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Discuz代码分析——index.php

/*

[Discuz!] (C)2001-2007 Comsenz Inc.

This is NOT a freeware, use is subject to license terms

$Id: index.php 13764 2008-05-19 03:14:01Z heyond $

*/

define('CURSCRIPT', 'index');//定义当前运行脚本名

require_once './include/common.inc.php';//引入common文件

require_once DISCUZ_ROOT.'./include/forum.func.php';//引入版块处理函数forum.func.php

$discuz_action = 1;//?

if($cacheindexlife && !$discuz_uid && $showoldetails != 'yes' && (!$_DCACHE['settings']['frameon'] || $_DCACHE['settings']['frameon'] && $_GET['frameon'] != 'yes') && empty($gid)) {

//分析:$cacheindexlife-首页缓存有效期,$discuz_uid存在,$showoldetails-显示在线详情,$_DCACHE['settings']['frameon']-左右分栏模式开关,$gid-版块组id,自己看看吧,大概就是判断是否使用一个静态htm页面的条件,这个由后台是否开启首页缓存时间来决定的

$indexcache = getcacheinfo(0);//得到首页缓存,此函数见include/forum.func.php 157行,主要是处理index.htm

//下面一段就是判断是否过期咯,如果过期,就删除index.htm,否则读取文件,并根据系统配置决定是否显示debug信息

if($timestamp - $indexcache['filemtime'] > $cacheindexlife) {

@unlink($indexcache['filename']);

define('CACHE_FILE', $indexcache['filename']);

$styleid = $_DCACHE['settings']['styleid'];

} elseif($indexcache['filename']) {

@readfile($indexcache['filename']);

$debug && debuginfo();

$debug ? die('<mce:script type="text/javascript"><!--

document.getElementById("debuginfo").innerHTML = " '.($debug ? 'Updated at '.gmdate("H:i:s", $indexcache['filemtime'] + 3600 * 8).', Processed in '.$debuginfo['time'].' second(s), '.$debuginfo['queries'].' Queries'.($gzipcompress ? ', Gzip enabled' : '') : '').'";

// --></mce:script>') : die();

}

}

//$validdays?用户组有效时间?

$validdays = $discuz_uid && !empty($groupexpiry) && $groupexpiry >= $timestamp ? ceil(($groupexpiry - $timestamp) / 86400) : 0;

//是否显示在线情况

if(isset($showoldetails)) {

switch($showoldetails) {

case 'no': dsetcookie('onlineindex', 0, 86400 * 365); break;

case 'yes': dsetcookie('onlineindex', 1, 86400 * 365); break;

}

} else {

$showoldetails = false;

}

$currenttime = gmdate($timeformat, $timestamp + $timeoffset * 3600);//当前时间

$lastvisittime = gmdate("$dateformat $timeformat", $lastvisit + $timeoffset * 3600);//上次访问时间

$memberenc = rawurlencode($lastmember);//最后注册用户-对URL进行了编码

$newthreads = round(($timestamp - $lastvisit + 600) / 1000) * 1000;//这个变量不知道干啥的?

$rsshead = $rssstatus ? ('<link rel="alternate" type="application/rss+xml" title="'.$bbname.'" href="'.$boardurl.'rss.php?auth='.$rssauth." target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" mce_href="'.$boardurl.'rss.php?auth='.$rssauth." target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" /" />/n") : '';//rss的链接

$customtopics = '';

if($qihoo['maxtopics']) {

foreach(explode("/t", isset($_DCOOKIE['customkw']) ? $_DCOOKIE['customkw'] : '') as $topic) {

$topic = dhtmlspecialchars(trim(stripslashes($topic)));

$customtopics .= '<a href="topic.php?keyword='.rawurlencode($topic).'" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" mce_href="topic.php?keyword='.rawurlencode($topic).'" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank">'.$topic.'</a>  ';

}

}//以上两段,qihoo专题?-后台的扩展-qihoo搜索那里可以设置

$hottagstatus = $tagstatus && $hottags && $_DCACHE['tags'];//显示热门标签

$catlist = $forumlist = $sublist = $forumname = $collapseimg = $collapse = array();//初始化区、版块、子版等数组

