(Swift 3,4,5...) Upload File in Blocks (with Content-MD5 header) and Commit the Block List

Demonstrates how to upload a file in blocks and then commit the block list. This example includes a Content-MD5 header for each block.

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func chilkatTest() {
    // Azure Blob Service Example: Upload a file in blocks, and then commit the block list.
    // See also: https://msdn.microsoft.com/en-us/library/azure/dd135726.aspx

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

    let rest = CkoRest()!

    // Connect to the Azure Storage Blob Service
    var bTls: Bool = true
    var port: Int = 443
    var bAutoReconnect: Bool = true
    // In this example, the storage account name is "chilkat".
    var success: Bool = rest.connect("chilkat.blob.core.windows.net", port: port, tls: bTls, autoReconnect: bAutoReconnect)
    if success != true {
        print("\(rest.lastErrorText!)")
        return
    }

    // Provide Azure Cloud credentials for the REST call.
    let azAuth = CkoAuthAzureStorage()!
    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: 2020-08-04" header to be automatically added.
    azAuth.xMsVersion = "2020-08-04"
    success = rest.setAuthAzureStorage(azAuth)

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

    // As the blocks are uploaded, we'll keep an XML block list for the subsequent commit..
    let xml = CkoXml()!
    xml.tag = "BlockList"

    // Any type of file can be uploaded in this way.  It can a text file, binary file, anything...
    // This example will upload an XML file that is approximately 275K in size.  It can be downloaded
    // at http://www.chilkatsoft.com/hamlet.xml
    let fac = CkoFileAccess()!
    success = fac.open(forRead: "qa_data/xml/hamlet.xml")
    // Assuming success for the example..

    // We'll upload in 16K blocks (normally a program would upload in larger block sizes than this,
    // but this is just an example...)
    var blockSize: Int = 16384

    // How many 16K blocks?  (Including 1 for the last partial block)
    var numBlocks: Int = fac.getNumBlocks(blockSize).intValue

    let crypt = CkoCrypt2()!
    crypt.hashAlgorithm = "md5"

    let sbResponseBody = CkoStringBuilder()!
    let uriPath = CkoStringBuilder()!
    var blockId: String?
    let dataBlock = CkoBinData()!
    var contentMd5: String?
    var i: Int = 0
    while i < numBlocks {

        dataBlock.clear()
        success = fac.readBlockBd(i, blockSize: blockSize, bd: dataBlock)
        if success == false {
            print("\(fac.lastErrorText!)")
            return
        }

        // Generate a base64 block ID.  
        // (Chilkat provides a helper method named GenBlockId to make this easy)
        // A pre-base64 encoded block ID length of 4 is sufficient in this case because
        // this file certainly won't have more than 99,999 blocks..
        blockId = fac.genBlockId(i, length: 4, encoding: "base64")

        // Add this blockId to the list of blocks to be committed.
        xml.newChild2("Latest", content: blockId)

        // Build the URI path
        uriPath.clear()
        success = uriPath.append("/mycontainer/hamlet.xml?comp=block&blockId=")
        success = uriPath.append(blockId)

        contentMd5 = crypt.hashBdENC(dataBlock)
        rest.addHeader("Content-MD5", value: contentMd5)

        // Upload this block..
        sbResponseBody.clear()
        success = rest.fullRequestBd("PUT", uriPath: uriPath.getAsString(), binData: dataBlock, responseBody: sbResponseBody)
        if success == false {
            print("\(rest.lastErrorText!)")
            return
        }

        // Verify that we received a 201 status code.
        if rest.responseStatusCode.intValue != 201 {
            // Examine the request/response to see what happened.
            print("response status code = \(rest.responseStatusCode.intValue)")
            print("response status text = \(rest.responseStatusText!)")
            print("response header: \(rest.responseHeader!)")
            print("response body (if any): \(sbResponseBody.getAsString()!)")
            print("---")
            print("LastRequestStartLine: \(rest.lastRequestStartLine!)")
            print("LastRequestHeader: \(rest.lastRequestHeader!)")
            return
        }

        i = i + 1
    }

    fac.fileClose()

    // Now commit the blocks.
    // Let's have a look at the XML that will commit the blocks:
    var xmlStr: String? = xml.getXml()
    print("\(xmlStr!)")

    // The XML will look like this:

    // <?xml version="1.0" encoding="utf-8" ?>
    // <BlockList>
    //     <Latest>MDAwMA==</Latest>
    //     <Latest>MDAwMQ==</Latest>
    //     <Latest>MDAwMg==</Latest>
    //     <Latest>MDAwMw==</Latest>
    //     <Latest>MDAwNA==</Latest>
    //     <Latest>MDAwNQ==</Latest>
    //     <Latest>MDAwNg==</Latest>
    //     <Latest>MDAwNw==</Latest>
    //     <Latest>MDAwOA==</Latest>
    //     <Latest>MDAwOQ==</Latest>
    //     <Latest>MDAxMA==</Latest>
    //     <Latest>MDAxMQ==</Latest>
    //     <Latest>MDAxMg==</Latest>
    //     <Latest>MDAxMw==</Latest>
    //     <Latest>MDAxNA==</Latest>
    //     <Latest>MDAxNQ==</Latest>
    //     <Latest>MDAxNg==</Latest>
    //     <Latest>MDAxNw==</Latest>
    // </BlockList>

    // --------------------------------------------------------------------------
    // IMPORTANT: Remove the Content-MD5 header previously set in the loop above.
    // --------------------------------------------------------------------------
    rest.removeHeader("Content-MD5")

    // Send the PUT Block List...
    var responseStr: String? = rest.fullRequest("PUT", uriPath: "/mycontainer/hamlet.xml?comp=blocklist", bodyText: xmlStr)
    if rest.lastMethodSuccess != true {
        print("\(rest.lastErrorText!)")
        return
    }

    // When successful, the Azure Storage service will respond with a 201 response status code,
    // with no response body.

    if rest.responseStatusCode.intValue != 201 {
        // Examine the request/response to see what happened.
        print("response status code = \(rest.responseStatusCode.intValue)")
        print("response status text = \(rest.responseStatusText!)")
        print("response header: \(rest.responseHeader!)")
        print("response body (if any): \(responseStr!)")
        print("---")
        print("LastRequestStartLine: \(rest.lastRequestStartLine!)")
        print("LastRequestHeader: \(rest.lastRequestHeader!)")
        return
    }

    print("Success.")

}