/// <summary>
/// Validates the request.
/// </summary>
/// <returns>The validation result.</returns>
private async Task <Tuple <bool, BlobS3HandlerResult, CloudBlockBlob> > ValidateRequestAsync()
{
BlobS3HandlerResult result = null;
if (!await this.BlobRepository.GetBlobContainerReference(this.SourceBlobContainer).ExistsAsync().ConfigureAwait(false))
{
result = new BlobS3HandlerResult
{
HasSucceeded = false,
Message = ContainerNotExists
};
return(new Tuple <bool, BlobS3HandlerResult, CloudBlockBlob>(false, result, null));
}
var blobToCopy = this.BlobRepository.GetBlockBlobReference(this.SourceBlob, this.SourceBlobContainer);
if (await blobToCopy.ExistsAsync().ConfigureAwait(false))
{
return(new Tuple <bool, BlobS3HandlerResult, CloudBlockBlob>(true, null, blobToCopy));
}
result = new BlobS3HandlerResult
{
HasSucceeded = false,
Message = BlobNotExists
};
return(new Tuple <bool, BlobS3HandlerResult, CloudBlockBlob>(false, result, null));
}
/// <summary>
/// Processes the BLOB an copy to s3.
/// </summary>
/// <returns>Returns the result of copy from BLOB to S3.</returns>
private async Task <BlobS3HandlerResult> ProcessBlobAndCopyToS3Async()
{
var result = new BlobS3HandlerResult();
var validationResult = await this.ValidateRequestAsync().ConfigureAwait(false);
if (!validationResult.Item1)
{
return(validationResult.Item2);
}
var blobToCopy = validationResult.Item3;
await blobToCopy.FetchAttributesAsync().ConfigureAwait(false);
var remainingBytes = blobToCopy.Properties.Length;
long readPosition = 0; // To be used offset / position from where to start reading from BLOB.
var initiateMultipartUploadRequest = new InitiateMultipartUploadRequest
{
BucketName = this.TargetS3Bucket,
Key = this.TargetS3File
};
// Will use UploadId from this response.
var initiateMultipartUploadResponse = this.S3Client.InitiateMultipartUpload(initiateMultipartUploadRequest);
var uploadPartResponses = new List <UploadPartResponse>();
try
{
var partCounter = 0; // To increment on each read of parts and use it as part number.
var sha256 = new SHA256Managed();
while (remainingBytes > 0)
{
// Determine the size when final block reached as it might be less than Part size.
// Will be PartSize except final block.
var bytesToCopy = Math.Min(PartSize, remainingBytes);
using (MemoryStream memoryStream = new MemoryStream())
{
// To download part from BLOB.
await blobToCopy.DownloadRangeToStreamAsync(memoryStream, readPosition, bytesToCopy).ConfigureAwait(false);
memoryStream.Position = 0;
partCounter++;
var uploadRequest = new UploadPartRequest
{
BucketName = this.TargetS3Bucket,
Key = this.TargetS3File,
UploadId = initiateMultipartUploadResponse.UploadId,
PartNumber = partCounter,
PartSize = bytesToCopy,
InputStream = memoryStream
};
var uploadPartResponse = this.S3Client.UploadPart(uploadRequest);
uploadPartResponses.Add(uploadPartResponse);
remainingBytes -= bytesToCopy;
readPosition += bytesToCopy;
// $"Uploaded part with part number {partCounter}, size {bytesToCopy}bytes and remaining {remainingBytes}bytes to read.")
// Calculate the checksum value.
if (remainingBytes <= 0)
{
sha256.TransformFinalBlock(memoryStream.ToArray(), 0, (int)bytesToCopy);
}
else
{
var bytesToSend = memoryStream.ToArray();
sha256.TransformBlock(bytesToSend, 0, (int)bytesToCopy, bytesToSend, 0);
}
}
}
result.Sha256CheckSum = BitConverter.ToString(sha256.Hash).Replace("-", string.Empty);
var completeMultipartUploadRequest = new CompleteMultipartUploadRequest
{
BucketName = this.TargetS3Bucket,
Key = this.TargetS3File,
UploadId = initiateMultipartUploadResponse.UploadId
};
completeMultipartUploadRequest.AddPartETags(uploadPartResponses);
var completeMultipartUploadResponse = await this.S3Client.CompleteMultipartUploadAsync(completeMultipartUploadRequest).ConfigureAwait(false);
result.HasSucceeded = true;
result.S3Path = completeMultipartUploadResponse.Location;
}
catch (Exception exception)
{
result.HasSucceeded = false;
result.Message = exception.Message;
var abortMultipartUploadRequest = new AbortMultipartUploadRequest
{
BucketName = this.TargetS3Bucket,
Key = this.TargetS3File,
UploadId = initiateMultipartUploadResponse.UploadId
};
await this.S3Client.AbortMultipartUploadAsync(abortMultipartUploadRequest).ConfigureAwait(false);
}
return(result);
}
