/active_support/cache.rb', line 937

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

#expires_at ⇒ Object 



941
942
943
 
# File 'lib/active_support/cache.rb', line 941

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

#expires_at=(value) ⇒ Object 



945
946
947
948
949
950
951
 
# File 'lib/active_support/cache.rb', line 945

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

#local? ⇒ Boolean

Returns:

  • (Boolean) 


994
995
996
 
# File 'lib/active_support/cache.rb', line 994

def local?
  false
end

#mismatched?(version) ⇒ Boolean

Returns:

  • (Boolean) 


931
932
933
 
# File 'lib/active_support/cache.rb', line 931

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

#pack ⇒ Object 



1010
1011
1012
1013
1014
 
# File 'lib/active_support/cache.rb', line 1010

def pack
  members = [value, expires_at, version]
  members.pop while !members.empty? && members.last.nil?
  members
end

#value ⇒ Object 



927
928
929
 
# File 'lib/active_support/cache.rb', line 927

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