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Other than a few safeguards missing and (in my opinion) unnecessarily increasing the size of the saved data, all looks fine.
Many thanks to your valuable advice. I have changed the codes accordingly as follows:aehimself wrote: ↑05.11.2021, 09:50 Other than a few safeguards missing and (in my opinion) unnecessarily increasing the size of the saved data, all looks fine.
- ReadBlob and WriteBlob is missing the Try...Finally block.
- At Required, you are saving Boolean as Integer. Boolean having the size of 1, LongInt having the size of 4, you are wasting FieldCount * 3 bytes there
- I also think it's unnecessary to put the data type in the data part of the stream. We have the field type from the recently created FieldDefs. With this, you are adding FieldCount * 4 bytes bloat.
Code: Select all
procedure TZAbstractMemTable.LoadFromStream(AStream: TStream);
var
len, ftype, a, b, cc, kk: Integer; tx: string; req: Boolean;
tb: TBytes;
function ReadByte: Byte;
begin
AStream.Read(result, 1)
end;
function ReadInt: longint;
begin
AStream.Read(result, Sizeof(longint));
end;
function ReadStr: string;
begin
cc := ReadInt;
SetLength(result, cc);
AStream.Readbuffer(Pointer(result)^, cc);
end;
procedure ReadBlob;
var ms: TMemoryStream;
begin
cc := ReadInt;
if cc > 0 then
begin
ms := TMemoryStream.Create;
try
ms.CopyFrom(AStream, cc);
(Fields[b] as TBlobField).LoadFromStream(ms);
finally
ms.Free;
end;
end;
end;
procedure ReadData;
begin
cc := ReadInt;
SetLength(tb, cc);
AStream.ReadBuffer(Pointer(tb)^, cc);
Fields[b].SetData(Pointer(tb));
end;
begin
CheckInactive;
//Close;
FieldDefs.Clear;
DisableControls;
AStream.Position:= 0;
kk := ReadInt; //fieldcount
try
for a := 1 To kk do
begin
//tx := AStream.ReadAnsiString;
tx := ReadStr;
ftype := ReadInt;
len := ReadInt;
req := ReadByte > 0;
FieldDefs.Add(tx, TFieldType(fType), len, req);
end;
Open; // Open - setup fields structure for memtable
kk := ReadInt; // recordcount
for a := 1 to kk do
begin
Append;
for b := 0 to FieldCount - 1 do
begin
case Fields[b].DataType of
ftString, ftMemo: Fields[b].AsString := ReadStr;
ftBlob: try ReadBlob; except end;
else ReadData;
end; //case
end;
Post;
end;
{try
while true do
begin
Append;
for b := 0 to FieldCount - 1 do
begin
cc := ReadInt;
case cc of
-maxint..-1: ReadBlob;
0: ; //No data - ignore
1..1000: ReadData; //simple type
1001: Fields[b].AsString := ReadStr;
end; //case
end;
if AStream.Position < AStream.Size then
Post
else
begin
Cancel ;
Break
end;
end;
except
end; }
First;
finally
EnableControls;
end;
// end;
end;
procedure TZAbstractMemTable.SaveToStream(AStream: TStream);
var bm: TBookMark; a, cc: Integer;
tb: TBytes;
procedure WriteByte(bb: byte);
begin
AStream.Write(bb, 1);
end;
procedure WriteInt(ii: longint);
begin
AStream.Write(ii, Sizeof(longint))
end;
procedure WriteStr(tx: string);
begin
cc := Length(tx); WriteInt(cc);
AStream.WriteBuffer(Pointer(tx)^, cc);
end;
procedure WriteBlob;
var ms: TMemoryStream;
begin
ms:= TMemoryStream.Create;
try
(Fields[a] as TBlobField).SaveToStream(ms);
cc := ms.Size;
WriteInt(cc);
if cc > 0 then
begin
