Implemented Transactions

src/pocketmine/inventory/BaseInventory.php

@@ -94,7 +94,7 @@ abstract class BaseInventory implements Inventory{
 	}
 
 	public function getItem($index){
-		return isset($this->slots[$index]) ? $this->slots[$index] : Item::get(Item::AIR, null, 0);
+		return isset($this->slots[$index]) ? clone $this->slots[$index] : Item::get(Item::AIR, null, 0);
 	}
 
 	public function getContents(){
@@ -121,6 +121,7 @@ abstract class BaseInventory implements Inventory{
 	}
 
 	public function setItem($index, Item $item){
+		$item = clone $item;
 		if($index < 0 or $index >= $this->size){
 			return false;
 		}elseif($item->getID() === 0){

src/pocketmine/inventory/BaseTransaction.php

@@ -0,0 +1,64 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+namespace pocketmine\inventory;
+
+use pocketmine\item\Item;
+
+class BaseTransaction implements Transaction{
+	/** @var Inventory */
+	protected $inventory;
+	/** @var int */
+	protected $slot;
+	/** @var Item */
+	protected $sourceItem;
+	/** @var Item */
+	protected $targetItem;
+
+	/**
+	 * @param Inventory $inventory
+	 * @param int       $slot
+	 * @param Item      $sourceItem
+	 * @param Item      $targetItem
+	 */
+	public function __construct(Inventory $inventory, $slot, Item $sourceItem, Item $targetItem){
+		$this->inventory = $inventory;
+		$this->slot = (int) $slot;
+		$this->sourceItem = clone $sourceItem;
+		$this->targetItem = clone $targetItem;
+	}
+
+	public function getInventory(){
+		return $this->inventory;
+	}
+
+	public function getSlot(){
+		return $this->slot;
+	}
+
+	public function getSourceItem(){
+		return clone $this->sourceItem;
+	}
+
+	public function getTargetItem(){
+		return clone $this->targetItem;
+	}
+}

src/pocketmine/inventory/CraftingInventory.php

@@ -0,0 +1,60 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+namespace pocketmine\inventory;
+
+/**
+ * Manages crafting operations
+ * This class includes future methods for shaped crafting
+ *
+ * TODO: add small matrix inventory
+ */
+class CraftingInventory extends BaseInventory{
+
+	/** @var Inventory */
+	private $resultInventory;
+
+	/**
+	 * @param InventoryHolder $holder
+	 * @param Inventory       $resultInventory
+	 * @param InventoryType   $inventoryType
+	 *
+	 * @throws \Exception
+	 */
+	public function __construct(InventoryHolder $holder, Inventory $resultInventory, InventoryType $inventoryType){
+		if($inventoryType->getDefaultTitle() !== "Crafting"){
+			throw new \Exception("Invalid Inventory type, expected CRAFTING or WORKBENCH");
+		}
+		$this->resultInventory = $resultInventory;
+		parent::__construct($holder, $inventoryType);
+	}
+
+	/**
+	 * @return Inventory
+	 */
+	public function getResultInventory(){
+		return $this->resultInventory;
+	}
+
+	public function getSize(){
+		return $this->getResultInventory()->getSize() + parent::getSize();
+	}
+}

src/pocketmine/inventory/CraftingManager.php

@@ -0,0 +1,73 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+namespace pocketmine\inventory;
+
+class CraftingManager{
+
+	/** @var Recipe[] */
+	public $recipes = [];
+	/** @var FurnaceRecipe[] */
+	public $furnaceRecipes = [];
+
+	public function __construct(){
+		//TODO: add crafting recipes
+	}
+
+	public function sort(){
+		//TODO: recipe sort
+	}
+
+	/**
+	 * @param ShapedRecipe $recipe
+	 */
+	public function registerShapedRecipe(ShapedRecipe $recipe){
+
+	}
+
+	/**
+	 * @param ShapelessRecipe $recipe
+	 */
+	public function registerShapelessRecipe(ShapelessRecipe $recipe){
+
+	}
+
+	/**
+	 * @param FurnaceRecipe $recipe
+	 */
+	public function registerFurnaceRecipe(FurnaceRecipe $recipe){
+
+	}
+
+	/**
+	 * @param Recipe $recipe
+	 */
+	public function registerRecipe(Recipe $recipe){
+		if($recipe instanceof ShapedRecipe){
+			$this->registerShapedRecipe($recipe);
+		}elseif($recipe instanceof ShapelessRecipe){
+			$this->registerShapelessRecipe($recipe);
+		}elseif($recipe instanceof FurnaceRecipe){
+			$this->registerFurnaceRecipe($recipe);
+		}
+	}
+
+}

