From ad997093a31baedd299476b4f23bcf3d96fa8b29 Mon Sep 17 00:00:00 2001
From: Takashi Kokubun <takashikkbn@gmail.com>
Date: Wed, 2 Nov 2022 17:28:37 -0700
Subject: [PATCH] Collect C method stats on railsbench

---
 benchmarks/railsbench/benchmark.rb | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/benchmarks/railsbench/benchmark.rb b/benchmarks/railsbench/benchmark.rb
index 4ccbd159..b61b4531 100644
--- a/benchmarks/railsbench/benchmark.rb
+++ b/benchmarks/railsbench/benchmark.rb
@@ -21,6 +21,21 @@
 rng = Random.new(0x1be52551fc152997)
 visiting_routes = Array.new(visit_count) { possible_routes.sample(random: rng) }
 
+c_calls = Hash.new { 0 }
+c_loops = Hash.new { 0 }
+
+TracePoint.new(:c_call) do |tp|
+  method_name = "#{tp.defined_class}##{tp.method_id}"
+  c_calls[method_name] += 1
+
+  case tp.method_id
+  when /(\A|_)each(_|\z)/, /(\A|_)map\!?\z/
+    c_loops[method_name] += tp.self.size if tp.self.respond_to?(:size)
+  when 'times'
+    c_loops[method_name] += Integer(tp.self)
+  end
+end.enable
+
 run_benchmark(10) do
   visiting_routes.each do |path|
     # The app mutates `env`, so we need to create one every time.
@@ -31,3 +46,14 @@
     end
   end
 end
+
+puts "Top C loop method iterations:"
+c_loops.sort_by(&:last).reverse_each do |method, count|
+  puts '%8d %s' % [count, method]
+end
+puts
+
+puts "Top 100 C method calls:"
+c_calls.sort_by(&:last).reverse[0...100].each do |method, count|
+  puts '%8d %s' % [count, method]
+end