Class: StatsdRack::Rack

Inherits:
Object
  • Object
show all
Defined in:
lib/statsd-rack/rack.rb

Defined Under Namespace

Classes: Body

Constant Summary collapse

REQUEST_METHOD = 
'REQUEST_METHOD'.freeze
VALID_METHODS = 
['GET', 'HEAD', 'POST', 'PUT', 'DELETE'].freeze

Instance Method Summary collapse

Constructor Details

#initialize(app, prefix = nil) ⇒ Rack

Initializes the middleware

prefix - String prefix for Statsd key.

Defaults to 'rack'



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# File 'lib/statsd-rack/rack.rb', line 15

def initialize(app, prefix=nil)
  @app = app
  stats_prefix = prefix || 'rack'
  @track_gc = GC.respond_to?(:time)
  if !$statsd
    $statsd = ::Statsd.new('localhost', 9125).tap{|sd| sd.namespace = stats_prefix}
  end
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/statsd-rack/rack.rb', line 99

def call(env)
  @start = Time.now
  GC.clear_stats if @track_gc
  status, headers, body = @app.call(env)
  body = Body.new(body) { record_request(status, env) }
  [status, headers, body]
end

#record_request(status, env) ⇒ Object

called after request is processed.



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# File 'lib/statsd-rack/rack.rb', line 25

def record_request(status, env)
  now = Time.now
  diff = (now - @start)

  if $statsd
    $statsd.timing("response_time", diff * 1000)
    if VALID_METHODS.include?(env[REQUEST_METHOD])
      stat = "response_time.#{env[REQUEST_METHOD].downcase}"
      $statsd.timing(stat, diff * 1000)
    end

    if suffix = status_suffix(status)
      $statsd.increment "status_code.#{status_suffix(status)}"
    end
    if @track_gc && GC.time > 0
      $statsd.timing "gc.time", GC.time / 1000
      $statsd.count  "gc.collections", GC.collections
    end
  end

rescue => boom
  warn "Statsd::Rack#record_request failed: #{boom}"
end

#status_suffix(status) ⇒ Object 



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# File 'lib/statsd-rack/rack.rb', line 49

def status_suffix(status)
  suffix = case status.to_i
    when 200 then :ok
    when 201 then :created
    when 202 then :accepted
    when 301 then :moved_permanently
    when 302 then :found
    when 303 then :see_other
    when 304 then :not_modified
    when 305 then :use_proxy
    when 307 then :temporary_redirect
    when 400 then :bad_request
    when 401 then :unauthorized
    when 402 then :payment_required
    when 403 then :forbidden
    when 404 then :missing
    when 410 then :gone
    when 422 then :invalid
    when 500 then :error
    when 502 then :bad_gateway
    when 503 then :node_down
    when 504 then :gateway_timeout
  end
end