src/pocketmine/inventory/CraftingTransactionGroup.php

@@ -0,0 +1,36 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+namespace pocketmine\inventory;
+
+class CraftingTransactionGroup extends SimpleTransactionGroup{
+
+	public function __construct(TransactionGroup $group){
+		parent::__construct();
+		$this->transactions = $group->getTransactions();
+		$this->inventories = $group->getInventories();
+	}
+
+	public function canExecute(){
+		//TODO: search in crafting recipes
+		return false;
+	}
+}

src/pocketmine/inventory/FurnaceRecipe.php

@@ -0,0 +1,114 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+namespace pocketmine\inventory;
+
+use pocketmine\item\Item;
+
+class FurnaceRecipe implements Recipe{
+	/** @var Item */
+	private $output;
+
+	/** @var Item */
+	private $ingredient;
+
+	/**
+	 * @param Item $result
+	 * @param Item $ingredient
+	 */
+	public function __construct(Item $result, Item $ingredient){
+		$this->output = clone $result;
+		$this->ingredient = clone $ingredient;
+	}
+
+	/**
+	 * @param Item $item
+	 */
+	public function setInput(Item $item){
+		$this->ingredient = clone $item;
+	}
+
+	/**
+	 * @return Item
+	 */
+	public function getInput(){
+		return clone $this->ingredient;
+	}
+
+	/**
+	 * @return Item
+	 */
+	public function getResult(){
+		return clone $this->output;
+	}
+
+	/**
+	 * @param Item $item
+	 *
+	 * @returns ShapelessRecipe
+	 *
+	 * @throws \Exception
+	 */
+	public function addIngredient(Item $item){
+		if(count($this->ingredients) >= 9){
+			throw new \Exception("Shapeless recipes cannot have more than 9 ingredients");
+		}
+
+		$it = clone $item;
+		$it->setCount(1);
+
+		while($item->getCount() > 0){
+			$this->ingredients[] = clone $it;
+			$item->setCount($item->getCount() - 1);
+		}
+
+		return $this;
+	}
+
+	/**
+	 * @param Item $item
+	 *
+	 * @return $this
+	 */
+	public function removeIngredient(Item $item){
+		foreach($this->ingredients as $index => $ingredient){
+			if($item->getCount() <= 0){
+				break;
+			}
+			if($ingredient->equals($item, $item->getDamage() === null ? false : true)){
+				unset($this->ingredients[$index]);
+				$item->setCount($item->getCount() - 1);
+			}
+		}
+		return $this;
+	}
+
+	/**
+	 * @return Item[]
+	 */
+	public function getIngredientList(){
+		$ingredients = [];
+		foreach($this->ingredients as $ingredient){
+			$ingredients[] = clone $ingredient;
+		}
+		return $ingredients;
+	}
+}

src/pocketmine/inventory/Recipe.php

@@ -0,0 +1,32 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+namespace pocketmine\inventory;
+
+interface Recipe{
+
+	/**
+	 * @return \pocketmine\item\Item
+	 */
+	public function getResult();
+
+	public function registerToCraftingManager();
+}

