includes/AjaxResponse.php

   1 <?php
   2 if( !defined( 'MEDIAWIKI' ) ) {
   3         die( 1 );
   4 }
   5
   6 /**
   7  * @todo document
   8  * @addtogroup Ajax
   9  */
  10 class AjaxResponse {
  11         var $mCacheDuration;
  12         var $mVary;
  13
  14         var $mDisabled;
  15         var $mText;
  16         var $mResponseCode;
  17         var $mLastModified;
  18         var $mContentType;
  19
  20         function __construct( $text = NULL ) {
  21                 $this->mCacheDuration = NULL;
  22                 $this->mVary = NULL;
  23
  24                 $this->mDisabled = false;
  25                 $this->mText = '';
  26                 $this->mResponseCode = '200 OK';
  27                 $this->mLastModified = false;
  28                 $this->mContentType= 'text/html; charset=utf-8';
  29
  30                 if ( $text ) {
  31                         $this->addText( $text );
  32                 }
  33         }
  34
  35         function setCacheDuration( $duration ) {
  36                 $this->mCacheDuration = $duration;
  37         }
  38
  39         function setVary( $vary ) {
  40                 $this->mVary = $vary;
  41         }
  42
  43         function setResponseCode( $code ) {
  44                 $this->mResponseCode = $code;
  45         }
  46
  47         function setContentType( $type ) {
  48                 $this->mContentType = $type;
  49         }
  50
  51         function disable() {
  52                 $this->mDisabled = true;
  53         }
  54
  55         function addText( $text ) {
  56                 if ( ! $this->mDisabled && $text ) {
  57                         $this->mText .= $text;
  58                 }
  59         }
  60
  61         function printText() {
  62                 if ( ! $this->mDisabled ) {
  63                         print $this->mText;
  64                 }
  65         }
  66
  67         function sendHeaders() {
  68                 global $wgUseSquid, $wgUseESI;
  69
  70                 if ( $this->mResponseCode ) {
  71                         $n = preg_replace( '/^ *(\d+)/', '\1', $this->mResponseCode );
  72                         header( "Status: " . $this->mResponseCode, true, (int)$n );
  73                 }
  74
  75                 header ("Content-Type: " . $this->mContentType );
  76
  77                 if ( $this->mLastModified ) {
  78                         header ("Last-Modified: " . $this->mLastModified );
  79                 }
  80                 else {
  81                         header ("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
  82                 }
  83
  84                 if ( $this->mCacheDuration ) {
  85
  86                         # If squid caches are configured, tell them to cache the response,
  87                         # and tell the client to always check with the squid. Otherwise,
  88                         # tell the client to use a cached copy, without a way to purge it.
  89
  90                         if( $wgUseSquid ) {
  91
  92                                 # Expect explicite purge of the proxy cache, but require end user agents
  93                                 # to revalidate against the proxy on each visit.
  94                                 # Surrogate-Control controls our Squid, Cache-Control downstream caches
  95
  96                                 if ( $wgUseESI ) {
  97                                         header( 'Surrogate-Control: max-age='.$this->mCacheDuration.', content="ESI/1.0"');
  98                                         header( 'Cache-Control: s-maxage=0, must-revalidate, max-age=0' );
  99                                 } else {
 100                                         header( 'Cache-Control: s-maxage='.$this->mCacheDuration.', must-revalidate, max-age=0' );
 101                                 }
 102
 103                         } else {
 104
 105                                 # Let the client do the caching. Cache is not purged.
 106                                 header ("Expires: " . gmdate( "D, d M Y H:i:s", time() + $this->mCacheDuration ) . " GMT");
 107                                 header ("Cache-Control: s-max-age={$this->mCacheDuration},public,max-age={$this->mCacheDuration}");
 108                         }
 109
 110                 } else {
 111                         # always expired, always modified
 112                         header ("Expires: Mon, 26 Jul 1997 05:00:00 GMT");    // Date in the past
 113                         header ("Cache-Control: no-cache, must-revalidate");  // HTTP/1.1
 114                         header ("Pragma: no-cache");                          // HTTP/1.0
 115                 }
 116
 117                 if ( $this->mVary ) {
 118                         header ( "Vary: " . $this->mVary );
 119                 }
 120         }
 121
 122         /**
 123          * checkLastModified tells the client to use the client-cached response if
 124          * possible. If sucessful, the AjaxResponse is disabled so that
 125          * any future call to AjaxResponse::printText() have no effect. The method
 126          * returns true iff the response code was set to 304 Not Modified.
