PHP大文件上传限制解决方案：动态配置与分块上传实践

<?php
// 尝试将单个文件上传大小限制设置为600MB
ini_set("upload_max_filesize", "600M");
ini_set("memory_limit", "1024M"); // 建议同时调整内存限制以处理大文件

// 后续的文件上传处理逻辑
if (isset($_FILES['video']) && $_FILES['video']['error'] == UPLOAD_ERR_OK) {
    $uploadDir = 'uploads/';
    $uploadFile = $uploadDir . basename($_FILES['video']['name']);

    if (move_uploaded_file($_FILES['video']['tmp_name'], $uploadFile)) {
        echo "文件上传成功！";
    } else {
        echo "文件上传失败。";
    }
} else {
    echo "没有文件上传或上传出错。错误码：" . ($_FILES['video']['error'] ?? '未知');
}
?>

<?php
// 设置响应头，允许跨域请求（如果前端和后端部署在不同域名）
header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: POST, GET, OPTIONS');
header('Access-Control-Allow-Headers: Content-Type, Authorization, X-Requested-With');

// 确保上传目录存在且可写
$uploadDir = 'uploads/';
if (!is_dir($uploadDir)) {
    mkdir($uploadDir, 0777, true);
}

if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') {
    // 预检请求直接返回成功
    http_response_code(200);
    exit();
}

if (isset($_FILES['chunk']) && $_FILES['chunk']['error'] == UPLOAD_ERR_OK) {
    $fileName = $_POST['fileName'] ?? 'unknown_file';
    $fileIdentifier = $_POST['fileIdentifier'] ?? uniqid(); // 文件的唯一标识符
    $chunkIndex = (int)($_POST['chunkIndex'] ?? 0);
    $totalChunks = (int)($_POST['totalChunks'] ?? 1);

    // 为当前文件创建一个独立的临时存储目录
    $tempFileDir = $uploadDir . $fileIdentifier . '/';
    if (!is_dir($tempFileDir)) {
        mkdir($tempFileDir, 0777, true);
    }

    // 将当前块保存到临时目录
    $chunkFilePath = $tempFileDir . $chunkIndex . '.part';
    if (move_uploaded_file($_FILES['chunk']['tmp_name'], $chunkFilePath)) {
        // 检查所有块是否都已上传
        $allChunksUploaded = true;
        for ($i = 0; $i < $totalChunks; $i++) {
            if (!file_exists($tempFileDir . $i . '.part')) {
                $allChunksUploaded = false;
                break;
            }
        }

        if ($allChunksUploaded) {
            // 所有块都已上传，开始合并
            $finalFilePath = $uploadDir . $fileName;
            $outputFile = fopen($finalFilePath, 'wb');

            for ($i = 0; $i < $totalChunks; $i++) {
                $partFilePath = $tempFileDir . $i . '.part';
                $chunkContent = file_get_contents($partFilePath);
                fwrite($outputFile, $chunkContent);
                unlink($partFilePath); // 合并后删除分块文件
            }
            fclose($outputFile);
            rmdir($tempFileDir); // 删除临时目录

            echo json_encode(['status' => 'success', 'message' => '文件上传并合并完成！', 'filePath' => $finalFilePath]);
        } else {
            echo json_encode(['status' => 'success', 'message' => '块 ' . $chunkIndex . ' 接收成功。等待其他块。']);
        }
    } else {
        echo json_encode(['status' => 'error', 'message' => '无法保存文件块。']);
    }
} else {
    echo json_encode(['status' => 'error', 'message' => '没有文件块上传或上传出错。']);
}
?>

// 这是一个高度简化的概念，实际应用需要更复杂的逻辑，如错误重试、进度条、UI交互等。
async function uploadFileInChunks(file) {
    const chunkSize = 1024 * 1024 * 5; // 5MB chunks
    const totalChunks = Math.ceil(file.size / chunkSize);
    const fileIdentifier = Date.now() + '-' + file.name; // 唯一标识符

    for (let i = 0; i < totalChunks; i++) {
        const start = i * chunkSize;
        const end = Math.min(file.size, start + chunkSize);
        const chunk = file.slice(start, end);

        const formData = new FormData();
        formData.append('chunk', chunk);
        formData.append('fileName', file.name);
        formData.append('fileIdentifier', fileIdentifier);
        formData.append('chunkIndex', i);
        formData.append('totalChunks', totalChunks);

        try {
            const response = await fetch('upload_handler.php', {
                method: 'POST',
                body: formData,
            });
            const result = await response.json();
            console.log(`Chunk ${i}/${totalChunks} uploaded:`, result);
            // 更新进度条等
        } catch (error) {
            console.error(`Error uploading chunk ${i}:`, error);
            // 处理上传失败，可能需要重试
            return;
        }
    }
    console.log('All chunks uploaded and merged!');
}

// 示例调用
// const fileInput = document.getElementById('fileInput');
// fileInput.addEventListener('change', (event) => {
//     const selectedFile = event.target.files[0];
//     if (selectedFile) {
//         uploadFileInChunks(selectedFile);
//     }
// });