src/pocketmine/inventory/ShapedRecipe.php

@@ -0,0 +1,101 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+namespace pocketmine\inventory;
+
+use pocketmine\item\Item;
+
+class ShapedRecipe implements Recipe{
+	/** @var Item */
+	private $output;
+
+	/** @var string[] */
+	private $rows = [];
+
+	/** @var Item[] */
+	private $ingredients = [];
+
+	/**
+	 * @param Item     $result
+	 * @param string[] $shape
+	 *
+	 * @throws \Exception
+	 */
+	public function __construct(Item $result, array $shape = []){
+		if(count($shape) === 0){
+			throw new \Exception("Must provide a shape");
+		}
+		if(count($shape) > 3){
+			throw new \Exception("Crafting recipes should  be 1, 2, 3 rows, not ".count($shape));
+		}
+		foreach($shape as $row){
+			if(strlen($row) === 0 or strlen($row) > 3){
+				throw new \Exception("Crafting rows should  be 1, 2, 3 characters, not ".count($row));
+			}
+			$this->rows[] = $row;
+			$len = strlen($row);
+			for($i = 0; $i < $len; ++$i){
+				$this->ingredients[$row{$i}] = null;
+			}
+		}
+
+		$this->output = clone $result;
+	}
+
+	/**
+	 * @param string $key
+	 * @param Item   $item
+	 *
+	 * @return $this
+	 * @throws \Exception
+	 */
+	public function setIngredient($key, Item $item){
+		if(!isset($this->ingredients[$key])){
+			throw new \Exception("Symbol does not appear in the shape: ". $key);
+		}
+
+		$this->ingredients[$key] = $item;
+
+		return $this;
+	}
+
+	/**
+	 * @return Item[]
+	 */
+	public function getIngredientMap(){
+		$ingredients = [];
+		foreach($this->ingredients as $key => $ingredient){
+			if($ingredient instanceof Item){
+				$ingredients[$key] = clone $ingredient;
+			}else{
+				$ingredients[$key] = $ingredient;
+			}
+		}
+		return $ingredients;
+	}
+
+	/**
+	 * @return string[]
+	 */
+	public function getShape(){
+		return $this->rows;
+	}
+}

src/pocketmine/inventory/ShapelessRecipe.php

@@ -0,0 +1,92 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+namespace pocketmine\inventory;
+
+use pocketmine\item\Item;
+
+class ShapelessRecipe implements Recipe{
+	/** @var Item */
+	private $output;
+
+	/** @var Item[] */
+	private $ingredients = [];
+
+	public function __construct(Item $result){
+		$this->output = clone $result;
+	}
+
+	public function getResult(){
+		return clone $this->output;
+	}
+
+	/**
+	 * @param Item $item
+	 *
+	 * @returns ShapelessRecipe
+	 *
+	 * @throws \Exception
+	 */
+	public function addIngredient(Item $item){
+		if(count($this->ingredients) >= 9){
+			throw new \Exception("Shapeless recipes cannot have more than 9 ingredients");
+		}
+
+		$it = clone $item;
+		$it->setCount(1);
+
+		while($item->getCount() > 0){
+			$this->ingredients[] = clone $it;
+			$item->setCount($item->getCount() - 1);
+		}
+
+		return $this;
+	}
+
+	/**
+	 * @param Item $item
+	 *
+	 * @return $this
+	 */
+	public function removeIngredient(Item $item){
+		foreach($this->ingredients as $index => $ingredient){
+			if($item->getCount() <= 0){
+				break;
+			}
+			if($ingredient->equals($item, $item->getDamage() === null ? false : true)){
+				unset($this->ingredients[$index]);
+				$item->setCount($item->getCount() - 1);
+			}
+		}
+		return $this;
+	}
+
+	/**
+	 * @return Item[]
+	 */
+	public function getIngredientList(){
+		$ingredients = [];
+		foreach($this->ingredients as $ingredient){
+			$ingredients[] = clone $ingredient;
+		}
+		return $ingredients;
+	}
+}

