Benchmark the perf difference with a load path of different sizes.

Author: myronmarston

benchmarks/boot_time_with_many_load_path_dirs.sh

@@ -0,0 +1,123 @@
+ruby -v
+
+function run_benchmark_with_load_path_size {
+  pushd tmp
+  mkdir -p boot_time_benchmark
+
+  local load_path_size=$1
+  for (( i=0; i < $load_path_size; i++ )); do
+    mkdir -p "boot_time_benchmark/dir_$i"
+  done
+
+  local load_path=`ruby -e 'puts Array.new(Integer(ARGV.first)) { |i| "boot_time_benchmark/dir_#{i}" }.join(":")' $load_path_size`
+
+  echo "3 runs with $load_path_size dirs on load path, booting 50 times, using $2"
+  for i in {1..3}; do
+    time (for i in {1..50}; do ruby -I$load_path:../lib:../../rspec-support/lib -e 'require "rspec/core"'; done)
+  done
+  popd
+}
+
+run_benchmark_with_load_path_size 10   "require"
+run_benchmark_with_load_path_size 100  "require"
+run_benchmark_with_load_path_size 1000 "require"
+
+export REQUIRE_RELATIVE=1
+
+run_benchmark_with_load_path_size 10   "require_relative"
+run_benchmark_with_load_path_size 100  "require_relative"
+run_benchmark_with_load_path_size 1000 "require_relative"
+
+: <<'result_comment'
+ruby 2.0.0p247 (2013-06-27 revision 41674) [x86_64-darwin12.4.0]
+~/code/rspec-core/tmp ~/code/rspec-core
+3 runs with 10 dirs on load path, booting 50 times, using require
+
+real  0m3.815s
+user  0m3.205s
+sys 0m0.519s
+
+real  0m3.850s
+user  0m3.234s
+sys 0m0.527s
+
+real  0m3.840s
+user  0m3.225s
+sys 0m0.525s
+~/code/rspec-core
+~/code/rspec-core/tmp ~/code/rspec-core
+3 runs with 100 dirs on load path, booting 50 times, using require
+
+real  0m5.086s
+user  0m3.887s
+sys 0m1.107s
+
+real  0m5.063s
+user  0m3.870s
+sys 0m1.098s
+
+real  0m5.061s
+user  0m3.871s
+sys 0m1.097s
+~/code/rspec-core
+~/code/rspec-core/tmp ~/code/rspec-core
+3 runs with 1000 dirs on load path, booting 50 times, using require
+
+real  0m18.850s
+user  0m11.057s
+sys 0m7.679s
+
+real  0m18.783s
+user  0m11.012s
+sys 0m7.657s
+
+real  0m18.747s
+user  0m10.992s
+sys 0m7.639s
+~/code/rspec-core
+~/code/rspec-core/tmp ~/code/rspec-core
+3 runs with 10 dirs on load path, booting 50 times, using require_relative
+
+real  0m3.794s
+user  0m3.200s
+sys 0m0.506s
+
+real  0m3.769s
+user  0m3.180s
+sys 0m0.502s
+
+real  0m3.787s
+user  0m3.192s
+sys 0m0.502s
+~/code/rspec-core
+~/code/rspec-core/tmp ~/code/rspec-core
+3 runs with 100 dirs on load path, booting 50 times, using require_relative
+
+real  0m4.626s
+user  0m3.620s
+sys 0m0.910s
+
+real  0m4.652s
+user  0m3.642s
+sys 0m0.915s
+
+real  0m4.678s
+user  0m3.662s
+sys 0m0.924s
+~/code/rspec-core
+~/code/rspec-core/tmp ~/code/rspec-core
+3 runs with 1000 dirs on load path, booting 50 times, using require_relative
+
+real  0m14.400s
+user  0m8.615s
+sys 0m5.675s
+
+real  0m14.495s
+user  0m8.672s
+sys 0m5.711s
+
+real  0m14.541s
+user  0m8.705s
+sys 0m5.727s
+~/code/rspec-core
+result_comment