PHP curl_multi_exec函数

示例 4：错误处理与重试机制

@php
class RobustMultiExecutor {
    private $multiHandle;
    private $requests = [];
    private $maxRetries;
    private $timeout;

    public function __construct($maxRetries = 3, $timeout = 30) {
        $this->multiHandle = curl_multi_init();
        $this->maxRetries = $maxRetries;
        $this->timeout = $timeout;
    }

    public function addRequest($url, $id = null) {
        if ($id === null) {
            $id = uniqid('req_');
        }

        $this->requests[$id] = [
            'url' => $url,
            'handle' => null,
            'retries' => 0,
            'completed' => false,
            'result' => null
        ];

        $this->createHandle($id);

        return $id;
    }

    private function createHandle($id) {
        $request = &$this->requests[$id];

        if ($request['handle'] && is_resource($request['handle'])) {
            curl_multi_remove_handle($this->multiHandle, $request['handle']);
            curl_close($request['handle']);
        }

        $ch = curl_init();
        curl_setopt_array($ch, [
            CURLOPT_URL => $request['url'],
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT => $this->timeout,
            CURLOPT_CONNECTTIMEOUT => 10
        ]);

        $request['handle'] = $ch;
        curl_multi_add_handle($this->multiHandle, $ch);

        $request['retries']++;
    }

    public function execute() {
        echo "开始执行（最大重试次数: {$this->maxRetries}）...\n";

        $startTime = microtime(true);
        $active = null;

        do {
            // 执行多句柄
            $status = curl_multi_exec($this->multiHandle, $active);

            if ($status !== CURLM_OK) {
                $this->handleExecutionError($status);
                // 继续执行，不立即退出
            }

            // 处理完成的请求
            $this->processCompletedRequests();

            // 处理需要重试的请求
            $this->processRetries();

            // 显示进度
            $this->showProgress();

            // 等待活动
            if ($active > 0) {
                curl_multi_select($this->multiHandle, 0.1);
            }

            // 超时检查
            if (microtime(true) - $startTime > $this->timeout * 2) {
                echo "执行超时，强制结束\n";
                break;
            }

        } while ($active > 0 || $this->hasPendingRetries());

        $totalTime = microtime(true) - $startTime;
        echo "\n执行完成！总耗时: " . round($totalTime, 2) . " 秒\n";

        return $this->collectResults();
    }

    private function processCompletedRequests() {
        while ($info = curl_multi_info_read($this->multiHandle)) {
            $handle = $info['handle'];
            $id = $this->findRequestId($handle);

            if ($id !== null) {
                $this->handleRequestCompletion($id, $handle, $info);
            }
        }
    }

    private function findRequestId($handle) {
        foreach ($this->requests as $id => $request) {
            if ($request['handle'] === $handle) {
                return $id;
            }
        }
        return null;
    }

    private function handleRequestCompletion($id, $handle, $info) {
        $request = &$this->requests[$id];

        $content = curl_multi_getcontent($handle);
        $curlInfo = curl_getinfo($handle);
        $error = curl_error($handle);

        $result = [
            'success' => ($info['result'] === CURLE_OK),
            'http_code' => $curlInfo['http_code'],
            'content' => $content,
            'error' => $error,
            'errno' => $info['result'],
            'retries' => $request['retries'] - 1, // 减1因为当前尝试不算重试
            'total_time' => $curlInfo['total_time']
        ];

        // 检查是否需要重试
        if (!$result['success'] && $request['retries'] <= $this->maxRetries) {
            echo "请求 {$id} 失败，准备重试 ({$request['retries']}/{$this->maxRetries})...\n";
            $this->createHandle($id); // 重新创建句柄进行重试
            return;
        }

        // 请求完成（成功或达到最大重试次数）
        $request['completed'] = true;
        $request['result'] = $result;

        curl_multi_remove_handle($this->multiHandle, $handle);
        curl_close($handle);

        $status = $result['success'] ? '成功' : '最终失败';
        echo "请求 {$id}: {$status} (尝试: {$request['retries']}次)\n";
    }

    private function processRetries() {
        // 可以在这里实现延迟重试逻辑
        // 当前实现是立即重试
    }

    private function hasPendingRetries() {
        foreach ($this->requests as $request) {
            if (!$request['completed'] && $request['retries'] <= $this->maxRetries) {
                return true;
            }
        }
        return false;
    }

    private function showProgress() {
        static $lastUpdate = 0;

        $currentTime = microtime(true);
        if ($currentTime - $lastUpdate < 1.0) {
            return;
        }

        $completed = 0;
        $total = count($this->requests);

        foreach ($this->requests as $request) {
            if ($request['completed']) {
                $completed++;
            }
        }

        echo "进度: {$completed}/{$total} 完成\n";
        $lastUpdate = $currentTime;
    }

    private function handleExecutionError($status) {
        $errors = [
            CURLM_BAD_HANDLE => '无效的多句柄',
            CURLM_OUT_OF_MEMORY => '内存不足',
            CURLM_INTERNAL_ERROR => '内部错误'
        ];

        $errorMsg = $errors[$status] ?? "错误代码: {$status}";
        echo "多句柄执行错误: {$errorMsg}\n";
    }

    private function collectResults() {
        $results = [];
        foreach ($this->requests as $id => $request) {
            if ($request['completed']) {
                $results[$id] = $request['result'];
            }
        }
        return $results;
    }

    public function close() {
        foreach ($this->requests as $request) {
            if ($request['handle'] && is_resource($request['handle'])) {
                curl_multi_remove_handle($this->multiHandle, $request['handle']);
                curl_close($request['handle']);
            }
        }

        if (is_resource($this->multiHandle)) {
            curl_multi_close($this->multiHandle);
        }

        $this->requests = [];
    }

    public function __destruct() {
        $this->close();
    }
}

// 使用健壮的执行器（包含错误处理和重试）
$executor = new RobustMultiExecutor(2, 10); // 最大重试2次，超时10秒

// 添加一些可能失败的请求进行测试
$urls = [
    'good' => 'https://httpbin.org/get',
    'slow' => 'https://httpbin.org/delay/2',
    'timeout' => 'https://httpbin.org/delay/5', // 可能超时
    'invalid' => 'https://invalid-url-12345.com' // 会失败
];

foreach ($urls as $id => $url) {
    $executor->addRequest($url, $id);
}

$results = $executor->execute();

// 分析结果
echo "\n最终结果分析:\n";
$successCount = 0;
foreach ($results as $id => $result) {
    if ($result['success']) {
        $successCount++;
        echo "✓ {$id}: 成功 (尝试: {$result['retries']}次, 耗时: " . round($result['total_time'], 2) . "秒)\n";
    } else {
        echo "✗ {$id}: 失败 (尝试: {$result['retries']}次, 错误: {$result['error']})\n";
    }
}

echo "\n统计: {$successCount}/" . count($urls) . " 成功\n";

$executor->close();
@endphp