PHP 用trait实现的单例

trait.php

<?php
trait Service_Data_Base_Singleton
{
    private static $singleton;
    private function __construct(){}

    public static function getInstance() {
        if( !(self::$singleton instanceof self) ) {
            self::$singleton = new self();
        }
        return self::$singleton;
    }
}

trait2.php

<?php
class Model_Rpc_Merchant extends Sflib_RpcBase
{
    use Service_Data_Base_Singleton;
    
    public function getStockAlarmInfo( $shop_id ) {
        $params = [
            'shop_id'   => $shop_id
        ];
        $path = '/api/merchant/api/checkskustock';
        return $this->_get( $path, $params );
    }
}

trait3.php

<?php 
$sku_info = Model_Rpc_Merchant::getInstance()->getSkuInfoWithShop( $shop_id, $sku_params );