如何上传超过大小限制的分片？

function uploadFile(file) {
    const chunkSize = 1024 * 1024; // 1MB
    const chunks = Math.ceil(file.size / chunkSize);
    let currentChunk = 0;

    function uploadChunk() {
        const start = currentChunk * chunkSize;
        const end = Math.min(file.size, start + chunkSize);
        const chunk = file.slice(start, end);

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

        const xhr = new XMLHttpRequest();
        xhr.open('POST', '/upload', true);
        xhr.onload = function() {
            if (xhr.status === 200) {
                currentChunk++;
                if (currentChunk < chunks) {
                    uploadChunk();
                } else {
                    console.log('Upload complete');
                }
            } else {
                console.error('Upload failed');
            }
        };
        xhr.send(formData);
    }

    uploadChunk();
}

// 示例调用
const fileInput = document.getElementById('fileInput');
fileInput.addEventListener('change', function(event) {
    const file = event.target.files[0];
    uploadFile(file);
});