Merged in feature/from-pantheon (pull request #16)

code from pantheon

* code from pantheon

wp/wp-content/plugins/woocommerce/src/Caching/CacheEngine.php

@@ -0,0 +1,61 @@
+<?php
+
+namespace Automattic\WooCommerce\Caching;
+
+/**
+ * Interface for cache engines used by objects inheriting from ObjectCache.
+ * Here "object" means either an array or an actual PHP object.
+ */
+interface CacheEngine {
+
+	/**
+	 * Retrieves an object cached under a given key.
+	 *
+	 * @param string $key They key under which the object to retrieve is cached.
+	 * @param string $group The group under which the object is cached.
+	 *
+	 * @return array|object|null The cached object, or null if there's no object cached under the passed key.
+	 */
+	public function get_cached_object( string $key, string $group = '' );
+
+	/**
+	 * Caches an object under a given key, and with a given expiration.
+	 *
+	 * @param string       $key The key under which the object will be cached.
+	 * @param array|object $object The object to cache.
+	 * @param int          $expiration Expiration for the cached object, in seconds.
+	 * @param string       $group The group under which the object will be cached.
+	 *
+	 * @return bool True if the object is cached successfully, false otherwise.
+	 */
+	public function cache_object( string $key, $object, int $expiration, string $group = '' ): bool;
+
+	/**
+	 * Removes a cached object from the cache.
+	 *
+	 * @param string $key They key under which the object is cached.
+	 * @param string $group The group under which the object is cached.
+	 *
+	 * @return bool True if the object is removed from the cache successfully, false otherwise (because the object wasn't cached or for other reason).
+	 */
+	public function delete_cached_object( string $key, string $group = '' ): bool;
+
+	/**
+	 * Checks if an object is cached under a given key.
+	 *
+	 * @param string $key The key to verify.
+	 * @param string $group The group under which the object is cached.
+	 *
+	 * @return bool True if there's an object cached under the given key, false otherwise.
+	 */
+	public function is_cached( string $key, string $group = '' ): bool;
+
+	/**
+	 * Deletes all cached objects under a given group.
+	 *
+	 * @param string $group The group to delete.
+	 *
+	 * @return bool True if the group is deleted successfully, false otherwise.
+	 */
+	public function delete_cache_group( string $group = '' ): bool;
+}

wp/wp-content/plugins/woocommerce/src/Caching/CacheException.php

@@ -0,0 +1,85 @@
+<?php
+
+namespace Automattic\WooCommerce\Caching;
+
+/**
+ * Exception thrown by classes derived from ObjectCache.
+ */
+class CacheException extends \Exception {
+
+	/**
+	 * Error messages.
+	 *
+	 * @var array
+	 */
+	private $errors;
+
+	/**
+	 * The object that threw the exception.
+	 *
+	 * @var ObjectCache
+	 */
+	private $thrower;
+
+	/**
+	 * The id of the cached object, if available.
+	 *
+	 * @var int|string|null
+	 */
+	private $cached_id;
+
+	/**
+	 * Creates a new instance of the class.
+	 *
+	 * @param string          $message The exception message.
+	 * @param ObjectCache     $thrower The object that is throwing the exception.
+	 * @param int|string|null $cached_id The involved cached object id, if available.
+	 * @param array|null      $errors An array of error messages, if available.
+	 * @param mixed           $code An error code, if available.
+	 * @param \Throwable|null $previous The previous exception, if available.
+	 */
+	public function __construct( string $message, ObjectCache $thrower, $cached_id = null, ?array $errors = null, $code = 0, \Throwable $previous = null ) {
+		$this->errors    = $errors ?? array();
+		$this->thrower   = $thrower;
+		$this->cached_id = $cached_id;
+
+		parent::__construct( $message, $code, $previous );
+	}
+
+	/**
+	 * Get a string representation of the exception object.
+	 *
+	 * @return string String representation of the exception object.
+	 */
+	public function __toString(): string {
+		$cached_id_part = $this->cached_id ? ", id: {$this->cached_id}" : '';
+		return "CacheException: [{$this->thrower->get_object_type()}{$cached_id_part}]: {$this->message}";
+	}
+
+	/**
+	 * Gets the array of error messages passed to the exception constructor.
+	 *
+	 * @return array Error messages passed to the exception constructor.
+	 */
+	public function get_errors(): array {
+		return $this->errors;
+	}
+
+	/**
+	 * Gets the object that threw the exception as passed to the exception constructor.
+	 *
+	 * @return object The object that threw the exception.
+	 */
+	public function get_thrower(): object {
+		return $this->thrower;
+	}
+
+	/**
+	 * Gets the id of the cached object as passed to the exception constructor.
+	 *
+	 * @return int|string|null The id of the cached object.
+	 */
+	public function get_cached_id() {
+		return $this->cached_id;
+	}
+}

