(Go) 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.

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    // 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.

    rest := chilkat.NewRest()

    // Connect to the Azure Storage Blob Service
    bTls := true
    port := 443
    bAutoReconnect := true
    // In this example, the storage account name is "chilkat".
    success := rest.Connect("chilkat.file.core.windows.net",port,bTls,bAutoReconnect)
    if success != true {
        fmt.Println(rest.LastErrorText())
        rest.DisposeRest()
        return
    }

    // This example will upload a larger file.
    localFilePath := "qa_data/zips/somethingBig.zip"
    fac := chilkat.NewFileAccess()
    // 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.
    szLocalFile := fac.FileSize(localFilePath)
    if szLocalFile < 0 {
        fmt.Println(fac.LastErrorText())
        rest.DisposeRest()
        fac.DisposeFileAccess()
        return
    }

    // Provide Azure Cloud credentials for the REST calls.
    azAuth := chilkat.NewAuthAzureStorage()
    azAuth.SetAccessKey("AZURE_ACCESS_KEY")
    // The account name used here should match the 1st part of the domain passed in the call to Connect (above).
    azAuth.SetAccount("chilkat")
    azAuth.SetScheme("SharedKey")
    azAuth.SetService("File")
    // This causes the "x-ms-version: 2020-08-04" header to be automatically added.
    azAuth.SetXMsVersion("2020-08-04")
    success = rest.SetAuthAzureStorage(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:
    rest.AddHeader("x-ms-type","file")

    // This required header specifies the final size of the file (or the maximum size it can be).
    sbFileSize := chilkat.NewStringBuilder()
    sbFileSize.AppendInt(szLocalFile)
    rest.AddHeader("x-ms-content-length",*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"
    responseStr := rest.FullRequestNoBody("PUT","/pip/somethingBig.zip")
    if rest.LastMethodSuccess() != true {
        fmt.Println(rest.LastErrorText())
        rest.DisposeRest()
        fac.DisposeFileAccess()
        azAuth.DisposeAuthAzureStorage()
        sbFileSize.DisposeStringBuilder()
        return
    }

    // 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 rest.ResponseStatusCode() != 201 {
        // Examine the request/response to see what happened.
        fmt.Println("response status code = ", rest.ResponseStatusCode())
        fmt.Println("response status text = ", rest.ResponseStatusText())
        fmt.Println("response header: ", rest.ResponseHeader())
        fmt.Println("response body (if any): ", *responseStr)
        fmt.Println("---")
        fmt.Println("LastRequestStartLine: ", rest.LastRequestStartLine())
        fmt.Println("LastRequestHeader: ", rest.LastRequestHeader())
        rest.DisposeRest()
        fac.DisposeFileAccess()
        azAuth.DisposeAuthAzureStorage()
        sbFileSize.DisposeStringBuilder()
        return
    }

    fmt.Println("Successfully created somethingBig.zip")

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

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

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

    sbRange := chilkat.NewStringBuilder()
    sbResponseBody := chilkat.NewStringBuilder()
    bdFileData := chilkat.NewBinData()

    // Open the file.  We'll be reading and uploading in chunks..
    success = fac.OpenForRead(localFilePath)
    if success != true {
        fmt.Println(fac.LastErrorText())
        rest.DisposeRest()
        fac.DisposeFileAccess()
        azAuth.DisposeAuthAzureStorage()
        sbFileSize.DisposeStringBuilder()
        sbRange.DisposeStringBuilder()
        sbResponseBody.DisposeStringBuilder()
        bdFileData.DisposeBinData()
        return
    }

    numBytesLeft := szLocalFile
    curIndex := 0
    for numBytesLeft > 0 {

        chunkSize := numBytesLeft
        // Azure allows for 4MB max chunks  (4 x 1024 x 1024 = 4194304)
        if chunkSize > 4194304 {
            chunkSize = 4194304
        }

        // 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
        sbRange.Clear()
        sbRange.Append("bytes=")
        sbRange.AppendInt(curIndex)
        sbRange.Append("-")
        sbRange.AppendInt(curIndex + chunkSize - 1)

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

        // Read the next chunk from the local file.
        bdFileData.Clear()
        success = fac.FileReadBd(chunkSize,bdFileData)

        success = rest.FullRequestBd("PUT","/pip/somethingBig.zip?comp=range",bdFileData,sbResponseBody)
        if success != true {
            // This would indicate a failure where no response was received.
            fmt.Println(rest.LastErrorText())
            rest.DisposeRest()
            fac.DisposeFileAccess()
            azAuth.DisposeAuthAzureStorage()
            sbFileSize.DisposeStringBuilder()
            sbRange.DisposeStringBuilder()
            sbResponseBody.DisposeStringBuilder()
            bdFileData.DisposeBinData()
            return
        }

        // A 201 response indicates the chunk was uploaded.
        if rest.ResponseStatusCode() != 201 {
            // Examine the request/response to see what happened.
            fmt.Println("response status code = ", rest.ResponseStatusCode())
            fmt.Println("response status text = ", rest.ResponseStatusText())
            fmt.Println("response header: ", rest.ResponseHeader())
            fmt.Println("response body (if any): ", *responseStr)
            fmt.Println("---")
            fmt.Println("LastRequestStartLine: ", rest.LastRequestStartLine())
            fmt.Println("LastRequestHeader: ", rest.LastRequestHeader())
            rest.DisposeRest()
            fac.DisposeFileAccess()
            azAuth.DisposeAuthAzureStorage()
            sbFileSize.DisposeStringBuilder()
            sbRange.DisposeStringBuilder()
            sbResponseBody.DisposeStringBuilder()
            bdFileData.DisposeBinData()
            return
        }

        fmt.Println("Uploaded chunk from ", curIndex, " to ", curIndex + chunkSize - 1)

        curIndex = curIndex + chunkSize
        numBytesLeft = numBytesLeft - chunkSize
    }

    fac.FileClose()

    fmt.Println("success.")

    rest.DisposeRest()
    fac.DisposeFileAccess()
    azAuth.DisposeAuthAzureStorage()
    sbFileSize.DisposeStringBuilder()
    sbRange.DisposeStringBuilder()
    sbResponseBody.DisposeStringBuilder()
    bdFileData.DisposeBinData()