快速失败

php中文网 2024-12-04 14:33:22

核心原则

故障发生后立即检测并报告，防止无效状态在系统中传播。

1. 输入验证

class userregistration {
    public function register(array $data): void {
        // validate all inputs immediately
        $this->validateemail($data['email']);
        $this->validatepassword($data['password']);
        $this->validateage($data['age']);

        // only proceed if all validations pass
        $this->createuser($data);
    }

    private function validateemail(string $email): void {
        if (!filter_var($email, filter_validate_email)) {
            throw new validationexception('invalid email format');
        }
        if ($this->emailexists($email)) {
            throw new duplicateemailexception('email already registered');
        }
    }
}

目的：

防止无效数据进入系统
通过在复杂操作之前失败来节省资源
向用户提供清晰的错误消息
维护数据完整性

2. 配置加载

class appconfig {
    private array $config;

    public function __construct(string $configpath) {
        if (!file_exists($configpath)) {
            throw new configurationexception("config file not found: $configpath");
        }

        $config = parse_ini_file($configpath, true);
        if ($config === false) {
            throw new configurationexception("invalid config file format");
        }

        $this->validaterequiredsettings($config);
        $this->config = $config;
    }

    private function validaterequiredsettings(array $config): void {
        $required = ['database', 'api_key', 'environment'];
        foreach ($required as $key) {
            if (!isset($config[$key])) {
                throw new configurationexception("missing required config: $key");
            }
        }
    }
}

目的：

确保应用程序以有效配置启动
防止由于缺少设置而导致运行时错误
使配置问题立即可见
简化调试配置问题

3. 资源初始化

class databaseconnection {
    private pdo $connection;

    public function __construct(array $config) {
        try {
            $this->validatedatabaseconfig($config);
            $this->connection = new pdo(
                $this->builddsn($config),
                $config['username'],
                $config['password'],
                [pdo::attr_errmode => pdo::errmode_exception]
            );
        } catch (pdoexception $e) {
            throw new databaseconnectionexception(
                "failed to connect to database: " . $e->getmessage()
            );
        }
    }

    private function validatedatabaseconfig(array $config): void {
        $required = ['host', 'port', 'database', 'username', 'password'];
        foreach ($required as $param) {
            if (!isset($config[$param])) {
                throw new databaseconfigexception("missing $param in database config");
            }
        }
    }
}

目的：

确保资源正确初始化
防止应用程序使用无效资源运行
使资源问题在启动期间可见
避免由于无效资源导致的级联失败

4. 外部服务调用

class paymentgateway {
    public function processpayment(order $order): paymentresult {
        // validate api credentials
        if (!$this->validateapicredentials()) {
            throw new apiconfigurationexception('invalid api credentials');
        }

        // validate order before external call
        if (!$order->isvalid()) {
            throw new invalidorderexception('invalid order state');
        }

        try {
            $response = $this->apiclient->charge($order);

            if (!$response->issuccessful()) {
                throw new paymentfailedexception($response->geterror());
            }

            return new paymentresult($response);
        } catch (apiexception $e) {
            throw new paymentprocessingexception(
                "payment processing failed: " . $e->getmessage()
            );
        }
    }
}

目的：

防止使用无效数据进行不必要的 api 调用
节省时间和资源
提供有关 api 问题的即时反馈
在外部服务交互期间保持系统可靠性

5. 数据处理管道

class DataProcessor {
    public function processBatch(array $records): array {
        $this->validateBatchSize($records);

        $results = [];
        foreach ($records as $index => $record) {
            try {
                $this->validateRecord($record);
                $results[] = $this->processRecord($record);
            } catch (ValidationException $e) {
                throw new BatchProcessingException(
                    "Failed at record $index: " . $e->getMessage()
                );
            }
        }

        return $results;
    }

    private function validateBatchSize(array $records): void {
        if (empty($records)) {
            throw new EmptyBatchException('Empty batch provided');
        }

        if (count($records) > 1000) {
            throw new BatchSizeException('Batch size exceeds maximum limit');
        }
    }
}

目的：