Class: Datadog::DI::CaptureExpressionEvaluator Private

Inherits:
Object
  • Object
show all
Defined in:
lib/datadog/di/capture_expression_evaluator.rb

This class is part of a private API. You should avoid using this class if possible, as it may be removed or be changed in the future.

Constant Summary collapse

TELEMETRY_NAMESPACE =

This constant is part of a private API. You should avoid using this constant if possible, as it may be removed or be changed in the future. 

"dynamic_instrumentation"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(settings:, serializer:, logger:, telemetry: nil) ⇒ CaptureExpressionEvaluator

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a new instance of CaptureExpressionEvaluator.



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# File 'lib/datadog/di/capture_expression_evaluator.rb', line 12

def initialize(settings:, serializer:, logger:, telemetry: nil)
  @settings = settings
  @serializer = serializer
  @logger = logger
  @telemetry = telemetry
end

Instance Attribute Details

#logger ⇒ Object (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/datadog/di/capture_expression_evaluator.rb', line 23

def logger
  @logger
end

#serializer ⇒ Object (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/datadog/di/capture_expression_evaluator.rb', line 21

def serializer
  @serializer
end

#settings ⇒ Object (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/datadog/di/capture_expression_evaluator.rb', line 19

def settings
  @settings
end

#telemetry ⇒ Object (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/datadog/di/capture_expression_evaluator.rb', line 25

def telemetry
  @telemetry
end

Instance Method Details

#evaluate(probe, context) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/datadog/di/capture_expression_evaluator.rb', line 27

def evaluate(probe, context)
  budget_ns = settings.dynamic_instrumentation.max_time_to_serialize_ms * 1_000_000
  deadline_ns = ::Process.clock_gettime(::Process::CLOCK_MONOTONIC, :nanosecond) + budget_ns

  output = {}
  evaluation_errors = []

  probe.capture_expressions.each do |capture_expression|
    name = capture_expression.name

    if ::Process.clock_gettime(::Process::CLOCK_MONOTONIC, :nanosecond) >= deadline_ns
      output[name] = {notCapturedReason: "timeout"}
      telemetry&.inc(TELEMETRY_NAMESPACE, "capture_expressions_skipped_by_timeout", 1)
      next
    end

    begin
      value = capture_expression.expr.evaluate(context)
      limits = CaptureLimits.resolve(
        expr_limits: capture_expression.limits,
        probe: probe,
        settings: settings,
      )
      output[name] = serializer.serialize_value(
        value, name: name,
        depth: limits[:depth],
        attribute_count: limits[:attribute_count],
        length: limits[:length],
        collection_size: limits[:collection_size],
      )
    rescue Exception => exc # standard:disable Lint/RescueException
      Datadog::DI.reraise_if_fatal(exc)
      evaluation_errors << {expr: name, message: "#{exc.class}: #{exc.message}"}
      logger.debug do
        "di: probe #{probe.id}: capture expression #{name}: evaluation failed: #{exc.class}: #{exc.message}"
      end
      telemetry&.report(exc, description: "DI capture-expression evaluation failed")
    end
  end

  [output, evaluation_errors]
end