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* Playing around with double-linked indexes, part II
git-svn-id: trunk@9166 -
This commit is contained in:
joost
parent
4e507bd2ef
commit
03ea1bc4c3
@ -83,9 +83,16 @@ type
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TBufDataset = class(TDBDataSet)
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private
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FIndexesCount : integer;
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FCurrentIndex : integer;
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FCurrentRecBuf : PBufRecLinkItem;
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FLastRecBuf : PBufRecLinkItem;
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FFirstRecBuf : PBufRecLinkItem;
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FLastRecBufs : array of PBufRecLinkItem;
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FFirstRecBufs : array of PBufRecLinkItem;
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FFilterBuffer : pchar;
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FBRecordCount : integer;
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@ -154,6 +161,8 @@ type
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procedure LoadBlobIntoBuffer(FieldDef: TFieldDef;ABlobBuf: PBufBlobField); virtual; abstract;
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public
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procedure AddSecondIndex;
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constructor Create(AOwner: TComponent); override;
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function GetFieldData(Field: TField; Buffer: Pointer;
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NativeFormat: Boolean): Boolean; override;
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@ -185,6 +194,12 @@ uses variants, dbconst;
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constructor TBufDataset.Create(AOwner : TComponent);
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begin
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Inherited Create(AOwner);
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FIndexesCount:=2;
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FCurrentIndex:=0;
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setlength(FFirstRecBufs,FIndexesCount);
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SetLength(FLastRecBufs,FIndexesCount);
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SetLength(FUpdateBuffer,0);
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SetLength(FBlobBuffers,0);
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SetLength(FUpdateBlobBuffers,0);
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@ -212,7 +227,7 @@ end;
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function TBufDataset.intAllocRecordBuffer: PChar;
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begin
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// Note: Only the internal buffers of TDataset provide bookmark information
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result := AllocMem(FRecordsize+sizeof(TBufRecLinkItem));
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result := AllocMem(FRecordsize+sizeof(TBufRecLinkItem)*FIndexesCount);
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end;
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function TBufDataset.AllocRecordBuffer: PChar;
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@ -335,13 +350,13 @@ begin
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Acceptable := True;
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case GetMode of
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gmPrior :
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if not assigned(PBufRecLinkItem(FCurrentRecBuf)^.prior) then
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if not assigned(FCurrentRecBuf[FCurrentIndex].prior) then
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begin
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Result := grBOF;
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end
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else
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begin
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FCurrentRecBuf := PBufRecLinkItem(FCurrentRecBuf)^.prior;
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FCurrentRecBuf := FCurrentRecBuf[FCurrentIndex].prior;
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end;
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gmCurrent :
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if FCurrentRecBuf = FLastRecBuf then
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@ -352,11 +367,11 @@ begin
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if getnextpacket = 0 then result := grEOF;
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end
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else if FCurrentRecBuf = nil then FCurrentRecBuf := FFirstRecBuf
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else if (PBufRecLinkItem(FCurrentRecBuf)^.next = FLastRecBuf) then
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else if (FCurrentRecBuf[FCurrentIndex].next = FLastRecBuf) then
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begin
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if getnextpacket > 0 then
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begin
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FCurrentRecBuf := PBufRecLinkItem(FCurrentRecBuf)^.next;
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FCurrentRecBuf := FCurrentRecBuf[FCurrentIndex].next;
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end
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else
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begin
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@ -365,7 +380,7 @@ begin
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end
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else
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begin
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FCurrentRecBuf := PBufRecLinkItem(FCurrentRecBuf)^.next;
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FCurrentRecBuf := FCurrentRecBuf[FCurrentIndex].next;
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end;
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end;
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@ -377,7 +392,7 @@ begin
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BookmarkData := FCurrentRecBuf;
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BookmarkFlag := bfCurrent;
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end;
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move((pointer(FCurrentRecBuf)+sizeof(TBufRecLinkItem))^,buffer^,FRecordSize);
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move((pointer(FCurrentRecBuf)+sizeof(TBufRecLinkItem)*FIndexesCount)^,buffer^,FRecordSize);
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GetCalcFields(Buffer);
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if Filtered then
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@ -459,13 +474,13 @@ begin
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exit;
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end;
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i := 0;
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pb := pchar(pointer(FLastRecBuf)+sizeof(TBufRecLinkItem));
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pb := pchar(pointer(FLastRecBuf)+sizeof(TBufRecLinkItem)*FIndexesCount);
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while ((i < FPacketRecords) or (FPacketRecords = -1)) and (loadbuffer(pb) = grOk) do
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begin
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FLastRecBuf^.next := pointer(IntAllocRecordBuffer);
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FLastRecBuf^.next^.prior := FLastRecBuf;
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FLastRecBuf := FLastRecBuf^.next;
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pb := pchar(pointer(FLastRecBuf)+sizeof(TBufRecLinkItem));
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pb := pchar(pointer(FLastRecBuf)+sizeof(TBufRecLinkItem)*FIndexesCount);
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inc(i);
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end;
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FBRecordCount := FBRecordCount + i;
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@ -568,7 +583,7 @@ begin
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result := false;
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exit;
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end;
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currbuff := FUpdateBuffer[FCurrentUpdateBuffer].OldValuesBuffer+sizeof(TBufRecLinkItem);
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currbuff := FUpdateBuffer[FCurrentUpdateBuffer].OldValuesBuffer+sizeof(TBufRecLinkItem)*FIndexesCount;
