}
/**
- * Handy class for dealing with PoolCounters using class members instead of callbacks.
+ * Class for dealing with PoolCounters using class members
*/
abstract class PoolCounterWork {
protected $cacheable = false; //Does this override getCachedWork() ?
}
/**
- * Get the result of the work (whatever it is), or false.
+ * Get the result of the work (whatever it is), or the result of the error() function.
+ * This returns the result of the first applicable method that returns a non-false value,
+ * where the methods are checked in the following order:
+ * - a) doWork() : Applies if the work is exclusive or no another process
+ * is doing it, and on the condition that either this process
+ * successfully entered the pool or the pool counter is down.
+ * - b) doCachedWork() : Applies if the work is cacheable and this blocked on another
+ * process which finished the work.
+ * - c) fallback() : Applies for all remaining cases.
+ * If these all fall through (by returning false), then the result of error() is returned.
+ *
* @param $skipcache bool
- * @return bool|mixed
+ * @return mixed
*/
public function execute( $skipcache = false ) {
if ( $this->cacheable && !$skipcache ) {
}
}
}
+
+/**
+ * Convenience class for dealing with PoolCounters using callbacks
+ * @since 1.22
+ */
+class PoolCounterWorkViaCallback extends PoolCounterWork {
+ /** @var callable */
+ protected $doWork;
+ /** @var callable|null */
+ protected $doCachedWork;
+ /** @var callable|null */
+ protected $fallback;
+ /** @var callable|null */
+ protected $error;
+
+ /**
+ * Build a PoolCounterWork class from a type, key, and callback map.
+ *
+ * The callback map must at least have a callback for the 'doWork' method.
+ * Additionally, callbacks can be provided for the 'doCachedWork', 'fallback',
+ * and 'error' methods. Methods without callbacks will be no-ops that return false.
+ * If a 'doCachedWork' callback is provided, then execute() may wait for any prior
+ * process in the pool to finish and reuse its cached result.
+ *
+ * @param string $type
+ * @param string $key
+ * @param array $callbacks Map of callbacks
+ * @throws MWException
+ */
+ public function __construct( $type, $key, array $callbacks ) {
+ parent::__construct( $type, $key );
+ foreach ( array( 'doWork', 'doCachedWork', 'fallback', 'error' ) as $name ) {
+ if ( isset( $callbacks[$name] ) ) {
+ if ( !is_callable( $callbacks[$name] ) ) {
+ throw new MWException( "Invalid callback provided for '$name' function." );
+ }
+ $this->$name = $callbacks[$name];
+ }
+ }
+ if ( !isset( $this->doWork ) ) {
+ throw new MWException( "No callback provided for 'doWork' function." );
+ }
+ $this->cacheable = isset( $this->doCachedWork );
+ }
+
+ public function doWork() {
+ return call_user_func_array( $this->doWork, array() );
+ }
+
+ public function getCachedWork() {
+ if ( $this->doCachedWork ) {
+ return call_user_func_array( $this->doCachedWork, array() );
+ }
+ return false;
+ }
+
+ function fallback() {
+ if ( $this->fallback ) {
+ return call_user_func_array( $this->fallback, array() );
+ }
+ return false;
+ }
+
+ function error( $status ) {
+ if ( $this->error ) {
+ return call_user_func_array( $this->error, array( $status ) );
+ }
+ return false;
+ }
+}