Class: Rperf::RackMiddleware

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

Constant Summary collapse

UUID_RE = 
%r{/[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}(?=/|\z)}i
NUMERIC_RE = 
%r{/\d+(?=/|\z)}

Instance Method Summary collapse

Constructor Details

#initialize(app, label_key: :endpoint, label: nil) ⇒ RackMiddleware

Options:

label_key: - Symbol key for the endpoint label (default: :endpoint)
label:     - Proc(env) -> String to customize the label value.
            Default: "METHOD /path" with dynamic segments normalized
            (numeric IDs → :id, UUIDs → :uuid) to keep label cardinality low.
            Set label: :raw to use PATH_INFO as-is (not recommended for
            routes with dynamic segments — each unique path persists in
            memory for the profiling session).



13
14
15
16
17
 
# File 'lib/rperf/rack.rb', line 13

def initialize(app, label_key: :endpoint, label: nil)
  @app = app
  @label_key = label_key
  @label_proc = label
end

Instance Method Details

#call(env) ⇒ Object 



22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
 
# File 'lib/rperf/rack.rb', line 22

def call(env)
  # No-op when the profiler is not running (Rperf.profile would raise):
  # the app may boot without Rperf.start, stop mid-run, or run in a forked
  # worker where the atfork handler silently stopped profiling.
  return @app.call(env) unless Rperf.running?

  endpoint = if @label_proc == :raw
    "#{env["REQUEST_METHOD"]} #{env["PATH_INFO"]}"
  elsif @label_proc
    @label_proc.call(env)
  else
    path = env["PATH_INFO"]
      .gsub(UUID_RE, "/:uuid")
      .gsub(NUMERIC_RE, "/:id")
    "#{env["REQUEST_METHOD"]} #{path}"
  end
  Rperf.profile(@label_key => endpoint) do
    @app.call(env)
  end
end