📄 myldbbaseengine.pas
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// scan records bitmap to find record
function FindRecordByBitmapScan(SessionID: TMYLDBSessionID;
Restart, GoForward: Boolean;
CurrentRecordID: TMYLDBRecordID;
var ResultRecordID: TMYLDBRecordID;
RecordBitmap: TMYLDBRecordBitmap;
IndexID: TMYLDBObjectID): Boolean;
// return true if record was found and is visible by cursor
// prepares params for FindRecordByScan and calls it
function FindRecord(
Cursor: TMYLDBCursor;
SearchExpression: TMYLDBExpression; // locate
KeyCondition: TMYLDBScanSearchCondition; // find key
// find first or last record in order specified by index settings
Restart: Boolean;
// go from first record to last or vice versa
GoForward: Boolean;
// if record was found then return record id
ResultRecordID: PMYLDBRecordID;
RecordBitmap: TMYLDBRecordBitmap;
// if specified - fill the whole record bitmap
ForceFillWholeBitmap: Boolean = False
): Boolean;
// return true if record match specified condition
function IsRecordMatchCondition(
var Condition: TMYLDBScanSearchCondition;
RecordBuffer: TMYLDBRecordBuffer
): Boolean;
// need to check conditions or index conditions are enough
function NeedToCheckOtherConditions(
Conditions: TMYLDBScanSearchConditionArray;
ExcludedConditionNo: Integer; // INVALID_ID4 if not specified
ExcludedConditionNo2: Integer; // INVALID_ID4 if not specified
FilterRecordPtr: Pointer): Boolean;
// return true if record match specified conditions
function IsRecordMatchConditions(
Conditions: TMYLDBScanSearchConditionArray;
ExcludedConditionNo: Integer; // INVALID_ID4 if not specified
ExcludedConditionNo2: Integer; // INVALID_ID4 if not specified
FilterRecordPtr: Pointer;
Dataset: Pointer;
RecordBuffer: TMYLDBRecordBuffer;
RecordID: TMYLDBRecordID
): Boolean;
// scan all records and check conditions
function FindRecordByScanWithoutCondition(
SessionID: TMYLDBSessionID;
Conditions: TMYLDBScanSearchConditionArray;
ScanConditionNo: Integer; // INVALID_ID4 if not specified
ScanEndConditionNo: Integer; // INVALID_ID4 if not specified
CurrentIndexID: TMYLDBObjectID; // INVALID_OBJECT_ID if not specified
FilterRecordPtr: Pointer;
Dataset: Pointer;
CurrentRecordID: TMYLDBRecordID;
// find first or last record in order specified by index settings
Restart: Boolean;
// go from first record to last or vice versa
GoForward: Boolean;
// if record was found then return record id
ResultRecordID: PMYLDBRecordID;
// if specified - fill record bitmap
RecordBitmap: TMYLDBRecordBitmap;
ForceFillWholeBitmap: Boolean
): Boolean;
// find records by index and condition specified by ScanConditionNo
// condition index is the same as CurrentIndex
function FindRecordByScanWithConditionAndConditionIndex(
SessionID: TMYLDBSessionID;
Conditions: TMYLDBScanSearchConditionArray;
ScanConditionNo: Integer; // INVALID_ID4 if not specified
ScanEndConditionNo: Integer; // INVALID_ID4 if not specified
CurrentIndexID: TMYLDBObjectID; // INVALID_OBJECT_ID if not specified
FilterRecordPtr: Pointer;
Dataset: Pointer;
CurrentRecordID: TMYLDBRecordID;
// find first or last record in order specified by index settings
Restart: Boolean;
// go from first record to last or vice versa
GoForward: Boolean;
// if record was found then return record id
ResultRecordID: PMYLDBRecordID;
// if specified - fill record bitmap
RecordBitmap: TMYLDBRecordBitmap;
ForceFillWholeBitmap: Boolean
): Boolean;
// find records by index and condition specified by ScanConditionNo
// there is no active index
function FindRecordByScanWithConditionAndWihtoutCurrentIndex(
SessionID: TMYLDBSessionID;
Conditions: TMYLDBScanSearchConditionArray;
ScanConditionNo: Integer; // INVALID_ID4 if not specified
ScanEndConditionNo: Integer; // INVALID_ID4 if not specified
CurrentIndexID: TMYLDBObjectID; // INVALID_OBJECT_ID if not specified
FilterRecordPtr: Pointer;
Dataset: Pointer;
CurrentRecordID: TMYLDBRecordID;
// find first or last record in order specified by index settings
Restart: Boolean;
// go from first record to last or vice versa
GoForward: Boolean;
// if record was found then return record id
ResultRecordID: PMYLDBRecordID;
// if specified - fill record bitmap
RecordBitmap: TMYLDBRecordBitmap;
ForceFillWholeBitmap: Boolean
): Boolean;
// find records by index and condition specified by ScanConditionNo
// condition index is NOT the same as CurrentIndex
function FindRecordByScanWithConditionAndNonConditionIndex(
SessionID: TMYLDBSessionID;
Conditions: TMYLDBScanSearchConditionArray;
ScanConditionNo: Integer; // INVALID_ID4 if not specified
ScanEndConditionNo: Integer; // INVALID_ID4 if not specified
CurrentIndexID: TMYLDBObjectID; // INVALID_OBJECT_ID if not specified
FilterRecordPtr: Pointer;
Dataset: Pointer;
CurrentRecordID: TMYLDBRecordID;
// find first or last record in order specified by index settings
Restart: Boolean;
// go from first record to last or vice versa
GoForward: Boolean;
// if record was found then return record id
ResultRecordID: PMYLDBRecordID;
// if specified - fill record bitmap
RecordBitmap: TMYLDBRecordBitmap;
ForceFillWholeBitmap: Boolean
): Boolean;
// return true if record was found
function FindRecordByScan(
SessionID: TMYLDBSessionID;
Conditions: TMYLDBScanSearchConditionArray;
ScanConditionNo: Integer; // INVALID_ID4 if not specified
ScanEndConditionNo: Integer; // INVALID_ID4 if not specified
CurrentIndexID: TMYLDBObjectID; // INVALID_OBJECT_ID if not specified
FilterRecordPtr: Pointer;
Dataset: Pointer;
CurrentRecordID: TMYLDBRecordID;
// find first or last record in order specified by index settings
Restart: Boolean;
// go from first record to last or vice versa
GoForward: Boolean;
// if record was found then return record id
ResultRecordID: PMYLDBRecordID;
RecordBitmap: TMYLDBRecordBitmap;
// if specified - fill record bitmap
ForceFillWholeBitmap: Boolean
): Boolean;
// used by GetRecordBuffer - find or get record
function InternalFindOrGetRecordBuffer(
Cursor: TMYLDBCursor;
GetRecordMode: TMYLDBGetRecordMode;
// if specified - fill record bitmap
ForceFillWholeBitmap: Boolean=False
): TMYLDBGetRecordResult;
// get record using current index or physical order
procedure InternalGetRecordBuffer(
SessionID: TMYLDBSessionID;
var NavigationInfo: TMYLDBNavigationInfo;
IndexPositionCache: TMYLDBIndexPositionCache;
TableState: Integer
);
public
procedure ClearBlobsCacheInRecordBuffer(Buffer: TMYLDBRecordBuffer); virtual;
// read record with Distinct, SQLFilter, SQLTopRowCount, Filter, Range, OnFilterRecord
function GetRecordBuffer(
Cursor: TMYLDBCursor;
GetRecordMode: TMYLDBGetRecordMode
): TMYLDBGetRecordResult; virtual;
// locate
function Locate(Cursor: TMYLDBCursor; SearchExpression: TMYLDBExpression): Boolean; virtual;
// find key
function FindKey(Cursor: TMYLDBCursor; SearchCondition: TMYLDBSearchCondition): Boolean; virtual;
//---------------------------------------------------------------------------
// BLOB methods
//---------------------------------------------------------------------------
procedure WriteBLOBFieldToRecordBuffer(
Cursor: TMYLDBCursor;
FieldNo: Integer;
BLOBStream: TMYLDBStream
); virtual; abstract;
procedure ClearBLOBFieldInRecordBuffer(
RecordBuffer: TMYLDBRecordBuffer;
FieldNo: Integer
); virtual;
procedure ClearBLOBFieldsInRecordBuffer(
RecordBuffer: TMYLDBRecordBuffer
); virtual;
function InternalCreateBlobStream(
Cursor: TMYLDBCursor;
ToInsert: Boolean;
FieldNo: Integer;
OpenMode: TMYLDBBLOBOpenMode
): TMYLDBStream; virtual; abstract;
procedure GetDirectBlobData(
Cursor: TMYLDBCursor;
FieldNo: Integer;
RecordBuffer: TMYLDBRecordBuffer;
var BLOBDescriptor: TMYLDBPartialTemporaryBLOBDescriptor;
var pBlobData: PChar); virtual; abstract;
procedure SetDirectBlobData(
Cursor: TMYLDBCursor;
FieldNo: Integer;
RecordBuffer: TMYLDBRecordBuffer;
var BLOBDescriptor: TMYLDBPartialTemporaryBLOBDescriptor;
var pBlobData: PChar); virtual; abstract;
procedure FreeDirectBlobData(
Cursor: TMYLDBCursor;
FieldNo: Integer;
RecordBuffer: TMYLDBRecordBuffer;
var BLOBDescriptor: TMYLDBPartialTemporaryBLOBDescriptor;
var pBlobData: PChar); virtual; abstract;
function InsertRecord(var Cursor: TMYLDBCursor): Boolean; virtual; abstract;
function DeleteRecord(Cursor: TMYLDBCursor): Boolean; virtual; abstract;
function UpdateRecord(Cursor: TMYLDBCursor): Boolean; virtual; abstract;
// record operations
function GetRecordCount(Cursor: TMYLDBCursor): TMYLDBRecordNo;
procedure SetRecNo(Cursor: TMYLDBCursor; RecNo: TMYLDBRecordNo); virtual;
function GetRecNo(Cursor: TMYLDBCursor): TMYLDBRecordNo; virtual;
procedure InternalSetRecNo(Cursor: TMYLDBCursor; RecNo: TMYLDBRecordNo); virtual; abstract;
function InternalGetRecNo(Cursor: TMYLDBCursor): TMYLDBRecordNo; virtual; abstract;
function InternalGetRecordCount(Cursor: TMYLDBCursor): TMYLDBRecordNo; virtual; abstract;
function LastAutoincValue(FieldNo: Integer; Session: TMYLDBBaseSession): Int64; virtual;
// transaction
procedure Rollback(SessionID: TMYLDBSessionID); virtual;
procedure RebuildTemporaryIndexes(SessionID: TMYLDBSessionID);
public
property TableName: String read FTableName write FTableName;
property DatabaseData: TMYLDBDatabaseData read FDatabaseData;
property FieldManager: TMYLDBBaseFieldManager read FFieldManager;
property RecordManager: TMYLDBBaseRecordManager read FRecordManager;
property ConstraintManager: TMYLDBBaseConstraintManager read FConstraintManager;
property IndexManager: TMYLDBBaseIndexManager read FIndexManager;
property PageManager: TMYLDBPageManager read FPageManager;
property CursorList: TList read FCursorList;
property IsRepairing: Boolean read FIsRepairing write FIsRepairing;
end; // TMYLDBTableData
////////////////////////////////////////////////////////////////////////////////
//
// TMYLDBDatabaseData
//
////////////////////////////////////////////////////////////////////////////////
TMYLDBDatabaseData = class (TObject)
protected
FCSect: TRTLCriticalSection;
FSessionList: TList;
FTableDataList: TList;
FDatabaseName: String;
FPageManager: TMYLDBPageManager;
FReadOnly: Boolean;
FTryCount: Integer;
FDelayMS: Integer;
FMultiUser: Boolean;
// 5.12 fix read-only problem in multiuser mode within application
FSessionName: string;
public
constructor Create;
destructor Destroy; override;
procedure Lock;
procedure Unlock;
procedure ConnectSession(Session: TMYLDBBaseSession); virtual;
procedure DisconnectSession(Session: TMYLDBBaseSession); virtual;
procedure FreeIfNoSessionsConnected; virtual;
procedure GetTablesList(List: TStrings); virtual;
function TableExists(TableName: String): Boolean;
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