From 222040f82de941792736c7bb7fb21c68a7f13b0b Mon Sep 17 00:00:00 2001
From: justindossey <jbd@justindossey.com>
Date: Tue, 25 May 2010 14:34:47 -0700
Subject: [PATCH] Added Set for use in membership tests, optimizing out the
 expensive call to Array#include?

---
 lib/bson/ordered_hash.rb | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/lib/bson/ordered_hash.rb b/lib/bson/ordered_hash.rb
index 3968500..009fbc1 100644
--- a/lib/bson/ordered_hash.rb
+++ b/lib/bson/ordered_hash.rb
@@ -20,6 +20,8 @@
 #
 # Under Ruby 1.9 and greater, this class has no added methods because Ruby's
 # Hash already keeps its keys ordered by order of insertion.
+require 'set'
+
 module BSON
   class OrderedHash < Hash
 
@@ -55,6 +57,7 @@ module BSON
       def initialize(*a, &b)
         super
         @ordered_keys = []
+        @ordered_set = Set.new
       end
 
       def keys
@@ -63,7 +66,11 @@ module BSON
 
       def []=(key, value)
         @ordered_keys ||= []
-        @ordered_keys << key unless @ordered_keys.include?(key)
+        @ordered_set ||= Set.new
+        unless @ordered_set.member?(key)
+          @ordered_keys << key
+          @ordered_set.add(key)
+        end
         super(key, value)
       end
 
@@ -93,6 +100,7 @@ module BSON
         @ordered_keys ||= []
         @ordered_keys += other.keys # unordered if not an BSON::OrderedHash
         @ordered_keys.uniq!
+        @ordered_set = Set.new(@ordered_keys)
         super(other)
       end
 
@@ -106,6 +114,7 @@ module BSON
 
       def delete(key, &block)
         @ordered_keys.delete(key) if @ordered_keys
+        @ordered_set.delete(key) if @ordered_set
         super
       end
 
@@ -119,6 +128,7 @@ module BSON
 
       def clear
         super
+        @ordered_set.clear
         @ordered_keys = []
       end