I have written a Post
method in ASP.NET Core to compress the requests body and upload it to Azure Blob Storage. The method takes parameters as follows:
public async Task<IActionResult> Post([FromHeader] string AssignmentId)
Various strings are then set, including fetching the connection string for the storage:
string fileName = $"{AssignmentId}.gz";
string compressedFilePath = Path.Combine(hostEnvironment.ContentRootPath, $"Test JSONs/{fileName}");
string connectionString = Environment.GetEnvironmentVariable("AZURE_STORAGE_CONNECTION_STRING");
I initialize the BlobClient
:
BlobClient blobClient = new BlobClient(connectionString, "assignments", fileName);
Then I create a file, and compress the body stream of the request using GZipStream
to the file:
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);
}
Finally I read the file I just wrote and upload using the FileStream
:
using (FileStream fileStream = System.IO.File.OpenRead(compressedFilePath))
{
await blobClient.UploadAsync(fileStream);
}
This solution works, but I am concerned about the constant reading and writing of the file, in terms of speed. I attempted to use a MemoryStream
passed into the GZipStream
, however it ended up only uploading 10B files when the files should be 1KB+.
I appreciate any suggestions.
Here is the complete method:
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();
}
I eventually solved this by both leaving the compression stream open, and by resetting the position of the memory stream the compression stream is writing to (thanks to @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);