includes/libs/objectcache/RESTBagOStuff.php

   1 <?php
   2
   3 /**
   4  * Interface to key-value storage on HTTP RESTful server, such as RESTBase.
   5  * Uses URL of the form URL/{KEY} to store/fetch/delete.
   6  * E.g., when base URL is /v1/sessions/ then the store would do:
   7  * PUT /v1/sessions/12345758
   8  * and fetch would do:
   9  * GET /v1/sessions/12345758
  10  * delete would do:
  11  * DELETE /v1/sessions/12345758
  12  *
  13  * Configure with:
  14  * @code
  15  * $wgObjectCaches['sessions'] = array(
  16  *      'class' => 'RESTBagOStuff',
  17  *      'url' => 'http://localhost:7231/wikimedia.org/v1/sessions/'
  18  * );
  19  * @endcode
  20  */
  21 class RESTBagOStuff extends BagOStuff {
  22
  23         /**
  24          * @var MultiHttpClient
  25          */
  26         private $client;
  27
  28         /**
  29          * REST URL to use for storage.
  30          * @var string
  31          */
  32         private $url;
  33
  34         public function __construct( $params ) {
  35                 if ( empty( $params['url'] ) ) {
  36                         throw new InvalidArgumentException( 'URL parameter is required' );
  37                 }
  38                 parent::__construct( $params );
  39                 if ( empty( $params['client'] ) ) {
  40                         $this->client = new MultiHttpClient( [] );
  41                 } else {
  42                         $this->client = $params['client'];
  43                 }
  44                 // Make sure URL ends with /
  45                 $this->url = rtrim( $params['url'], '/' ) . '/';
  46         }
  47
  48         /**
  49          * @param string  $key
  50          * @param integer $flags Bitfield of BagOStuff::READ_* constants [optional]
  51          * @return mixed Returns false on failure and if the item does not exist
  52          */
  53         protected function doGet( $key, $flags = 0 ) {
  54                 $req = [
  55                         'method' => 'GET',
  56                     'url' => $this->url . rawurlencode( $key ),
  57
  58                 ];
  59                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->client->run( $req );
  60                 if ( $rcode === 200 ) {
  61                         if ( is_string( $rbody ) ) {
  62                                 return unserialize( $rbody );
  63                         }
  64                         return false;
  65                 }
  66                 if ( $rcode === 0 || ( $rcode >= 400 && $rcode != 404 ) ) {
  67                         return $this->handleError( "Failed to fetch $key", $rcode, $rerr );
  68                 }
  69                 return false;
  70         }
  71
  72         /**
  73          * Handle storage error
  74          * @param string $msg Error message
  75          * @param int    $rcode Error code from client
  76          * @param string $rerr Error message from client
  77          * @return false
  78          */
  79         protected function handleError( $msg, $rcode, $rerr ) {
  80                 $this->logger->error( "$msg : ({code}) {error}", [
  81                         'code' => $rcode,
  82                         'error' => $rerr
  83                 ] );
  84                 $this->setLastError( $rcode === 0 ? self::ERR_UNREACHABLE : self::ERR_UNEXPECTED );
  85                 return false;
  86         }
  87
  88         /**
  89          * Set an item
  90          *
  91          * @param string $key
  92          * @param mixed  $value
  93          * @param int    $exptime Either an interval in seconds or a unix timestamp for expiry
  94          * @param int    $flags Bitfield of BagOStuff::WRITE_* constants
  95          * @return bool Success
  96          */
  97         public function set( $key, $value, $exptime = 0, $flags = 0 ) {
  98                 $req = [
  99                         'method' => 'PUT',
 100                         'url' => $this->url . rawurlencode( $key ),
 101                         'body' => serialize( $value )
 102                 ];
 103                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->client->run( $req );
 104                 if ( $rcode === 200 || $rcode === 201 ) {
 105                         return true;
 106                 }
 107                 return $this->handleError( "Failed to store $key", $rcode, $rerr );
 108         }
 109
 110         /**
 111          * Delete an item.
 112          *
 113          * @param string $key
 114          * @return bool True if the item was deleted or not found, false on failure
 115          */
 116         public function delete( $key ) {
 117                 $req = [
 118                         'method' => 'DELETE',
 119                         'url' => $this->url . rawurlencode( $key ),
 120                 ];
 121                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $this->client->run( $req );
 122                 if ( $rcode === 200 || $rcode === 204 || $rcode === 205 ) {
 123                         return true;
 124                 }
 125                 return $this->handleError( "Failed to delete $key", $rcode, $rerr );
 126         }
 127 }