includes/AjaxResponse.php

   1 <?php
   2 if( !defined( 'MEDIAWIKI' ) ) {
   3         die( 1 );
   4 }
   5
   6 /**
   7  * @todo document
   8  */
   9 class AjaxResponse {
  10         var $mCacheDuration;
  11         var $mVary;
  12
  13         var $mDisabled;
  14         var $mText;
  15         var $mResponseCode;
  16         var $mLastModified;
  17         var $mContentType;
  18
  19         function __construct( $text = NULL ) {
  20                 $this->mCacheDuration = NULL;
  21                 $this->mVary = NULL;
  22
  23                 $this->mDisabled = false;
  24                 $this->mText = '';
  25                 $this->mResponseCode = '200 OK';
  26                 $this->mLastModified = false;
  27                 $this->mContentType= 'text/html; charset=utf-8';
  28
  29                 if ( $text ) {
  30                         $this->addText( $text );
  31                 }
  32         }
  33
  34         function setCacheDuration( $duration ) {
  35                 $this->mCacheDuration = $duration;
  36         }
  37
  38         function setVary( $vary ) {
  39                 $this->mVary = $vary;
  40         }
  41
  42         function setResponseCode( $code ) {
  43                 $this->mResponseCode = $code;
  44         }
  45
  46         function setContentType( $type ) {
  47                 $this->mContentType = $type;
  48         }
  49
  50         function disable() {
  51                 $this->mDisabled = true;
  52         }
  53
  54         function addText( $text ) {
  55                 if ( ! $this->mDisabled && $text ) {
  56                         $this->mText .= $text;
  57                 }
  58         }
  59
  60         function printText() {
  61                 if ( ! $this->mDisabled ) {
  62                         print $this->mText;
  63                 }
  64         }
  65
  66         function sendHeaders() {
  67                 global $wgUseSquid, $wgUseESI;
  68
  69                 if ( $this->mResponseCode ) {
  70                         $n = preg_replace( '/^ *(\d+)/', '\1', $this->mResponseCode );
  71                         header( "Status: " . $this->mResponseCode, true, (int)$n );
  72                 }
  73
  74                 header ("Content-Type: " . $this->mContentType );
  75
  76                 if ( $this->mLastModified ) {
  77                         header ("Last-Modified: " . $this->mLastModified );
  78                 }
  79                 else {
  80                         header ("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
  81                 }
  82
  83                 if ( $this->mCacheDuration ) {
  84
  85                         # If squid caches are configured, tell them to cache the response,
  86                         # and tell the client to always check with the squid. Otherwise,
  87                         # tell the client to use a cached copy, without a way to purge it.
  88
  89                         if( $wgUseSquid ) {
  90
  91                                 # Expect explicite purge of the proxy cache, but require end user agents
  92                                 # to revalidate against the proxy on each visit.
  93                                 # Surrogate-Control controls our Squid, Cache-Control downstream caches
  94
  95                                 if ( $wgUseESI ) {
  96                                         header( 'Surrogate-Control: max-age='.$this->mCacheDuration.', content="ESI/1.0"');
  97                                         header( 'Cache-Control: s-maxage=0, must-revalidate, max-age=0' );
  98                                 } else {
  99                                         header( 'Cache-Control: s-maxage='.$this->mCacheDuration.', must-revalidate, max-age=0' );
 100                                 }
 101
 102                         } else {
 103
 104                                 # Let the client do the caching. Cache is not purged.
 105                                 header ("Expires: " . gmdate( "D, d M Y H:i:s", time() + $this->mCacheDuration ) . " GMT");
 106                                 header ("Cache-Control: s-max-age={$this->mCacheDuration},public,max-age={$this->mCacheDuration}");
 107                         }
 108
 109                 } else {
 110                         # always expired, always modified
 111                         header ("Expires: Mon, 26 Jul 1997 05:00:00 GMT");    // Date in the past
 112                         header ("Cache-Control: no-cache, must-revalidate");  // HTTP/1.1
 113                         header ("Pragma: no-cache");                          // HTTP/1.0
 114                 }
 115
 116                 if ( $this->mVary ) {
 117                         header ( "Vary: " . $this->mVary );
 118                 }
 119         }
 120
 121         /**
 122          * checkLastModified tells the client to use the client-cached response if
 123          * possible. If sucessful, the AjaxResponse is disabled so that
 124          * any future call to AjaxResponse::printText() have no effect. The method
 125          * returns true iff the response code was set to 304 Not Modified.
