fpc/fcl/inc/streams.inc
2001-03-08 19:38:32 +00:00

665 lines
14 KiB
PHP

{
$Id$
This file is part of the Free Component Library (FCL)
Copyright (c) 1999-2000 by the Free Pascal development team
See the file COPYING.FPC, included in this distribution,
for details about the copyright.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
**********************************************************************}
{****************************************************************************}
{* TStream *}
{****************************************************************************}
function TStream.GetPosition: Longint;
begin
Result:=Seek(0,soFromCurrent);
end;
procedure TStream.SetPosition(Pos: Longint);
begin
Seek(pos,soFromBeginning);
end;
function TStream.GetSize: Longint;
var
p : longint;
begin
p:=GetPosition;
GetSize:=Seek(0,soFromEnd);
Seek(p,soFromBeginning);
end;
procedure TStream.SetSize(NewSize: Longint);
begin
// We do nothing. Pipe streams don't support this
// As wel as possible read-ony streams !!
end;
procedure TStream.ReadBuffer(var Buffer; Count: Longint);
begin
if Read(Buffer,Count)<Count then
Raise EReadError.Create(SReadError);
end;
procedure TStream.WriteBuffer(const Buffer; Count: Longint);
begin
if Write(Buffer,Count)<Count then
Raise EWriteError.Create(SWriteError);
end;
function TStream.CopyFrom(Source: TStream; Count: Longint): Longint;
var
i : longint;
buffer : array[0..1023] of byte;
begin
CopyFrom:=0;
while Count>0 do
begin
if (Count>sizeof(buffer)) then
i:=sizeof(Buffer)
else
i:=Count;
i:=Source.Read(buffer,i);
i:=Write(buffer,i);
dec(count,i);
CopyFrom:=CopyFrom+i;
if i=0 then
exit;
end;
end;
function TStream.ReadComponent(Instance: TComponent): TComponent;
var
Reader: TReader;
begin
Reader := TReader.Create(Self, 4096);
try
Result := Reader.ReadRootComponent(Instance);
finally
Reader.Free;
end;
end;
function TStream.ReadComponentRes(Instance: TComponent): TComponent;
begin
ReadResHeader;
Result := ReadComponent(Instance);
end;
procedure TStream.WriteComponent(Instance: TComponent);
begin
WriteDescendent(Instance, nil);
end;
procedure TStream.WriteComponentRes(const ResName: string; Instance: TComponent);
begin
WriteDescendentRes(ResName, Instance, nil);
end;
procedure TStream.WriteDescendent(Instance, Ancestor: TComponent);
var
Driver : TAbstractObjectWriter;
Writer : TWriter;
begin
Driver := TBinaryObjectWriter.Create(Self, 4096);
Try
Writer := TWriter.Create(Driver);
Try
Writer.WriteDescendent(Instance, Ancestor);
Finally
Writer.Destroy;
end;
Finally
Driver.Free;
end;
end;
procedure TStream.WriteDescendentRes(const ResName: string; Instance, Ancestor: TComponent);
var
FixupInfo: Integer;
begin
{ Write a resource header }
WriteResourceHeader(ResName, FixupInfo);
{ Write the instance itself }
WriteDescendent(Instance, Ancestor);
{ Insert the correct resource size into the resource header }
FixupResourceHeader(FixupInfo);
end;
procedure TStream.WriteResourceHeader(const ResName: string; {!!!: out} var FixupInfo: Integer);
begin
{ Numeric resource type }
WriteByte($ff);
{ Application defined data }
WriteWord($0a);
{ write the name as asciiz }
WriteBuffer(ResName[1],length(ResName));
WriteByte(0);
{ Movable, Pure and Discardable }
WriteWord($1030);
{ Placeholder for the resource size }
WriteDWord(0);
{ Return current stream position so that the resource size can be
inserted later }
FixupInfo := Position;
end;
procedure TStream.FixupResourceHeader(FixupInfo: Integer);
var
ResSize : Integer;
begin
ResSize := Position - FixupInfo;
{ Insert the correct resource size into the placeholder written by
WriteResourceHeader }
Position := FixupInfo - 4;
WriteDWord(ResSize);
{ Seek back to the end of the resource }
Position := FixupInfo + ResSize;
end;
procedure TStream.ReadResHeader;
begin
try
{ application specific resource ? }
if ReadByte<>$ff then
raise EInvalidImage.Create(SInvalidImage);
if ReadWord<>$000a then
raise EInvalidImage.Create(SInvalidImage);
{ read name }
while ReadByte<>0 do
;
{ check the access specifier }
if ReadWord<>$1030 then
raise EInvalidImage.Create(SInvalidImage);
{ ignore the size }
ReadDWord;
except
on EInvalidImage do
raise;
else
raise EInvalidImage.create(SInvalidImage);
end;
end;
function TStream.ReadByte : Byte;
var
b : Byte;
begin
ReadBuffer(b,1);
ReadByte:=b;
end;
function TStream.ReadWord : Word;
var
w : Word;
begin
ReadBuffer(w,2);
ReadWord:=w;
end;
function TStream.ReadDWord : Cardinal;
var
d : Cardinal;
begin
ReadBuffer(d,4);
ReadDWord:=d;
end;
Function TStream.ReadAnsiString : String;
Type
PByte = ^Byte;
Var
TheSize : Longint;
P : PByte ;
begin
ReadBuffer (TheSize,SizeOf(TheSize));
SetLength(Result,TheSize);
// Illegal typecast if no AnsiStrings defined.
