From 7eca14987bf2df02836c5d405d16c2e8eb82e42b Mon Sep 17 00:00:00 2001
From: pranavbabu <54139019+pranavbabu@users.noreply.github.com>
Date: Fri, 18 Jul 2025 21:05:45 +0200
Subject: [PATCH] Improve performance of find_by_iso_numeric method
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ruby 3.3.3 (2024-06-12 revision f1c7b6f435) [arm64-darwin23]
Warming up --------------------------------------
 Before optimization     2.135k i/100ms
  After optimization    55.681k i/100ms
Calculating -------------------------------------
 Before optimization     21.148k (± 0.8%) i/s   (47.29 μs/i) -    106.750k in   5.048173s
  After optimization    549.315k (± 0.6%) i/s    (1.82 μs/i) -      2.784M in   5.068425s

Comparison:
  After optimization:   549314.7 i/s
 Before optimization:    21147.5 i/s - 25.98x  slower
---
 lib/money/currency.rb | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/lib/money/currency.rb b/lib/money/currency.rb
index f8b2a1d5df..db4f7062ef 100644
--- a/lib/money/currency.rb
+++ b/lib/money/currency.rb
@@ -83,8 +83,8 @@ def find(id)
       def find_by_iso_numeric(num)
         num = num.to_s.rjust(3, '0')
         return if num.empty?
-        id, _ = self.table.find { |key, currency| currency[:iso_numeric] == num }
-        new(id)
+        id = iso_numeric_index[num]
+        new(id) if id
       rescue UnknownCurrency
         nil
       end
@@ -215,6 +215,12 @@ def reset!
       end
 
       private
+            
+      def iso_numeric_index
+        @iso_numeric_index ||= table.each_with_object({}) do |(id, attrs), index|
+          index[attrs[:iso_numeric]] = id
+        end
+      end
 
       def stringify_keys
         table.keys.each_with_object(Set.new) { |k, set| set.add(k.to_s.downcase) }