Module: Datadog::Tracing::Contrib::Rack::RouteInference

Defined in:
lib/datadog/tracing/contrib/rack/route_inference.rb

Overview

This module provides logic for inferring HTTP route pattern from an HTTP path.

Constant Summary collapse

MAX_NUMBER_OF_SEGMENTS = 
8
INT_PARAM_REGEX = 
/\A[0-9]+\z/.freeze
INT_ID_PARAM_REGEX = 
/\A(?=.*\d)[\d._-]{3,}\z/.freeze
HEX_PARAM_REGEX = 
/\A(?=.*\d)[A-Fa-f0-9]{6,}\z/.freeze
HEX_ID_PARAM_REGEX = 
/\A(?=.*\d)[A-Fa-f0-9._-]{6,}\z/.freeze
STRING_PARAM_REGEX = 
/\A.{20,}|.*[%&'()*+,:=@].*\z/.freeze
DATADOG_INFERRED_ROUTE_ENV_KEY = 
'datadog.inferred_route'

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.infer(path) ⇒ Object 



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# File 'lib/datadog/tracing/contrib/rack/route_inference.rb', line 27

def infer(path)
  count = 0
  result = []

  split(path, '/') do |segment|
    next if segment.empty?
    break if count >= MAX_NUMBER_OF_SEGMENTS
    count += 1

    result << case segment
    when INT_PARAM_REGEX then '{param:int}'
    when INT_ID_PARAM_REGEX then '{param:int_id}'
    when HEX_PARAM_REGEX then '{param:hex}'
    when HEX_ID_PARAM_REGEX then '{param:hex_id}'
    when STRING_PARAM_REGEX then '{param:str}'
    else segment
    end
  end

  result.empty? ? '/' : "/#{result.join('/')}"
rescue
  nil
end

.read_or_infer(request_env) ⇒ Object 



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# File 'lib/datadog/tracing/contrib/rack/route_inference.rb', line 22

def read_or_infer(request_env)
  request_env[DATADOG_INFERRED_ROUTE_ENV_KEY] ||=
    infer(request_env['SCRIPT_NAME'].to_s + request_env['PATH_INFO'].to_s)
end

Instance Method Details

#split(path, pattern = nil, &block) ⇒ Object 



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# File 'lib/datadog/tracing/contrib/rack/route_inference.rb', line 52

def split(path, pattern = nil, &block)
  path.split(pattern, &block)
end