add benchmark rake task

Rakefile

@@ -19,6 +19,8 @@ CLEAN.include FileList['**/*{.o,.so,.dylib,.bundle}'],
               FileList['**/Makefile'],
               FileList['pkg/']
 
+Rake.add_rakelib 'tasks'
+
 desc 'Default: run specs'
 task default: [:spec]
 

tasks/benchmark.rake

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+require 'benchmark/memory'
+require 'benchmark/ips'
+require 'prometheus/client'
+
+namespace :benchmark do
+  task :increment do
+    counter = Prometheus::Client::Counter.new(:counter, 'Benchmark counter')
+
+    Benchmark.memory do |x|
+      x.report('counter.increment') { counter.increment }
+      x.report('counter.increment(exemplars)') { counter.increment({}, 1, 'trace_id', '123') }
+
+      x.compare!
+    end
+
+    Benchmark.ips do |x|
+      x.report('counter.increment') { counter.increment }
+      x.report('counter.increment(exemplars)') { counter.increment({}, 1, 'trace_id', '123') }
+
+      x.compare!
+    end
+  end
+end