Class: OneApm::Transaction::TransactionSampleBuffer

Inherits:
Object
  • Object
show all
Defined in:
lib/one_apm/transaction/sample_buffer/transaction_sample_buffer.rb

Constant Summary collapse

OA_SINGLE_BUFFER_MAX = 
20
OA_NO_SAMPLES = 
[].freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ TransactionSampleBuffer

Returns a new instance of TransactionSampleBuffer.



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# File 'lib/one_apm/transaction/sample_buffer/transaction_sample_buffer.rb', line 11

def initialize
  @samples = []
end

Instance Attribute Details

#samples ⇒ Object (readonly)

Returns the value of attribute samples.



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# File 'lib/one_apm/transaction/sample_buffer/transaction_sample_buffer.rb', line 6

def samples
  @samples
end

Instance Method Details

#allow_sample?(sample) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/one_apm/transaction/sample_buffer/transaction_sample_buffer.rb', line 29

def allow_sample?(sample)
  true
end

#capacity ⇒ Object

Capacity is the desired number of samples a buffer will hold. This can be user dictated via config if a feature wants.

This value will be forcibly capped by the max_capacity

Raises:

  • (NotImplementedError) 


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# File 'lib/one_apm/transaction/sample_buffer/transaction_sample_buffer.rb', line 61

def capacity
  raise NotImplementedError.new("TransactionSampleBuffer subclasses must provide a capacity override")
end

#enabled? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/one_apm/transaction/sample_buffer/transaction_sample_buffer.rb', line 15

def enabled?
  true
end

#full? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/one_apm/transaction/sample_buffer/transaction_sample_buffer.rb', line 53

def full?
  @samples.length >= max_capacity
end

#harvest_samples ⇒ Object 



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# File 'lib/one_apm/transaction/sample_buffer/transaction_sample_buffer.rb', line 23

def harvest_samples
  @samples
ensure
  reset!
end

#max_capacity ⇒ Object

Apply hard upper limit to the capacity to prevent users from consuming too much memory buffering TT’s.

A typical buffer should NOT override this method (although we do for odd things like dev-mode)



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# File 'lib/one_apm/transaction/sample_buffer/transaction_sample_buffer.rb', line 70

def max_capacity
  capacity > OA_SINGLE_BUFFER_MAX ? OA_SINGLE_BUFFER_MAX : capacity
end

#reset! ⇒ Object 



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# File 'lib/one_apm/transaction/sample_buffer/transaction_sample_buffer.rb', line 19

def reset!
  @samples = []
end

#store(sample) ⇒ Object 



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# File 'lib/one_apm/transaction/sample_buffer/transaction_sample_buffer.rb', line 33

def store(sample)
  return unless enabled?
  if allow_sample?(sample)
    add_sample(sample)
    truncate_samples_if_needed
  end
end

#store_previous(previous_samples) ⇒ Object 



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# File 'lib/one_apm/transaction/sample_buffer/transaction_sample_buffer.rb', line 41

def store_previous(previous_samples)
  return unless enabled?
  previous_samples.each do |sample|
    add_sample(sample) if allow_sample?(sample)
  end
  truncate_samples_if_needed
end

#truncate_samples ⇒ Object

Our default truncation strategy is to keep max_capacity worth of the longest samples. Override this method for alternate behavior.

This doesn’t use the more convenient #last and #sort_by to avoid additional array allocations (and abundant alliteration)



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# File 'lib/one_apm/transaction/sample_buffer/transaction_sample_buffer.rb', line 80

def truncate_samples
  @samples.sort!{|a,b| a.duration <=> b.duration}
  @samples.slice!(0..-(max_capacity + 1))
end

#truncate_samples_if_needed ⇒ Object 



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# File 'lib/one_apm/transaction/sample_buffer/transaction_sample_buffer.rb', line 49

def truncate_samples_if_needed
  truncate_samples if full?
end

#visit_segment ⇒ Object

When pushing a scope different sample buffers potentially want to know about what’s happening to annotate the incoming segments



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# File 'lib/one_apm/transaction/sample_buffer/transaction_sample_buffer.rb', line 87

def visit_segment(*)
  # no-op
end