代码如何优化

有时候在写代码的时候只关注功能的实现，代码的质量很差，这里用一个修改某个表中数值的例子来说明，如何实现代码逐步优化的过程：

实例1：

第一种实现方式：

if($enableQuantity >= $transactionQuantity){
                //更新锁定库存的数量
                $inventory_locked_data = array(
                    "locked_quantity" => $inventoryItem['locked_quantity'] + $transactionQuantity,
                    "locked_real_quantity" => $inventoryItem['locked_real_quantity'] + $transactionQuantity * $inventoryItem['unit_quantity']
                );
                
                //记录库存锁定交易过程
                $inventory_locked_transaction_data = array(
                    "inventory_item_id" => $inventoryItem['inventory_item_id'],
                    "quantity" => $transactionQuantity,
                    "real_quantity" => $transactionQuantity * $inventoryItem['unit_quantity'],
                    "created_user" => $params['created_user']
                );
                $transactionQuantity = 0; 
            }else{
                //更新锁定库存的数量
                $inventory_locked_data = array(
                    "locked_quantity" => $inventoryItem['locked_quantity'] + $enableQuantity,
                    "locked_real_quantity" => $inventoryItem['locked_real_quantity'] + $enableQuantity * $inventoryItem['unit_quantity']
                );
                
                //记录库存锁定交易过程
                $inventory_locked_transaction_data = array(
                    "inventory_item_id" => $inventoryItem['inventory_item_id'],
                    "quantity" => $enableQuantity,
                    "real_quantity" => $enableQuantity * $inventoryItem['unit_quantity'],
                    "created_user" => $params['created_user']
                );
                $transactionQuantity -= $enableQuantity;
            }

第二种实现方式：

$inventory_locked_transaction_data_list = array();
$inventory_item_ids = explode("," , ModelPalletModel::getInventoryItemIdsByPalletIds($params['pallet_id']));
$transactionQuantity = $params['quantity'];
foreach($inventory_item_ids as $inventory_item_id){
    $inventoryItem = ModelInventoryItemModel::getInventoryItemById($inventory_item_id);
    
    $enableQuantity = $inventoryItem['quantity'] - $inventoryItem['locked_quantity'];
    
    if($enableQuantity <= 0){
        continue;
    }
    
    if ($transactionQuantity == 0) {
        break;
    }
    //原先使用了if条件进行判断的，导致了下面代码的冗余
    $locked_quantity = $enableQuantity >= $transactionQuantity ? $inventoryItem['locked_quantity'] + $transactionQuantity : $inventoryItem['locked_quantity'] + $enableQuantity;
    $transaction_locked_quantity = $enableQuantity >= $transactionQuantity ? $transactionQuantity : $enableQuantity;
    
    //更新锁定库存的数量
    $inventory_locked_data = array(
        "locked_quantity" => $locked_quantity,
        "locked_real_quantity" => $locked_quantity * $inventoryItem['unit_quantity']
    );
    
    //记录库存锁定交易过程
    $inventory_locked_transaction_data = array(
        "inventory_item_id" => $inventoryItem['inventory_item_id'],
        "quantity" => $transaction_locked_quantity,
        "real_quantity" => $transaction_locked_quantity * $inventoryItem['unit_quantity'],
        "created_user" => $params['created_user']
    );
    
    $transactionQuantity -= $transaction_locked_quantity;
    
    ModelInventoryItemModel::updateInventoryItem($inventoryItem['inventory_item_id'] , $inventory_locked_data);
    ModelInventoryItemModel::createInventoryLockedTransaction($inventory_locked_transaction_data);
    array_push($inventory_locked_transaction_data_list , $inventory_locked_transaction_data);
}

第三种实现方式：

$inventory_locked_transaction_data_list = array();
        $inventory_item_ids = explode("," , ModelPalletModel::getInventoryItemIdsByPalletIds($params['pallet_id']));
        $transactionQuantity = $params['quantity'];
        foreach($inventory_item_ids as $inventory_item_id){
            $inventoryItem = ModelInventoryItemModel::getInventoryItemById($inventory_item_id);
            
            $enableQuantity = $inventoryItem['quantity'] - $inventoryItem['locked_quantity'];
            
            if($enableQuantity <= 0){
                continue;
            }
            
            if ($transactionQuantity == 0) {
                break;
            }
            //优化后的代码
            $locked_quantity = min($enableQuantity , $transactionQuantity);
            
            //更新锁定库存的数量
            $inventory_locked_data = array(
                "locked_quantity" => $locked_quantity + $inventoryItem['locked_quantity'],
                "locked_real_quantity" => ($locked_quantity + $inventoryItem['locked_quantity']) * $inventoryItem['unit_quantity']
            );
            
            //记录库存锁定交易过程
            $inventory_locked_transaction_data = array(
                "inventory_item_id" => $inventoryItem['inventory_item_id'],
                "quantity" => $locked_quantity,
                "real_quantity" => $locked_quantity * $inventoryItem['unit_quantity'],
                "created_user" => $params['created_user']
            );
            
