Multiple GB file stream in AWS S3 from ASP.NET Core Web API

Question

I want to create a large (multi-GB) file in an AWS S3 bucket from the ASP.NET Core Web API. The file is large enough that I do not load Streaminto memory before loading it into AWS S3.

Usage PutObjectAsync()I have to pre-fill Streambefore transferring it to the AWS SDK, as shown below:

var putObjectRequest = new PutObjectRequest
{
    BucketName = "my-s3-bucket",
    Key = "my-file-name.txt",
    InputStream = stream
};
var putObjectResponse = await amazonS3Client.PutObjectAsync(putObjectRequest);

My ideal template would include an AWS SDK returning StreamWriter(out of kind), I could Write()many times, and then Finalise()when I finished.

Two questions regarding my task:

• I misinformed us about the need to pre-fill Streambefore the call PutObjectAsync()?
• How do I upload my large (multi-GB) file?

Answer 1

AWS docs :

• AWS.NET SDK (API )
• AWS.NET SDK (API )

API TransferUtilityUploadRequest PartSize, . StreamTransferProgress . , .

API, , , - , . :

var s3Client = new AmazonS3Client(Amazon.RegionEndpoint.USEast1);

// List to store upload part responses.
var uploadResponses = new List<UploadPartResponse>();

// 1. Initialize.
var initiateRequest = new InitiateMultipartUploadRequest
    {
        BucketName = existingBucketName,
        Key = keyName
    };

var initResponse = s3Client.InitiateMultipartUpload(initRequest);

// 2. Upload Parts.
var contentLength = new FileInfo(filePath).Length;
var partSize = 5242880; // 5 MB

try
{
    long filePosition = 0;
    for (var i = 1; filePosition < contentLength; ++i)
    {
        // Create request to upload a part.
        var uploadRequest = new UploadPartRequest
            {
                BucketName = existingBucketName,
                Key = keyName,
                UploadId = initResponse.UploadId,
                PartNumber = i,
                PartSize = partSize,
                FilePosition = filePosition,
                FilePath = filePath
            };

       // Upload part and add response to our list.
       uploadResponses.Add(s3Client.UploadPart(uploadRequest));

       filePosition += partSize;
   }

   // Step 3: complete.
   var completeRequest = new CompleteMultipartUploadRequest
       {
           BucketName = existingBucketName,
           Key = keyName,
           UploadId = initResponse.UploadId,
        };

   // add ETags for uploaded files
   completeRequest.AddPartETags(uploadResponses);

   var completeUploadResponse = s3Client.CompleteMultipartUpload(completeRequest);     
}
catch (Exception exception)
{
    Console.WriteLine("Exception occurred: {0}", exception.ToString());
    var abortMPURequest = new AbortMultipartUploadRequest
        {
            BucketName = existingBucketName,
            Key = keyName,
            UploadId = initResponse.UploadId
        };
    s3Client.AbortMultipartUpload(abortMPURequest);
}

UploadPart, , .