Delphi Magazine Collection 2001/Delphi Magazine Collection 20001 (2001).iso/DISKS/Issue48/Alfresco/TstCRC.dpr

Text File | 1999-06-20 | 5.2 KB | 177 lines

program TstCRC;

{$IFDEF Win32}
{$APPTYPE CONSOLE}
{$ENDIF}

uses
  SysUtils,
  {$IFDEF Windows}
  WinCrt,
  {$ENDIF}
  AACRC in 'AACRC.pas';


var
  i : integer;
  CRC16 : TaaCRC16;
  CRC32 : TaaCRC32;
  CRCTbl16 : Taa16BitCRCTable;

  CRC16Calc : TaaCRC16Calculator;
  CRC32Calc : TaaCRC32Calculator;

  AAL5Cell : array [0..47] of byte;

  St : array [0..47] of char;
begin
  writeln('Testing CRC routines');
  try
    {set up a test message}
    Fillchar(St, sizeof(St), 0);
    StrCopy(St, 'a phrase for which the CRC is wanted');

    {calculate the 16-bit CRC with the $1021 polynomial}
    writeln('Standard 16-bit CRC (without extra 16 zero bits)');
    CRC16 := AAGet16BitCRCStd(St, StrLen(St), PolyXMODEMCRC);
    writeln(Format('$%4x', [CRC16]));
    writeln('Standard 16-bit CRC (with extra 16 zero bits)');
    CRC16 := AAGet16BitCRCStd(St, StrLen(St) + 2, PolyXMODEMCRC);
    writeln(Format('$%4x', [CRC16]));

    {calculate the 16-bit CRC table}
    AACalc16BitCRCTable(CRCTbl16, PolyXMODEMCRC);

    {calculate the 16-bit CRC with this table}
    writeln('Standard 16-bit CRC using table');
    CRC16 := AAGet16BitCRCTbl(St, StrLen(St), CRCTbl16);
    writeln(Format('$%4x', [CRC16]));

    readln;

    writeln('Testing 16-bit CRC class');
    CRC16Calc := TaaCRC16Calculator.Create(PolyXMODEMCRC, false, 0, false);
    try
      writeln('..optimized bit by bit method');
      CRC16 := CRC16Calc.GetCRCStd(St, StrLen(St));
      writeln(Format('$%4x', [CRC16]));

      writeln('..table method');
      CRC16 := CRC16Calc.GetCRC(St, StrLen(St));
      writeln(Format('$%4x', [CRC16]));

      writeln('..byte by byte method');
      CRC16 := 0;
      for i := 0 to pred(StrLen(St)) do
        CRC16 := CRC16Calc.UpdateCRC(ord(St[i]), CRC16);
      writeln(Format('$%4x', [CRC16]));

      writeln('..saving to include file test16.inc');
      CRC16Calc.SaveToIncFile('test16.inc');
    finally
      CRC16Calc.Free;
    end;
    readln;

    writeln('Testing 32-bit CRC class with CRC32 method');
    CRC32Calc := TaaCRC32Calculator.Create(PolyCRC32, true, $FFFFFFFF, true);
    try
      writeln('..optimized bit by bit method');
      CRC32 := CRC32Calc.GetCRCStd(St, StrLen(St));
      writeln(Format('$%8x', [CRC32]));

      writeln('..table method');
      CRC32 := CRC32Calc.GetCRC(St, StrLen(St));
      writeln(Format('$%8x', [CRC32]));

      writeln('..byte by byte method');
      CRC32 := $FFFFFFFF;
      for i := 0 to pred(StrLen(St)) do
        CRC32 := CRC32Calc.UpdateCRC(ord(St[i]), CRC32);
      CRC32 := not CRC32;
      writeln(Format('$%4x', [CRC32]));

      writeln('..saving to include file test32.inc');
      CRC32Calc.SaveToIncFile('test32.inc');
    finally
      CRC32Calc.Free;
    end;
    readln;


    writeln('Testing 32-bit CRC class with standard AAL5 tests, bitbybit method');
    CRC32Calc := TaaCRC32Calculator.Create(PolyAAL5, false, $FFFFFFFF, true);
    try
      writeln('..all zeros: CRC should be $864d7f99');
      fillchar(AAL5Cell, sizeof(AAL5Cell), 0);
      AAL5Cell[40] := 0;
      AAL5Cell[41] := 0;
      AAL5Cell[42] := 0;
      AAL5Cell[43] := 40;
      CRC32 := CRC32Calc.GetCRCStd(AAL5Cell, 44);
      writeln(Format('$%8x', [CRC32]));
      writeln('..all ones: CRC should be $c55e457a');
      fillchar(AAL5Cell, sizeof(AAL5Cell), $ff);
      AAL5Cell[40] := 0;
      AAL5Cell[41] := 0;
      AAL5Cell[42] := 0;
      AAL5Cell[43] := 40;
      CRC32 := CRC32Calc.GetCRCStd(AAL5Cell, 44);
      writeln(Format('$%8x', [CRC32]));
      writeln('..sequential from 1: CRC should be $bf671ed0');
      for i := 0 to 39 do
        AAL5Cell[i] := succ(i);
      AAL5Cell[40] := 0;
      AAL5Cell[41] := 0;
      AAL5Cell[42] := 0;
      AAL5Cell[43] := 40;
      CRC32 := CRC32Calc.GetCRCStd(AAL5Cell, 44);
      writeln(Format('$%8x', [CRC32]));
    finally
      CRC32Calc.Free;
    end;
    readln;

    writeln('Testing 32-bit CRC class with standard AAL5 tests, table method');
    CRC32Calc := TaaCRC32Calculator.Create(PolyAAL5, false, $FFFFFFFF, true);
    try
      writeln('..all zeros: CRC should be $864d7f99');
      fillchar(AAL5Cell, sizeof(AAL5Cell), 0);
      AAL5Cell[40] := 0;
      AAL5Cell[41] := 0;
      AAL5Cell[42] := 0;
      AAL5Cell[43] := 40;
      CRC32 := CRC32Calc.GetCRC(AAL5Cell, 44);
      writeln(Format('$%8x', [CRC32]));
      writeln('..all ones: CRC should be $c55e457a');
      fillchar(AAL5Cell, sizeof(AAL5Cell), $ff);
      AAL5Cell[40] := 0;
      AAL5Cell[41] := 0;
      AAL5Cell[42] := 0;
      AAL5Cell[43] := 40;
      CRC32 := CRC32Calc.GetCRC(AAL5Cell, 44);
      writeln(Format('$%8x', [CRC32]));
      writeln('..sequential from 1: CRC should be $bf671ed0');
      for i := 0 to 39 do
        AAL5Cell[i] := succ(i);
      AAL5Cell[40] := 0;
      AAL5Cell[41] := 0;
      AAL5Cell[42] := 0;
      AAL5Cell[43] := 40;
      CRC32 := CRC32Calc.GetCRC(AAL5Cell, 44);
      writeln(Format('$%8x', [CRC32]));

      writeln('..saving to include file test32a.inc');
      CRC32Calc.SaveToIncFile('test32a.inc');
    finally
      CRC32Calc.Free;
    end;

  except
    on E:Exception do
      writeln(E.Message);
  end;
  writeln('Done, press Enter to close');
  readln;
end.