wp/wp-content/plugins/woocommerce/src/Caching/CacheNameSpaceTrait.php

@@ -0,0 +1,66 @@
+<?php
+
+namespace Automattic\WooCommerce\Caching;
+
+/**
+ * Implements namespacing algorithm to simulate grouping and namespacing for wp_cache, memcache and other caching engines that don't support grouping natively.
+ *
+ * See the algorithm details here: https://github.com/memcached/memcached/wiki/ProgrammingTricks#namespacing.
+ *
+ * To use the namespacing algorithm in the CacheEngine class:
+ * 1. Use a group string to identify all objects of a type.
+ * 2. Before setting cache, prefix the cache key by using the `get_cache_prefix`.
+ * 3. Use `invalidate_cache_group` function to invalidate all caches in entire group at once.
+ */
+trait CacheNameSpaceTrait {
+
+	/**
+	 * Get prefix for use with wp_cache_set. Allows all cache in a group to be invalidated at once.
+	 *
+	 * @param  string $group Group of cache to get.
+	 * @return string Prefix.
+	 */
+	public static function get_cache_prefix( $group ) {
+		// Get cache key - uses cache key wc_orders_cache_prefix to invalidate when needed.
+		$prefix = wp_cache_get( 'wc_' . $group . '_cache_prefix', $group );
+
+		if ( false === $prefix ) {
+			$prefix = microtime();
+			wp_cache_set( 'wc_' . $group . '_cache_prefix', $prefix, $group );
+		}
+
+		return 'wc_cache_' . $prefix . '_';
+	}
+
+	/**
+	 * Increment group cache prefix (invalidates cache).
+	 *
+	 * @param string $group Group of cache to clear.
+	 */
+	public static function incr_cache_prefix( $group ) {
+		wc_deprecated_function( 'WC_Cache_Helper::incr_cache_prefix', '3.9.0', 'WC_Cache_Helper::invalidate_cache_group' );
+		self::invalidate_cache_group( $group );
+	}
+
+	/**
+	 * Invalidate cache group.
+	 *
+	 * @param string $group Group of cache to clear.
+	 * @since 3.9.0
+	 */
+	public static function invalidate_cache_group( $group ) {
+		return wp_cache_set( 'wc_' . $group . '_cache_prefix', microtime(), $group );
+	}
+
+	/**
+	 * Helper method to get prefixed key.
+	 *
+	 * @param  string $key   Key to prefix.
+	 * @param  string $group Group of cache to get.
+	 *
+	 * @return string Prefixed key.
+	 */
+	public static function get_prefixed_key( $key, $group ) {
+		return self::get_cache_prefix( $group ) . $key;
+	}
+}

