(Delphi DLL) Compress Text Feed to Binary

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

The purpose is to demonstrate the BeginCompressString, MoreCompressString, and EndCompressString methods.

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, BinData, StringBuilder, CkByteData, Compression;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
compressedData: HCkBinData;
compressedBytes: HCkByteData;
compress: HCkCompression;
sbIndex: HCkStringBuilder;
i: Integer;
originalText: PWideChar;

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

compressedData := CkBinData_Create();
compressedBytes := CkByteData_Create();

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

sbIndex := CkStringBuilder_Create();

for i := 0 to 24 do
  begin
    // Note: It is possible (and normal) for a BeginCompress* or MoreCompress* method to return
    // an empty string (or 0 bytes).  When this happens, the input data is not lost.  It will be flushed
    // in a subsequent call.
    CkStringBuilder_Clear(sbIndex);
    CkStringBuilder_AppendInt(sbIndex,i);
    if (i = 0) then
      begin
        success := CkCompression_BeginCompressString(compress,CkStringBuilder__getAsString(sbIndex),compressedBytes);
      end
    else
      begin
        success := CkCompression_MoreCompressString(compress,CkStringBuilder__getAsString(sbIndex),compressedBytes);
      end;
    CkBinData_AppendBinary(compressedData,compressedBytes);
    success := CkCompression_MoreCompressString(compress,': This is a line of data to be compressed...' + #13#10,compressedBytes);
    CkBinData_AppendBinary(compressedData,compressedBytes);
  end;

// Flush any remaining output.
success := CkCompression_EndCompressString(compress,compressedBytes);
CkBinData_AppendBinary(compressedData,compressedBytes);

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

// Now decompress in one call:
success := CkBinData_GetBinary(compressedData,compressedBytes);
originalText := CkCompression__decompressString(compress,compressedBytes);
Memo1.Lines.Add(originalText);

CkBinData_Dispose(compressedData);
CkByteData_Dispose(compressedBytes);
CkCompression_Dispose(compress);
CkStringBuilder_Dispose(sbIndex);

end;