            $transactionQuantity -= $locked_quantity;
            
            ModelInventoryItemModel::updateInventoryItem($inventoryItem['inventory_item_id'] , $inventory_locked_data);
            ModelInventoryItemModel::createInventoryLockedTransaction($inventory_locked_transaction_data);
            array_push($inventory_locked_transaction_data_list , $inventory_locked_transaction_data);
        }
        
        if($transactionQuantity > 0){
            Flight::throwException($transactionQuantity , 40002);
        }

第四种实现方式：

        try {
            
            $inventory_locked_transaction_data_list = array();
            $inventory_item_ids = explode("," , ModelPalletModel::getInventoryItemIdsByPalletIds($params['pallet_id']));
            $transactionQuantity = $params['quantity'];
            foreach($inventory_item_ids as $inventory_item_id){
                if ($transactionQuantity == 0) {
                    break;
                }
                
                $inventoryItem = ModelInventoryItemModel::getInventoryItemById($inventory_item_id);
                
                $enableQuantity = bcsub($inventoryItem['quantity'] , $inventoryItem['locked_quantity'], 6);
                
                if($enableQuantity <= 0){
                    continue;
                }
                
                $locked_quantity = min($enableQuantity, $transactionQuantity);
                
                //更新锁定库存的数量
                $inventory_locked_data = array(
                    "locked_quantity" => bcadd($locked_quantity, $inventoryItem['locked_quantity'], 6),
                    "locked_real_quantity" => bcmul(bcadd($locked_quantity, $inventoryItem['locked_quantity'], 6), $inventoryItem['unit_quantity'], 6)
                );
                
                //记录库存锁定交易过程
                $inventory_locked_transaction_data = array(
                    "inventory_item_id" => $inventoryItem['inventory_item_id'],
                    "quantity" => $locked_quantity,
                    "real_quantity" => bcmul($locked_quantity, $inventoryItem['unit_quantity'], 6),
                    "created_user" => $params['created_user']
                );
                //使用高精度计算
                $transactionQuantity = bcsub($transactionQuantity,$locked_quantity,6);
                
                ModelInventoryItemModel::updateInventoryItem($inventoryItem['inventory_item_id'] , $inventory_locked_data);
                ModelInventoryItemModel::createInventoryLockedTransaction($inventory_locked_transaction_data);
                array_push($inventory_locked_transaction_data_list , $inventory_locked_transaction_data);
            }
            
            if($transactionQuantity > 0){
                throw new Exception("inventory quantity not sufficient");
            }
            
            Flight::db()->commit();
            Flight::sendRouteResult(array('inventory_item_list' => $inventory_locked_transaction_data_list));
        } catch (Exception $e) {
            Flight::db()->rollback();
            Flignt::sendRouteResult('error_info'=>$e->getMessage(), 'error_code'=>$e->getCode());
        }

这四种代码实现方式主要优化过程在于避免代码冗余，代码处理顺序，数值计算使用高精度等；

实例2：下面是实现一个字符串插入数据库，要求每个字符串唯一；

优化前：

                $res = true;
                for($i = 1; $res; $i++){
                    $inventory_batch_sn = 'F-'.date("YmdHis").'-P-'.$i;
                    if(!empty(InventoryItemModel::getInventoryItemByInventoryBatchSn($inventory_batch_sn))){
                        $res = true;
                    }else{
                        $res = false;
                    }
                }
                $inventory_item_data['inventory_batch_sn'] = $inventory_batch_sn;

优化后1：

 

 $inventory_batch_sn = $params['facility_id'] . '-' . date("YmdHis") . '-' . $params['product_id'] . '-';
 $count = InventoryItemModel::getCountInventoryItemByInventoryBatchSn($inventory_batch_sn);
 $inventory_item_data['inventory_batch_sn'] = $inventory_batch_sn . ($count+1);

减少了代码量；

 

 

优化后2,：

 

                $inventory_batch_sn = $params['facility_id'] . '-' . date("YmdHis") . '-' . $params['product_id'] . '-';
                $inventoryItem = InventoryItemModel::getInventoryItemByInventoryBatchSn($inventory_batch_sn . "1");
                if(empty($inventoryItem)){
                    $inventory_item_data['inventory_batch_sn'] = $inventory_batch_sn . "1";
                } else {
                    $count = InventoryItemModel::getCountInventoryItemByInventoryBatchSn($inventory_batch_sn);
                    $inventory_item_data['inventory_batch_sn'] = $inventory_batch_sn . ($count+1);
                }
 
    public static function getCountInventoryItemByInventoryBatchSn($inventory_batch_sn) {
        $sql = "select count(distinct inventory_batch_sn) from ws_inventory_item where inventory_batch_sn like '{$inventory_batch_sn}%' limit 1 ";
        return Flight::db()->getOne($sql);
    }

这种方式保证了查询性能；