以下是一个简单的PHP商城队列实现实例，用于处理订单和库存的更新。我们将使用数组作为队列的存储结构。
| 步骤 | 描述 | 代码示例 |
| --- | --- | --- |
| 1 | 创建队列类 | ```php
class Queue {
private $items = [];
public function enqueue($item) {
array_push($this->items, $item);
}
public function dequeue() {
if (count($this->items) > 0) {
return array_shift($this->items);
}
return null;
}
public function isEmpty() {
return count($this->items) == 0;
}
}
``` |
| 2 | 创建订单类 | ```php
class Order {
public $id;
public $product_id;
public $quantity;
public function __construct($id, $product_id, $quantity) {
$this->id = $id;
$this->product_id = $product_id;
$this->quantity = $quantity;
}
}
``` |
| 3 | 创建库存类 | ```php
class Inventory {
private $products = [];
public function addProduct($product_id, $quantity) {
$this->products[$product_id] = $quantity;
}
public function decreaseQuantity($product_id, $quantity) {
if (isset($this->products[$product_id])) {
$this->products[$product_id] -= $quantity;
if ($this->products[$product_id] <= 0) {
unset($this->products[$product_id]);
}
}
}
public function getQuantity($product_id) {
return isset($this->products[$product_id]) ? $this->products[$product_id] : 0;
}
}
``` |
| 4 | 创建订单处理类 | ```php
class OrderProcessor {
private $queue;
private $inventory;
public function __construct() {
$this->queue = new Queue();
$this->inventory = new Inventory();
}
public function processOrder($order) {
if ($this->inventory->getQuantity($order->product_id) >= $order->quantity) {
$this->inventory->decreaseQuantity($order->product_id, $order->quantity);
$this->queue->enqueue($order);
}
}
public function processQueue() {
while (!$this->queue->isEmpty()) {
$order = $this->queue->dequeue();
// 处理订单逻辑
echo "
