Delphi DLL

Compress Text Feed to Binary

See more Compression Examples

This example receives incoming text data in chunks, compresses as a stream, and accumulates the compressed binary data. Delphi DLL

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
bdCompressed: HCkBinData;
compress: HCkCompression;
sbUncompressedChunk: HCkStringBuilder;
i: Integer;
bdDecompressed: HCkBinData;
originalText: PWideChar;

begin
success := False;

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

bdCompressed := CkBinData_Create();

compress := CkCompression_Create();
CkCompression_putAlgorithm(compress,'deflate');
CkCompression_putCharset(compress,'utf-8');

sbUncompressedChunk := CkStringBuilder_Create();

CkCompression_putFirstChunk(compress,True);
CkCompression_putLastChunk(compress,False);

for i := 0 to 24 do
  begin
    if (i = 24) then
      begin
        CkCompression_putLastChunk(compress,True);
      end;

    CkStringBuilder_Clear(sbUncompressedChunk);
    CkStringBuilder_AppendInt(sbUncompressedChunk,i);
    CkStringBuilder_Append(sbUncompressedChunk,': This is a line of data to be compressed...' + #13#10);

    CkCompression_CompressSb(compress,sbUncompressedChunk,bdCompressed);

    CkCompression_putFirstChunk(compress,False);
  end;

// Show the compressed data in hex format:
Memo1.Lines.Add('The hex encoded compressed text:');
Memo1.Lines.Add(CkBinData__getEncoded(bdCompressed,'hex'));

// Now decompress in one call.  It is important to set both FirstChunk and LastChunk = True
bdDecompressed := CkBinData_Create();
CkCompression_putFirstChunk(compress,True);
CkCompression_putLastChunk(compress,True);
success := CkCompression_DecompressBd2(compress,bdCompressed,bdDecompressed);
if (success = False) then
  begin
    Memo1.Lines.Add(CkCompression__lastErrorText(compress));
    Exit;
  end;

originalText := CkBinData__getString(bdDecompressed,'utf-8');
Memo1.Lines.Add(originalText);

CkBinData_Dispose(bdCompressed);
CkCompression_Dispose(compress);
CkStringBuilder_Dispose(sbUncompressedChunk);
CkBinData_Dispose(bdDecompressed);

end;