c# upload in real time from client to server to am

问题:

Good morning, I have an desktop app that uploads files to a WCF service and then WCF Service uploads to Amazon S3.

This is my WCF method that receives the file and uploads to S3.

public void UploadFile(RemoteFileInfo request)
        {
            config = new AmazonS3Config();
            config.CommunicationProtocol = Protocol.HTTP;
            accessKeyID = "XXXXXXX"; 
            secretAccessKeyID = "YYYYYYYY";
            client = Amazon.AWSClientFactory.CreateAmazonS3Client(accessKeyID, secretAccessKeyID, config);

            int chunkSize = 2048;
            byte[] buffer = new byte[chunkSize];

            using (System.IO.MemoryStream writeStream = new System.IO.MemoryStream())
            {
                do
                {
                    // read bytes from input stream
                    int bytesRead = request.FileByteStream.Read(buffer, 0, chunkSize);
                    if (bytesRead == 0) break;

                    // simulates slow connection
                    System.Threading.Thread.Sleep(3);

                    // write bytes to output stream
                    writeStream.Write(buffer, 0, bytesRead);
                } while (true);

                // report end
                Console.WriteLine("Done!");

                // start the uploading to S3
                PutObjectRequest fileRequest = new PutObjectRequest();
                fileRequest.WithInputStream(writeStream);
                fileRequest.Key = "testfile.pdf";
                fileRequest.WithBucketName("tempbucket");
                fileRequest.CannedACL = S3CannedACL.Private;
                fileRequest.StorageClass = S3StorageClass.Standard;
                client.PutObject(fileRequest);

                writeStream.Close();
            }

        }

On my client I get the progress in real time when upload the file to the WCF Service but when I get the 100% complete it doesnt mean that the file has already uploaded to S3, so I would like to know if its possible to being uploading the file to S3 while Im writing the stream (inside of the using

(System.IO.MemoryStream writeStream = new System.IO.MemoryStream())
            {

Is this possible? Any guideline on how to do it?

Appreciate in advance.

回答1:

You can use InputStream property of PutObjectRequest

public void UploadFile(RemoteFileInfo request)
{
    config = new AmazonS3Config();
    config.CommunicationProtocol = Protocol.HTTP;
    accessKeyID = "XXXXXXX"; 
    secretAccessKeyID = "YYYYYYYY";
    client = Amazon.AWSClientFactory.CreateAmazonS3Client(accessKeyID,secretAccessKeyID,config);

    int chunkSize = 2048;
    byte[] buffer = new byte[chunkSize];

    PutObjectRequest fileRequest = new PutObjectRequest();

    fileRequest.Key = "testfile.pdf";
    fileRequest.WithBucketName("tempbucket");
    fileRequest.CannedACL = S3CannedACL.Private;
    fileRequest.StorageClass = S3StorageClass.Standard;

    using (fileRequest.InputStream = new System.IO.MemoryStream())
    {
      do
      {
         // read bytes from input stream
         int bytesRead = request.FileByteStream.Read(buffer, 0, chunkSize);
         if (bytesRead == 0) break;

         // simulates slow connection
         System.Threading.Thread.Sleep(3);

         // write bytes to output stream
         fileRequest.InputStream.Write(buffer, 0, bytesRead);
       } while (true);

       // report end
       Console.WriteLine("Done!");

       client.PutObject(fileRequest);

    }
 }

回答2:

I would recommend uploading the file to the WCF as chunks instead of a stream. I did so and it works just fine. also you need to return a message of the actual bytes written to the amazon later on you can increase the progress bar based on that. I know it will cause you to write a while loop in the client application but it will help you to show the progress with 100% accuracy for large files. Your WCF function should take the parameter like these

[DataContract]
class RemoteFileInfo
{
    [DataMember]
    Byte[] myChunk;
    [DataMember]
    long myOffset;
    // other stuff you think you need to be sent each time.

}