if TheSize>0 then
begin
ReadBuffer (Pointer(Result)^,TheSize);
P:=Pointer(Result)+TheSize;
p^:=0;
end;
end;
Procedure TStream.WriteAnsiString (S : String);
Var L : Longint;
begin
L:=Length(S);
WriteBuffer (L,SizeOf(L));
WriteBuffer (Pointer(S)^,L);
end;
procedure TStream.WriteByte(b : Byte);
begin
WriteBuffer(b,1);
end;
procedure TStream.WriteWord(w : Word);
begin
WriteBuffer(w,2);
end;
procedure TStream.WriteDWord(d : Cardinal);
begin
WriteBuffer(d,4);
end;
{****************************************************************************}
{* THandleStream *}
{****************************************************************************}
Constructor THandleStream.Create(AHandle: Integer);
begin
FHandle:=AHandle;
end;
function THandleStream.Read(var Buffer; Count: Longint): Longint;
begin
Result:=FileRead(FHandle,Buffer,Count);
If Result=-1 then Result:=0;
end;
function THandleStream.Write(const Buffer; Count: Longint): Longint;
begin
Result:=FileWrite (FHandle,Buffer,Count);
If Result=-1 then Result:=0;
end;
{****************************************************************************}
{* TFileStream *}
{****************************************************************************}
constructor TFileStream.Create(const AFileName: string; Mode: Word);
begin
FFileName:=AFileName;
If Mode=fmcreate then
FHandle:=FileCreate(AFileName)
else
FHAndle:=FileOpen(AFileName,Mode);
If FHandle<0 then
If Mode=fmcreate then
raise EFCreateError.createfmt(SFCreateError,[AFileName])
else
raise EFOpenError.Createfmt(SFOpenError,[AFilename]);
end;
destructor TFileStream.Destroy;
begin
FileClose(FHandle);
end;
Procedure TFileStream.SetSize(NewSize: Longint);
begin
FileTruncate(FHandle,NewSize);
end;
function TFileStream.Seek(Offset: Longint; Origin: Word): Longint;
begin
Result:=FileSeek(FHandle,Offset,Origin);
end;
{****************************************************************************}
{* TCustomMemoryStream *}
{****************************************************************************}
procedure TCustomMemoryStream.SetPointer(Ptr: Pointer; ASize: Longint);
begin
FMemory:=Ptr;
FSize:=ASize;
end;
function TCustomMemoryStream.Read(var Buffer; Count: Longint): Longint;
begin
Result:=0;
If (FSize>0) and (FPosition<Fsize) then
begin
Result:=FSize-FPosition;
If Result>Count then Result:=Count;
Move ((FMemory+FPosition)^,Buffer,Result);
FPosition:=Fposition+Result;
end;
end;
function TCustomMemoryStream.Seek(Offset: Longint; Origin: Word): Longint;
begin
Case Origin of
soFromBeginning : FPosition:=Offset;
soFromEnd : FPosition:=FSize+Offset;
soFromCurrent : FpoSition:=FPosition+Offset;
end;
Result:=FPosition;
end;
procedure TCustomMemoryStream.SaveToStream(Stream: TStream);
begin
if FSize>0 then Stream.WriteBuffer (FMemory^,FSize);
end;
procedure TCustomMemoryStream.SaveToFile(const FileName: string);
Var S : TFileStream;
begin
Try
S:=TFileStream.Create (FileName,fmCreate);
SaveToStream(S);
finally
S.free;
end;
end;
{****************************************************************************}
{* TMemoryStream *}
{****************************************************************************}
Const TMSGrow = 4096; { Use 4k blocks. }
procedure TMemoryStream.SetCapacity(NewCapacity: Longint);
begin
SetPointer (Realloc(NewCapacity),Fsize);
FCapacity:=NewCapacity;
end;
function TMemoryStream.Realloc(var NewCapacity: Longint): Pointer;
Var MoveSize : Longint;
begin
If NewCapacity>0 Then // round off to block size.
