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* Fix 19851 19852 19855 (modified patch by Chad B)

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git-svn-id: trunk@18193 -
This commit is contained in:
michael 2011-08-13 18:51:23 +00:00
parent 09371b21e9
commit 6692595a33
1 changed files with 33 additions and 27 deletions
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60
packages/fcl-base/src/iostream.pp
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@ -22,17 +22,22 @@ type
TIOSType = (iosInput,iosOutPut,iosError);
EIOStreamError = class(EStreamError);
{ TIOStream }
TIOStream = class(THandleStream)
private
FType : longint;
FPos : Int64;
zIOSType : TIOSType;
protected
procedure SetSize(const NewSize: Int64); override;
function GetPosition: Int64; override;
procedure InvalidSeek; override;
public
constructor Create(aIOSType : TiosType);
function Read(var Buffer; Count : LongInt) : Longint; override;
function Write(const Buffer; Count : LongInt) : LongInt; override;
procedure SetSize(NewSize: Longint); override;
function Seek(Offset: Longint; Origin: Word): Longint; override;
function Seek(const Offset: int64; Origin: TSeekOrigin): int64; override;
end;
implementation
@ -42,9 +47,24 @@ const
SWriteOnlyStream = 'Cannot read from an output stream.';
SInvalidOperation = 'Cannot perform this operation on a IOStream.';
procedure TIOStream.SetSize(const NewSize: Int64);
begin
raise EIOStreamError.Create(SInvalidOperation);
end;
function TIOStream.GetPosition: Int64;
begin
Result:=FPos;
end;
procedure TIOStream.InvalidSeek;
begin
raise EIOStreamError.Create(SInvalidOperation);
end;
constructor TIOStream.Create(aIOSType : TIOSType);
begin
{$ifdef win32}
{$ifdef windows}
case aIOSType of
iosInput : FType := StdInputHandle;
iosOutput : FType := StdOutputHandle;
@ -77,32 +97,18 @@ begin
end;
end;
procedure TIOStream.SetSize(NewSize: Longint);
begin
raise EIOStreamError.Create(SInvalidOperation);
end;
function TIOStream.Seek(Offset: Longint; Origin: Word): Longint;
const
BufSize = 1024;
var
Buf : array[1..BufSize] of Byte;
function TIOStream.Seek(const Offset: int64; Origin: TSeekOrigin): int64;
begin
If (Origin=soFromCurrent) and (Offset=0) then
result:=FPos;
{ Try to fake seek by reading and discarding }
if (zIOSType = iosOutput) or
Not((Origin=soFromCurrent) and (Offset>=0) or
((Origin=soFrombeginning) and (OffSet>=FPos))) then
Raise EIOStreamError.Create(SInvalidOperation);
if Origin=soFromBeginning then
Dec(Offset,FPos);
While ((Offset Div BufSize)>0)
and (Read(Buf,SizeOf(Buf))=BufSize) do
Dec(Offset,BufSize);
If (Offset>0) then
Read(Buf,BufSize);
Result:=FPos;
if (Origin=soCurrent) and (Offset=0) then
Result:=FPos
else
begin
if zIOSType in [iosOutput,iosError] then
InvalidSeek;
FakeSeekForward(Offset,Origin,FPos);
Result:=FPos;
end;
end;
end.