 126          */
 127         function checkLastModified ( $timestamp ) {
 128                 global $wgCachePages, $wgCacheEpoch, $wgUser;
 129                 $fname = 'AjaxResponse::checkLastModified';
 130
 131                 if ( !$timestamp || $timestamp == '19700101000000' ) {
 132                         wfDebug( "$fname: CACHE DISABLED, NO TIMESTAMP\n" );
 133                         return;
 134                 }
 135                 if( !$wgCachePages ) {
 136                         wfDebug( "$fname: CACHE DISABLED\n", false );
 137                         return;
 138                 }
 139                 if( $wgUser->getOption( 'nocache' ) ) {
 140                         wfDebug( "$fname: USER DISABLED CACHE\n", false );
 141                         return;
 142                 }
 143
 144                 $timestamp = wfTimestamp( TS_MW, $timestamp );
 145                 $lastmod = wfTimestamp( TS_RFC2822, max( $timestamp, $wgUser->mTouched, $wgCacheEpoch ) );
 146
 147                 if( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 148                         # IE sends sizes after the date like this:
 149                         # Wed, 20 Aug 2003 06:51:19 GMT; length=5202
 150                         # this breaks strtotime().
 151                         $modsince = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 152                         $modsinceTime = strtotime( $modsince );
 153                         $ismodsince = wfTimestamp( TS_MW, $modsinceTime ? $modsinceTime : 1 );
 154                         wfDebug( "$fname: -- client send If-Modified-Since: " . $modsince . "\n", false );
 155                         wfDebug( "$fname: --  we might send Last-Modified : $lastmod\n", false );
 156                         if( ($ismodsince >= $timestamp ) && $wgUser->validateCache( $ismodsince ) && $ismodsince >= $wgCacheEpoch ) {
 157                                 $this->setResponseCode( "304 Not Modified" );
 158                                 $this->disable();
 159                                 $this->mLastModified = $lastmod;
 160
 161                                 wfDebug( "$fname: CACHED client: $ismodsince ; user: $wgUser->mTouched ; page: $timestamp ; site $wgCacheEpoch\n", false );
 162
 163                                 return true;
 164                         } else {
 165                                 wfDebug( "$fname: READY  client: $ismodsince ; user: $wgUser->mTouched ; page: $timestamp ; site $wgCacheEpoch\n", false );
 166                                 $this->mLastModified = $lastmod;
 167                         }
 168                 } else {
 169                         wfDebug( "$fname: client did not send If-Modified-Since header\n", false );
 170                         $this->mLastModified = $lastmod;
 171                 }
 172         }
 173
 174         function loadFromMemcached( $mckey, $touched ) {
 175                 global $wgMemc;
 176                 if ( !$touched ) return false;
 177
 178                 $mcvalue = $wgMemc->get( $mckey );
 179                 if ( $mcvalue ) {
 180                         # Check to see if the value has been invalidated
 181                         if ( $touched <= $mcvalue['timestamp'] ) {
 182                                 wfDebug( "Got $mckey from cache\n" );
 183                                 $this->mText = $mcvalue['value'];
 184                                 return true;
 185                         } else {
 186                                 wfDebug( "$mckey has expired\n" );
 187                         }
 188                 }
 189
 190                 return false;
 191         }
 192
 193         function storeInMemcached( $mckey, $expiry = 86400 ) {
 194                 global $wgMemc;
 195
 196                 $wgMemc->set( $mckey,
 197                         array(
 198                                 'timestamp' => wfTimestampNow(),
 199                                 'value' => $this->mText
 200                         ), $expiry
 201                 );
 202
 203                 return true;
 204         }
 205 }
 206 ?>