Class: Riak::Client::Decaying

Inherits:

Object

• Object
• Riak::Client::Decaying

show all

Defined in:

lib/riak/client/decaying.rb

Instance Attribute Summary (collapse)

• - (Object) e

  A float which decays exponentially with time.

• - (Object) p

  Returns the value of attribute p.

Instance Method Summary (collapse)

• - (Object) <<(d)

  Add d to current value.

• - (Decaying) initialize(opts = {}) constructor

  @param The initial value @param Exponent base @param Timescale.

• - (Object) value

  Return current value.

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# File 'lib/riak/client/decaying.rb', line 9

def initialize(opts = {})
  @p = opts[:p] || 0
  @e = opts[:e] || Math::E
  @r = opts[:r] || Math.log(0.5) / 10
  @t0 = Time.now
end

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# File 'lib/riak/client/decaying.rb', line 4

def e
  @e
end

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# File 'lib/riak/client/decaying.rb', line 5

def p
  @p
end

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# File 'lib/riak/client/decaying.rb', line 17

def <<(d)
  @p = value + d
end

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# File 'lib/riak/client/decaying.rb', line 22

def value
  now = Time.now
  dt = now - @t0
  @t0 = now
  @p = @p * (@e ** (@r * dt))
end