client/3.0/FB30Blob.pas

(*
 *  Firebird Interface (fbintf). The fbintf components provide a set of
 *  Pascal language bindings for the Firebird API.
 *
 *  The contents of this file are subject to the Initial Developer's
 *  Public License Version 1.0 (the "License"); you may not use this
 *  file except in compliance with the License. You may obtain a copy
 *  of the License here:
 *
 *    http://www.firebirdsql.org/index.php?op=doc&id=idpl
 *
 *  Software distributed under the License is distributed on an "AS
 *  IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 *  implied. See the License for the specific language governing rights
 *  and limitations under the License.
 *
 *  The Initial Developer of the Original Code is Tony Whyman.
 *
 *  The Original Code is (C) 2016 Tony Whyman, MWA Software
 *  (http://www.mwasoftware.co.uk).
 *
 *  All Rights Reserved.
 *
 *  Contributor(s): ______________________________________.
 *
*)
unit FB30Blob;
{$IFDEF MSWINDOWS} 
{$DEFINE WINDOWS} 
{$ENDIF}

{$IFDEF FPC}
{$mode delphi}
{$interfaces COM}
{$ENDIF}

interface

uses
  Classes, SysUtils, Firebird, IB, IBHeader, IBExternals, FBClientAPI, FB30ClientAPI, FB30Attachment,
  FBTransaction, FB30Transaction,  FBBlob, FBOutputBlock;

type

   { TFB30BlobMetaData }

   TFB30BlobMetaData  = class(TFBBlobMetaData, IBlobMetaData)
   private
     FHasFullMetaData: boolean;
     FAttachment: TFB30Attachment;
     FTransaction: TFB30Transaction;
   protected
     procedure NeedFullMetadata; override;
   public
     constructor Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
       RelationName, ColumnName: AnsiString); overload;
     constructor Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
       RelationName, ColumnName: AnsiString; SubType: integer); overload;

  end;


  { TFB30Blob }

  TFB30Blob = class(TFBBlob,IBlob)
  private
    FBlobIntf: Firebird.IBlob;
    FEOB: boolean;
  protected
    procedure CheckReadable; override;
    procedure CheckWritable; override;
    function GetIntf: IBlob; override;
    procedure GetInfo(Request: array of byte; Response: IBlobInfo); override;
    procedure InternalClose(Force: boolean); override;
    procedure InternalCancel(Force: boolean); override;
  public
    constructor Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
                       MetaData: IBlobMetaData; BPB: IBPB); overload;
    constructor Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
                       SubType: integer; CharSetID: cardinal; BPB: IBPB); overload;
    constructor Create(Attachment: TFB30Attachment; Transaction: TFBTransaction;
                       MetaData: IBlobMetaData; BlobID: TISC_QUAD; BPB: IBPB); overload;
    property BlobIntf: Firebird.IBlob read FBlobIntf;

  {IBlob}
  public
    function Read(var Buffer; Count: Longint): Longint; override;
    function Write(const Buffer; Count: Longint): Longint; override;
  end;

implementation

uses FBMessages, FB30Statement, FBParamBlock, Math;

const
  sLookupBlobMetaData = 'Select F.RDB$FIELD_SUB_TYPE, F.RDB$SEGMENT_LENGTH, RDB$CHARACTER_SET_ID, F.RDB$FIELD_TYPE '+
    'From RDB$FIELDS F JOIN RDB$RELATION_FIELDS R On R.RDB$FIELD_SOURCE = F.RDB$FIELD_NAME '+
  'Where Trim(R.RDB$RELATION_NAME) = Upper(Trim(?)) and Trim(R.RDB$FIELD_NAME) = Upper(Trim(?))';

{ TFB30BlobMetaData }

procedure TFB30BlobMetaData.NeedFullMetadata;
var stmt: IStatement;
begin
  if FHasFullMetaData then Exit;

  FSegmentSize := 80;
  if (GetColumnName <> '') and (GetRelationName <> '') then
  begin
    stmt := TFB30Statement.Create(FAttachment,FTransaction, sLookupBlobMetaData ,FAttachment.SQLDialect);
    with stmt do
    begin
      SQLParams[0].AsString := GetRelationName;
      SQLParams[1].AsString := GetColumnName;
      with OpenCursor do
      if FetchNext then
      begin
        if Data[3].AsInteger <> blr_blob then
          IBError(ibxeInvalidBlobMetaData,[nil]);
        FSubType := Data[0].AsInteger;
        FSegmentSize := Data[1].AsInteger;
        if FUnconfirmedCharacterSet then
          FCharSetID := Data[2].AsInteger;
      end
      else
        IBError(ibxeInvalidBlobMetaData,[nil]);

    end;
  end;

    if FUnconfirmedCharacterSet and (FCharSetID > 1) and FAttachment.HasDefaultCharSet then
    begin
      FCharSetID := FAttachment.CharSetID;
      FUnconfirmedCharacterSet := false;
    end;