$threads = $posts = $todayposts = $fids = $announcepm = 0;//初始化帖子、回复、今日回复、版块id等数组

$postdata = $historyposts ? explode("/t", $historyposts) : array();//历史发帖?

foreach(array('forumlinks', 'birthdays') as $key) {//处理友情链接与生日用户的显示

if(!isset($_COOKIE['discuz_collapse']) || strpos($_COOKIE['discuz_collapse'], $key) === FALSE) {

$collapseimg[$key] = 'collapsed_no.gif';

$collapse[$key] = '';

} else {

$collapseimg[$key] = 'collapsed_yes.gif';

$collapse[$key] = 'display: none';

}

}

$gid = !empty($gid) ? intval($gid) : 0;//区显示方式

if(!$gid) {//如果不是区显示方式,即默认的显示所有版块的首页

$announcements = '';//此句与下面一段是处理论坛公告

if($_DCACHE['announcements']) {

$readapmids = !empty($_DCOOKIE['readapmid']) ? explode('D', $_DCOOKIE['readapmid']) : array();

foreach($_DCACHE['announcements'] as $announcement) {

if(empty($announcement['groups']) || in_array($groupid, $announcement['groups'])) {

if(empty($announcement['type'])) {

$announcements .= '<li><a href="announcement.php?id='.$announcement['id'].'" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" mce_href="announcement.php?id='.$announcement['id'].'" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" >'.$announcement['subject'].

'<i>('.gmdate($dateformat, $announcement['starttime'] + $timeoffset * 3600).')</i></a></li>';

} elseif($announcement['type'] == 1) {

$announcements .= '<li><a href="'.$announcement['message'].'" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" mce_href="'.$announcement['message'].'" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank">'.$announcement['subject'].

'<i>('.gmdate($dateformat, $announcement['starttime'] + $timeoffset * 3600).')</i></a></li>';

}

}

}

}

unset($_DCACHE['announcements']);//得到公告的字符串后,及时清空这个公告数组

//选出论坛列表的sql,注意这里判断了是否有访问限制,如果$accessmasks不为空,则根据某用户的特殊访问规则选出了 a.allowview这个字段等

$sql = !empty($accessmasks) ?

"SELECT f.fid, f.fup, f.type, f.name, f.threads, f.posts, f.todayposts, f.lastpost, f.inheritedmod, f.forumcolumns, f.simple, ff.description, ff.moderators, ff.icon, ff.viewperm, ff.redirect, a.allowview FROM {$tablepre}forums f

LEFT JOIN {$tablepre}forumfields ff ON ff.fid=f.fid

LEFT JOIN {$tablepre}access a ON a.uid='$discuz_uid' AND a.fid=f.fid

WHERE f.status>0 ORDER BY f.type, f.displayorder"

: "SELECT f.fid, f.fup, f.type, f.name, f.threads, f.posts, f.todayposts, f.lastpost, f.inheritedmod, f.forumcolumns, f.simple, ff.description, ff.moderators, ff.icon, ff.viewperm, ff.redirect FROM {$tablepre}forums f

LEFT JOIN {$tablepre}forumfields ff USING(fid)

WHERE f.status>0 ORDER BY f.type, f.displayorder";

$query = $db->query($sql);

while($forum = $db->fetch_array($query)) {//从这里开始得到两个重要数组$catlist $forumlist,保存区信息与版块列表信息

$forumname[$forum['fid']] = strip_tags($forum['name']);//去掉html与php标记,并存入$forumname数组,以fid为键

if($forum['type'] != 'group') {//如果是普通版块(如type=forum或forum=sub)而不是分区

$threads += $forum['threads'];//主题总数

$posts += $forum['posts'];//帖子总数(主题与回复)

$todayposts += $forum['todayposts'];//今日帖子

if($forum['type'] == 'forum') {//非最终子版(即type不等于sub和group)的版块

if(forum($forum)) {//forum函数来自include/forum.func.php,处理版块,得到比如版主啊图标啊什么的

$catlist[$forum['fup']]['forums'][] = $forum['fid'];//分区数组$catlist更新

$forum['orderid'] = $catlist[$forum['fup']]['forumscount']++;//得到版块的排序,所在分区的版块总数加1,每得到一个子版,就自增1

$forum['subforums'] = '';//将子版字符串设置为空的,这里不是很明白,forum函数里得到了一个相同名的字符串,这里为何要清空?

