From 9eac89cf6d7fd75dabfba8201cebf85cbeb7c8b1 Mon Sep 17 00:00:00 2001
From: Pierre Martin <pierre@front-commerce.com>
Date: Mon, 8 Mar 2021 15:40:45 +0100
Subject: [PATCH] Better illustrate the purpose

---
 web/compromise.php    |  9 +++++++++
 web/index.php         | 10 ++++++++--
 web/slow-but-fast.php |  4 ++--
 web/slow.php          |  2 +-
 4 files changed, 20 insertions(+), 5 deletions(-)
 create mode 100644 web/compromise.php

diff --git a/web/compromise.php b/web/compromise.php
new file mode 100644
index 0000000..3fd794b
--- /dev/null
+++ b/web/compromise.php
@@ -0,0 +1,9 @@
+<?php
+header('Cache-Control: s-max-age=60, stale-while-revalidate=82800');
+sleep(5);
+print('This is a slow test with data cached for 1 min but updated smartly so that for 23 hours people will experience a fast experience. ' . date('Y-m-d H:i:s'));
+?>
+<p id="js-date"></p>
+<script type="text/javascript">
+  document.getElementById('js-date').innerText = new Date().toISOString();
+</script>
\ No newline at end of file
diff --git a/web/index.php b/web/index.php
index 71f39a2..847f06f 100644
--- a/web/index.php
+++ b/web/index.php
@@ -1,11 +1,17 @@
 <?php
-header('Cache-Control: s-max-age=10, stale-while-revalidate=20');
+// First visit -> 5s, times match
+// Second visit -> instant, times don't match
+// … T+14 -> instant, times don't match
+// … T+15 (or 16) -> instant, times match (or almost)
+// Nothing for 30s -> 5s, times match
+header('Cache-Control: s-max-age=60, stale-while-revalidate=20');
 sleep(5);
-print('This is a slow test. ' . date('Y-m-d H:i:s'));
+print('This is a slow test with data cached for 10s but updated smartly. ' . date('Y-m-d H:i:s'));
 ?>
 <ul>
   <li><a href="./slow.php">Slow</a></li>
   <li><a href="./slow-but-fast.php">Slow but fast</a></li>
+  <li><a href="./compromise.php">A good compromise to deal with slow pages fast</a></li>
 </ul>
 <p id="js-date"></p>
 <script type="text/javascript">
diff --git a/web/slow-but-fast.php b/web/slow-but-fast.php
index 027920b..825bf47 100644
--- a/web/slow-but-fast.php
+++ b/web/slow-but-fast.php
@@ -1,7 +1,7 @@
 <?php
-header('Cache-Control: s-max-age=1, stale-while-revalidate=20');
+header('Cache-Control: s-max-age=1, stale-while-revalidate=99999999');
 sleep(5);
-print('This is a slow instant test. ' . date('Y-m-d H:i:s'));
+print('This is a slow test with as fresh data as possible. ' . date('Y-m-d H:i:s'));
 ?>
 <p id="js-date"></p>
 <script type="text/javascript">
diff --git a/web/slow.php b/web/slow.php
index 897bfdf..6ef1a0e 100644
--- a/web/slow.php
+++ b/web/slow.php
@@ -1,7 +1,7 @@
 <?php
 header('Cache-Control: s-max-age=10');
 sleep(5);
-print('This is a slow instant test. ' . date('Y-m-d H:i:s'));
+print('This is a slow test with 10s caching. ' . date('Y-m-d H:i:s'));
 ?>
 <p id="js-date"></p>
 <script type="text/javascript">