  FHasFullMetaData := true;
  FHasSubType := true;
end;

constructor TFB30BlobMetaData.Create(Attachment: TFB30Attachment;
  Transaction: TFB30Transaction; RelationName, ColumnName: AnsiString);
begin
  inherited Create(Transaction,RelationName,ColumnName);
  FAttachment := Attachment;
  FTransaction := Transaction;
end;

constructor TFB30BlobMetaData.Create(Attachment: TFB30Attachment;
  Transaction: TFB30Transaction; RelationName, ColumnName: AnsiString;
  SubType: integer);
begin
  Create(Attachment,Transaction,RelationName,ColumnName);
  FSubType := SubType;
  FHasSubType := true;
end;

{ TFB30Blob }

procedure TFB30Blob.CheckReadable;
begin
  if FCreating or (FBlobIntf = nil) then
    IBError(ibxeBlobCannotBeRead, [nil]);
end;

procedure TFB30Blob.CheckWritable;
begin
  if not FCreating or (FBlobIntf = nil) then
    IBError(ibxeBlobCannotBeWritten, [nil]);
end;

function TFB30Blob.GetIntf: IBlob;
begin
  Result := self;
end;

procedure TFB30Blob.GetInfo(Request: array of byte; Response: IBlobInfo);
begin
  if FBlobIntf = nil then
    IBError(ibxeBlobNotOpen,[nil]);

  with Firebird30ClientAPI, Response as TBlobInfo do
  begin
    FBlobIntf.getInfo(StatusIntf,Length(Request),BytePtr(@Request),
                                               GetBufSize, BytePtr(Buffer));
    Check4DataBaseError;
    SignalActivity;
  end;
end;

procedure TFB30Blob.InternalClose(Force: boolean);
begin
  if FBlobIntf = nil then
    Exit;
  with Firebird30ClientAPI do
  begin
    FBlobIntf.close(StatusIntf);
    if not Force then Check4DataBaseError;
  end;
  FBlobIntf.release;
  FBlobIntf := nil;
end;

procedure TFB30Blob.InternalCancel(Force: boolean);
begin
  if FBlobIntf = nil then
    Exit;
  with Firebird30ClientAPI do
  begin
    FBlobIntf.cancel(StatusIntf);
    if not Force then Check4DataBaseError;
  end;
  FBlobIntf.release;
  FBlobIntf := nil;
end;

constructor TFB30Blob.Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
  MetaData: IBlobMetaData; BPB: IBPB);
begin
    inherited Create(Attachment,Transaction,MetaData,BPB);
    with Firebird30ClientAPI do
    begin
      if BPB = nil then
        FBlobIntf := Attachment.AttachmentIntf.createBlob(StatusIntf,Transaction.TransactionIntf,
                        @FBlobID,0,nil)
      else
      with BPB as TBPB do
        FBlobIntf := Attachment.AttachmentIntf.createBlob(StatusIntf,Transaction.TransactionIntf,
                      @FBlobID,getDataLength, BytePtr(getBuffer));
      Check4DataBaseError;
    end;
end;

constructor TFB30Blob.Create(Attachment: TFB30Attachment;
  Transaction: TFB30Transaction; SubType: integer; CharSetID: cardinal;
  BPB: IBPB);
var MetaData: TFB30BlobMetaData;
begin
  MetaData := TFB30BlobMetaData.Create(Attachment,Transaction,'','',SubType);
  MetaData.FCharSetID := CharSetID;
  MetaData.FHasFullMetaData := true;
  inherited Create(Attachment,Transaction,MetaData,BPB);
  with Firebird30ClientAPI do
  begin
    if BPB = nil then
      FBlobIntf := Attachment.AttachmentIntf.createBlob(StatusIntf,Transaction.TransactionIntf,
                      @FBlobID,0,nil)
    else
    with BPB as TBPB do
      FBlobIntf := Attachment.AttachmentIntf.createBlob(StatusIntf,Transaction.TransactionIntf,
                    @FBlobID,getDataLength, BytePtr(getBuffer));
    Check4DataBaseError;
  end;
end;

constructor TFB30Blob.Create(Attachment: TFB30Attachment;
  Transaction: TFBTransaction; MetaData: IBlobMetaData; BlobID: TISC_QUAD; BPB: IBPB);
begin
  inherited Create(Attachment,Transaction,MetaData,BlobID,BPB);
  if (BlobID.gds_quad_high = 0) and (BlobID.gds_quad_low = 0) then
    Exit;