$forumlist[$forum['fid']] = $forum;//将$forum数组赋值给$forumlist的一个元素

}

} elseif(isset($forumlist[$forum['fup']])) {//如果此版块的父版块id在$forumlist中存在(由上面的if中得到),则

$forumlist[$forum['fup']]['threads'] += $forum['threads'];

$forumlist[$forum['fup']]['posts'] += $forum['posts'];

$forumlist[$forum['fup']]['todayposts'] += $forum['todayposts'];//累加三个值

if($subforumsindex && $forumlist[$forum['fup']]['permission'] == 2 && !($forumlist[$forum['fup']]['simple'] & 16) || ($forumlist[$forum['fup']]['simple'] & 8)) {

$forumlist[$forum['fup']]['subforums'] .= '<a href="forumdisplay.php?fid='.$forum['fid'].'" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" mce_href="forumdisplay.php?fid='.$forum['fid'].'" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" >'.$forum['name'].'</a>  ';

}//对版块的子版字符串进行处理

}

} else {//否则,如果是分区

if(!isset($_COOKIE['discuz_collapse']) || strpos($_COOKIE['discuz_collapse'], 'category_'.$forum['fid']) === FALSE) {

$forum['collapseimg'] = 'collapsed_no.gif';

$collapse['category_'.$forum['fid']] = '';

} else {

$forum['collapseimg'] = 'collapsed_yes.gif';

$collapse['category_'.$forum['fid']] = 'display: none';

}//上面是对分区开启关闭按钮的处理?

if($forum['moderators']) {

$forum['moderators'] = moddisplay($forum['moderators'], 'flat');

}//区版主

$forum['forumscount'] = 0;

$catlist[$forum['fid']] = $forum;//更新区版块数组

}

}

foreach($catlist as $catid => $category) {//对分区的显示进行处理,如表格宽度,是否横排版块等等

if($catlist[$catid]['forumscount'] && $category['forumcolumns']) {

$catlist[$catid]['forumcolwidth'] = floor(100 / $category['forumcolumns']).'%';

$catlist[$catid]['endrows'] = '';

if($colspan = $category['forumscount'] % $category['forumcolumns']) {

while(($category['forumcolumns'] - $colspan) > 0) {

$catlist[$catid]['endrows'] .= '<td> </td>';

$colspan ++;

}

$catlist[$catid]['endrows'] .= '</tr>';

}

} elseif(empty($category['forumscount'])) {

unset($catlist[$catid]);

}

}

unset($catid, $category);

if(isset($catlist[0]) && $catlist[0]['forumscount']) {//0表示比分区更大一级的一个“虚拟分区”(暂时这么理解,因为有时候url中有fid=0这样的出现)

$catlist[0]['fid'] = 0;

$catlist[0]['type'] = 'group';

$catlist[0]['name'] = $bbname;

$catlist[0]['collapseimg'] = 'collapsed_no.gif';

} else {

unset($catlist[0]);

}

if($whosonlinestatus == 1 || $whosonlinestatus == 3) {//显示在线情况

$whosonlinestatus = 1;

$onlineinfo = explode("/t", $onlinerecord);//$onlineinfo变量,$onlinerecord来自index.php的extract($_DCACHE)处理

if(empty($_DCOOKIE['onlineusernum'])) {

$onlinenum = $db->result_first("SELECT COUNT(*) FROM {$tablepre}sessions");//在线人数

if($onlinenum > $onlineinfo[0]) {//如果当前数据库中取得的在线人数大于原来在线人数,则更新$onlinerecord

$_DCACHE['settings']['onlinerecord'] = $onlinerecord = "$onlinenum/t$timestamp";

