www.pudn.com > Indy_9_00_14_src.zip > IdHashElf.pas

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{ $Log:  10181: IdHashElf.pas  
{ 
{   Rev 1.0    2002.11.12 10:40:14 PM  czhower 
} 
unit IdHashElf; 
 
interface 
 
uses 
  Classes, 
  IdHash; 
 
type 
  TIdHashElf = class(TIdHash32) 
  public 
    function HashValue(AStream: TStream): LongWord; override; 
  end; 
 
implementation 
 
{ TIdHashElf } 
 
function TIdHashElf.HashValue(AStream: TStream): LongWord; 
var 
  i: Integer; 
  LByte: Byte; 
	LTemp: LongWord; 
begin 
	Result := 0; 
  AStream.Position := 0; 
  // Faster than a while - While would read .Size which is slow 
  for i := 1 to AStream.Size do begin 
    AStream.ReadBuffer(LByte, SizeOf(LByte)); 
		Result := (Result shl 4) + LByte; 
		LTemp := Result and $F0000000; 
		if LTemp <> 0 then begin 
    	Result := Result xor (LTemp Shr 24); 
    end; 
		Result := Result and not LTemp; 
	end; 
end; 
 
end.