Add benchmarks for parsing

Gemfile

@@ -3,6 +3,8 @@ gemspec name: "dotenv"
 gemspec name: "dotenv-rails"
 
 gem "railties", "~> #{ENV["RAILS_VERSION"] || "7.1"}"
+gem "benchmark-ips"
+gem "stackprof"
 
 group :guard do
   gem "guard-rspec"

benchmark/parse_ips.rb

@@ -0,0 +1,15 @@
+require "bundler/setup"
+require "dotenv"
+require "benchmark/ips"
+require "tempfile"
+
+f = Tempfile.create("benchmark_ips.env")
+1000.times.map { |i| f.puts "VAR_#{i}=#{i}" }
+f.close
+
+Benchmark.ips do |x|
+  x.report("parse, overwrite:false") { Dotenv.parse(f.path, overwrite: false) }
+  x.report("parse, overwrite:true") { Dotenv.parse(f.path, overwrite: true) }
+end
+
+File.unlink(f.path)

benchmark/parse_profile.rb

@@ -0,0 +1,23 @@
+require "bundler/setup"
+require "dotenv"
+require "stackprof"
+require "benchmark/ips"
+require "tempfile"
+
+f = Tempfile.create("benchmark_ips.env")
+1000.times.map { |i| f.puts "VAR_#{i}=#{i}" }
+f.close
+
+profile = StackProf.run(mode: :wall, interval: 1_000) do
+  10_000.times do
+    Dotenv.parse(f.path, overwrite: false)
+  end
+end
+
+result = StackProf::Report.new(profile)
+puts
+result.print_text
+puts "\n\n\n"
+result.print_method(/Dotenv.parse/)
+
+File.unlink(f.path)