如何在不写入文件的情况下压缩流并将其上传到 Azure Blob 存储？

Question

我在 ASP.NET Core 中编写了一个 Post 方法来压缩请求正文并将其上传到 Azure Blob 存储。该方法采用如下参数：

public async Task<IActionResult> Post([FromHeader] string AssignmentId)

然后设置各种字符串，包括获取存储的连接字符串：

string fileName = $"{AssignmentId}.gz";
string compressedFilePath = Path.Combine(hostEnvironment.ContentRootPath, $"Test JSONs/{fileName}");
string connectionString = Environment.GetEnvironmentVariable("AZURE_STORAGE_CONNECTION_STRING");

我初始化 BlobClient:

BlobClient blobClient = new BlobClient(connectionString, "assignments", fileName);

然后我创建一个文件，并使用 GZipStream 将请求的主体流压缩到文件中：

using (FileStream compressedFileStream = System.IO.File.Create(compressedFilePath))
{
    using GZipStream compressionStream = new GZipStream(compressedFileStream, CompressionMode.Compress);
    using Stream bodyStream = HttpContext.Request.Body;
    await bodyStream.CopyToAsync(compressionStream);
}

最后我阅读了我刚刚编写的文件并使用 FileStream:

上传

using (FileStream fileStream = System.IO.File.OpenRead(compressedFilePath))
{
    await blobClient.UploadAsync(fileStream);
}

这个解决方案有效，但我担心文件的不断读写，在速度方面。我尝试使用传递到 GZipStream 的 MemoryStream，但它最终只上传了 10B 文件，而文件应该是 1KB+。

我很感激任何建议。

完整方法如下：

public async Task<IActionResult> Post([FromHeader] string AssignmentId)
{
    string fileName = $"{AssignmentId}.gz";
    string compressedFilePath = Path.Combine(hostEnvironment.ContentRootPath, $"Test JSONs/{fileName}");
    string connectionString = Environment.GetEnvironmentVariable("AZURE_STORAGE_CONNECTION_STRING");

    BlobClient blobClient = new BlobClient(connectionString, "assignments", fileName);
    
    using (FileStream compressedFileStream = System.IO.File.Create(compressedFilePath))
    {
        using GZipStream compressionStream = new GZipStream(compressedFileStream, CompressionMode.Compress);
        using Stream bodyStream = HttpContext.Request.Body;
        await bodyStream.CopyToAsync(compressionStream);
    }

    using (FileStream fileStream = System.IO.File.OpenRead(compressedFilePath))
    {
        await blobClient.UploadAsync(fileStream);
    }
    
    return Ok();
}

Answer 1

我最终解决了这个问题，既让压缩流保持打开状态，又通过重置压缩流正在写入的内存流的位置（感谢@MitchWheat！）。

using MemoryStream memoryStream = new MemoryStream() ;
using (Stream bodyStream = HttpContext.Request.Body)
{
    using (GZipStream compressionStream = new GZipStream(memoryStream, 
    CompressionMode.Compress, true))
    {
        await bodyStream.CopyToAsync(compressionStream);
    }
}
memoryStream.Position = 0;

await blobClient.UploadAsync(memoryStream, overwrite: true);

如何在不写入文件的情况下压缩流并将其上传到 Azure Blob 存储？

How do you compress a stream and upload it to Azure Blob Storage without writing to a file?

c#

asp.net

gzipstream

azure-blob-storage