Module: Datadog::Contrib::MongoDB

Defined in:
lib/ddtrace/contrib/mongodb/parsers.rb,
lib/ddtrace/contrib/mongodb/patcher.rb,
lib/ddtrace/contrib/mongodb/subscribers.rb

Overview

MongoDB module includes classes and functions to instrument MongoDB clients

Defined Under Namespace

Modules: Patcher Classes: MongoCommandSubscriber

Constant Summary collapse

SKIP_KEYS =

skipped keys are related to command names, since they are already extracted by the query_builder

[:_id].freeze
PLACEHOLDER = 
'?'.freeze
APP = 
'mongodb'.freeze
SERVICE = 
'mongodb'.freeze

Class Method Summary collapse

Class Method Details

.quantize_statement(statement, skip = []) ⇒ Object

removes the values from the given query; this quantization recursively replace elements available in a given query, so that Arrays, Hashes and so on are compacted. It ensures a low cardinality so that it can be used as a Span resource.



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# File 'lib/ddtrace/contrib/mongodb/parsers.rb', line 34

def quantize_statement(statement, skip = [])
  case statement
  when Hash
    statement.each_with_object({}) do |(key, value), quantized|
      quantized[key] = quantize_value(value, skip) unless skip.include?(key)
    end
  else
    quantize_value(statement, skip)
  end
end

.quantize_value(value, skip = []) ⇒ Object 



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# File 'lib/ddtrace/contrib/mongodb/parsers.rb', line 45

def quantize_value(value, skip = [])
  case value
  when Hash
    quantize_statement(value, skip)
  when Array
    quantize_value(value.first, skip)
  else
    PLACEHOLDER
  end
end

.query_builder(command_name, database_name, command) ⇒ Object

returns a formatted and normalized query



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# File 'lib/ddtrace/contrib/mongodb/parsers.rb', line 13

def query_builder(command_name, database_name, command)
  # always skip the command name
  skip = SKIP_KEYS | [command_name.to_s]

  result = {
    operation: command_name,
    database: database_name,
    collection: command.values.first
  }

  command.each do |key, value|
    result[key] = quantize_statement(value, skip) unless skip.include?(key)
  end

  result
end