📄 abstempengine.pas
字号:
// AddIndex
//------------------------------------------------------------------------------
procedure TABSTemporaryTableData.AddIndex(IndexDef: TABSIndexDef; Cursor: TABSCursor);
begin
Lock;
try
inherited AddIndex(IndexDef, Cursor);
if (not Cursor.Session.InTransaction) then
PageManager.ApplyChanges(Cursor.Session.SessionID);
finally
Unlock;
end;
end;// AddIndex
//------------------------------------------------------------------------------
// DeleteIndex
//------------------------------------------------------------------------------
procedure TABSTemporaryTableData.DeleteIndex(IndexID: TABSObjectID; Cursor: TABSCursor);
begin
Lock;
try
inherited DeleteIndex(IndexID, Cursor);
if (Cursor <> nil) then
begin
if (not Cursor.Session.InTransaction) then
PageManager.ApplyChanges(Cursor.Session.SessionID);
end
else
PageManager.ApplyChanges(SYSTEM_SESSION_ID);
finally
Unlock;
end;
end;// DeleteIndex
//------------------------------------------------------------------------------
// insert record
//------------------------------------------------------------------------------
function TABSTemporaryTableData.InsertRecord(var Cursor: TABSCursor): Boolean;
var RecordID: TABSRecordID;
begin
if (FRecordManager = nil) then
raise EABSException.Create(10134,ErrorLNilPointer);
if (Cursor.CurrentRecordBuffer = nil) then
raise EABSException.Create(10135,ErrorLNilPointer);
// add record to first empty space
try
Result := FRecordManager.AddRecord(Cursor.Session.SessionID,
Cursor.CurrentRecordBuffer,RecordID);
Move(RecordID,Cursor.CurrentRecordID,sizeof(Cursor.CurrentRecordID));
except
Result := False;
end;
if (Result) then
begin
if (TABSRecordBitmap(Cursor.RecordBitmap).Active) then
begin
if (IsRecordVisible(Cursor)) then
TABSRecordBitmap(Cursor.RecordBitmap).ShowRecord(Cursor.CurrentRecordID)
else
TABSRecordBitmap(Cursor.RecordBitmap).HideRecord(Cursor.CurrentRecordID);
end;
FIndexManager.InsertRecord(Cursor);
Cursor.FirstPosition := False;
Cursor.LastPosition := False;
if (not Cursor.Session.InTransaction) then
FPageManager.ApplyChanges(Cursor.Session.SessionID);
end;
end; // InsertRecord;
//------------------------------------------------------------------------------
// delete record
//------------------------------------------------------------------------------
function TABSTemporaryTableData.DeleteRecord(Cursor: TABSCursor): Boolean;
begin
Result := False;
end; // DeleteRecord
//------------------------------------------------------------------------------
// update record
//------------------------------------------------------------------------------
function TABSTemporaryTableData.UpdateRecord(Cursor: TABSCursor): Boolean;
begin
Result := False;
end; // UpdateRecord
//------------------------------------------------------------------------------
// return record count
//------------------------------------------------------------------------------
function TABSTemporaryTableData.InternalGetRecordCount(Cursor: TABSCursor): TABSRecordNo;
begin
if (FRecordManager = nil) then
raise EABSException.Create(10133,ErrorLNilPointer);
Result := FRecordManager.RecordCount;
end; // GetRecordCount
//------------------------------------------------------------------------------
// move cursor to specified position and set current record id in cursor
//------------------------------------------------------------------------------
procedure TABSTemporaryTableData.InternalSetRecNo(Cursor: TABSCursor; RecNo: TABSRecordNo);
var RecordID: TABSRecordNo;
begin
if (FRecordManager = nil) then
raise EABSException.Create(10136,ErrorLNilPointer);
if (RecNo > 1) then
RecordID := RecNo-1
else
RecordID := 0;
Move(RecordID,Cursor.CurrentRecordID,sizeof(Cursor.CurrentRecordID));
end; // SetRecNo
//------------------------------------------------------------------------------
// get current record position from cursor
//------------------------------------------------------------------------------
function TABSTemporaryTableData.InternalGetRecNo(Cursor: TABSCursor): TABSRecordNo;
begin
if (FRecordManager = nil) then
raise EABSException.Create(10137,ErrorLNilPointer);
Result := 0;
