includes/libs/objectcache/serialized/SerializedValueContainer.php

   1 <?php
   2
   3 /**
   4  * Helper class for segmenting large cache values without relying on serializing classes
   5  *
   6  * @since 1.34
   7  */
   8 class SerializedValueContainer {
   9         const SCHEMA = '__svc_schema__';
  10         const SCHEMA_UNIFIED = 'DAAIDgoKAQw'; // 64 bit UID
  11         const SCHEMA_SEGMENTED = 'CAYCDAgCDw4'; // 64 bit UID
  12
  13         const UNIFIED_DATA = '__data__';
  14         const SEGMENTED_HASHES = '__hashes__';
  15
  16         /**
  17          * @param string $serialized
  18          * @return stdClass
  19          */
  20         public static function newUnified( $serialized ) {
  21                 return (object)[
  22                         self::SCHEMA => self::SCHEMA_UNIFIED,
  23                         self::UNIFIED_DATA => $serialized
  24                 ];
  25         }
  26
  27         /**
  28          * @param string[] $segmentHashList Ordered list of hashes for each segment
  29          * @return stdClass
  30          */
  31         public static function newSegmented( array $segmentHashList ) {
  32                 return (object)[
  33                         self::SCHEMA => self::SCHEMA_SEGMENTED,
  34                         self::SEGMENTED_HASHES => $segmentHashList
  35                 ];
  36         }
  37
  38         /**
  39          * @param mixed $value
  40          * @return bool
  41          */
  42         public static function isUnified( $value ) {
  43                 return self::instanceOf( $value, self::SCHEMA_UNIFIED );
  44         }
  45
  46         /**
  47          * @param mixed $value
  48          * @return bool
  49          */
  50         public static function isSegmented( $value ) {
  51                 return self::instanceOf( $value, self::SCHEMA_SEGMENTED );
  52         }
  53
  54         /**
  55          * @param mixed $value
  56          * @param string $schema SCHEMA_* class constant
  57          * @return bool
  58          */
  59         private static function instanceOf( $value, $schema ) {
  60                 return (
  61                         $value instanceof stdClass &&
  62                         property_exists( $value, self::SCHEMA ) &&
  63                         $value->{self::SCHEMA} === $schema
  64                 );
  65         }
  66 }