Limit the max number of keys when scanning (#206)

* Add parameter scan_max

* Limit the max number of keys when scanning

* Rename parameter scan_max to scanmax

Author: LeoHsiao1

includes/config.environment.inc.php

@@ -11,6 +11,7 @@
 $config['keys']                    = getenv('KEYS')                        ?: false;
 $config['maxkeylen']               = getenv('MAX_KEY_LEN')                 ?: 100;
 $config['scansize']                = getenv('SCAN_SIZE')                   ?: 1000;
+$config['scanmax']                 = getenv('SCAN_MAX')                    ?: 1000;
 $config['seperator']               = getenv('SEPERATOR')                   ?: ':';
 $config['showEmptyNamespaceAsKey'] = getenv('SHOW_EMPTY_NAMESPACE_AS_KEY') ?: false;
 
@@ -64,6 +65,7 @@
       'port'     => $server_port,
       'filter'   => $config['filter'],
       'scansize' => $config['scansize'],
+      'scanmax'  => $config['scanmax'],
   );
 
   if (!empty($server_auth)) {

includes/config.sample.inc.php

@@ -32,7 +32,8 @@
       'flush'     => false,         // Set to true to enable the flushdb button for this instance.
       'charset'   => 'cp1251',      // Keys and values are stored in redis using this encoding (default utf-8).
       'keys'      => false,         // Use the old KEYS command instead of SCAN to fetch all keys for this server (default uses config default).
-      'scansize'  => 1000           // How many entries to fetch using each SCAN command for this server (default uses config default).
+      'scansize'  => 1000,          // How many entries to fetch using each SCAN command for this server (default uses config default).
+      'scanmax'   => 1000,          // In each query, SCAN command may be executed several times. To shorten the duration, it is recommended to limit the total number of entries to fetch.
     ),*/
   ),
 

index.php

@@ -17,6 +17,10 @@
             $next = $r[0];
             $keys = array_merge($keys, $r[1]);
 
+            if (count($keys) >= $server['scanmax']) {
+                break;
+            }
+
             if ($next == 0) {
                 break;
             }