$db->query("UPDATE {$tablepre}settings SET value='$onlinerecord' WHERE variable='onlinerecord'");//同时更新settings表

require_once DISCUZ_ROOT.'./include/cache.func.php';

updatesettings();//更新settings缓存

$onlineinfo = array($onlinenum, $timestamp);//更新$onlineinfo数组

}

dsetcookie('onlineusernum', intval($onlinenum), 300);//将在线人数写入cookie

} else {

$onlinenum = intval($_DCOOKIE['onlineusernum']);//如果cookie中在线人数不为空,直接读出

}

$onlineinfo[1] = gmdate($dateformat, $onlineinfo[1] + ($timeoffset * 3600));//更新在线情况的时间戳

$detailstatus = $showoldetails == 'yes' || (((!isset($_DCOOKIE['onlineindex']) && !$whosonline_contract) || $_DCOOKIE['onlineindex']) && $onlinenum < 500 && !$showoldetails);//判断在线详情变量,这里比较复杂,仔细看一下,主要是$showoldetails == 'yes'与cookie中的首页显示啊 一些条件

if($detailstatus) {//以下是处理在线人数列表的

@include language('actions');//引用语言文件 /templates/default/actions.lang.php

$discuz_uid && updatesession();//更新session

$membercount = $invisiblecount = 0;//初始化会员数量及隐身的数量

$whosonline = array();//初始化数组

$maxonlinelist = $maxonlinelist ? $maxonlinelist : 500;//最大在线人数,如果未设置,初始化为500

$query = $db->query("SELECT uid, username, groupid, invisible, action, lastactivity, fid FROM {$tablepre}sessions ".(isset($_DCACHE['onlinelist'][7]) ? '' : 'WHERE uid <> 0')." ORDER BY uid DESC LIMIT ".$maxonlinelist);

while($online = $db->fetch_array($query)) {

if($online['uid']) {//会员

$membercount ++;//会员总数

if($online['invisible']) {//隐身用户

$invisiblecount++;

continue;

} else {

$online['icon'] = isset($_DCACHE['onlinelist'][$online['groupid']]) ? $_DCACHE['onlinelist'][$online['groupid']] : $_DCACHE['onlinelist'][0];//用户组的图标

}

} else {//游客,区别是数据表session里,其uid为0

$online['icon'] = $_DCACHE['onlinelist'][7];

$online['username'] = $_DCACHE['onlinelist']['guest'];

}

$online['fid'] = $online['fid'] ? $forumname[$online['fid']] : 0;//用户正浏览版块?

$online['action'] = $actioncode[$online['action']];//用户正进行的动作

$online['lastactivity'] = gmdate($timeformat, $online['lastactivity'] + ($timeoffset * 3600));//用户上次访问?

$whosonline[] = $online;//赋值给$whosonline数组

}

unset($actioncode, $online);//清空两个变量

if($onlinenum > $maxonlinelist) {//如果总在线人数大于最大在线人数(系统默认为500),分别取出已登录用户和隐身用户

$membercount = $db->result_first("SELECT COUNT(*) FROM {$tablepre}sessions WHERE uid <> '0'");

$invisiblecount = $db->result_first("SELECT COUNT(*) FROM {$tablepre}sessions WHERE invisible = '1'");

}

if($onlinenum < $membercount) {//如果总在线人数小于在线会员数,则更新cookie中的在线用户人数,注意是onlineusernum而不是onlinenum

$onlinenum = $db->result_first("SELECT COUNT(*) FROM {$tablepre}sessions");

dsetcookie('onlineusernum', intval($onlinenum), 300);

}

//总结:这里有些混乱,比如总在线人数,在线会员等等,因为变量类似,很容易看错理解错误,多看几遍吧。。。

$guestcount = $onlinenum - $membercount;

$db->free_result($query);//释放数据库连接

unset($online);//清空,230行不是有么?又清空一次?

}

} else {

$whosonlinestatus = 0;//如果后台设置不显示在线人数,则不显示在线列表

}

} else {//对应第77行,如果是分区显示,如url为:index.php?gid=2,则调用下面这个文件,

require_once DISCUZ_ROOT.'./include/category.inc.php';

}

include template('discuz');//解析首页的模板文件