NewCapacity := (NewCapacity + (TMSGrow-1)) and not (TMSGROW-1);
// Only now check !
If NewCapacity=FCapacity then
Result:=FMemory
else
If NewCapacity=0 then
FreeMem (FMemory,Fcapacity)
else
begin
GetMem (Result,NewCapacity);
If Result=Nil then
Raise EStreamError.Create(SMemoryStreamError);
If FCapacity>0 then
begin
MoveSize:=FSize;
If MoveSize>NewCapacity then MoveSize:=NewCapacity;
Move (Fmemory^,Result^,MoveSize);
FreeMem (FMemory,FCapacity);
end;
end;
end;
destructor TMemoryStream.Destroy;
begin
Clear;
Inherited Destroy;
end;
procedure TMemoryStream.Clear;
begin
FSize:=0;
FPosition:=0;
SetCapacity (0);
end;
procedure TMemoryStream.LoadFromStream(Stream: TStream);
begin
Stream.Position:=0;
SetSize(Stream.Size);
If FSize>0 then Stream.ReadBuffer(FMemory^,FSize);
end;
procedure TMemoryStream.LoadFromFile(const FileName: string);
Var S : TFileStream;
begin
Try
S:=TFileStream.Create (FileName,fmOpenRead);
LoadFromStream(S);
finally
S.free;
end;
end;
procedure TMemoryStream.SetSize(NewSize: Longint);
begin
SetCapacity (NewSize);
FSize:=NewSize;
IF FPosition>FSize then
FPosition:=FSize;
end;
function TMemoryStream.Write(const Buffer; Count: Longint): Longint;
Var NewPos : Longint;
begin
If Count=0 then
exit(0);
NewPos:=FPosition+Count;
If NewPos>Fsize then
begin
IF NewPos>FCapacity then
SetCapacity (NewPos);
FSize:=Newpos;
end;
System.Move (Buffer,(FMemory+FPosition)^,Count);
FPosition:=NewPos;
Result:=Count;
end;
{****************************************************************************}
{* TStringStream *}
{****************************************************************************}
procedure TStringStream.SetSize(NewSize: Longint);
begin
Setlength(FDataString,NewSize);
If FPosition>NewSize then FPosition:=NewSize;
end;
constructor TStringStream.Create(const AString: string);
begin
Inherited create;
FDataString:=AString;
end;
function TStringStream.Read(var Buffer; Count: Longint): Longint;
begin
Result:=Length(FDataString)-FPosition;
If Result>Count then Result:=Count;
// This supposes FDataString to be of type AnsiString !
Move (Pchar(FDataString)[FPosition],Buffer,Count);
FPosition:=FPosition+Count;
end;
function TStringStream.ReadString(Count: Longint): string;
Var NewLen : Longint;
begin
NewLen:=Length(FDataString)-FPosition;
If NewLen>Count then NewLen:=Count;
SetLength(Result,NewLen);
Read (Pointer(Result)^,NewLen);
ReadString:='';
end;
function TStringStream.Seek(Offset: Longint; Origin: Word): Longint;
begin
Case Origin of
soFromBeginning : FPosition:=Offset;
soFromEnd : FPosition:=Length(FDataString)+Offset;
soFromCurrent : FpoSition:=FPosition+Offset;
end;
If FPosition>Length(FDataString) then FPosition:=Length(FDataString);
If FPosition<0 then FPosition:=0;
Result:=FPosition;
end;
function TStringStream.Write(const Buffer; Count: Longint): Longint;
begin
Result:=Count;
SetSize(FPosition+Count);
// This supposes that FDataString is of type AnsiString)
Move (Buffer,PCHar(FDataString)[Fposition],Count);
FPosition:=FPosition+Count;
end;
procedure TStringStream.WriteString(const AString: string);
begin
Write (PChar(Astring)[0],Length(AString));
end;
{****************************************************************************}
{* TResourceStream *}
{****************************************************************************}
procedure TResourceStream.Initialize(Instance: THandle; Name, ResType: PChar);
begin
end;
constructor TResourceStream.Create(Instance: THandle; const ResName: string; ResType: PChar);
begin
end;
constructor TResourceStream.CreateFromID(Instance: THandle; ResID: Integer; ResType: PChar);
begin
end;
destructor TResourceStream.Destroy;
begin
end;
function TResourceStream.Write(const Buffer; Count: Longint): Longint;
begin
Write:=0;
end;
{
$Log$
Revision 1.3 2001-03-08 19:38:32 michael
+ Merged changes, fixed stringstream
Revision 1.2 2000/07/13 11:33:00 michael
+ removed logs
}