src/pocketmine/inventory/SimpleTransactionGroup.php

@@ -0,0 +1,109 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+namespace pocketmine\inventory;
+
+use pocketmine\item\Item;
+
+/**
+ * This TransactionGroup only allows doing Transaction between one / two inventories
+ */
+class SimpleTransactionGroup implements TransactionGroup{
+	private $creationTime;
+	protected $hasExecuted = false;
+
+	/** @var Inventory[] */
+	protected $inventories = [];
+
+	/** @var Transaction[] */
+	protected $transactions = [];
+
+	public function __construct(){
+		$this->creationTime = microtime(true);
+	}
+
+	public function getCreationTime(){
+		return $this->creationTime;
+	}
+
+	public function getInventories(){
+		return $this->inventories;
+	}
+
+	public function getTransactions(){
+		return $this->transactions;
+	}
+
+	public function addTransaction(Transaction $transaction){
+		$this->transactions[spl_object_hash($transaction)] = $transaction;
+		$this->inventories[spl_object_hash($transaction->getInventory())] = $transaction->getInventory();
+	}
+
+	public function canExecute(){
+		/** @var Item[] $needItems */
+		$needItems = [];
+		/** @var Item[] $haveItems */
+		$haveItems = [];
+		foreach($this->transactions as $key => $ts){
+			$needItems[] = $ts->getTargetItem();
+			$checkSourceItem = $ts->getInventory()->getItem($ts->getSlot());
+			$sourceItem = $ts->getSourceItem();
+			if(!$checkSourceItem->equals($sourceItem, true) or $sourceItem->getCount() !== $checkSourceItem->getCount()){
+				return false;
+			}
+			$haveItems[] = $sourceItem;
+		}
+
+		foreach($needItems as $i => $needItem){
+			foreach($haveItems as $j => $haveItem){
+				if($needItem->equals($haveItem, true)){
+					$amount = min($needItem->getCount(), $haveItem->getCount());
+					$needItem->setCount($needItem->getCount() - $amount);
+					$haveItem->setCount($haveItem->getCount() - $amount);
+					if($haveItem->getCount() === 0){
+						unset($haveItems[$j]);
+					}
+					if($needItem->getCount() === 0){
+						unset($needItems[$i]);
+						break;
+					}
+				}
+			}
+		}
+
+		return count($haveItems) === 0 and count($needItems) === 0 and count($this->transactions) > 0;
+	}
+
+	public function execute(){
+		if($this->hasExecuted() or !$this->canExecute()){
+			return false;
+		}
+		foreach($this->transactions as $transaction){
+			$transaction->getInventory()->setItem($transaction->getSlot(), $transaction->getTargetItem());
+		}
+
+		return true;
+	}
+
+	public function hasExecuted(){
+		return $this->hasExecuted;
+	}
+}

src/pocketmine/inventory/Transaction.php

@@ -0,0 +1,47 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+namespace pocketmine\inventory;
+
+use pocketmine\item\Item;
+
+interface Transaction{
+
+	/**
+	 * @return Inventory
+	 */
+	public function getInventory();
+
+	/**
+	 * @return int
+	 */
+	public function getSlot();
+
+	/**
+	 * @return Item
+	 */
+	public function getSourceItem();
+
+	/**
+	 * @return Item
+	 */
+	public function getTargetItem();
+}

src/pocketmine/inventory/TransactionGroup.php

@@ -0,0 +1,63 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+namespace pocketmine\inventory;
+
+use pocketmine\item\Item;
+
+interface TransactionGroup{
+
+	/**
+	 * @return float
+	 */
+	function getCreationTime();
+
+	/**
+	 * @return Transaction[]
+	 */
+	function getTransactions();
+
+	/**
+	 * @return Inventory[]
+	 */
+	function getInventories();
+
+	/**
+	 * @param Transaction $transaction
+	 */
+	function addTransaction(Transaction $transaction);
+
+	/**
+	 * @return bool
+	 */
+	function canExecute();
+
+	/**
+	 * @return bool
+	 */
+	function execute();
+
+	/**
+	 * @return bool
+	 */
+	function hasExecuted();
+
+}