C＃Azure上传文件错误指定的Blob或块内容无效

Question

我正在将文件上传到Azure存储。

public class AzureBlob : ICloudBlob
{
    private string _fileName;
    public string FileName
    {
        get => _fileName;
        set
        {
            _fileName = value;
            _cloudBlockBlob = CloudBlobContainer.GetBlockBlobReference(value);
        }
    }
    public CloudBlobContainer CloudBlobContainer { get; set; }
    private CloudBlockBlob _cloudBlockBlob;

    public async Task UploadChunksFromPathAsync(string path, long fileLength)
    {
        const int blockSize = 256 * 1024;
        var bytesToUpload = fileLength;
        long bytesUploaded = 0;
        long startPosition = 0;

        var blockIds = new List<string>();
        var index = 0;

        do
        {
            var bytesToRead = Math.Min(blockSize, bytesToUpload);
            var blobContents = new byte[bytesToRead];

            using (var fs = new FileStream(path, FileMode.Open))
            {
                fs.Position = startPosition;
                fs.Read(blobContents, 0, (int) bytesToRead);
            }

            var blockId = Convert.ToBase64String(Encoding.UTF8.GetBytes(index.ToString("d6")));

            blockIds.Add(blockId);
            await _cloudBlockBlob.PutBlockAsync(blockId, new MemoryStream(blobContents), null);

            bytesUploaded += bytesToRead;
            bytesToUpload -= bytesToRead;
            startPosition += bytesToRead;
            index++;
        } while (bytesToUpload > 0);

        await _cloudBlockBlob.PutBlockListAsync(blockIds);   
    }
}

这对于一个文件上载效果很好，多个文件上载会在另一个上引发400错误_cloudBlockBlob.PutBlockListAsync且天蓝色错误的情况下调用此方法

指定的Blob或块内容无效。

如果我删除了await关键字，_cloudBlockBlob.PutBlockListAsync它就可以正常工作。

blockId的长度都相同。我究竟做错了什么？

编辑

在控制器中调用代码：

[HttpPost]
public async Task<IActionResult> Upload([FromBody] UploadViewModel model)
{
    var audioBlob = _cloudStorage.GetBlob(CloudStorageType.Audio, model.AudioName);

    await audioBlob.UploadChunksFromPathAsync(model.AudioPath, model.FileLength);

    return Ok();
}

存储：

public enum CloudStorageType
{
    Audio,
    Image,
}

public class AzureStorage : ICloudStorage
{
    public IDictionary<CloudStorageType, ICloudBlob> CloudBlobs { get; set; }

    public AzureStorage(IConfiguration configuration)
    {
        var storageAccount = CloudStorageAccount.Parse(configuration["ConnectionStrings:StorageConnectionString"]);
        var blobClient = storageAccount.CreateCloudBlobClient();

        CloudBlobs = new Dictionary<CloudStorageType, ICloudBlob>();

        foreach (CloudStorageType cloudStorageType in Enum.GetValues(typeof(CloudStorageType)))
        {
            CloudBlobs[cloudStorageType] = new AzureBlob(cloudStorageType.ToString().ToLower(), blobClient);
        }
    }

    public ICloudBlob GetBlob(CloudStorageType cloudStorageType, string fileName)
    {
        CloudBlobs[cloudStorageType].FileName = fileName;

        return CloudBlobs[cloudStorageType];
    }
}

启动文件

var azureStorage = new AzureStorage(_configuration);

// Add application services.
services.AddSingleton(_configuration);
services.AddSingleton<ICloudStorage>(azureStorage);

Answer 1

编辑：原因实际上是因为下载过程中途，下一个文件覆盖了Blob。基本上每次上传都会创建一个新的Blob，因此不会发生这种情况。

弄清楚了。第一次下载可以正常工作，但是如果之前的下载尚未完成，则第二次下载将引发错误，因为该块Blob已经在使用中，正在下载其他块。

解决方法是为每次下载创建一个新的块Blob，而不是仅使用一个。

public async Task UploadChunksFromPathAsync(string path, long fileLength)
{
    var cloudBlockBlob = CloudBlobContainer.GetBlockBlobReference(FileName);

    const int blockSize = 256 * 1024;
    var bytesToUpload = fileLength;
    long bytesUploaded = 0;
    long startPosition = 0;

    var blockIds = new List<string>();
    var index = 0;

    do
    {
        var bytesToRead = Math.Min(blockSize, bytesToUpload);
        var blobContents = new byte[bytesToRead];

        using (var fs = new FileStream(path, FileMode.Open))
        {
            fs.Position = startPosition;
            fs.Read(blobContents, 0, (int) bytesToRead);
        }

        var blockId = Convert.ToBase64String(Encoding.UTF8.GetBytes(index.ToString("d6")));

        blockIds.Add(blockId);
        await cloudBlockBlob.PutBlockAsync(blockId, new MemoryStream(blobContents), null);

        bytesUploaded += bytesToRead;
        bytesToUpload -= bytesToRead;
        startPosition += bytesToRead;
        index++;
    } while (bytesToUpload > 0);

    await cloudBlockBlob.PutBlockListAsync(blockIds);   
}