(PowerBuilder) Azure File Service: Upload Large File

Sample code to upload a large file to a directory in a share in the Azure File Service. A file is uploaded by first creating the file in the Azure share and then writing ranges of bytes to the file. Azure imposes a 4MB limit for each PUT to write a range. Files larger than 4MB need to be uploaded by making multiple "Put Range" calls. This example uploads a large file requiring multiple "Put Range" calls.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

integer li_rc
oleobject loo_Rest
integer li_BTls
integer li_Port
integer li_BAutoReconnect
integer li_Success
string ls_LocalFilePath
oleobject loo_Fac
integer li_SzLocalFile
oleobject loo_AzAuth
oleobject loo_SbFileSize
string ls_ResponseStr
oleobject loo_SbRange
oleobject loo_SbResponseBody
oleobject loo_BdFileData
integer li_NumBytesLeft
integer li_CurIndex
integer li_ChunkSize

// Azure File Service Example: Upload a large file.  
// See:  https://docs.microsoft.com/en-us/rest/api/storageservices/create-share
// also see: https://docs.microsoft.com/en-us/rest/api/storageservices/put-range

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

loo_Rest = create oleobject
// Use "Chilkat_9_5_0.Rest" for versions of Chilkat < 10.0.0
li_rc = loo_Rest.ConnectToNewObject("Chilkat.Rest")
if li_rc < 0 then
    destroy loo_Rest
    MessageBox("Error","Connecting to COM object failed")
    return
end if

// Connect to the Azure Storage Blob Service
li_BTls = 1
li_Port = 443
li_BAutoReconnect = 1
// In this example, the storage account name is "chilkat".
li_Success = loo_Rest.Connect("chilkat.file.core.windows.net",li_Port,li_BTls,li_BAutoReconnect)
if li_Success <> 1 then
    Write-Debug loo_Rest.LastErrorText
    destroy loo_Rest
    return
end if

// This example will upload a larger file.
ls_LocalFilePath = "qa_data/zips/somethingBig.zip"
loo_Fac = create oleobject
// Use "Chilkat_9_5_0.FileAccess" for versions of Chilkat < 10.0.0
li_rc = loo_Fac.ConnectToNewObject("Chilkat.FileAccess")

// Note: The FileSize method returns a signed 32-bit integer.  If the file is potentially larger than 2GB, call FileSizeStr instead to return
// the size of the file as a string, then convert to an integer value.
li_SzLocalFile = loo_Fac.FileSize(ls_LocalFilePath)
if li_SzLocalFile < 0 then
    Write-Debug loo_Fac.LastErrorText
    destroy loo_Rest
    destroy loo_Fac
    return
end if

// Provide Azure Cloud credentials for the REST calls.
loo_AzAuth = create oleobject
// Use "Chilkat_9_5_0.AuthAzureStorage" for versions of Chilkat < 10.0.0
li_rc = loo_AzAuth.ConnectToNewObject("Chilkat.AuthAzureStorage")

loo_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).
loo_AzAuth.Account = "chilkat"
loo_AzAuth.Scheme = "SharedKey"
loo_AzAuth.Service = "File"
// This causes the "x-ms-version: 2021-08-06" header to be automatically added.
loo_AzAuth.XMsVersion = "2021-08-06"
li_Success = loo_Rest.SetAuthAzureStorage(loo_AzAuth)

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

// However, a few additional headers are required for the "Create File" operation:
loo_Rest.AddHeader("x-ms-type","file")

// This required header specifies the final size of the file (or the maximum size it can be).
loo_SbFileSize = create oleobject
// Use "Chilkat_9_5_0.StringBuilder" for versions of Chilkat < 10.0.0
li_rc = loo_SbFileSize.ConnectToNewObject("Chilkat.StringBuilder")

loo_SbFileSize.AppendInt(li_SzLocalFile)
loo_Rest.AddHeader("x-ms-content-length",loo_SbFileSize.GetAsString())

// Send a PUT request to create the file (or replace the file if it already exists).
// This will initialize the file in the Azure file storage.  To upload content, we'll need
// to do the "Put Range" operation one or more times.

// The following will create the file "somethingBig.zip" in the share "pip"
ls_ResponseStr = loo_Rest.FullRequestNoBody("PUT","/pip/somethingBig.zip")
if loo_Rest.LastMethodSuccess <> 1 then
    Write-Debug loo_Rest.LastErrorText
    destroy loo_Rest
    destroy loo_Fac
    destroy loo_AzAuth
    destroy loo_SbFileSize
    return
end if

// When successful, the Azure File Service will respond with a 201 (Created) response status code,
// with no XML response body.  If an error response is returned, there will be an XML response body.

if loo_Rest.ResponseStatusCode <> 201 then
    // Examine the request/response to see what happened.
    Write-Debug "response status code = " + string(loo_Rest.ResponseStatusCode)
    Write-Debug "response status text = " + loo_Rest.ResponseStatusText
    Write-Debug "response header: " + loo_Rest.ResponseHeader
    Write-Debug "response body (if any): " + ls_ResponseStr
    Write-Debug "---"
    Write-Debug "LastRequestStartLine: " + loo_Rest.LastRequestStartLine
    Write-Debug "LastRequestHeader: " + loo_Rest.LastRequestHeader
    destroy loo_Rest
    destroy loo_Fac
    destroy loo_AzAuth
    destroy loo_SbFileSize
    return
end if

Write-Debug "Successfully created somethingBig.zip"

// --------------------------------------------------------------------------------
// Upload the file data...

