几个 GetHashCode 函数

几个 GetHashCode 函数：

DBTables.pas

Delphi/Pascal code

 

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function GetHashCode(Str: PChar): Integer;     var       Off, Len, Skip, I: Integer;     begin       Result := 0;       Off := 1;       Len := StrLen(Str);       if Len < 16 then         for I := (Len - 1) downto 0 do         begin           Result := (Result * 37) + Ord(Str[Off]);           Inc(Off);         end       else       begin         { Only sample some characters }         Skip := Len div 8;         I := Len - 1;         while I >= 0 do         begin           Result := (Result * 39) + Ord(Str[Off]);           Dec(I, Skip);           Inc(Off, Skip);         end;       end;     end;

Graphics.pas

Delphi/Pascal code

 

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function GetHashCode(const Buffer; Count: Integer): Word; assembler; asm         MOV     ECX,EDX         MOV     EDX,EAX         XOR     EAX,EAX @@1:    ROL     AX,5         XOR     AL,[EDX]         INC     EDX         DEC     ECX         JNE     @@1 end;

SysUtils.pas

Delphi/Pascal code

 

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function HashName(Name: PChar): Cardinal; asm   PUSH  ESI   PUSH  EBX   MOV   ESI, Name   XOR   EAX, EAX   @@loop:   ROL   EAX, 5   MOV   BL, [ESI]   CMP   BL, 0   JE    @@done   CMP   BL, 'A'   JL    @@LowerCased   CMP   BL, 'Z'   JG    @@LowerCased   OR    BL, 20H // make lower case @@LowerCased:   XOR   AL, BL   INC   ESI   JMP   @@loop @@done:   POP   EBX   POP   ESI   RET end;

HTTPParse.pas

Delphi/Pascal code

 

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function GetHashCode(Ident: PChar; Length: Integer): Word; asm       PUSH ESI {$IFNDEF PIC}     PUSH    EBX     XOR    EBX,EBX {$ENDIF}       MOV  ESI, EAX       XOR  EAX, EAX       XOR  ECX, ECX @@1:  MOV   AL,[ESI]       ROL    CX,5       XOR    CL,CharValue.Byte[EBX + EAX]       INC    ESI       DEC    EDX     JNE    @@1       MOV    EAX,ECX {$IFNDEF PIC}     POP    EBX {$ENDIF}       POP   ESI end;