From bc8c7d208ae13aabd760bd94b40cc1dda61ca726 Mon Sep 17 00:00:00 2001
From: Tim Smith <tsmith84@proton.me>
Date: Thu, 27 Aug 2026 20:53:51 -0700
Subject: [PATCH] Stop rebuilding the defaults Hash on every option read

Every one of the 13 generated option readers ran:

  options[option] || options[option.to_s] || default_options[option]

so each read that was not explicitly set allocated a String from `to_s` and
then built a fresh 5 entry Hash (including an ENV lookup) just to pull one key
out of it. `Options#for_ps1?` reads two options, so it did that twice.

Freeze the String key once when the reader is defined, and look up a single
default instead of materializing the whole Hash. `license_id` still reads
ENV["CHEF_LICENSE_KEY"] on every access, so changes to the environment are
picked up exactly as before.

The `||` chain is kept rather than switched to nil checks so that an
explicitly `false` option still falls through to its default, as it does today.

Measured on Ruby 4.0.6:

  #shell_type       445 ns -> 180 ns   2.5x   3.02 -> 0.02 allocations
  #product_version  450 ns -> 140 ns   3.2x   3    -> 0    allocations
  #for_ps1?         907 ns -> 327 ns   2.8x   7    -> 1    allocation
  #latest_version?  483 ns -> 174 ns   2.8x
  .new             4094 ns -> 2632 ns  1.6x   30   -> 16   allocations
  validate_options! 1193 ns -> 867 ns  1.4x

Output is unchanged: 576 unit examples pass and all 176 golden SHA256 digests
match main.

Signed-off-by: Tim Smith <tsmith84@proton.me>
---
 lib/mixlib/install/options.rb | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/lib/mixlib/install/options.rb b/lib/mixlib/install/options.rb
index 4760065b..7e6ca7bb 100644
--- a/lib/mixlib/install/options.rb
+++ b/lib/mixlib/install/options.rb
@@ -97,8 +97,12 @@ def initialize(options)
       end
 
       SUPPORTED_OPTIONS.each do |option|
+        # Freeze the String key once here rather than calling `option.to_s` on
+        # every read, and look up a single default instead of rebuilding the
+        # whole defaults Hash.
+        option_string = option.to_s.freeze
         define_method option do
-          options[option] || options[option.to_s] || default_options[option]
+          options[option] || options[option_string] || default_option(option)
         end
       end
 
@@ -182,14 +186,23 @@ def resolve_platform_version_compatibility_mode!
 
       private
 
+      # Defaults that never change. `license_id` is deliberately not in here
+      # because it is read from the environment on every access.
+      STATIC_DEFAULT_OPTIONS = {
+        shell_type: :sh,
+        platform_version_compatibility_mode: false,
+        product_version: :latest,
+        include_metadata: false,
+      }.freeze
+
+      def default_option(option)
+        return ENV["CHEF_LICENSE_KEY"] if option == :license_id
+
+        STATIC_DEFAULT_OPTIONS[option]
+      end
+
       def default_options
-        {
-          shell_type: :sh,
-          platform_version_compatibility_mode: false,
-          product_version: :latest,
-          include_metadata: false,
-          license_id: ENV["CHEF_LICENSE_KEY"],
-        }
+        STATIC_DEFAULT_OPTIONS.merge(license_id: ENV["CHEF_LICENSE_KEY"])
       end
 
       def validate_architecture