wp/wp-content/plugins/woocommerce/src/Caching/ObjectCache.php

@@ -0,0 +1,317 @@
+<?php
+
+namespace Automattic\WooCommerce\Caching;
+
+/**
+ * Base class for caching objects (or associative arrays) that have a unique identifier.
+ * At the very least, derived classes need to implement the 'get_object_type' method,
+ * but usually it will be convenient to override some of the other protected members.
+ *
+ * The actual caching is delegated to an instance of CacheEngine. By default WpCacheEngine is used,
+ * but a different engine can be used by either overriding the get_cache_engine_instance method
+ * or capturing the wc_object_cache_get_engine filter.
+ *
+ * Objects are identified by ids that are either integers or strings. The actual cache keys passed
+ * to the cache engine will be prefixed with the object type and a random string. The 'flush' operation
+ * just forces the generation a new prefix and lets the old cached objects expire.
+ */
+abstract class ObjectCache {
+
+	/**
+	 * Expiration value to be passed to 'set' to use the value of $default_expiration.
+	 */
+	public const DEFAULT_EXPIRATION = -1;
+
+	/**
+	 * Maximum expiration time value, in seconds, that can be passed to 'set'.
+	 */
+	public const MAX_EXPIRATION = MONTH_IN_SECONDS;
+
+	/**
+	 * This needs to be set in each derived class.
+	 *
+	 * @var string
+	 */
+	private $object_type;
+
+	/**
+	 * Default value for the duration of the objects in the cache, in seconds
+	 * (may not be used depending on the cache engine used WordPress cache implementation).
+	 *
+	 * @var int
+	 */
+	protected $default_expiration = HOUR_IN_SECONDS;
+
+	/**
+	 * Temporarily used when retrieving data in 'get'.
+	 *
+	 * @var array
+	 */
+	private $last_cached_data;
+
+	/**
+	 * The cache engine to use.
+	 *
+	 * @var ?CacheEngine
+	 */
+	private $cache_engine = null;
+
+	/**
+	 * Gets an identifier for the types of objects cached by this class.
+	 * This identifier will be used to compose the keys passed to the cache engine,
+	 * to the name of the option that stores the cache prefix, and the names of the hooks used.
+	 * It must be unique for each class inheriting from ObjectCache.
+	 *
+	 * @return string
+	 */
+	abstract public function get_object_type(): string;
+
+	/**
+	 * Creates a new instance of the class.
+	 *
+	 * @throws CacheException If get_object_type returns null or an empty string.
+	 */
+	public function __construct() {
+		$this->object_type = $this->get_object_type();
+		if ( empty( $this->object_type ) ) {
+			throw new CacheException( 'Class ' . get_class( $this ) . ' returns an empty value for get_object_type', $this );
+		}
+	}
+
+	/**
+	 * Get the default expiration time for cached objects, in seconds.
+	 *
+	 * @return int
+	 */
+	public function get_default_expiration_value(): int {
+		return $this->default_expiration;
+	}
+
+	/**
+	 * Get the cache engine to use and cache it internally.
+	 *
+	 * @return CacheEngine
+	 */
+	private function get_cache_engine(): CacheEngine {
+		if ( null === $this->cache_engine ) {
+			$engine = $this->get_cache_engine_instance();
+
+			/**
+			 * Filters the underlying cache engine to be used by an instance of ObjectCache.
+			 *
+			 * @since 7.4.0
+			 *
+			 * @param CacheEngine $engine The cache engine to be used by default.
+			 * @param ObjectCache $cache_instance The instance of ObjectCache that will use the cache engine.
+			 * @returns CacheEngine The actual cache engine that will be used.
+			 */
+			$this->cache_engine = apply_filters( 'wc_object_cache_get_engine', $engine, $this );
+		}
+		return $this->cache_engine;
+	}
+
+	/**
+	 * Add an object to the cache, or update an already cached object.
+	 *
+	 * @param object|array    $object The object to be cached.
+	 * @param int|string|null $id Id of the object to be cached, if null, get_object_id will be used to get it.
+	 * @param int             $expiration Expiration of the cached data in seconds from the current time, or DEFAULT_EXPIRATION to use the default value.
+	 * @return bool True on success, false on error.
+	 * @throws CacheException Invalid parameter, or null id was passed and get_object_id returns null too.
+	 */
+	public function set( $object, $id = null, int $expiration = self::DEFAULT_EXPIRATION ): bool {
+		if ( null === $object ) {
+			throw new CacheException( "Can't cache a null value", $this, $id );
+		}
+
+		if ( ! is_array( $object ) && ! is_object( $object ) ) {
+			throw new CacheException( "Can't cache a non-object, non-array value", $this, $id );
+		}
+
+		if ( ! is_string( $id ) && ! is_int( $id ) && ! is_null( $id ) ) {
+			throw new CacheException( "Object id must be an int, a string, or null for 'set'", $this, $id );
+		}
+
+		$this->verify_expiration_value( $expiration );
+
+		$errors = $this->validate( $object );
+		if ( ! is_null( $errors ) ) {
+			try {
+				$id = $this->get_id_from_object_if_null( $object, $id );
+			} catch ( \Throwable $ex ) { // phpcs:ignore Generic.CodeAnalysis.EmptyStatement.DetectedCatch
+				// Nothing else to do, we won't be able to add any significant object id to the CacheException and that's it.
+			}
+
+			if ( count( $errors ) === 1 ) {
+				throw new CacheException( 'Object validation/serialization failed: ' . $errors[0], $this, $id, $errors );
+			} elseif ( ! empty( $errors ) ) {
+				throw new CacheException( 'Object validation/serialization failed', $this, $id, $errors );
+			}
+		}
+
+		$id = $this->get_id_from_object_if_null( $object, $id );
+
+		$this->last_cached_data = $object;
+		return $this->get_cache_engine()->cache_object(
+			$id,
+			$object,
+			self::DEFAULT_EXPIRATION === $expiration ? $this->default_expiration : $expiration,
+			$this->get_object_type()
+		);
+	}
+
+	/**
+	 * Update an object in the cache, but only if an object is already cached with the same id.
+	 *
