From 0529467402781af1b15797facd952dc45413ba8d Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 6 Oct 2023 09:32:21 +0900
Subject: [PATCH 1/4] refactor: move logic for "Update the performance metrics"

---
 system/CodeIgniter.php | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/system/CodeIgniter.php b/system/CodeIgniter.php
index d854dac5ec11..48cb8595aad7 100644
--- a/system/CodeIgniter.php
+++ b/system/CodeIgniter.php
@@ -535,13 +535,6 @@ protected function handleRequest(?RouteCollectionInterface $routes, Cache $cache
             // Must be run after filters to preserve the Response headers.
             $this->pageCache->make($this->request, $this->response);
 
-            // Update the performance metrics
-            $body = $this->response->getBody();
-            if ($body !== null) {
-                $output = $this->displayPerformanceMetrics($body);
-                $this->response->setBody($output);
-            }
-
             // Save our current URI as the previous URI in the session
             // for safer, more accurate use with `previous_url()` helper function.
             $this->storePreviousURL(current_url(true));
@@ -1098,6 +1091,13 @@ public function spoofRequestMethod()
      */
     protected function sendResponse()
     {
+        // Update the performance metrics
+        $body = $this->response->getBody();
+        if ($body !== null) {
+            $output = $this->displayPerformanceMetrics($body);
+            $this->response->setBody($output);
+        }
+
         $this->response->send();
     }
 

From 12e724518692cc08f270a9b636a4610c8727b3ea Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 6 Oct 2023 09:39:49 +0900
Subject: [PATCH 2/4] feat: implement {memory_usage} replacement

It was in CI3.
https://codeigniter.com/userguide3/libraries/benchmark.html#displaying-memory-consumption
---
 system/CodeIgniter.php | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/system/CodeIgniter.php b/system/CodeIgniter.php
index 48cb8595aad7..daa8f26c47ba 100644
--- a/system/CodeIgniter.php
+++ b/system/CodeIgniter.php
@@ -773,11 +773,15 @@ protected function generateCacheName(Cache $config): string
     }
 
     /**
-     * Replaces the elapsed_time tag.
+     * Replaces the elapsed_time and memory_usage tag.
      */
     public function displayPerformanceMetrics(string $output): string
     {
-        return str_replace('{elapsed_time}', (string) $this->totalTime, $output);
+        return str_replace(
+            ['{elapsed_time}', '{memory_usage}'],
+            [(string) $this->totalTime, number_format(memory_get_peak_usage() / 1024 / 1024, 3)],
+            $output
+        );
     }
 
     /**

From b4a1e524cd0ca44226d75a3e27685ae6bd92756e Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 6 Oct 2023 09:41:17 +0900
Subject: [PATCH 3/4] feat: show memory usage in Welcome page

---
 app/Views/welcome_message.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/Views/welcome_message.php b/app/Views/welcome_message.php
index 6d5da23f1224..396f7f44d3fe 100644
--- a/app/Views/welcome_message.php
+++ b/app/Views/welcome_message.php
@@ -292,7 +292,7 @@
 <footer>
     <div class="environment">
 
-        <p>Page rendered in {elapsed_time} seconds</p>
+        <p>Page rendered in {elapsed_time} seconds using {memory_usage} MB of memory.</p>
 
         <p>Environment: <?= ENVIRONMENT ?></p>
 

From f515488665033a94004552441313733a02f16748 Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Mon, 9 Oct 2023 08:18:46 +0900
Subject: [PATCH 4/4] docs: add changelog

---
 user_guide_src/source/changelogs/v4.5.0.rst | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/user_guide_src/source/changelogs/v4.5.0.rst b/user_guide_src/source/changelogs/v4.5.0.rst
index f109180c8009..0b0c22a0432e 100644
--- a/user_guide_src/source/changelogs/v4.5.0.rst
+++ b/user_guide_src/source/changelogs/v4.5.0.rst
@@ -119,6 +119,8 @@ Others
 - **Autoloader:** Autoloading performance when using Composer has been improved.
   Adding the ``App`` namespace in the ``autoload.psr4`` setting in **composer.json**
   may also improve the performance of your app. See :ref:`autoloader-application-namespace`.
+- **CodeIgniter:** Added a pseudo-variable ``{memory_usage}`` to show your memory
+  usage in your view files, which was supported by CodeIgniter 3.
 
 Message Changes
 ***************