(DataFlex) 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

Use ChilkatAx-9.5.0-win32.pkg

Procedure Test
    Handle hoRest
    Boolean iBTls
    Integer iPort
    Boolean iBAutoReconnect
    Boolean iSuccess
    String sLocalFilePath
    Handle hoFac
    Integer iSzLocalFile
    Variant vAzAuth
    Handle hoAzAuth
    Handle hoSbFileSize
    String sResponseStr
    Handle hoSbRange
    Variant vSbResponseBody
    Handle hoSbResponseBody
    Variant vBdFileData
    Handle hoBdFileData
    Integer iNumBytesLeft
    Integer iCurIndex
    Integer iChunkSize
    String sTemp1
    Integer iTemp1
    Boolean bTemp1

    // 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.

    Get Create (RefClass(cComChilkatRest)) To hoRest
    If (Not(IsComObjectCreated(hoRest))) Begin
        Send CreateComObject of hoRest
    End

    // Connect to the Azure Storage Blob Service
    Move True To iBTls
    Move 443 To iPort
    Move True To iBAutoReconnect
    // In this example, the storage account name is "chilkat".
    Get ComConnect Of hoRest "chilkat.file.core.windows.net" iPort iBTls iBAutoReconnect To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoRest To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // This example will upload a larger file.
    Move "qa_data/zips/somethingBig.zip" To sLocalFilePath
    Get Create (RefClass(cComCkFileAccess)) To hoFac
    If (Not(IsComObjectCreated(hoFac))) Begin
        Send CreateComObject of hoFac
    End
    // 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.
    Get ComFileSize Of hoFac sLocalFilePath To iSzLocalFile
    If (iSzLocalFile < 0) Begin
        Get ComLastErrorText Of hoFac To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Provide Azure Cloud credentials for the REST calls.
    Get Create (RefClass(cComChilkatAuthAzureStorage)) To hoAzAuth
    If (Not(IsComObjectCreated(hoAzAuth))) Begin
        Send CreateComObject of hoAzAuth
    End
    Set ComAccessKey Of hoAzAuth To "AZURE_ACCESS_KEY"
    // The account name used here should match the 1st part of the domain passed in the call to Connect (above).
    Set ComAccount Of hoAzAuth To "chilkat"
    Set ComScheme Of hoAzAuth To "SharedKey"
    Set ComService Of hoAzAuth To "File"
    // This causes the "x-ms-version: 2020-08-04" header to be automatically added.
    Set ComXMsVersion Of hoAzAuth To "2020-08-04"
    Get pvComObject of hoAzAuth to vAzAuth
    Get ComSetAuthAzureStorage Of hoRest vAzAuth To iSuccess

    // 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:
    Get ComAddHeader Of hoRest "x-ms-type" "file" To iSuccess

    // This required header specifies the final size of the file (or the maximum size it can be).
    Get Create (RefClass(cComChilkatStringBuilder)) To hoSbFileSize
    If (Not(IsComObjectCreated(hoSbFileSize))) Begin
        Send CreateComObject of hoSbFileSize
    End
    Get ComAppendInt Of hoSbFileSize iSzLocalFile To iSuccess
    Get ComGetAsString Of hoSbFileSize To sTemp1
    Get ComAddHeader Of hoRest "x-ms-content-length" sTemp1 To iSuccess

    // 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"
    Get ComFullRequestNoBody Of hoRest "PUT" "/pip/somethingBig.zip" To sResponseStr
    Get ComLastMethodSuccess Of hoRest To bTemp1
    If (bTemp1 <> True) Begin
        Get ComLastErrorText Of hoRest To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // 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.