  with Firebird30ClientAPI do
  begin
    if BPB = nil then
      FBlobIntf := Attachment.AttachmentIntf.openBlob(StatusIntf,(Transaction as TFB30Transaction).TransactionIntf,
                     @FBlobID, 0, nil)
    else
    with BPB as TBPB do
    FBlobIntf := Attachment.AttachmentIntf.openBlob(StatusIntf,(Transaction as TFB30Transaction).TransactionIntf,
                   @FBlobID, getDataLength, BytePtr(getBuffer));
    Check4DataBaseError;
  end;
end;

function TFB30Blob.Read(var Buffer; Count: Longint): Longint;
var
  BytesRead : cardinal;
  LocalBuffer: PAnsiChar;
  returnCode: integer;
  localCount: uShort;
begin
  CheckReadable;
  Result := 0;
  if FEOB then
    Exit;

  LocalBuffer := PAnsiChar(@Buffer);
  repeat
    localCount := Min(Count,MaxuShort);
    with Firebird30ClientAPI do
      returnCode := FBlobIntf.getSegment(StatusIntf,localCount, LocalBuffer, @BytesRead);
    SignalActivity;
    Inc(LocalBuffer,BytesRead);
    Inc(Result,BytesRead);
    Dec(Count,BytesRead);
  until ((returncode <> Firebird.IStatus.Result_OK) and (returnCode <> Firebird.IStatus.Result_SEGMENT)) or (Count = 0);

  FEOB := returnCode = Firebird.IStatus.RESULT_NO_DATA;
  ClearStringCache;
  if (returnCode <> Firebird.IStatus.Result_OK) and
     (returnCode <> Firebird.IStatus.Result_SEGMENT) and
     (returnCode <> Firebird.IStatus.RESULT_NO_DATA) then
    Firebird30ClientAPI.IBDataBaseError
end;

function TFB30Blob.Write(const Buffer; Count: Longint): Longint;
var
  LocalBuffer: PAnsiChar;
  localCount: uShort;
begin
  CheckWritable;
  Result := 0;
  if Count = 0 then Exit;

  LocalBuffer := PAnsiChar(@Buffer);
  repeat
    localCount := Min(Count,MaxuShort);
    with Firebird30ClientAPI do
    begin
      FBlobIntf.putSegment(StatusIntf,localCount,LocalBuffer);
      Check4DataBaseError;
    end;
    Inc(LocalBuffer,localCount);
    Inc(Result,localCount);
    Dec(Count,localCount);
  until Count = 0;
  ClearStringCache;
  SignalActivity;
end;

end.

