BugTrack2/83: Overhaul: O(N) => O(1).

* 1000 unique-host-get-3-pages causes 3000 writes => 1000 writes + 2000 reads.
* Four crawler-get-300-pages causes 1200 writes => 4 writes + 1196 reads.
* 100 online plugin in a page causes 100 writes => 1 write + 99 caches

diff --git a/plugin/online.inc.php b/plugin/online.inc.php
index 9d6dad1..c446a2e 100644 (file)
--- a/plugin/online.inc.php
+++ b/plugin/online.inc.php
@@ -1,53 +1,156 @@
 <?php
-/////////////////////////////////////////////////
-// PukiWiki - Yet another WikiWikiWeb clone.
-//
-// $Id: online.inc.php,v 1.8 2004/03/18 10:02:13 arino Exp $
+// $Id: online.inc.php,v 1.9 2005/06/25 10:03:20 henoheno Exp $
+// Copyright (C)
+//   2002-2005 PukiWiki Developers Team
+//   2001-2002 Originally written by yu-ji
+// License: GPL v2 or (at your option) any later version
 //
+// Online plugin -- Just show the number 'users-on-line'
+
+define('PLUGIN_ONLINE_TIMEOUT', 60 * 5); // Count users in N seconds
+
+// ----
+
+// List of 'IP-address|last-access-time(seconds)'
+define('PLUGIN_ONLINE_USER_LIST', COUNTER_DIR . 'user.dat');
+
+// Regex of 'IP-address|last-access-time(seconds)'
+define('PLUGIN_ONLINE_LIST_REGEX', '/^([^\|]+)\|([0-9]+)$/');
 
-// user list file
-define('USR_LST', COUNTER_DIR.'user.dat');
-// time out sec
-define('TIMEOUT', 300);
+function plugin_online_convert()
+{
+       return plugin_online_itself(0);
+}
 
 function plugin_online_inline()
 {
-       return plugin_online_convert();
+       return plugin_online_itself(1);
 }
-function plugin_online_convert()
+
+function plugin_online_itself($type = 0)
 {
-       if (!file_exists(USR_LST))
-       {
-               $nf = fopen(USR_LST, 'w');
-               fclose($nf);
+       static $count, $result, $base;
+
+       if (! isset($count)) {
+               if (isset($_SERVER['REMOTE_ADDR'])) {
+                       $host  = & $_SERVER['REMOTE_ADDR'];
+               } else {
+                       $host  = '';
+               }
+
+               // Try read
+               if (plugin_online_check_online(& $count, $host)) {
+                       $result = TRUE;
+               } else {
+                       // Write
+                       $result = plugin_online_sweep_records($host);
+               }
+       }
+
+       if ($result) {
+               return $count; // Integer
+       } else {
+               if (! isset($base)) $base = basename(PLUGIN_ONLINE_USER_LIST);
+               $error = '"COUNTER_DIR/' . $base . '" not writable';
+               if ($type == 0) {
+                       $error = '#online: ' . $error . '<br />' . "\n";
+               } else {
+                       $error = '&online: ' . $error . ';';
+               }
+               return $error; // String
        }
-       CheckUser($_SERVER['REMOTE_ADDR']);
-       return UserCount();
 }
 
-function CheckUser($addr)
+// Check I am already online (recorded and not time-out)
+// & $count == Number of online users
+function plugin_online_check_online(& $count, $host = '')
 {
-       $usr_arr = file(USR_LST);
-       $fp = fopen(USR_LST, 'w');
+       if (! file_exists(PLUGIN_ONLINE_USER_LIST) &&
+           ! @touch(PLUGIN_ONLINE_USER_LIST))
+               return FALSE;
+
+       // Open
+       $fp = @fopen(PLUGIN_ONLINE_USER_LIST, 'r');
+       if ($fp == FALSE) return FALSE;
        set_file_buffer($fp, 0);
-       flock($fp,LOCK_EX);
-       rewind($fp);
-       $now = UTIME;
-       for ($i = 0; $i < count($usr_arr); $i++)
-       {
-               list($ip_addr,$tim_stmp) = explode('|', $usr_arr[$i]);
-               if (($now - $tim_stmp) < TIMEOUT and $ip_addr != $addr)
-               {
-                       fputs($fp, "$ip_addr|$tim_stmp");
-               }
+
+       // Init
+       $count   = 0;
+       $found   = FALSE;
+       $matches = array();
+
+       flock($fp, LOCK_SH);
+
+       // Read
+       while (! feof($fp)) {
+               $line = fgets($fp, 512);
+               if ($line === FALSE) continue;
+
+               // Ignore invalid-or-outdated lines
+               if (! preg_match(PLUGIN_ONLINE_LIST_REGEX, $line, $matches) ||
+                   ($matches[2] + PLUGIN_ONLINE_TIMEOUT) <= UTIME ||
+                   $matches[2] > UTIME) continue;
+
+               ++$count;
+               if (! $found && $matches[1] == $host) $found = TRUE;
        }
-       fputs($fp, "$addr|$now\n");
-       flock($fp,LOCK_UN);
-       fclose($fp);
+
+       flock($fp, LOCK_UN);
+
+       if(! fclose($fp)) return FALSE;
+
+       if (! $found && $host != '') ++$count; // About you
+
+       return $found;
 }
 
-function UserCount()
+// Cleanup outdated records, Add/Replace new record, Return the number of 'users in N seconds'
+// NOTE: Call this when plugin_online_check_online() returnes FALSE
+function plugin_online_sweep_records($host = '')
 {
-       return count(file(USR_LST));
+       // Open
+       $fp = @fopen(PLUGIN_ONLINE_USER_LIST, 'r+');
+       if ($fp == FALSE) return FALSE;
+       set_file_buffer($fp, 0);
+
+       flock($fp, LOCK_EX);
+
+       // Read to check
+       $lines = @file(PLUGIN_ONLINE_USER_LIST);
+       if ($lines === FALSE) $lines = array();
+
+       // Need modify?
+       $line_count = $count = count($lines);
+       $matches = array();
+       $dirty   = FALSE;
+       for ($i = 0; $i < $line_count; $i++) {
+               if (! preg_match(PLUGIN_ONLINE_LIST_REGEX, $lines[$i], $matches) ||
+                   ($matches[2] + PLUGIN_ONLINE_TIMEOUT) <= UTIME ||
+                   $matches[2] > UTIME ||
+                   $matches[1] == $host) {
+                       unset($lines[$i]); // Invalid or outdated or invalid date
+                       --$count;
+                       $dirty = TRUE;
+               }
+       }
+       if ($host != '' ) {
+               // Add new, at the top of the record
+               array_unshift($lines, strtr($host, "\n", '') . '|' . UTIME . "\n");
+               ++$count;
+               $dirty = TRUE;
+       }
+
+       if ($dirty) {
+               // Write
+               if (! ftruncate($fp, 0)) return FALSE;
+               rewind($fp);
+               fputs($fp, join('', $lines));
+       }
+
+       flock($fp, LOCK_UN);
+
+       if(! fclose($fp)) return FALSE;
+
+       return $count; // Number of lines == Number of users online
 }
 ?>