    Get ComResponseStatusCode Of hoRest To iTemp1
    If (iTemp1 <> 201) Begin
        // Examine the request/response to see what happened.
        Get ComResponseStatusCode Of hoRest To iTemp1
        Showln "response status code = " iTemp1
        Get ComResponseStatusText Of hoRest To sTemp1
        Showln "response status text = " sTemp1
        Get ComResponseHeader Of hoRest To sTemp1
        Showln "response header: " sTemp1
        Showln "response body (if any): " sResponseStr
        Showln "---"
        Get ComLastRequestStartLine Of hoRest To sTemp1
        Showln "LastRequestStartLine: " sTemp1
        Get ComLastRequestHeader Of hoRest To sTemp1
        Showln "LastRequestHeader: " sTemp1
        Procedure_Return
    End

    Showln "Successfully created somethingBig.zip"

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

    // Make sure the headers from the "Create File" operation are removed.
    Get ComClearAllHeaders Of hoRest To iSuccess

    // The x-ms-write header is required for each "Put Range" request.
    Get ComAddHeader Of hoRest "x-ms-write" "update" To iSuccess

    Get Create (RefClass(cComChilkatStringBuilder)) To hoSbRange
    If (Not(IsComObjectCreated(hoSbRange))) Begin
        Send CreateComObject of hoSbRange
    End
    Get Create (RefClass(cComChilkatStringBuilder)) To hoSbResponseBody
    If (Not(IsComObjectCreated(hoSbResponseBody))) Begin
        Send CreateComObject of hoSbResponseBody
    End
    Get Create (RefClass(cComChilkatBinData)) To hoBdFileData
    If (Not(IsComObjectCreated(hoBdFileData))) Begin
        Send CreateComObject of hoBdFileData
    End

    // Open the file.  We'll be reading and uploading in chunks..
    Get ComOpenForRead Of hoFac sLocalFilePath To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoFac To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Move iSzLocalFile To iNumBytesLeft
    Move 0 To iCurIndex
    While (iNumBytesLeft > 0)

        Move iNumBytesLeft To iChunkSize
        // Azure allows for 4MB max chunks  (4 x 1024 x 1024 = 4194304)
        If (iChunkSize > 4194304) Begin
            Move 4194304 To iChunkSize
        End

        // 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
        Send ComClear To hoSbRange
        Get ComAppend Of hoSbRange "bytes=" To iSuccess
        Get ComAppendInt Of hoSbRange iCurIndex To iSuccess
        Get ComAppend Of hoSbRange "-" To iSuccess
        Get ComAppendInt Of hoSbRange (iCurIndex + iChunkSize - 1) To iSuccess

        // This replaces the header if it already exists..
        Get ComGetAsString Of hoSbRange To sTemp1
        Get ComAddHeader Of hoRest "x-ms-range" sTemp1 To iSuccess

        // Read the next chunk from the local file.
        Get ComClear Of hoBdFileData To iSuccess
        Get pvComObject of hoBdFileData to vBdFileData
        Get ComFileReadBd Of hoFac iChunkSize vBdFileData To iSuccess

        Get pvComObject of hoBdFileData to vBdFileData
        Get pvComObject of hoSbResponseBody to vSbResponseBody
        Get ComFullRequestBd Of hoRest "PUT" "/pip/somethingBig.zip?comp=range" vBdFileData vSbResponseBody To iSuccess
        If (iSuccess <> True) Begin
            // This would indicate a failure where no response was received.
            Get ComLastErrorText Of hoRest To sTemp1
            Showln sTemp1
            Procedure_Return
        End

        // A 201 response indicates the chunk was uploaded.
        Get ComResponseStatusCode Of hoRest To iTemp1
        If (iTemp1 <> 201) Begin
            // Examine the request/response to see what happened.
            Get ComResponseStatusCode Of hoRest To iTemp1
            Showln "response status code = " iTemp1
            Get ComResponseStatusText Of hoRest To sTemp1
            Showln "response status text = " sTemp1
            Get ComResponseHeader Of hoRest To sTemp1
            Showln "response header: " sTemp1
            Showln "response body (if any): " sResponseStr
            Showln "---"
            Get ComLastRequestStartLine Of hoRest To sTemp1
            Showln "LastRequestStartLine: " sTemp1
            Get ComLastRequestHeader Of hoRest To sTemp1
            Showln "LastRequestHeader: " sTemp1
            Procedure_Return
        End

        Showln "Uploaded chunk from " iCurIndex " to " (iCurIndex + iChunkSize - 1)

        Move (iCurIndex + iChunkSize) To iCurIndex
        Move (iNumBytesLeft - iChunkSize) To iNumBytesLeft
    Loop

    Send ComFileClose To hoFac

    Showln "success."


End_Procedure