Use entity IDs in EntityDamageBy*EntityEvents, fixed memory leaks related to PvP/PvE/PvM (#418)

src/pocketmine/event/entity/EntityDamageByBlockEvent.php

@@ -24,6 +24,9 @@ namespace pocketmine\event\entity;
 use pocketmine\block\Block;
 use pocketmine\entity\Entity;
 
+/**
+ * Called when an entity takes damage from a block.
+ */
 class EntityDamageByBlockEvent extends EntityDamageEvent{
 
 	/** @var Block */

src/pocketmine/event/entity/EntityDamageByChildEntityEvent.php

@@ -23,10 +23,13 @@ namespace pocketmine\event\entity;
 
 use pocketmine\entity\Entity;
 
+/**
+ * Called when an entity takes damage from an entity sourced from another entity, for example being hit by a snowball thrown by a Player.
+ */
 class EntityDamageByChildEntityEvent extends EntityDamageByEntityEvent{
 
-	/** @var Entity */
-	private $childEntity;
+	/** @var int */
+	private $childEntityEid;
 
 
 	/**
@@ -37,15 +40,17 @@ class EntityDamageByChildEntityEvent extends EntityDamageByEntityEvent{
 	 * @param int|int[] $damage
 	 */
 	public function __construct(Entity $damager, Entity $childEntity, Entity $entity, $cause, $damage){
-		$this->childEntity = $childEntity;
+		$this->childEntityEid = $childEntity->getId();
 		parent::__construct($damager, $entity, $cause, $damage);
 	}
 
 	/**
-	 * @return Entity
+	 * Returns the entity which caused the damage, or null if the entity has been killed or closed.
+	 *
+	 * @return Entity|null
 	 */
 	public function getChild(){
-		return $this->childEntity;
+		return $this->getEntity()->getLevel()->getServer()->findEntity($this->childEntityEid, $this->getEntity()->getLevel());
 	}
 
 

src/pocketmine/event/entity/EntityDamageByEntityEvent.php

@@ -24,10 +24,13 @@ namespace pocketmine\event\entity;
 use pocketmine\entity\Effect;
 use pocketmine\entity\Entity;
 
+/**
+ * Called when an entity takes damage from another entity.
+ */
 class EntityDamageByEntityEvent extends EntityDamageEvent{
 
-	/** @var Entity */
-	private $damager;
+	/** @var int */
+	private $damagerEid;
 	/** @var float */
 	private $knockBack;
 
@@ -39,7 +42,7 @@ class EntityDamageByEntityEvent extends EntityDamageEvent{
 	 * @param float     $knockBack
 	 */
 	public function __construct(Entity $damager, Entity $entity, $cause, $damage, $knockBack = 0.4){
-		$this->damager = $damager;
+		$this->damagerEid = $damager->getId();
 		$this->knockBack = $knockBack;
 		parent::__construct($entity, $cause, $damage);
 		$this->addAttackerModifiers($damager);
@@ -56,10 +59,12 @@ class EntityDamageByEntityEvent extends EntityDamageEvent{
 	}
 
 	/**
-	 * @return Entity
+	 * Returns the attacking entity, or null if the attacker has been killed or closed.
+	 *
+	 * @return Entity|null
 	 */
 	public function getDamager(){
-		return $this->damager;
+		return $this->getEntity()->getLevel()->getServer()->findEntity($this->damagerEid, $this->getEntity()->getLevel());
 	}
 
 	/**

src/pocketmine/event/entity/EntityDamageEvent.php

@@ -25,6 +25,9 @@ use pocketmine\entity\Effect;
 use pocketmine\entity\Entity;
 use pocketmine\event\Cancellable;
 
+/**
+ * Called when an entity takes damage.
+ */
 class EntityDamageEvent extends EntityEvent implements Cancellable{
 	public static $handlerList = null;