Class: ActiveSupport::Cache::Entry

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

Overview

Entry that is put into caches. It supports expiration time on entries and can compress values to save space in the cache.

Constant Summary collapse

DEFAULT_COMPRESS_LIMIT =
16.kilobytes

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(value, options = {}) ⇒ Entry

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


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# File 'activesupport/lib/active_support/cache.rb', line 553

def initialize(value, options = {})
  @compressed = false
  @expires_in = options[:expires_in]
  @expires_in = @expires_in.to_f if @expires_in
  @created_at = Time.now.to_f
  if value.nil?
    @value = nil
  else
    @value = Marshal.dump(value)
    if should_compress?(@value, options)
      @value = Zlib::Deflate.deflate(@value)
      @compressed = true
    end
  end
end

Instance Attribute Details

#created_atObject (readonly)

Returns the value of attribute created_at


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# File 'activesupport/lib/active_support/cache.rb', line 533

def created_at
  @created_at
end

#expires_inObject (readonly)

Returns the value of attribute expires_in


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# File 'activesupport/lib/active_support/cache.rb', line 533

def expires_in
  @expires_in
end

Class Method Details

.create(raw_value, created_at, options = {}) ⇒ Object

Create an entry with internal attributes set. This method is intended to be used by implementations that store cache entries in a native format instead of as serialized Ruby objects.


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# File 'activesupport/lib/active_support/cache.rb', line 541

def create(raw_value, created_at, options = {})
  entry = new(nil)
  entry.instance_variable_set(:@value, raw_value)
  entry.instance_variable_set(:@created_at, created_at.to_f)
  entry.instance_variable_set(:@compressed, options[:compressed])
  entry.instance_variable_set(:@expires_in, options[:expires_in])
  entry
end

Instance Method Details

#compressed?Boolean

Returns:

  • (Boolean)

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# File 'activesupport/lib/active_support/cache.rb', line 594

def compressed?
  @compressed
end

#expired?Boolean

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

Returns:

  • (Boolean)

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# File 'activesupport/lib/active_support/cache.rb', line 600

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

#expires_atObject

Seconds since the epoch when the entry will expire.


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# File 'activesupport/lib/active_support/cache.rb', line 614

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

#expires_at=(time) ⇒ Object

Set a new time when the entry will expire.


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# File 'activesupport/lib/active_support/cache.rb', line 605

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

#raw_valueObject

Get the raw value. This value may be serialized and compressed.


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# File 'activesupport/lib/active_support/cache.rb', line 570

def raw_value
  @value
end

#sizeObject

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


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# File 'activesupport/lib/active_support/cache.rb', line 620

def size
  if @value.nil?
    0
  else
    @value.bytesize
  end
end

#valueObject

Get the value stored in the cache.


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# File 'activesupport/lib/active_support/cache.rb', line 575

def value
  # If the original value was exactly false @value is still true because
  # it is marshalled and eventually compressed. Both operations yield
  # strings.
  if @value
    # In rails 3.1 and earlier values in entries did not marshaled without
    # options[:compress] and if it's Numeric.
    # But after commit a263f377978fc07515b42808ebc1f7894fafaa3a
    # all values in entries are marshalled. And after that code below expects
    # that all values in entries will be marshaled (and will be strings). 
    # So here we need a check for old ones.
    begin
      Marshal.load(compressed? ? Zlib::Inflate.inflate(@value) : @value)
    rescue TypeError
      compressed? ? Zlib::Inflate.inflate(@value) : @value
    end
  end
end