Module: Datadog::Contrib::Redis::Patcher

Defined in:
lib/ddtrace/contrib/redis/patcher.rb

Overview

Patcher enables patching of ‘redis’ module. This is used in monkey.rb to automatically apply patches

Class Method Summary collapse

Class Method Details

.patch ⇒ Object

patch applies our patch if needed



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# File 'lib/ddtrace/contrib/redis/patcher.rb', line 17

def patch
  if !@patched && (defined?(::Redis::VERSION) && \
                   Gem::Version.new(::Redis::VERSION) >= Gem::Version.new('3.0.0'))
    begin
      # do not require these by default, but only when actually patching
      require 'ddtrace/monkey'
      require 'ddtrace/ext/app_types'
      require 'ddtrace/contrib/redis/tags'
      require 'ddtrace/contrib/redis/quantize'

      patch_redis()
      patch_redis_client()

      @patched = true
    rescue StandardError => e
      Datadog::Tracer.log.error("Unable to apply Redis integration: #{e}")
    end
  end
  @patched
end

.patch_redis ⇒ Object 



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# File 'lib/ddtrace/contrib/redis/patcher.rb', line 38

def patch_redis
  ::Redis.module_eval do
    def datadog_pin=(pin)
      # Forward the pin to client, which actually traces calls.
      Datadog::Pin.onto(client, pin)
    end

    def datadog_pin
      # Get the pin from client, which actually traces calls.
      Datadog::Pin.get_from(client)
    end
  end
end

.patch_redis_client ⇒ Object

rubocop:disable Metrics/MethodLength



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# File 'lib/ddtrace/contrib/redis/patcher.rb', line 53

def patch_redis_client
  ::Redis::Client.class_eval do
    alias_method :initialize_without_datadog, :initialize
    Datadog::Monkey.without_warnings do
      remove_method :initialize
    end

    def initialize(*args)
      pin = Datadog::Pin.new(SERVICE, app: 'redis', app_type: Datadog::Ext::AppTypes::DB)
      pin.onto(self)
      initialize_without_datadog(*args)
    end

    alias_method :call_without_datadog, :call
    remove_method :call
    def call(*args, &block)
      pin = Datadog::Pin.get_from(self)
      return call_without_datadog(*args, &block) unless pin && pin.tracer

      response = nil
      pin.tracer.trace('redis.command') do |span|
        span.service = pin.service
        span.span_type = Datadog::Ext::Redis::TYPE
        span.resource = Datadog::Contrib::Redis::Quantize.format_command_args(*args)
        span.set_tag(Datadog::Ext::Redis::RAWCMD, span.resource)
        Datadog::Contrib::Redis::Tags.set_common_tags(self, span)

        response = call_without_datadog(*args, &block)
      end

      response
    end

    alias_method :call_pipeline_without_datadog, :call_pipeline
    remove_method :call_pipeline
    def call_pipeline(*args, &block)
      pin = Datadog::Pin.get_from(self)
      return call_pipeline_without_datadog(*args, &block) unless pin && pin.tracer

      response = nil
      pin.tracer.trace('redis.command') do |span|
        span.service = pin.service
        span.span_type = Datadog::Ext::Redis::TYPE
        commands = args[0].commands.map { |c| Datadog::Contrib::Redis::Quantize.format_command_args(c) }
        span.resource = commands.join("\n")
        span.set_tag(Datadog::Ext::Redis::RAWCMD, span.resource)
        Datadog::Contrib::Redis::Tags.set_common_tags(self, span)

        response = call_pipeline_without_datadog(*args, &block)
      end

      response
    end
  end
end

.patched? ⇒ Boolean

patched? tells wether patch has been successfully applied



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# File 'lib/ddtrace/contrib/redis/patcher.rb', line 110

def patched?
  @patched
end