ms.Position := 0;
AStream.CopyFrom(ms, cc);
end;
finally
ms.Free;
end;
end;
procedure WriteData;
begin
cc := Fields[a].DataSize;
SetLength(tb, cc);
Fields[a].GetData(Pointer(tb));
WriteInt(cc);
AStream.Writebuffer(Pointer(tb)^, cc);
end;
begin
CheckActive;
bm := GetBookmark;
AStream.Position:= 0;
try
DisableControls;
try
WriteInt(FieldDefs.Count);
for a := 0 To FieldDefs.Count - 1 do
begin
WriteStr(FieldDefs[a].Name);
WriteInt(ord(FieldDefs[a].DataType));
WriteInt(FieldDefs[a].Size);
WriteByte(Byte(FieldDefs[a].Required));
end;
First;
WriteInt(RecordCount);
while not Eof Do
begin
for a := 0 To FieldCount - 1 Do
case Fields[a].DataType of
ftString, ftMemo: WriteStr(Fields[a].AsString);
ftBlob: WriteBlob;
else WriteData
end; //case
Next;
end;
finally
EnableControls;
end;
finally
GotoBookmark(bm);
end;
end;
procedure TZAbstractMemTable.LoadFromFile(Filename: TFilename);
var F1: TFileStream;
begin
F1 := TFileStream.Create(Filename, fmOpenRead + fmShareCompat);
try
Self.LoadFromStream(F1);
finally;
F1.Free;
end;
end;
procedure TZAbstractMemTable.SaveToFile(Filename: TFilename);
var F1: TFileStream;
begin
F1 := TFileStream.Create(Filename, fmCreate);
try
Self.SaveToStream(F1);
finally
F1.Free;
end;
end;
Michal,
This version still uses TBytes (which should be TValueBuffer anyway), which does not exist on earlier Delphi versions. It also disregards the WITH_TVALUEBUFFER directive, meaning it has no "backup" if it does not exist in the environment.
Code: Select all
[Pascal Error] ZMemTable.pas(544): E2003 Undeclared identifier: 'ReadData'
[Pascal Error] ZMemTable.pas(674): E2003 Undeclared identifier: 'WriteData'
[Pascal Error] ZMemTable.pas(715): E2035 Not enough actual parameters -- AStream.CopyFrom(ms);
[Pascal Error] ZMemTable.pas(739): E2008 Incompatible types -- AStream.Write(buf, Length(buf));Code: Select all
{$IFDEF ZMEMTABLE_ENABLE_STREAM_EXPORT_IMPORT}
Procedure TZAbstractMemTable.LoadFromStream(AStream: TStream);
Function ReadBool: Boolean;
Begin
AStream.Read(Result, SizeOf(Boolean));
End;
Function ReadInt: Integer;
Begin
AStream.Read(Result, SizeOf(Integer));
End;
Function ReadString: String;
Begin
SetLength(Result, ReadInt);
AStream.Read(Pointer(Result)^, Length(Result) * SizeOf(Char));
End;
Var
a, b, len, ftype, fsize: Integer;
fname: String;
buf: {$IFDEF WITH_TVALUEBUFFER}TValueBuffer{$ELSE}Pointer{$ENDIF};
ms: TMemoryStream;
Begin
Self.CheckInactive;
Self.FieldDefs.Clear;
Self.DisableControls;
Try
// Recreate FieldDefs
len := ReadInt;
For a := 0 To len - 1 Do
Begin
fname := ReadString;
ftype := ReadInt;
fsize := ReadInt;
Self.FieldDefs.Add(fname, TFieldType(ftype), fsize, ReadBool);
End;
// Activate the MemTable so we can write the data back
Self.Open;
// Now read each field of each record, one by one
len := ReadInt;
For a := 0 To len - 1 Do
Begin
Self.Append;
For b := 0 To Self.FieldCount - 1 Do
Begin
If Self.Fields[b] Is TBlobField Then
Begin
ms := TMemoryStream.Create;
Try
ms.CopyFrom(AStream, ReadInt);
ms.Position := 0;
(Self.Fields[b] As TBlobField).LoadFromStream(ms);
Finally
FreeAndNil(ms);
End;
End
Else
Begin
{$IFDEF WITH_TVALUEBUFFER}
SetLength(buf, ReadInt);