+	 * @param object|array    $object The new object that will replace the already cached one.
+	 * @param int|string|null $id Id of the object to be cached, if null, get_object_id will be used to get it.
+	 * @param int             $expiration Expiration of the cached data in seconds from the current time, or DEFAULT_EXPIRATION to use the default value.
+	 * @return bool True on success, false on error or if no object wiith the supplied id was cached.
+	 * @throws CacheException Invalid parameter, or null id was passed and get_object_id returns null too.
+	 */
+	public function update_if_cached( $object, $id = null, int $expiration = self::DEFAULT_EXPIRATION ): bool {
+		$id = $this->get_id_from_object_if_null( $object, $id );
+
+		if ( ! $this->is_cached( $id ) ) {
+			return false;
+		}
+
+		return $this->set( $object, $id, $expiration );
+	}
+
+	/**
+	 * Get the id from an object if the id itself is null.
+	 *
+	 * @param object|array    $object The object to get the id from.
+	 * @param int|string|null $id An object id or null.
+	 *
+	 * @return int|string|null Passed $id if it wasn't null, otherwise id obtained from $object using get_object_id.
+	 *
+	 * @throws CacheException Passed $id is null and get_object_id returned null too.
+	 */
+	private function get_id_from_object_if_null( $object, $id ) {
+		if ( null === $id ) {
+			$id = $this->get_object_id( $object );
+			if ( null === $id ) {
+				throw new CacheException( "Null id supplied and the cache class doesn't implement get_object_id", $this );
+			}
+		}
+
+		return $id;
+	}
+
+	/**
+	 * Check if the given expiration time value is valid, throw an exception if not.
+	 *
+	 * @param int $expiration Expiration time to check.
+	 * @return void
+	 * @throws CacheException Expiration time is negative or higher than MAX_EXPIRATION.
+	 */
+	private function verify_expiration_value( int $expiration ): void {
+		if ( self::DEFAULT_EXPIRATION !== $expiration && ( ( $expiration < 1 ) || ( $expiration > self::MAX_EXPIRATION ) ) ) {
+			throw new CacheException( 'Invalid expiration value, must be ObjectCache::DEFAULT_EXPIRATION or a value between 1 and ObjectCache::MAX_EXPIRATION', $this );
+		}
+	}
+
+	/**
+	 * Retrieve a cached object, and if no object is cached with the given id,
+	 * try to get one via get_from_datastore method or by supplying a callback and then cache it.
+	 *
+	 * If you want to provide a callable but still use the default expiration value,
+	 * pass "ObjectCache::DEFAULT_EXPIRATION" as the second parameter.
+	 *
+	 * @param int|string    $id The id of the object to retrieve.
+	 * @param int           $expiration Expiration of the cached data in seconds from the current time, used if an object is retrieved from datastore and cached.
+	 * @param callable|null $get_from_datastore_callback Optional callback to get the object if it's not cached, it must return an object/array or null.
+	 * @return object|array|null Cached object, or null if it's not cached and can't be retrieved from datastore or via callback.
+	 * @throws CacheException Invalid id parameter.
+	 */
+	public function get( $id, int $expiration = self::DEFAULT_EXPIRATION, callable $get_from_datastore_callback = null ) {
+		if ( ! is_string( $id ) && ! is_int( $id ) ) {
+			throw new CacheException( "Object id must be an int or a string for 'get'", $this );
+		}
+
+		$this->verify_expiration_value( $expiration );
+
+		$data = $this->get_cache_engine()->get_cached_object( $id, $this->get_object_type() );
+		if ( null === $data ) {
+			$object = null;
+			if ( $get_from_datastore_callback ) {
+				$object = $get_from_datastore_callback( $id );
+			}
+
+			if ( null === $object ) {
+				return null;
+			}
+			$this->set( $object, $id, $expiration );
+			$data = $this->last_cached_data;
+		}
+
+		return $data;
+	}
+
+	/**
+	 * Remove an object from the cache.
+	 *
+	 * @param int|string $id The id of the object to remove.
+	 * @return bool True if the object is removed from the cache successfully, false otherwise (because the object wasn't cached or for other reason).
+	 */
+	public function remove( $id ): bool {
+		return $this->get_cache_engine()->delete_cached_object( $id, $this->get_object_type() );
+	}
+
+	/**
+	 * Remove all the objects from the cache.
+	 *
+	 * @return bool True on success, false on error.
+	 */
+	public function flush(): bool {
+		return $this->get_cache_engine()->delete_cache_group( $this->get_object_type() );
+	}
+
+	/**
+	 * Is a given object cached?
+	 *
+	 * @param int|string $id The id of the object to check.
+	 * @return bool True if there's a cached object with the specified id.
+	 */
+	public function is_cached( $id ): bool {
+		return $this->get_cache_engine()->is_cached( $id, $this->get_object_type() );
+	}
+
+	/**
+	 * Get the id of an object. This is used by 'set' when a null id is passed.
+	 * If the object id can't be determined the method must return null.
+	 *
+	 * @param array|object $object The object to get the id for.
+	 * @return int|string|null
+	 */
+	abstract protected function get_object_id( $object );
+
+	/**
+	 * Validate an object before it's cached.
+	 *
+	 * @param array|object $object Object to validate.
+	 * @return array|null An array with validation error messages, null or an empty array if there are no errors.
+	 */
+	abstract protected function validate( $object ): ?array;
+
+	/**
+	 * Get the instance of the cache engine to use.
+	 *
+	 * @return CacheEngine
+	 */
+	protected function get_cache_engine_instance(): CacheEngine {
+		return wc_get_container()->get( WPCacheEngine::class );
+	}
+
+	/**
+	 * Get a random string to be used to compose the cache key prefix.
+	 * It should return a different string each time.
+	 *
+	 * @return string
+	 */
+	protected function get_random_string(): string {
+		return dechex( microtime( true ) * 1000 ) . bin2hex( random_bytes( 8 ) );
+	}
+}

