(Delphi DLL) 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.

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, FileAccess, AuthAzureStorage, Rest, BinData, StringBuilder, Xml, Crypt2;

...

procedure TForm1.Button1Click(Sender: TObject);
var
rest: HCkRest;
bTls: Boolean;
port: Integer;
bAutoReconnect: Boolean;
success: Boolean;
azAuth: HCkAuthAzureStorage;
xml: HCkXml;
fac: HCkFileAccess;
blockSize: Integer;
numBlocks: Integer;
crypt: HCkCrypt2;
sbResponseBody: HCkStringBuilder;
uriPath: HCkStringBuilder;
blockId: PWideChar;
dataBlock: HCkBinData;
contentMd5: PWideChar;
i: Integer;
xmlStr: PWideChar;
responseStr: PWideChar;

begin
// 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.

rest := CkRest_Create();

// Connect to the Azure Storage Blob Service
bTls := True;
port := 443;
bAutoReconnect := True;
// In this example, the storage account name is "chilkat".
success := CkRest_Connect(rest,'chilkat.blob.core.windows.net',port,bTls,bAutoReconnect);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkRest__lastErrorText(rest));
    Exit;
  end;

// Provide Azure Cloud credentials for the REST call.
azAuth := CkAuthAzureStorage_Create();
CkAuthAzureStorage_putAccessKey(azAuth,'AZURE_ACCESS_KEY');
// The account name used here should match the 1st part of the domain passed in the call to Connect (above).
CkAuthAzureStorage_putAccount(azAuth,'chilkat');
CkAuthAzureStorage_putScheme(azAuth,'SharedKey');
CkAuthAzureStorage_putService(azAuth,'Blob');
// This causes the "x-ms-version: 2021-08-06" header to be automatically added.
CkAuthAzureStorage_putXMsVersion(azAuth,'2021-08-06');
success := CkRest_SetAuthAzureStorage(rest,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..
xml := CkXml_Create();
CkXml_putTag(xml,'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
fac := CkFileAccess_Create();
success := CkFileAccess_OpenForRead(fac,'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...)
blockSize := 16384;

// How many 16K blocks?  (Including 1 for the last partial block)
numBlocks := CkFileAccess_GetNumBlocks(fac,blockSize);

crypt := CkCrypt2_Create();
CkCrypt2_putHashAlgorithm(crypt,'md5');

sbResponseBody := CkStringBuilder_Create();
uriPath := CkStringBuilder_Create();

dataBlock := CkBinData_Create();

i := 0;
while i < numBlocks do
  begin

    CkBinData_Clear(dataBlock);
    success := CkFileAccess_ReadBlockBd(fac,i,blockSize,dataBlock);
    if (success = False) then
      begin
        Memo1.Lines.Add(CkFileAccess__lastErrorText(fac));
        Exit;
      end;

    // 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 := CkFileAccess__genBlockId(fac,i,4,'base64');

    // Add this blockId to the list of blocks to be committed.
    CkXml_NewChild2(xml,'Latest',blockId);

    // Build the URI path
    CkStringBuilder_Clear(uriPath);
    success := CkStringBuilder_Append(uriPath,'/mycontainer/hamlet.xml?comp=block&blockId=');
    success := CkStringBuilder_Append(uriPath,blockId);

    contentMd5 := CkCrypt2__hashBdENC(crypt,dataBlock);
    CkRest_AddHeader(rest,'Content-MD5',contentMd5);

    // Upload this block..
    CkStringBuilder_Clear(sbResponseBody);
    success := CkRest_FullRequestBd(rest,'PUT',CkStringBuilder__getAsString(uriPath),dataBlock,sbResponseBody);
    if (success = False) then
      begin
        Memo1.Lines.Add(CkRest__lastErrorText(rest));
        Exit;
      end;

    // Verify that we received a 201 status code.
    if (CkRest_getResponseStatusCode(rest) <> 201) then
      begin
        // Examine the request/response to see what happened.
        Memo1.Lines.Add('response status code = ' + IntToStr(CkRest_getResponseStatusCode(rest)));
        Memo1.Lines.Add('response status text = ' + CkRest__responseStatusText(rest));
        Memo1.Lines.Add('response header: ' + CkRest__responseHeader(rest));
        Memo1.Lines.Add('response body (if any): ' + CkStringBuilder__getAsString(sbResponseBody));
        Memo1.Lines.Add('---');
        Memo1.Lines.Add('LastRequestStartLine: ' + CkRest__lastRequestStartLine(rest));
        Memo1.Lines.Add('LastRequestHeader: ' + CkRest__lastRequestHeader(rest));
        Exit;
      end;

    i := i + 1;
  end;

CkFileAccess_FileClose(fac);

// Now commit the blocks.
// Let's have a look at the XML that will commit the blocks:
xmlStr := CkXml__getXml(xml);
Memo1.Lines.Add(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.
// --------------------------------------------------------------------------
CkRest_RemoveHeader(rest,'Content-MD5');

// Send the PUT Block List...
responseStr := CkRest__fullRequestString(rest,'PUT','/mycontainer/hamlet.xml?comp=blocklist',xmlStr);
if (CkRest_getLastMethodSuccess(rest) <> True) then
  begin
    Memo1.Lines.Add(CkRest__lastErrorText(rest));
    Exit;
  end;

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

if (CkRest_getResponseStatusCode(rest) <> 201) then
  begin
    // Examine the request/response to see what happened.
    Memo1.Lines.Add('response status code = ' + IntToStr(CkRest_getResponseStatusCode(rest)));
    Memo1.Lines.Add('response status text = ' + CkRest__responseStatusText(rest));
    Memo1.Lines.Add('response header: ' + CkRest__responseHeader(rest));
    Memo1.Lines.Add('response body (if any): ' + responseStr);
    Memo1.Lines.Add('---');
    Memo1.Lines.Add('LastRequestStartLine: ' + CkRest__lastRequestStartLine(rest));
    Memo1.Lines.Add('LastRequestHeader: ' + CkRest__lastRequestHeader(rest));
    Exit;
  end;

Memo1.Lines.Add('Success.');

CkRest_Dispose(rest);
CkAuthAzureStorage_Dispose(azAuth);
CkXml_Dispose(xml);
CkFileAccess_Dispose(fac);
CkCrypt2_Dispose(crypt);
CkStringBuilder_Dispose(sbResponseBody);
CkStringBuilder_Dispose(uriPath);
CkBinData_Dispose(dataBlock);

end;