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." mce_href="'.$boardurl.'rss.php?auth='.$rssauth."/" />/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($topic).'" mce_href="topic.php?keyword='.rawurlencode($topic).'" 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'].'" mce_href="announcement.php?id='.$announcement['id'].'">'.$announcement['subject'].'<i>('.gmdate($dateformat, $announcement['starttime'] + $timeoffset * 3600).')</i></a></li>';} elseif($announcement['type'] == 1) {$announcements .= '<li><a href="'.$announcement['message'].'" mce_href="'.$announcement['message'].'" target="_blank">'.$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 fLEFT JOIN {$tablepre}forumfields ff ON ff.fid=f.fidLEFT JOIN {$tablepre}access a ON a.uid='$discuz_uid' AND a.fid=f.fidWHERE f.status>0 ORDER BY f.type, f.displayorder": "SELECT f.fid, f.fup, f.type, f.name, f.threads, f.posts, f.todayposts, f.lastpost, f.inheritedmod, f.forumcolumns, f.simple, ff.description, ff.moderators, ff.icon, ff.viewperm, ff.redirect FROM {$tablepre}forums fLEFT 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='.$forum['fid'].'" mce_href="forumdisplay.php?fid='.$forum['fid'].'">'.$forum['name'].'</a>  ';}//对版块的子版字符串进行处理}} else {//否则，如果是分区if(!isset($_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