wp/wp-content/plugins/woocommerce/src/Caching/WPCacheEngine.php

@@ -0,0 +1,76 @@
+<?php
+
+namespace Automattic\WooCommerce\Caching;
+
+/**
+ * Implementation of CacheEngine that uses the built-in WordPress cache.
+ */
+class WPCacheEngine implements CacheEngine {
+	use CacheNameSpaceTrait;
+
+	/**
+	 * Retrieves an object cached under a given key.
+	 *
+	 * @param string $key They key under which the object to retrieve is cached.
+	 * @param string $group The group under which the object is cached.
+	 *
+	 * @return array|object|null The cached object, or null if there's no object cached under the passed key.
+	 */
+	public function get_cached_object( string $key, string $group = '' ) {
+		$prefixed_key = self::get_prefixed_key( $key, $group );
+		$value        = wp_cache_get( $prefixed_key, $group );
+		return false === $value ? null : $value;
+	}
+
+	/**
+	 * Caches an object under a given key, and with a given expiration.
+	 *
+	 * @param string       $key The key under which the object will be cached.
+	 * @param array|object $object The object to cache.
+	 * @param int          $expiration Expiration for the cached object, in seconds.
+	 * @param string       $group The group under which the object will be cached.
+	 *
+	 * @return bool True if the object is cached successfully, false otherwise.
+	 */
+	public function cache_object( string $key, $object, int $expiration, string $group = '' ): bool {
+		$prefixed_key = self::get_prefixed_key( $key, $group );
+		return false !== wp_cache_set( $prefixed_key, $object, $group, $expiration );
+	}
+
+	/**
+	 * Removes a cached object from the cache.
+	 *
+	 * @param string $key They key under which the object is cached.
+	 * @param string $group The group under which the object is cached.
+	 *
+	 * @return bool True if the object is removed from the cache successfully, false otherwise (because the object wasn't cached or for other reason).
+	 */
+	public function delete_cached_object( string $key, string $group = '' ): bool {
+		$prefixed_key = self::get_prefixed_key( $key, $group );
+		return false !== wp_cache_delete( $prefixed_key, $group );
+	}
+
+	/**
+	 * Checks if an object is cached under a given key.
+	 *
+	 * @param string $key The key to verify.
+	 * @param string $group The group under which the object is cached.
+	 *
+	 * @return bool True if there's an object cached under the given key, false otherwise.
+	 */
+	public function is_cached( string $key, string $group = '' ): bool {
+		$prefixed_key = self::get_prefixed_key( $key, $group );
+		return false !== wp_cache_get( $prefixed_key, $group );
+	}
+
+	/**
+	 * Deletes all cached objects under a given group.
+	 *
+	 * @param string $group The group to delete.
+	 *
+	 * @return bool True if the group is deleted successfully, false otherwise.
+	 */
+	public function delete_cache_group( string $group = '' ): bool {
+		return false !== self::invalidate_cache_group( $group );
+	}
+}