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All Atlas Crypto components · Atlas Crypto guide

TAtlasCryptoProgressEvent

The method type of OnProgress on both components: bytes done, bytes in total, and a flag to cancel.

Type Unit Atlas.CryptoComponents · Product Atlas Crypto

Description

TAtlasCryptoProgressEvent = procedure(Sender: TObject; Done, Total: Int64; var Cancel: Boolean) of object;

Sender is the component. Done and Total are byte counts; Total is measured once, when the operation starts. For TAtlasHashCalculator they count bytes hashed. For TAtlasFileProtector: When encrypting, Done and Total count plain bytes and Total is the size of the source. When decrypting they count the sealed bytes after the header (ciphertext plus the 16-byte tag of each chunk), so the numbers are larger than the plain size, but Done still reaches Total at the end. Set Cancel to True to stop; the component then raises EAtlasCryptoError. The event is called synchronously, on the thread that called the component. The anonymous-method equivalent used by the class functions is TAtlasCryptoProgress.

This type has no members of its own beyond those listed in its description.

Examples

Log progress from a console program

An event handler has to be a method, so a console program uses a small class. Hashing 600,000 bytes prints TAtlasHashCalculator: 43%, 87%, 100% and a final 100% for the last, empty read.

pascal
uses System.SysUtils, System.Classes, Atlas.Crypto, Atlas.CryptoComponents;

type
  TProgressLog = class
    procedure Report(Sender: TObject; Done, Total: Int64; var Cancel: Boolean);
  end;

procedure TProgressLog.Report(Sender: TObject; Done, Total: Int64; var Cancel: Boolean);
begin
  if Total > 0 then
    WriteLn(Format('%s: %d%%', [Sender.ClassName, Done * 100 div Total]));
end;

procedure HashWithLog;
var
  Calculator: TAtlasHashCalculator;
  Log: TProgressLog;
  Data: TBytesStream;
begin
  Data := TBytesStream.Create(TAtlasRandom.Bytes(600000));
  Log := TProgressLog.Create;
  Calculator := TAtlasHashCalculator.Create(nil);
  try
    Calculator.OnProgress := Log.Report;
    Calculator.HashStream(Data);
  finally
    Calculator.Free;
    Log.Free;
    Data.Free;
  end;
end;

TAtlasHashCalculator · TAtlasFileProtector · TAtlasCryptoProgress

Also in Atlas Crypto

TAtlasHashCalculator · TAtlasFileProtector