includes/AjaxResponse.php

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