# frozen_string_literal: true
module Gitlab
module Middleware
class Speedscope
def initialize(app)
@app = app
end
def call(env)
request = ActionDispatch::Request.new(env)
return @app.call(env) unless rendering_flamegraph?(request)
body = nil
::Gitlab::SafeRequestStore[:capturing_flamegraph] = true
require 'stackprof'
begin
flamegraph = ::StackProf.run(
mode: :wall,
raw: true,
aggregate: false,
interval: ::Gitlab::StackProf::DEFAULT_INTERVAL_US
) do
_, _, body = @app.call(env)
end
ensure
body.close if body.respond_to?(:close)
end
render_flamegraph(flamegraph, request)
end
private
def rendering_flamegraph?(request)
request.params['performance_bar'] == 'flamegraph' && ::Gitlab::PerformanceBar.allowed_for_user?(request.env['warden']&.user)
end
def render_flamegraph(graph, request)
headers = { 'Content-Type' => 'text/html' }
path = request.env['PATH_INFO'].sub('//', '/')
speedscope_path = ::Gitlab::Utils.append_path(::Gitlab.config.gitlab.relative_url_root, '/-/speedscope/index.html')
html = <<~HTML
HTML
[200, headers, [html]]
end
end
end
end