AStream.Read(buf[0], Length(buf));
Self.Fields[b].SetData(buf);
{$ELSE}
fsize := ReadInt;
GetMem(buf, fsize);
Try
AStream.Read(buf^, fsize);
Self.Fields[b].SetData(buf);
Finally
FreeMem(buf);
End;
{$ENDIF}
End;
End;
Self.Post;
End;
Self.First;
Finally
Self.EnableControls;
End;
End;
{$ENDIF}
{$IFDEF ZMEMTABLE_ENABLE_STREAM_EXPORT_IMPORT}
Procedure TZAbstractMemTable.SaveToStream(AStream: TStream);
Procedure WriteBool(Const ABoolean: Boolean);
Begin
AStream.Write(ABoolean, SizeOf(Boolean));
End;
Procedure WriteInt(Const ANumber: Integer);
Begin
AStream.Write(ANumber, SizeOf(Integer));
End;
Procedure WriteString(Const AText: String);
Begin
WriteInt(Length(AText));
AStream.Write(Pointer(AText)^, Length(AText) * SizeOf(Char));
End;
Var
bm: TBookMark;
a: Integer;
buf: {$IFDEF WITH_TVALUEBUFFER}TValueBuffer{$ELSE}Pointer{$ENDIF};
ms: TMemoryStream;
Begin
Self.CheckActive;
bm := Self.GetBookmark;
Try
Self.DisableControls;
Try
// Write all FieldDefs
WriteInt(Self.FieldDefs.Count);
For a := 0 To Self.FieldDefs.Count - 1 Do
Begin
WriteString(Self.FieldDefs[a].Name);
WriteInt(Integer(Self.FieldDefs[a].DataType));
WriteInt(Self.FieldDefs[a].Size);
WriteBool(Self.FieldDefs[a].Required);
End;
// Write the number of records the MemTable holds
WriteInt(Self.RecordCount);
// Write each field of each record, one by one
Self.First;
While Not Self.Eof Do
Begin
For a := 0 To Self.FieldCount - 1 Do
Begin
If Self.Fields[a] Is TBlobField Then
Begin
ms := TMemoryStream.Create;
Try
(Self.Fields[a] As TBlobField).SaveToStream(ms);
ms.Position := 0;
WriteInt(ms.Size);
AStream.CopyFrom(ms, ms.Size);
Finally
FreeAndNil(ms);
End;
End
Else
Begin
{$IFDEF WITH_TVALUEBUFFER}
SetLength(buf, Self.Fields[a].DataSize);
Self.Fields[a].GetData(buf);
// If buf[High(buf)] = 0 Then
// For b := High(buf) - 1 DownTo Low(buf) Do
// If buf[b] <> 0 Then
// Begin
// SetLength(buf, b + 1);
// Break;
// End;
WriteInt(Length(buf));
AStream.Write(buf, Length(buf));
{$ELSE}
GetMem(buf, Self.Fields[a].DataSize);
Try
Self.Fields[a].GetData(buf);
WriteInt(Self.Fields[a].DataSize);
AStream.Write(buf^, Length(buf));
Finally
FreeMem(buf);
End;
{$ENDIF}
End;
End;
Self.Next;
End;
Finally
Self.EnableControls;
End;
Finally
Self.GotoBookmark(bm);
End;
End;
{$ENDIF}Please change that line to
Code: Select all
AStream.Write(buf^, Self.Fields[a].DataSize);Code: Select all
If Self.Fields[b] Is TBlobField Then
Begin
ms := TMemoryStream.Create;
Try
ms.CopyFrom(AStream, ReadInt); <<<<<<<<<<<<<================= AFTER THIS LINE
ms.Position := 0;
(Self.Fields[b] As TBlobField).LoadFromStream(ms);
Finally
FreeAndNil(ms);
End;
EndHmm - the virtual machines that are used for Jenkins have some more Delphi Versions installed. If it helps, I could add an account there for you
We even could check if it still works good enough with a solution like X2Go - so we could add better security to it. The systems could be moved to a seperate subnet. Another option might be to use a VPN solution and then RDP through the VPN. I also could make some Linux machines available that host Lazarus and some database systems (SQL Server 2019 for Linux, Oracle) this way.Hi aehimself,