Move(Cursor.CurrentRecordID,Result,sizeof(Cursor.CurrentRecordID));
Inc(Result);
end; // GetRecNo
//---------------------------------------------------------------------------
// write BLOB field to record buffer
//---------------------------------------------------------------------------
procedure TABSTemporaryTableData.WriteBLOBFieldToRecordBuffer(
Cursor: TABSCursor;
FieldNo: Integer;
BLOBStream: TABSStream
);
var
WriteSize,WriteBytes: Integer;
PartialBLOBDescriptor: TABSPartialTemporaryBLOBDescriptor;
DiskOffset: Int64;
begin
if (FBLOBFile = nil) then
raise EABSException.Create(10144,ErrorLNilPointer);
if (BLOBStream.Modified) then
begin
if (BLOBStream.Size = 0) then
begin
// empty stream
SetNullFlag(True,FieldNo,Cursor.CurrentRecordBuffer);
end
else
begin
PartialBLOBDescriptor.NumBlocks := TABSCompressedBLOBStream(
TABSLocalBLOBStream(BLOBStream).TemporaryStream).BLOBDescriptor.NumBlocks;
PartialBLOBDescriptor.UncompressedSize := TABSCompressedBLOBStream(
TABSLocalBLOBStream(BLOBStream).TemporaryStream).BLOBDescriptor.UncompressedSize;
PartialBLOBDescriptor.CompressedSize := TABSCompressedBLOBStream(
TABSLocalBLOBStream(BLOBStream).TemporaryStream).CompressedSize;
SetStreamPosition(FBLOBFile,FBLOBFile.Size,10422);
DiskOffset := FBLOBFile.Position;
// save blob descriptor
WriteSize := sizeof(PartialBLOBDescriptor);
WriteBytes := FBLOBFile.Write(PartialBLOBDescriptor,WriteSize);
if (WriteBytes <> WriteSize) then
raise EABSException.Create(10145,ErrorLCannotWriteToStream,
[DiskOffset,FBLOBFile.Size,WriteSize,WriteBytes]);
// save compressed data to blob file
TABSStream(TABSCompressedBLOBStream(TABSLocalBLOBStream(BLOBStream).TemporaryStream).
CompressedStream).SaveToStream(FBLOBFile);
// store offset of blob descriptor in blob file to record buffer
Move(DiskOffset,PChar(Cursor.CurrentRecordBuffer +
FieldManager.FieldDefs[FieldNo].MemoryOffset)^,sizeof(DiskOffset));
SetNullFlag(False,FieldNo,Cursor.CurrentRecordBuffer);
end; // not empty stream
end; // Modified
end; // WriteBLOBFieldToRecordBuffer
//---------------------------------------------------------------------------
// create BLOB stream
//---------------------------------------------------------------------------
function TABSTemporaryTableData.InternalCreateBlobStream(
Cursor: TABSCursor;
ToInsert: Boolean;
FieldNo: Integer;
OpenMode: TABSBLOBOpenMode
): TABSStream;
var TempStream: TABSTemporaryStream;
CompressedStream: TABSCompressedBLOBStream;
Offset: Integer;
DiskOffset,OldPos: Int64;
ReadBytes,ReadSize: Integer;
BLOBDescriptor: TABSBLOBDescriptor;
PartialBLOBDescriptor: TABSPartialTemporaryBLOBDescriptor;
begin
if (FBLOBFile = nil) then
raise EABSException.Create(10140,ErrorLNilPointer);
BLOBDescriptor.CompressionAlgorithm :=
Byte(FieldManager.FieldDefs[FieldNo].BLOBCompressionAlgorithm);
BLOBDescriptor.CompressionMode := FieldManager.FieldDefs[FieldNo].BLOBCompressionMode;
BLOBDescriptor.BlockSize := FieldManager.FieldDefs[FieldNo].BLOBBlockSize;
BLOBDescriptor.StartPosition := 0;
TempStream := TABSTemporaryStream.Create(FDisableTempFiles);
// create new compressed stream
if ((ToInsert) or (OpenMode = bomWrite) or
(CheckNullFlag(FieldNo,Cursor.CurrentRecordBuffer))) then
begin
// empty stream
BLOBDescriptor.NumBlocks := 0;
BLOBDescriptor.UncompressedSize := 0;
CompressedStream := TABSCompressedBLOBStream.Create(TempStream,
BLOBDescriptor,True);
Result := TABSLocalBLOBStream.Create(CompressedStream,Cursor,OpenMode,FieldNo);
end // empty stream
else
begin
// copy value from TableData
Offset := FieldManager.FieldDefs[FieldNo].MemoryOffset;
// offset to blob field data
Move(PChar(Cursor.CurrentRecordBuffer + Offset)^,DiskOffset,Sizeof(DiskOffset));
OldPos := FBLOBFile.Position;
// set position in BLOB file
FBLOBFile.Position := DiskOffset;
if (FBLOBFile.Position <> DiskOffset) then
raise EABSException.Create(10141,ErrorLCannotSetPosition,
[DiskOffset,OldPos,FBLOBFile.Size]);
// read partial BLOB descriptor
OldPos := FBLOBFile.Position;
ReadSize := sizeof(TABSPartialTemporaryBLOBDescriptor);
ReadBytes := FBLOBFile.Read(PartialBLOBDescriptor,ReadSize);
if (ReadBytes <> ReadSize) then
raise EABSException.Create(10142,ErrorLCannotReadFromStream,