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end
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else
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begin
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@ -624,7 +639,7 @@ begin
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exit;
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end;
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if state = dsFilter then // Set the value into the 'temporary' FLastRecBuf buffer for Locate and Lookup
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CurrBuff := pointer(FLastRecBuf) + sizeof(TBufRecLinkItem)
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CurrBuff := pointer(FLastRecBuf) + sizeof(TBufRecLinkItem)*FIndexesCount
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else
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CurrBuff := GetCurrentBuffer;
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If Field.Fieldno > 0 then // If = 0, then calculated field or something
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@ -715,7 +730,7 @@ begin
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begin
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if UpdateKind = ukModify then
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begin
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move(pchar(OldValuesBuffer+sizeof(TBufRecLinkItem))^,pchar(BookmarkData+sizeof(TBufRecLinkItem))^,FRecordSize);
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move(pchar(OldValuesBuffer+sizeof(TBufRecLinkItem)*FIndexesCount)^,pchar(BookmarkData+sizeof(TBufRecLinkItem)*FIndexesCount)^,FRecordSize);
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FreeRecordBuffer(OldValuesBuffer);
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end
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else if UpdateKind = ukDelete then
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@ -931,7 +946,7 @@ begin
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begin
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// Update the oldvalues-buffer
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FUpdateBuffer[FCurrentUpdateBuffer].OldValuesBuffer := intAllocRecordBuffer;
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move(FCurrentRecBuf^,FUpdateBuffer[FCurrentUpdateBuffer].OldValuesBuffer^,FRecordSize+sizeof(TBufRecLinkItem));
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move(FCurrentRecBuf^,FUpdateBuffer[FCurrentUpdateBuffer].OldValuesBuffer^,FRecordSize+sizeof(TBufRecLinkItem)*FIndexesCount);
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FUpdateBuffer[FCurrentUpdateBuffer].UpdateKind := ukModify;
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end
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else
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@ -939,7 +954,7 @@ begin
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end;
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CurrBuff := pchar(FCurrentRecBuf);
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inc(Currbuff,sizeof(TBufRecLinkItem));
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inc(Currbuff,sizeof(TBufRecLinkItem)*FIndexesCount);
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move(ActiveBuffer^,CurrBuff^,FRecordSize);
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end;
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@ -1221,6 +1236,41 @@ begin
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Refresh;
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end;
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procedure TBufDataset.AddSecondIndex;
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var ALinkItem,
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ANewLinkItem : PBufRecLinkItem;
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begin
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ALinkItem:=FLastRecBuf[0].prior;
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ANewLinkItem:=FLastRecBuf[0].prior;
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FFirstRecBufs[1]:=ANewLinkItem;
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while ALinkItem<>FFirstRecBuf do
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begin
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ANewLinkItem[1].next:=ALinkItem[0].prior;
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ANewLinkItem[1].prior:=ALinkItem[0].next;
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ALinkItem:=ALinkItem[0].prior;
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ANewLinkItem:=ANewLinkItem[1].next;
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end;
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FLastRecBufs[1]:=FLastRecBuf;
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ANewLinkItem[1].next:=FLastRecBufs[1];
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FLastRecBufs[1][1].prior:=ANewLinkItem;
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FFirstRecBufs[1][1].prior:=nil;
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FLastRecBufs[1][1].next:=nil;
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// Stel in op tweede index:
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FCurrentIndex:=1;
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FLastRecBuf:=FLastRecBufs[FCurrentIndex];
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FFirstRecBuf:=FFirstRecBufs[FCurrentIndex];
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FCurrentRecBuf:=FFirstRecBuf;
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Resync([rmExact,rmCenter]);
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end;
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procedure TBufDataset.ParseFilter(const AFilter: string);
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begin
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// parser created?
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@ -1303,7 +1353,7 @@ begin
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FieldBufPos := FFieldBufPositions[keyfield.FieldNo-1];
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VBLength := keyfield.DataSize;
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ValueBuffer := AllocMem(VBLength);
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currbuff := pointer(FLastRecBuf)+sizeof(TBufRecLinkItem)+FieldBufPos;
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currbuff := pointer(FLastRecBuf)+sizeof(TBufRecLinkItem)*FIndexesCount+FieldBufPos;
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move(currbuff^,ValueBuffer^,VBLength);
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end;
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@ -1312,7 +1362,7 @@ begin
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if CheckNull then
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begin
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repeat
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currbuff := pointer(CurrLinkItem)+sizeof(TBufRecLinkItem);
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currbuff := pointer(CurrLinkItem)+sizeof(TBufRecLinkItem)*FIndexesCount;
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if GetFieldIsnull(pbyte(CurrBuff),keyfield.Fieldno-1) then
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begin
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result := True;
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@ -1325,7 +1375,7 @@ begin
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else if keyfield.DataType = ftString then
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begin
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repeat
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currbuff := pointer(CurrLinkItem)+sizeof(TBufRecLinkItem);
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currbuff := pointer(CurrLinkItem)+sizeof(TBufRecLinkItem)*FIndexesCount;
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if not GetFieldIsnull(pbyte(CurrBuff),keyfield.Fieldno-1) then
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begin
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inc(CurrBuff,FieldBufPos);
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@ -1342,7 +1392,7 @@ begin
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else
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begin
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repeat
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currbuff := pointer(CurrLinkItem)+sizeof(TBufRecLinkItem);
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currbuff := pointer(CurrLinkItem)+sizeof(TBufRecLinkItem)*FIndexesCount;
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if not GetFieldIsnull(pbyte(CurrBuff),keyfield.Fieldno-1) then
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begin
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inc(CurrBuff,FieldBufPos);
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