Node.js

Upload File in Blocks (with Content-MD5 header) and Commit the Block List

See more Azure Cloud Storage Examples

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

NODEJS_PRELUDE

function chilkatExample() {

    var success = false;

    // 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.

    var rest = new chilkat.Rest();

    // Connect to the Azure Storage Blob Service
    var bTls = true;
    var port = 443;
    var bAutoReconnect = true;
    // In this example, the storage account name is "chilkat".
    success = rest.Connect("chilkat.blob.core.windows.net",port,bTls,bAutoReconnect);
    if (success !== true) {
        console.log(rest.LastErrorText);
        return;
    }

    // Provide Azure Cloud credentials for the REST call.
    var azAuth = 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);

    // 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..
    var xml = new chilkat.Xml();
    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
    var fac = new chilkat.FileAccess();
    success = fac.OpenForRead("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 = 16384;

    // How many 16K blocks?  (Including 1 for the last partial block)
    var numBlocks = fac.GetNumBlocks(blockSize);

    var crypt = new chilkat.Crypt2();
    crypt.HashAlgorithm = "md5";

    var sbResponseBody = new chilkat.StringBuilder();
    var uriPath = new chilkat.StringBuilder();
    var blockId;
    var dataBlock = new chilkat.BinData();
    var contentMd5;
    var i = 0;
    while (i < numBlocks) {

        dataBlock.Clear();
        success = fac.ReadBlockBd(i,blockSize,dataBlock);
        if (success == false) {
            console.log(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,4,"base64");

        // Add this blockId to the list of blocks to be committed.
        xml.NewChild2("Latest",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",contentMd5);

        // Upload this block..
        sbResponseBody.Clear();
        success = rest.FullRequestBd("PUT",uriPath.GetAsString(),dataBlock,sbResponseBody);
        if (success == false) {
            console.log(rest.LastErrorText);
            return;
        }

        // Verify that we received a 201 status code.
        if (rest.ResponseStatusCode !== 201) {
            // Examine the request/response to see what happened.
            console.log("response status code = " + rest.ResponseStatusCode);
            console.log("response status text = " + rest.ResponseStatusText);
            console.log("response header: " + rest.ResponseHeader);
            console.log("response body (if any): " + sbResponseBody.GetAsString());
            console.log("---");
            console.log("LastRequestStartLine: " + rest.LastRequestStartLine);
            console.log("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 = xml.GetXml();
    console.log(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 = rest.FullRequestString("PUT","/mycontainer/hamlet.xml?comp=blocklist",xmlStr);
    if (rest.LastMethodSuccess !== true) {
        console.log(rest.LastErrorText);
        return;
    }

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

    if (rest.ResponseStatusCode !== 201) {
        // Examine the request/response to see what happened.
        console.log("response status code = " + rest.ResponseStatusCode);
        console.log("response status text = " + rest.ResponseStatusText);
        console.log("response header: " + rest.ResponseHeader);
        console.log("response body (if any): " + responseStr);
        console.log("---");
        console.log("LastRequestStartLine: " + rest.LastRequestStartLine);
        console.log("LastRequestHeader: " + rest.LastRequestHeader);
        return;
    }

    console.log("Success.");

}

chilkatExample();