From 4648267b62c3ac64a39b1437b468af7de0bb3c08 Mon Sep 17 00:00:00 2001
From: Akira Matsuda <ronnie@dio.jp>
Date: Sun, 4 Jan 2026 11:05:08 +0900
Subject: [PATCH 1/3] Cache root_id per Message

maybe we'd better store this in messages table, but let's do in-memory
for now...
---
 app/controllers/messages_controller.rb | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/app/controllers/messages_controller.rb b/app/controllers/messages_controller.rb
index 38e843a..e7686e8 100644
--- a/app/controllers/messages_controller.rb
+++ b/app/controllers/messages_controller.rb
@@ -39,20 +39,21 @@ def show(list_name:, list_seq:)
   private
 
   def calculate_navigation_links
-    # Find root of current thread
-    root = @message
-    while root.parent_id
-      root = Message.find(root.parent_id)
+    # Find root of current thread (cached)
+    root_id = Rails.cache.fetch("message:#{@message.id}:root_id") do
+      root = @message
+      root = Message.find(root.parent_id) while root.parent_id
+      root.id
     end
 
     # Find previous/next thread (root messages)
-    @prev_thread_seq = Message.where(list_id: @list, parent_id: nil).where('id < ?', root.id).order(id: :desc).pick(:list_seq)
-    @next_thread_seq = Message.where(list_id: @list, parent_id: nil).where('id > ?', root.id).order(:id).pick(:list_seq)
+    @prev_thread_seq = Message.where(list_id: @list, parent_id: nil).where('id < ?', root_id).order(id: :desc).pick(:list_seq)
+    @next_thread_seq = Message.where(list_id: @list, parent_id: nil).where('id > ?', root_id).order(:id).pick(:list_seq)
 
     # Get all messages in this thread
     thread_messages = Message.with_recursive(
       thread_msgs: [
-        Message.where(id: root.id),
+        Message.where(id: root_id),
         Message.joins('inner join thread_msgs on messages.parent_id = thread_msgs.id')
       ]
     ).joins('inner join thread_msgs on thread_msgs.id = messages.id').order(:id).pluck(:id, :list_seq)

From 60e134810dcba3cf3114c7cc2179be4c336926cd Mon Sep 17 00:00:00 2001
From: Akira Matsuda <ronnie@dio.jp>
Date: Sun, 4 Jan 2026 11:14:12 +0900
Subject: [PATCH 2/3] Cache thread query

---
 app/controllers/messages_controller.rb | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/app/controllers/messages_controller.rb b/app/controllers/messages_controller.rb
index e7686e8..b55fec4 100644
--- a/app/controllers/messages_controller.rb
+++ b/app/controllers/messages_controller.rb
@@ -50,13 +50,15 @@ def calculate_navigation_links
     @prev_thread_seq = Message.where(list_id: @list, parent_id: nil).where('id < ?', root_id).order(id: :desc).pick(:list_seq)
     @next_thread_seq = Message.where(list_id: @list, parent_id: nil).where('id > ?', root_id).order(:id).pick(:list_seq)
 
-    # Get all messages in this thread
-    thread_messages = Message.with_recursive(
-      thread_msgs: [
-        Message.where(id: root_id),
-        Message.joins('inner join thread_msgs on messages.parent_id = thread_msgs.id')
-      ]
-    ).joins('inner join thread_msgs on thread_msgs.id = messages.id').order(:id).pluck(:id, :list_seq)
+    # Get all messages in this thread (cached)
+    thread_messages = Rails.cache.fetch("thread:#{root_id}:messages") do
+      Message.with_recursive(
+        thread_msgs: [
+          Message.where(id: root_id),
+          Message.joins('inner join thread_msgs on messages.parent_id = thread_msgs.id')
+        ]
+      ).joins('inner join thread_msgs on thread_msgs.id = messages.id').order(:id).pluck(:id, :list_seq)
+    end
 
     # Find previous/next message in thread
     current_index = thread_messages.index {|(id, _)| id == @message.id }

From 7151af8e7e399153f7e108dec89c8ee29bcb5857 Mon Sep 17 00:00:00 2001
From: Akira Matsuda <ronnie@dio.jp>
Date: Sun, 4 Jan 2026 22:51:34 +0900
Subject: [PATCH 3/3] Cache YYYYMM list per mailing list

---
 app/controllers/messages_controller.rb | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/app/controllers/messages_controller.rb b/app/controllers/messages_controller.rb
index b55fec4..8b90eee 100644
--- a/app/controllers/messages_controller.rb
+++ b/app/controllers/messages_controller.rb
@@ -72,7 +72,10 @@ def render_threads(yyyymm: nil, q: nil)
     if q
       root_query.where!('body %> ?', q)
     else
-      @yyyymms = Message.distinct.where(list_id: @list, parent_id: nil).order('yyyymm').pluck('yyyymm')
+      # Cache YYYYMM list per mailing list
+      @yyyymms = Rails.cache.fetch("list:#{@list.id}:yyyymms") do
+        Message.distinct.where(list_id: @list, parent_id: nil).order('yyyymm').pluck('yyyymm')
+      end
       @yyyymm = yyyymm || @yyyymms.last
       root_query.where!(yyyymm: @yyyymm)
     end