MediaWiki  master
ExternalStoreMwstore.php
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1 <?php
22 
36  private $fbGroup;
37 
43  public function __construct( array $params ) {
44  parent::__construct( $params );
45  if ( !isset( $params['fbGroup'] ) || !( $params['fbGroup'] instanceof FileBackendGroup ) ) {
46  throw new InvalidArgumentException( "FileBackendGroup required in 'fbGroup' field." );
47  }
48  $this->fbGroup = $params['fbGroup'];
49  }
50 
58  public function fetchFromURL( $url ) {
59  $be = $this->fbGroup->backendFromPath( $url );
60  if ( $be instanceof FileBackend ) {
61  // We don't need "latest" since objects are immutable and
62  // backends should at least have "read-after-create" consistency.
63  return $be->getFileContents( [ 'src' => $url ] );
64  }
65 
66  return false;
67  }
68 
76  public function batchFetchFromURLs( array $urls ) {
77  $pathsByBackend = [];
78  foreach ( $urls as $url ) {
79  $be = $this->fbGroup->backendFromPath( $url );
80  if ( $be instanceof FileBackend ) {
81  $pathsByBackend[$be->getName()][] = $url;
82  }
83  }
84  $blobs = [];
85  foreach ( $pathsByBackend as $backendName => $paths ) {
86  $be = $this->fbGroup->get( $backendName );
87  $blobs += $be->getFileContentsMulti( [ 'srcs' => $paths ] );
88  }
89 
90  return $blobs;
91  }
92 
93  public function store( $backend, $data ) {
94  $be = $this->fbGroup->get( $backend );
95  // Get three random base 36 characters to act as shard directories
96  $rand = Wikimedia\base_convert( (string)mt_rand( 0, 46655 ), 10, 36, 3 );
97  // Make sure ID is roughly lexicographically increasing for performance
98  $id = str_pad( UIDGenerator::newTimestampedUID128( 32 ), 26, '0', STR_PAD_LEFT );
99  // Segregate items by DB domain ID for the sake of bookkeeping
100  $domain = $this->isDbDomainExplicit
101  ? $this->dbDomain
102  // @FIXME: this does not include the schema for b/c but it ideally should
103  : WikiMap::getWikiIdFromDbDomain( $this->dbDomain );
104  $url = $be->getContainerStoragePath( 'data' ) . '/' . rawurlencode( $domain );
105  // Use directory/container sharding
106  $url .= ( $be instanceof FSFileBackend )
107  ? "/{$rand[0]}/{$rand[1]}/{$rand[2]}/{$id}" // keep directories small
108  : "/{$rand[0]}/{$rand[1]}/{$id}"; // container sharding is only 2-levels
109 
110  $be->prepare( [ 'dir' => dirname( $url ), 'noAccess' => 1, 'noListing' => 1 ] );
111  $status = $be->create( [ 'dst' => $url, 'content' => $data ] );
112 
113  if ( $status->isOK() ) {
114  return $url;
115  }
116 
117  throw new MWException( __METHOD__ . ": operation failed: $status" );
118  }
119 
120  public function isReadOnly( $backend ) {
121  if ( parent::isReadOnly( $backend ) ) {
122  return true;
123  }
124 
125  $be = $this->fbGroup->get( $backend );
126 
127  return $be->isReadOnly();
128  }
129 }
Base class for external storage.
array $params
Usage context options for this instance.
External storage in a FileBackend.
batchFetchFromURLs(array $urls)
Fetch data from given external store URLs.
isReadOnly( $backend)
Check if a given location is read-only.
store( $backend, $data)
Insert a data item into a given location.
fetchFromURL( $url)
Fetch data from a given external store URL.
Class for a file system (FS) based file backend.
Class to handle file backend registration.
Base class for all file backend classes (including multi-write backends).
Definition: FileBackend.php:99
MediaWiki exception.
Definition: MWException.php:32
Helper tools for dealing with other locally-hosted wikis.
Definition: WikiMap.php:33
static newTimestampedUID128( $base=10)
Get a statistically unique 128-bit unsigned integer ID string.