From 75c901a111566b6e74b09a3c267c3d578142888d Mon Sep 17 00:00:00 2001
From: jokob-sk <jokob.sk@gmail.com>
Date: Fri, 5 Aug 2022 15:26:28 +1000
Subject: [PATCH] Optimisation no 4: cache device totals for 5min

---
 front/php/server/devices.php | 56 +++++++++++++++++++++++++++---------
 1 file changed, 43 insertions(+), 13 deletions(-)

diff --git a/front/php/server/devices.php b/front/php/server/devices.php
index 9600a225..a45f587e 100644
--- a/front/php/server/devices.php
+++ b/front/php/server/devices.php
@@ -478,22 +478,35 @@ function PiaToggleArpScan() {
 //  Query total numbers of Devices by status
 //------------------------------------------------------------------------------
 function getDevicesTotals() {
-  global $db;
 
-  // combined query
-  $result = $db->query(
-        'SELECT 
-        (SELECT COUNT(*) FROM Devices '. getDeviceCondition ('all').') as devices, 
-        (SELECT COUNT(*) FROM Devices '. getDeviceCondition ('connected').') as connected, 
-        (SELECT COUNT(*) FROM Devices '. getDeviceCondition ('favorites').') as favorites, 
-        (SELECT COUNT(*) FROM Devices '. getDeviceCondition ('new').') as new, 
-        (SELECT COUNT(*) FROM Devices '. getDeviceCondition ('down').') as down, 
-        (SELECT COUNT(*) FROM Devices '. getDeviceCondition ('archived').') as archived
-   ');
+  $resultJSON = "";
 
-  $row = $result -> fetchArray (SQLITE3_NUM);   
+  if(getCache("getDevicesTotals") != "")
+  {
+    $resultJSON = getCache("getDevicesTotals");
+  } else
+  {
+    global $db;
 
-  echo (json_encode (array ($row[0], $row[1], $row[2], $row[3], $row[4], $row[5])));
+    // combined query
+    $result = $db->query(
+          'SELECT 
+          (SELECT COUNT(*) FROM Devices '. getDeviceCondition ('all').') as devices, 
+          (SELECT COUNT(*) FROM Devices '. getDeviceCondition ('connected').') as connected, 
+          (SELECT COUNT(*) FROM Devices '. getDeviceCondition ('favorites').') as favorites, 
+          (SELECT COUNT(*) FROM Devices '. getDeviceCondition ('new').') as new, 
+          (SELECT COUNT(*) FROM Devices '. getDeviceCondition ('down').') as down, 
+          (SELECT COUNT(*) FROM Devices '. getDeviceCondition ('archived').') as archived
+    ');
+
+    $row = $result -> fetchArray (SQLITE3_NUM); 
+    $resultJSON = json_encode (array ($row[0], $row[1], $row[2], $row[3], $row[4], $row[5]));
+
+    // save to cache
+    setCache("getDevicesTotals", $resultJSON );
+  }  
+
+  echo ($resultJSON);
 }
 
 
@@ -798,4 +811,21 @@ function getDeviceCondition ($deviceStatus) {
   }
 }
 
+//------------------------------------------------------------------------------
+//  Simple cookie cache
+//------------------------------------------------------------------------------
+function getCache($key) {
+  if( isset($_COOKIE[$key]))
+  {
+    return $_COOKIE[$key];
+  }else
+  {
+    return "";
+  }
+}
+
+function setCache($key, $value) {
+  setcookie($key,  $value, time()+300, "/","", 0); // 5min cache
+}
+
 ?>