 127          */
 128         function checkLastModified ( $timestamp ) {
 129                 global $wgCachePages, $wgCacheEpoch, $wgUser;
 130                 $fname = 'AjaxResponse::checkLastModified';
 131
 132                 if ( !$timestamp || $timestamp == '19700101000000' ) {
 133                         wfDebug( "$fname: CACHE DISABLED, NO TIMESTAMP\n" );
 134                         return;
 135                 }
 136                 if( !$wgCachePages ) {
 137                         wfDebug( "$fname: CACHE DISABLED\n", false );
 138                         return;
 139                 }
 140                 if( $wgUser->getOption( 'nocache' ) ) {
 141                         wfDebug( "$fname: USER DISABLED CACHE\n", false );
 142                         return;
 143                 }
 144
 145                 $timestamp = wfTimestamp( TS_MW, $timestamp );
 146                 $lastmod = wfTimestamp( TS_RFC2822, max( $timestamp, $wgUser->mTouched, $wgCacheEpoch ) );
 147
 148                 if( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 149                         # IE sends sizes after the date like this:
 150                         # Wed, 20 Aug 2003 06:51:19 GMT; length=5202
 151                         # this breaks strtotime().
 152                         $modsince = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 153                         $modsinceTime = strtotime( $modsince );
 154                         $ismodsince = wfTimestamp( TS_MW, $modsinceTime ? $modsinceTime : 1 );
 155                         wfDebug( "$fname: -- client send If-Modified-Since: " . $modsince . "\n", false );
 156                         wfDebug( "$fname: --  we might send Last-Modified : $lastmod\n", false );
 157                         if( ($ismodsince >= $timestamp ) && $wgUser->validateCache( $ismodsince ) && $ismodsince >= $wgCacheEpoch ) {
 158                                 $this->setResponseCode( "304 Not Modified" );
 159                                 $this->disable();
 160                                 $this->mLastModified = $lastmod;
 161
 162                                 wfDebug( "$fname: CACHED client: $ismodsince ; user: $wgUser->mTouched ; page: $timestamp ; site $wgCacheEpoch\n", false );
 163
 164                                 return true;
 165                         } else {
 166                                 wfDebug( "$fname: READY  client: $ismodsince ; user: $wgUser->mTouched ; page: $timestamp ; site $wgCacheEpoch\n", false );
 167                                 $this->mLastModified = $lastmod;
 168                         }
 169                 } else {
 170                         wfDebug( "$fname: client did not send If-Modified-Since header\n", false );
 171                         $this->mLastModified = $lastmod;
 172                 }
 173         }
 174
 175         function loadFromMemcached( $mckey, $touched ) {
 176                 global $wgMemc;
 177                 if ( !$touched ) return false;
 178
 179                 $mcvalue = $wgMemc->get( $mckey );
 180                 if ( $mcvalue ) {
 181                         # Check to see if the value has been invalidated
 182                         if ( $touched <= $mcvalue['timestamp'] ) {
 183                                 wfDebug( "Got $mckey from cache\n" );
 184                                 $this->mText = $mcvalue['value'];
 185                                 return true;
 186                         } else {
 187                                 wfDebug( "$mckey has expired\n" );
 188                         }
 189                 }
 190
 191                 return false;
 192         }
 193
 194         function storeInMemcached( $mckey, $expiry = 86400 ) {
 195                 global $wgMemc;
 196
 197                 $wgMemc->set( $mckey,
 198                         array(
 199                                 'timestamp' => wfTimestampNow(),
 200                                 'value' => $this->mText
 201                         ), $expiry
 202                 );
 203
 204                 return true;
 205         }
 206 }
 207 ?>