// Make sure the headers from the "Create File" operation are removed.
loo_Rest.ClearAllHeaders()

// The x-ms-write header is required for each "Put Range" request.
loo_Rest.AddHeader("x-ms-write","update")

loo_SbRange = create oleobject
// Use "Chilkat_9_5_0.StringBuilder" for versions of Chilkat < 10.0.0
li_rc = loo_SbRange.ConnectToNewObject("Chilkat.StringBuilder")

loo_SbResponseBody = create oleobject
// Use "Chilkat_9_5_0.StringBuilder" for versions of Chilkat < 10.0.0
li_rc = loo_SbResponseBody.ConnectToNewObject("Chilkat.StringBuilder")

loo_BdFileData = create oleobject
// Use "Chilkat_9_5_0.BinData" for versions of Chilkat < 10.0.0
li_rc = loo_BdFileData.ConnectToNewObject("Chilkat.BinData")

// Open the file.  We'll be reading and uploading in chunks..
li_Success = loo_Fac.OpenForRead(ls_LocalFilePath)
if li_Success <> 1 then
    Write-Debug loo_Fac.LastErrorText
    destroy loo_Rest
    destroy loo_Fac
    destroy loo_AzAuth
    destroy loo_SbFileSize
    destroy loo_SbRange
    destroy loo_SbResponseBody
    destroy loo_BdFileData
    return
end if

li_NumBytesLeft = li_SzLocalFile
li_CurIndex = 0
do while li_NumBytesLeft > 0

    li_ChunkSize = li_NumBytesLeft
    // Azure allows for 4MB max chunks  (4 x 1024 x 1024 = 4194304)
    if li_ChunkSize > 4194304 then
        li_ChunkSize = 4194304
    end if

    // The only tricky part here is to correctly add the x-ms-range header.
    // It will be formatted like this:
    // x-ms-range: bytes=0-759623
    loo_SbRange.Clear()
    loo_SbRange.Append("bytes=")
    loo_SbRange.AppendInt(li_CurIndex)
    loo_SbRange.Append("-")
    loo_SbRange.AppendInt(li_CurIndex + li_ChunkSize - 1)

    // This replaces the header if it already exists..
    loo_Rest.AddHeader("x-ms-range",loo_SbRange.GetAsString())

    // Read the next chunk from the local file.
    loo_BdFileData.Clear()
    li_Success = loo_Fac.FileReadBd(li_ChunkSize,loo_BdFileData)

    li_Success = loo_Rest.FullRequestBd("PUT","/pip/somethingBig.zip?comp=range",loo_BdFileData,loo_SbResponseBody)
    if li_Success <> 1 then
        // This would indicate a failure where no response was received.
        Write-Debug loo_Rest.LastErrorText
        destroy loo_Rest
        destroy loo_Fac
        destroy loo_AzAuth
        destroy loo_SbFileSize
        destroy loo_SbRange
        destroy loo_SbResponseBody
        destroy loo_BdFileData
        return
    end if

    // A 201 response indicates the chunk was uploaded.
    if loo_Rest.ResponseStatusCode <> 201 then
        // Examine the request/response to see what happened.
        Write-Debug "response status code = " + string(loo_Rest.ResponseStatusCode)
        Write-Debug "response status text = " + loo_Rest.ResponseStatusText
        Write-Debug "response header: " + loo_Rest.ResponseHeader
        Write-Debug "response body (if any): " + ls_ResponseStr
        Write-Debug "---"
        Write-Debug "LastRequestStartLine: " + loo_Rest.LastRequestStartLine
        Write-Debug "LastRequestHeader: " + loo_Rest.LastRequestHeader
        destroy loo_Rest
        destroy loo_Fac
        destroy loo_AzAuth
        destroy loo_SbFileSize
        destroy loo_SbRange
        destroy loo_SbResponseBody
        destroy loo_BdFileData
        return
    end if

    Write-Debug "Uploaded chunk from " + string(li_CurIndex) + " to " + string(li_CurIndex + li_ChunkSize - 1)

    li_CurIndex = li_CurIndex + li_ChunkSize
    li_NumBytesLeft = li_NumBytesLeft - li_ChunkSize
loop

loo_Fac.FileClose()

Write-Debug "success."


destroy loo_Rest
destroy loo_Fac
destroy loo_AzAuth
destroy loo_SbFileSize
destroy loo_SbRange
destroy loo_SbResponseBody
destroy loo_BdFileData