[OldPos,FBLOBFile.Size,ReadSize,ReadBytes]);
// read compressed blob data
TempStream.LoadFromStreamWithPosition(FBLOBFile,FBLOBFile.Position,
PartialBLOBDescriptor.CompressedSize);
// copy partial blob descriptor
BLOBDescriptor.NumBlocks := PartialBLOBDescriptor.NumBlocks;
BLOBDescriptor.UncompressedSize := PartialBLOBDescriptor.UncompressedSize;
CompressedStream := TABSCompressedBLOBStream.Create(TempStream,
BLOBDescriptor,False);
Result := TABSLocalBLOBStream.Create(CompressedStream,Cursor,OpenMode,FieldNo);
end; // copy value from TableData
end; // InternalCreateBlobStream
//------------------------------------------------------------------------------
// GetDirectBlobData
//------------------------------------------------------------------------------
procedure TABSTemporaryTableData.GetDirectBlobData(
Cursor: TABSCursor;
FieldNo: Integer;
RecordBuffer: TABSRecordBuffer;
var BLOBDescriptor: TABSPartialTemporaryBLOBDescriptor;
var pBlobData: PChar);
var
Offset: Integer;
DiskOffset,OldPos: Int64;
ReadBytes,ReadSize: Integer;
begin
if (CheckNullFlag(FieldNo,RecordBuffer)) then
begin
// empty stream
BLOBDescriptor.NumBlocks := 0;
BLOBDescriptor.UncompressedSize := 0;
BLOBDescriptor.CompressedSize := 0;
pBlobData := nil;
end // empty stream
else
begin
// copy value from TableData
Offset := FieldManager.FieldDefs[FieldNo].MemoryOffset;
// offset to blob field data
Move(PChar(RecordBuffer + Offset)^,DiskOffset,Sizeof(DiskOffset));
OldPos := FBLOBFile.Position;
// set position in BLOB file
FBLOBFile.Position := DiskOffset;
if (FBLOBFile.Position <> DiskOffset) then
raise EABSException.Create(10509,ErrorLCannotSetPosition,
[DiskOffset,OldPos,FBLOBFile.Size]);
// read partial BLOB descriptor
OldPos := FBLOBFile.Position;
ReadSize := sizeof(TABSPartialTemporaryBLOBDescriptor);
ReadBytes := FBLOBFile.Read(BLOBDescriptor,ReadSize);
if (ReadBytes <> ReadSize) then
raise EABSException.Create(10510,ErrorLCannotReadFromStream,
[OldPos,FBLOBFile.Size,ReadSize,ReadBytes]);
// read compressed blob data
pBlobData := MemoryManager.GetMem(BLOBDescriptor.CompressedSize);
FBLOBFile.ReadBuffer(pBlobData^, BLOBDescriptor.CompressedSize);
FBLOBFile.Position := OldPos;
end; // copy value from TableData
end;// GetDirectBlobData
//------------------------------------------------------------------------------
// SetDirectBlobData
//------------------------------------------------------------------------------
procedure TABSTemporaryTableData.SetDirectBlobData(
Cursor: TABSCursor;
FieldNo: Integer;
RecordBuffer: TABSRecordBuffer;
var BLOBDescriptor: TABSPartialTemporaryBLOBDescriptor;
var pBlobData: PChar);
var
WriteSize,WriteBytes: Integer;
DiskOffset: Int64;
begin
if (FBLOBFile = nil) then
raise EABSException.Create(10506,ErrorLNilPointer);
if (BLOBDescriptor.UncompressedSize = 0) then
SetNullFlag(True,FieldNo,Cursor.CurrentRecordBuffer)
else
begin
SetStreamPosition(FBLOBFile,FBLOBFile.Size,10507);
DiskOffset := FBLOBFile.Position;
// save blob descriptor
WriteSize := sizeof(BLOBDescriptor);
WriteBytes := FBLOBFile.Write(BLOBDescriptor,WriteSize);
if (WriteBytes <> WriteSize) then
raise EABSException.Create(10508,ErrorLCannotWriteToStream,
[DiskOffset,FBLOBFile.Size,WriteSize,WriteBytes]);
// save compressed data to blob file
FBLOBFile.WriteBuffer(pBlobData^,BLOBDescriptor.CompressedSize);
// store offset of blob descriptor in blob file to record buffer
Move(DiskOffset,PChar(Cursor.CurrentRecordBuffer +
FieldManager.FieldDefs[FieldNo].MemoryOffset)^,sizeof(DiskOffset));
SetNullFlag(False,FieldNo,Cursor.CurrentRecordBuffer);
end;
end;// SetDirectBlobData
//------------------------------------------------------------------------------
// FreeDirectBlobData
//------------------------------------------------------------------------------
procedure TABSTemporaryTableData.FreeDirectBlobData(
Cursor: TABSCursor;
FieldNo: Integer;
RecordBuffer: TABSRecordBuffer;
var BLOBDescriptor: TABSPartialTemporaryBLOBDescriptor;
var pBlobData: PChar);
begin
if (pBlobData <> nil) then
MemoryManager.FreeAndNillMem(pBlobData);
end;// FreeDirectBlobData
end.
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -