(VB.NET) REST Asynchronous Streaming Upload File

Demonstrates how to asynchronous streaming upload a file to cloud storage. This particular example demonstrates an upload to the Azure Cloud Storage service. The same concepts apply to S3, Google Cloud, and Google Drive.

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' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim rest As New Chilkat.Rest

' Connect to the Azure Storage Blob Service
Dim bTls As Boolean = True
Dim port As Integer = 443
Dim bAutoReconnect As Boolean = True
' In this example, the storage account name is "chilkat".
Dim success As Boolean = rest.Connect("chilkat.blob.core.windows.net",port,bTls,bAutoReconnect)
If (success <> True) Then
    Debug.WriteLine(rest.LastErrorText)
    Exit Sub
End If


' Provide Azure Cloud credentials for the REST call.
Dim azAuth As New Chilkat.AuthAzureStorage
azAuth.AccessKey = "AZURE_ACCESS_KEY"
' The account name used here should match the 1st part of the domain passed in the call to Connect (above).
azAuth.Account = "chilkat"
azAuth.Scheme = "SharedKey"
azAuth.Service = "Blob"
' This causes the "x-ms-version: 2021-08-06" header to be automatically added.
azAuth.XMsVersion = "2021-08-06"
success = rest.SetAuthAzureStorage(azAuth)

' Set some request headers.
success = rest.AddHeader("x-ms-blob-content-disposition","attachment; filename=""thisIsATest.txt""")
success = rest.AddHeader("x-ms-blob-type","BlockBlob")
success = rest.AddHeader("x-ms-meta-m1","v1")
success = rest.AddHeader("x-ms-meta-m2","v2")

' Note: The application does not need to explicitly set the following
' headers: x-ms-date, Authorization, and Content-Length.  These headers
' are automatically set by Chilkat.

Dim sendStream As New Chilkat.Stream

' Define the source data for the stream to be a file.
sendStream.SourceFile = "qa_data/hamlet.xml"

' Create a background thread task to upload from the stream
' The name of the Azure storage container is "test".
Dim task As Chilkat.Task = rest.FullRequestStreamAsync("PUT","/test/thisIsATest.txt",sendStream)

' Start the task. 
success = task.Run()

' In this example, we'll simply sleep and periodically
' check to see if the REST upload if finished.
Dim curPctDone As Integer = 0
While task.Finished <> True
    task.SleepMs(100)
End While


' Check to see if the call to FullRequestStream in the background thread pool succeeded.
If (task.TaskSuccess <> True) Then
    ' Show what would've been the LastErrorText had FullRequestStream been called synchronously
    Debug.WriteLine(task.ResultErrorText)

    Exit Sub
End If


Dim responseStatusCode As Integer = rest.ResponseStatusCode

' When successful, the Azure Storage service will respond with a 201 response code,
' with an empty body.  Therefore, in the success condition, the responseStr is empty.
If (responseStatusCode = 201) Then
    Debug.WriteLine("File uploaded.")
Else
    ' It failed, so examine the response body, if one was returned:
    ' Given that FullRequestStream returns a string, the return value is obtained via GetResultString.
    Dim responseBodyStr As String = task.GetResultString()
    Debug.WriteLine("response body (if any): " & responseBodyStr)

    ' Examine the request/response to see what happened.
    Debug.WriteLine("response status code = " & rest.ResponseStatusCode)
    Debug.WriteLine("response status text = " & rest.ResponseStatusText)
    Debug.WriteLine("response header: " & rest.ResponseHeader)
    Debug.WriteLine("---")
    Debug.WriteLine("LastRequestStartLine: " & rest.LastRequestStartLine)
    Debug.WriteLine("LastRequestHeader: " & rest.LastRequestHeader)
End If