- File: class-sitemaps-cache-validator.php
- Full Path: /home/matthif/www/wp-content/plugins/wordpress-seo/inc/sitemaps/class-sitemaps-cache-validator.php
- Date Modified: 02/24/2024 11:29 PM
- File size: 9.42 KB
- MIME-type: text/x-php
- Charset: utf-8
<?php
/**
* WPSEO plugin file.
*
* @package WPSEO\XML_Sitemaps
*/
/**
* Handles storage keys for sitemaps caching and invalidation.
*
* @since 3.2
*/
class WPSEO_Sitemaps_Cache_Validator {
/**
* Prefix of the transient key for sitemap caches.
*
* @var string
*/
public const STORAGE_KEY_PREFIX = 'yst_sm_';
/**
* Name of the option that holds the global validation value.
*
* @var string
*/
public const VALIDATION_GLOBAL_KEY = 'wpseo_sitemap_cache_validator_global';
/**
* The format which creates the key of the option that holds the type validation value.
*
* @var string
*/
public const VALIDATION_TYPE_KEY_FORMAT = 'wpseo_sitemap_%s_cache_validator';
/**
* Get the cache key for a certain type and page.
*
* A type of cache would be something like 'page', 'post' or 'video'.
*
* Example key format for sitemap type "post", page 1: wpseo_sitemap_post_1:akfw3e_23azBa .
*
* @since 3.2
*
* @param string|null $type The type to get the key for. Null or self::SITEMAP_INDEX_TYPE for index cache.
* @param int $page The page of cache to get the key for.
*
* @return bool|string The key where the cache is stored on. False if the key could not be generated.
*/
public static function get_storage_key( $type = null, $page = 1 ) {
// Using SITEMAP_INDEX_TYPE for sitemap index cache.
$type = is_null( $type ) ? WPSEO_Sitemaps::SITEMAP_INDEX_TYPE : $type;
$global_cache_validator = self::get_validator();
$type_cache_validator = self::get_validator( $type );
$prefix = self::STORAGE_KEY_PREFIX;
$postfix = sprintf( '_%d:%s_%s', $page, $global_cache_validator, $type_cache_validator );
try {
$type = self::truncate_type( $type, $prefix, $postfix );
} catch ( OutOfBoundsException $exception ) {
// Maybe do something with the exception, for now just mark as invalid.
return false;
}
// Build key.
$full_key = $prefix . $type . $postfix;
return $full_key;
}
/**
* If the type is over length make sure we compact it so we don't have any database problems.
*
* When there are more 'extremely long' post types, changes are they have variations in either the start or ending.
* Because of this, we cut out the excess in the middle which should result in less chance of collision.
*
* @since 3.2
*
* @param string $type The type of sitemap to be used.
* @param string $prefix The part before the type in the cache key. Only the length is used.
* @param string $postfix The part after the type in the cache key. Only the length is used.
*
* @return string The type with a safe length to use
*
* @throws OutOfRangeException When there is less than 15 characters of space for a key that is originally longer.
*/
public static function truncate_type( $type, $prefix = '', $postfix = '' ) {
/*
* This length has been restricted by the database column length of 64 in the past.
* The prefix added by WordPress is '_transient_' because we are saving to a transient.
* We need to use a timeout on the transient, otherwise the values get autoloaded, this adds
* another restriction to the length.
*/
$max_length = 45; // 64 - 19 ('_transient_timeout_')
$max_length -= strlen( $prefix );
$max_length -= strlen( $postfix );
if ( strlen( $type ) > $max_length ) {
if ( $max_length < 15 ) {
/*
* If this happens the most likely cause is a page number that is too high.
*
* So this would not happen unintentionally.
* Either by trying to cause a high server load, finding backdoors or misconfiguration.
*/
throw new OutOfRangeException(
__(
'Trying to build the sitemap cache key, but the postfix and prefix combination leaves too little room to do this. You are probably requesting a page that is way out of the expected range.',
'wordpress-seo'
)
);
}
$half = ( $max_length / 2 );
$first_part = substr( $type, 0, ( ceil( $half ) - 1 ) );
$last_part = substr( $type, ( 1 - floor( $half ) ) );
$type = $first_part . '..' . $last_part;
}
return $type;
}
/**
* Invalidate sitemap cache.
*
* @since 3.2
*
* @param string|null $type The type to get the key for. Null for all caches.
*
* @return void
*/
public static function invalidate_storage( $type = null ) {
// Global validator gets cleared when no type is provided.
$old_validator = null;
// Get the current type validator.
if ( ! is_null( $type ) ) {
$old_validator = self::get_validator( $type );
}
// Refresh validator.
self::create_validator( $type );
if ( ! wp_using_ext_object_cache() ) {
// Clean up current cache from the database.
self::cleanup_database( $type, $old_validator );
}
// External object cache pushes old and unretrieved items out by itself so we don't have to do anything for that.
}
/**
* Cleanup invalidated database cache.
*
* @since 3.2
*
* @param string|null $type The type of sitemap to clear cache for.
* @param string|null $validator The validator to clear cache of.
*
* @return void
*/
public static function cleanup_database( $type = null, $validator = null ) {
global $wpdb;
if ( is_null( $type ) ) {
// Clear all cache if no type is provided.
$like = sprintf( '%s%%', self::STORAGE_KEY_PREFIX );
}
else {
// Clear type cache for all type keys.
$like = sprintf( '%1$s%2$s_%%', self::STORAGE_KEY_PREFIX, $type );
}
/*
* Add slashes to the LIKE "_" single character wildcard.
*
* We can't use `esc_like` here because we need the % in the query.
*/
$where = [];
$where[] = sprintf( "option_name LIKE '%s'", addcslashes( '_transient_' . $like, '_' ) );
$where[] = sprintf( "option_name LIKE '%s'", addcslashes( '_transient_timeout_' . $like, '_' ) );
// Delete transients.
//phpcs:disable WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- We need to use a direct query here.
//phpcs:disable WordPress.DB.DirectDatabaseQuery.NoCaching -- Reason: No relevant caches.
$wpdb->query(
$wpdb->prepare(
//phpcs:disable WordPress.DB.PreparedSQLPlaceholders -- %i placeholder is still not recognized.
'DELETE FROM %i WHERE ' . implode( ' OR', array_fill( 0, count( $where ), '%s' ) ),
array_merge( [ $wpdb->options ], $where )
)
);
wp_cache_delete( 'alloptions', 'options' );
}
/**
* Get the current cache validator.
*
* Without the type the global validator is returned.
* This can invalidate -all- keys in cache at once.
*
* With the type parameter the validator for that specific type can be invalidated.
*
* @since 3.2
*
* @param string $type Provide a type for a specific type validator, empty for global validator.
*
* @return string|null The validator for the supplied type.
*/
public static function get_validator( $type = '' ) {
$key = self::get_validator_key( $type );
$current = get_option( $key, null );
if ( ! is_null( $current ) ) {
return $current;
}
if ( self::create_validator( $type ) ) {
return self::get_validator( $type );
}
return null;
}
/**
* Get the cache validator option key for the specified type.
*
* @since 3.2
*
* @param string $type Provide a type for a specific type validator, empty for global validator.
*
* @return string Validator to be used to generate the cache key.
*/
public static function get_validator_key( $type = '' ) {
if ( empty( $type ) ) {
return self::VALIDATION_GLOBAL_KEY;
}
return sprintf( self::VALIDATION_TYPE_KEY_FORMAT, $type );
}
/**
* Refresh the cache validator value.
*
* @since 3.2
*
* @param string $type Provide a type for a specific type validator, empty for global validator.
*
* @return bool True if validator key has been saved as option.
*/
public static function create_validator( $type = '' ) {
$key = self::get_validator_key( $type );
// Generate new validator.
$microtime = microtime();
// Remove space.
list( $milliseconds, $seconds ) = explode( ' ', $microtime );
// Transients are purged every 24h.
$seconds = ( $seconds % DAY_IN_SECONDS );
$milliseconds = intval( substr( $milliseconds, 2, 3 ), 10 );
// Combine seconds and milliseconds and convert to integer.
$validator = intval( $seconds . '' . $milliseconds, 10 );
// Apply base 61 encoding.
$compressed = self::convert_base10_to_base61( $validator );
return update_option( $key, $compressed, false );
}
/**
* Encode to base61 format.
*
* This is base64 (numeric + alpha + alpha upper case) without the 0.
*
* @since 3.2
*
* @param int $base10 The number that has to be converted to base 61.
*
* @return string Base 61 converted string.
*
* @throws InvalidArgumentException When the input is not an integer.
*/
public static function convert_base10_to_base61( $base10 ) {
if ( ! is_int( $base10 ) ) {
throw new InvalidArgumentException( __( 'Expected an integer as input.', 'wordpress-seo' ) );
}
// Characters that will be used in the conversion.
$characters = '123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
$length = strlen( $characters );
$remainder = $base10;
$output = '';
do {
// Building from right to left in the result.
$index = ( $remainder % $length );
// Prepend the character to the output.
$output = $characters[ $index ] . $output;
// Determine the remainder after removing the applied number.
$remainder = floor( $remainder / $length );
// Keep doing it until we have no remainder left.
} while ( $remainder );
return $output;
}
}