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FileContentsHasher.php
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1 <?php
23  private const ALGO = 'md4';
24 
26  protected $cache;
27 
29  private static $instance;
30 
31  public function __construct() {
32  $this->cache = function_exists( 'apcu_fetch' ) ? new APCUBagOStuff() : new EmptyBagOStuff();
33  }
34 
40  public static function singleton() {
41  if ( !self::$instance ) {
42  self::$instance = new self;
43  }
44 
45  return self::$instance;
46  }
47 
55  private function getFileContentsHashInternal( $filePath ) {
56  // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged
57  $mtime = @filemtime( $filePath );
58  if ( $mtime === false ) {
59  return false;
60  }
61 
62  $cacheKey = $this->cache->makeGlobalKey( __CLASS__, $filePath, $mtime, self::ALGO );
63  return $this->cache->getWithSetCallback(
64  $cacheKey,
65  $this->cache::TTL_DAY,
66  static function () use ( $filePath ) {
67  // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged
68  $contents = @file_get_contents( $filePath );
69  if ( $contents === false ) {
70  // Don't cache false
71  return false;
72  }
73 
74  return hash( self::ALGO, $contents );
75  }
76  );
77  }
78 
87  public static function getFileContentsHash( $filePaths ) {
88  $instance = self::singleton();
89 
90  if ( !is_array( $filePaths ) ) {
91  $filePaths = (array)$filePaths;
92  }
93 
94  if ( count( $filePaths ) === 1 ) {
95  $hash = $instance->getFileContentsHashInternal( $filePaths[0] );
96  return $hash;
97  }
98 
99  sort( $filePaths );
100  $hashes = [];
101  foreach ( $filePaths as $filePath ) {
102  $hashes[] = $instance->getFileContentsHashInternal( $filePath ) ?: '';
103  }
104 
105  $hashes = implode( '', $hashes );
106  return $hashes ? hash( self::ALGO, $hashes ) : false;
107  }
108 }
This is a wrapper for APCu's shared memory functions.
A BagOStuff object with no objects in it.
static singleton()
Get the singleton instance of this class.
static getFileContentsHash( $filePaths)
Get a hash of the combined contents of one or more files, either by retrieving a previously-computed ...