...Stop memory leaks with the Masks.MatchesMask procedure?
Author: Aaron Murgatroyd
// The Masks unit has a bug when specifying
// masks that start with with a set, this bug
// even occurrs is a * is first and then a set.
// This is due to a small memory freeing issue
// If you step through the masks unit you
// will find it. Here is a replacement unit for
// the Masks unit which has the fixes in it.
{ *************************************************************************** }
{ }
{ Kylix and Delphi Cross-Platform Visual Component Library }
{ }
{ Copyright (c) 1995, 2001 Borland Software Corporation }
{ }
{ *************************************************************************** }
unit untMasks;
interface
uses SysUtils;
type
EMaskException = class(Exception);
TMask = class
private
FMask: Pointer;
FSize: Integer;
public
constructor Create(const MaskValue: string);
destructor Destroy; override;
function Matches(const FileName: string): Boolean;
end;
function MatchesMask(const FileName, Mask: string): Boolean;
implementation
uses RTLConsts;
const
MaxCards = 30;
type
PMaskSet = ^TMaskSet;
TMaskSet = set of Char;
TMaskStates = (msLiteral, msAny, msSet, msMBCSLiteral);
TMaskState = record
SkipTo: Boolean;
case State: TMaskStates of
msLiteral: (Literal: Char);
msAny: ();
msSet: (Negate: Boolean;
CharSet: PMaskSet);
msMBCSLiteral: (LeadByte, TrailByte: Char);
end;
PMaskStateArray = ^TMaskStateArray;
TMaskStateArray = array[0..128] of TMaskState;
function InitMaskStates(const Mask: string;
var MaskStates: array of TMaskState; bDontAllocate: Boolean = False): Integer;
var
I: Integer;
SkipTo: Boolean;
Literal: Char;
LeadByte, TrailByte: Char;
P: PChar;
Negate: Boolean;
CharSet: TMaskSet;
Cards: Integer;
procedure InvalidMask;
begin
raise EMaskException.CreateResFmt(@SInvalidMask, [Mask,
P - PChar(Mask) + 1]);
end;
procedure Reset;
begin
SkipTo := False;
Negate := False;
CharSet := [];
end;
procedure WriteScan(MaskState: TMaskStates);
begin
if I <= High(MaskStates) then
begin
if SkipTo then
begin
Inc(Cards);
if Cards > MaxCards then InvalidMask;
end;
MaskStates[I].SkipTo := SkipTo;
MaskStates[I].State := MaskState;
case MaskState of
msLiteral: MaskStates[I].Literal := UpCase(Literal);
msSet:
begin
MaskStates[I].Negate := Negate;
if not bDontAllocate then
begin
New(MaskStates[I].CharSet);
MaskStates[I].CharSet^ := CharSet;
end
else
MaskStates[I].CharSet := nil;
end;
msMBCSLiteral:
begin
MaskStates[I].LeadByte := LeadByte;
MaskStates[I].TrailByte := TrailByte;
end;
end;
end;
Inc(I);
Reset;
end;
procedure ScanSet;
var
LastChar: Char;
C: Char;
begin
Inc(P);
if P^ = '!' then
begin
Negate := True;
Inc(P);
end;
LastChar := #0;
while not (P^ in [#0, ']']) do
begin
// MBCS characters not supported in msSet!
if P^ in LeadBytes then
Inc(P)
else
case P^ of
'-':
if LastChar = #0 then InvalidMask
else
begin
Inc(P);
for C := LastChar to UpCase(P^) do Include(CharSet, C);
end;
else
LastChar := UpCase(P^);
Include(CharSet, LastChar);
end;
Inc(P);
end;
if (P^ <> ']') or (CharSet = []) then InvalidMask;
WriteScan(msSet);
end;
begin
P := PChar(Mask);
I := 0;
Cards := 0;
Reset;
while P^ <> #0 do
begin
case P^ of
'*': SkipTo := True;
'?': if not SkipTo then WriteScan(msAny);
'[': ScanSet;
else
if P^ in LeadBytes then
begin
LeadByte := P^;
Inc(P);
TrailByte := P^;
WriteScan(msMBCSLiteral);
end
else
begin
Literal := P^;
WriteScan(msLiteral);
end;
end;
Inc(P);
end;
Literal := #0;
WriteScan(msLiteral);
Result := I;
end;
function MatchesMaskStates(const FileName: string;
const MaskStates: array of TMaskState): Boolean;
type
TStackRec = record
sP: PChar;
sI: Integer;
end;
var
T: Integer;
S: array[0..MaxCards - 1] of TStackRec;
I: Integer;
P: PChar;
procedure Push(P: PChar; I: Integer);
begin
with S[T] do
begin
sP := P;
sI := I;
end;
Inc(T);
end;
function Pop(var P: PChar; var I: Integer): Boolean;
begin
if T = 0 then
Result := False
else
begin
Dec(T);
with S[T] do
begin
P := sP;
I := sI;
end;
Result := True;
end;
end;
function Matches(P: PChar; Start: Integer): Boolean;
var
I: Integer;
begin
Result := False;
for I := Start to High(MaskStates) do
with MaskStates[I] do
begin
if SkipTo then
begin
case State of
msLiteral:
while (P^ <> #0) and (UpperCase(P^) <> Literal) do Inc(P);
msSet:
while (P^ <> #0) and not (Negate xor (UpCase(P^) in CharSet^)) do Inc(P);
msMBCSLiteral:
while (P^ <> #0) do
begin
if (P^ <> LeadByte) then Inc(P, 2)
else
begin
Inc(P);
if (P^ = TrailByte) then Break;
Inc(P);
end;
end;
end;
if P^ <> #0 then Push(@P[1], I);
end;
case State of
msLiteral: if UpperCase(P^) <> Literal then Exit;
msSet: if not (Negate xor (UpCase(P^) in CharSet^)) then Exit;
msMBCSLiteral:
begin
if P^ <> LeadByte then Exit;
Inc(P);
if P^ <> TrailByte then Exit;
end;
end;
Inc(P);
end;
Result := True;
end;
begin
Result := True;
T := 0;
P := PChar(FileName);
I := Low(MaskStates);
repeat
if Matches(P, I) then Exit;
until not Pop(P, I);
Result := False;
end;
procedure DoneMaskStates(var MaskStates: array of TMaskState);
var
I: Integer;
begin
for I := Low(MaskStates) to High(MaskStates) do
if MaskStates[I].State = msSet then Dispose(MaskStates[I].CharSet);
end;
{ TMask }
constructor TMask.Create(const MaskValue: string);
var
A: array[0..0] of TMaskState;
begin
FSize := InitMaskStates(MaskValue, A, True);
FMask := AllocMem(FSize * SizeOf(TMaskState));
InitMaskStates(MaskValue, Slice(PMaskStateArray(FMask)^, FSize));
end;
destructor TMask.Destroy;
begin
if FMask <> nil then
begin
DoneMaskStates(Slice(PMaskStateArray(FMask)^, FSize));
FreeMem(FMask, FSize * SizeOf(TMaskState));
end;
end;
function TMask.Matches(const FileName: string): Boolean;
begin
Result := MatchesMaskStates(FileName, Slice(PMaskStateArray(FMask)^, FSize));
end;
function MatchesMask(const FileName, Mask: string): Boolean;
var
CMask: TMask;
begin
CMask := TMask.Create(Mask);
try
Result := CMask.Matches(FileName);
finally
CMask.Free;
end;
end;
end.
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