(Delphi ActiveX) Azure Storage: Lease Container

Azure Storage Blob Service REST API: Sample code to establishes a lock on a container for delete operations. The lock duration can be 15 to 60 seconds, or can be infinite.

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

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
rest: TChilkatRest;
bTls: Integer;
port: Integer;
bAutoReconnect: Integer;
success: Integer;
azAuth: TChilkatAuthAzureStorage;
crypt: TChilkatCrypt2;
guid: WideString;
responseStr: WideString;

begin
// Azure Blob Service Example: Lease Container
// See also: https://msdn.microsoft.com/en-us/library/azure/jj159103.aspx

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

rest := TChilkatRest.Create(Self);

// Connect to the Azure Storage Blob Service
bTls := 1;
port := 443;
bAutoReconnect := 1;
// In this example, the storage account name is "chilkat".
success := rest.Connect('chilkat.blob.core.windows.net',port,bTls,bAutoReconnect);
if (success <> 1) then
  begin
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  end;

// Provide Azure Cloud credentials for the REST call.
azAuth := TChilkatAuthAzureStorage.Create(Self);
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.ControlInterface);

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

// The lease ID needs to be a GUID.  (UUID and GUID are synonymous)
crypt := TChilkatCrypt2.Create(Self);
guid := crypt.GenerateUuid();
Memo1.Lines.Add('Lease ID: ' + guid);
success := rest.AddHeader('x-ms-lease-id',guid);

// The action can be "acquire", "renew", "change", "release", or "break".
// See https://msdn.microsoft.com/en-us/library/azure/jj159103.aspx
success := rest.AddHeader('x-ms-lease-action','acquire');

// The lease duration..
success := rest.AddHeader('x-ms-lease-duration','15');

// In this example, we are acquiring a lease for the container named "mycontainer".
responseStr := rest.FullRequestNoBody('PUT','/mycontainer?restype=container&comp=lease');
if (rest.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  end;

// When successful, the Azure Storage service will respond with a 200, 201, or 202 response status code,
// with no response body.

// The status code depends on the operation:
//    Acquire: A successful operation returns status code 201 (Created).
//    Renew: A successful operation returns status code 200 (OK).
//    Change: A successful operation returns status code 200 (OK).
//    Release: A successful operation returns status code 200 (OK).
//    Break: A successful operation returns status code 202 (Accepted).

if ((rest.ResponseStatusCode < 200) or (rest.ResponseStatusCode > 202)) then
  begin
    // Examine the request/response to see what happened.
    Memo1.Lines.Add('response status code = ' + IntToStr(rest.ResponseStatusCode));
    Memo1.Lines.Add('response status text = ' + rest.ResponseStatusText);
    Memo1.Lines.Add('response header: ' + rest.ResponseHeader);
    Memo1.Lines.Add('response body (if any): ' + responseStr);
    Memo1.Lines.Add('---');
    Memo1.Lines.Add('LastRequestStartLine: ' + rest.LastRequestStartLine);
    Memo1.Lines.Add('LastRequestHeader: ' + rest.LastRequestHeader);
    Exit;
  end;

Memo1.Lines.Add('Success: Lease acquired.');
end;