Revision:	56
Committed:	Mon Mar 6 10:20:02 2017 UTC (7 years, 1 month ago) by tony
Content type:	text/x-pascal
File size:	10003 byte(s)
Log Message:	Committing updates for Trunk
#	Content
1	(*
2	* Firebird Interface (fbintf). The fbintf components provide a set of
3	* Pascal language bindings for the Firebird API.
4	*
5	* The contents of this file are subject to the Initial Developer's
6	* Public License Version 1.0 (the "License"); you may not use this
7	* file except in compliance with the License. You may obtain a copy
8	* of the License here:
9	*
10	* http://www.firebirdsql.org/index.php?op=doc&id=idpl
11	*
12	* Software distributed under the License is distributed on an "AS
13	* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
14	* implied. See the License for the specific language governing rights
15	* and limitations under the License.
16	*
17	* The Initial Developer of the Original Code is Tony Whyman.
18	*
19	* The Original Code is (C) 2016 Tony Whyman, MWA Software
20	* (http://www.mwasoftware.co.uk).
21	*
22	* All Rights Reserved.
23	*
24	* Contributor(s): ______________________________________.
25	*
26	*)
27	unit FB30Blob;
28	{$IFDEF MSWINDOWS}
29	{$DEFINE WINDOWS}
30	{$ENDIF}
31
32	{$IFDEF FPC}
33	{$mode delphi}
34	{$interfaces COM}
35	{$ENDIF}
36
37	interface
38
39	uses
40	Classes, SysUtils, Firebird, IB, IBHeader, IBExternals, FBClientAPI, FB30ClientAPI, FB30Attachment,
41	FBTransaction, FB30Transaction, FBBlob, FBOutputBlock;
42
43	type
44
45	{ TFB30BlobMetaData }
46
47	TFB30BlobMetaData = class(TFBBlobMetaData, IBlobMetaData)
48	private
49	FHasFullMetaData: boolean;
50	FAttachment: TFB30Attachment;
51	FTransaction: TFB30Transaction;
52	protected
53	procedure NeedFullMetadata; override;
54	public
55	constructor Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
56	RelationName, ColumnName: AnsiString); overload;
57	constructor Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
58	RelationName, ColumnName: AnsiString; SubType: integer); overload;
59
60	end;
61
62
63	{ TFB30Blob }
64
65	TFB30Blob = class(TFBBlob,IBlob)
66	private
67	FBlobIntf: Firebird.IBlob;
68	FEOB: boolean;
69	protected
70	procedure CheckReadable; override;
71	procedure CheckWritable; override;
72	function GetIntf: IBlob; override;
73	procedure GetInfo(Request: array of byte; Response: IBlobInfo); override;
74	procedure InternalClose(Force: boolean); override;
75	procedure InternalCancel(Force: boolean); override;
76	public
77	constructor Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
78	MetaData: IBlobMetaData; BPB: IBPB); overload;
79	constructor Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
80	SubType: integer; CharSetID: cardinal; BPB: IBPB); overload;
81	constructor Create(Attachment: TFB30Attachment; Transaction: TFBTransaction;
82	MetaData: IBlobMetaData; BlobID: TISC_QUAD; BPB: IBPB); overload;
83	property BlobIntf: Firebird.IBlob read FBlobIntf;
84
85	{IBlob}
86	public
87	function Read(var Buffer; Count: Longint): Longint; override;
88	function Write(const Buffer; Count: Longint): Longint; override;
89	end;
90
91	implementation
92
93	uses FBMessages, FB30Statement, FBParamBlock, Math;
94
95	const
96	sLookupBlobMetaData = 'Select F.RDB$FIELD_SUB_TYPE, F.RDB$SEGMENT_LENGTH, RDB$CHARACTER_SET_ID, F.RDB$FIELD_TYPE '+
97	'From RDB$FIELDS F JOIN RDB$RELATION_FIELDS R On R.RDB$FIELD_SOURCE = F.RDB$FIELD_NAME '+
98	'Where Trim(R.RDB$RELATION_NAME) = Upper(Trim(?)) and Trim(R.RDB$FIELD_NAME) = Upper(Trim(?))';
99
100	{ TFB30BlobMetaData }
101
102	procedure TFB30BlobMetaData.NeedFullMetadata;
103	var stmt: IStatement;
104	begin
105	if FHasFullMetaData then Exit;
106
107	FSegmentSize := 80;
108	if (GetColumnName <> '') and (GetRelationName <> '') then
109	begin
110	stmt := TFB30Statement.Create(FAttachment,FTransaction, sLookupBlobMetaData ,FAttachment.SQLDialect);
111	with stmt do
112	begin
113	SQLParams[0].AsString := GetRelationName;
114	SQLParams[1].AsString := GetColumnName;
115	with OpenCursor do
116	if FetchNext then
117	begin
118	if Data[3].AsInteger <> blr_blob then
119	IBError(ibxeInvalidBlobMetaData,[nil]);
120	FSubType := Data[0].AsInteger;
121	FSegmentSize := Data[1].AsInteger;
122	if FUnconfirmedCharacterSet then
123	FCharSetID := Data[2].AsInteger;
124	end
125	else
126	IBError(ibxeInvalidBlobMetaData,[nil]);
127
128	end;
129	end;
130
131	if FUnconfirmedCharacterSet and (FCharSetID > 1) and FAttachment.HasDefaultCharSet then
132	begin
133	FCharSetID := FAttachment.CharSetID;
134	FUnconfirmedCharacterSet := false;
135	end;
136
137	FHasFullMetaData := true;
138	FHasSubType := true;
139	end;
140
141	constructor TFB30BlobMetaData.Create(Attachment: TFB30Attachment;
142	Transaction: TFB30Transaction; RelationName, ColumnName: AnsiString);
143	begin
144	inherited Create(Transaction,RelationName,ColumnName);
145	FAttachment := Attachment;
146	FTransaction := Transaction;
147	end;
148
149	constructor TFB30BlobMetaData.Create(Attachment: TFB30Attachment;
150	Transaction: TFB30Transaction; RelationName, ColumnName: AnsiString;
151	SubType: integer);
152	begin
153	Create(Attachment,Transaction,RelationName,ColumnName);
154	FSubType := SubType;
155	FHasSubType := true;
156	end;
157
158	{ TFB30Blob }
159
160	procedure TFB30Blob.CheckReadable;
161	begin
162	if FCreating or (FBlobIntf = nil) then
163	IBError(ibxeBlobCannotBeRead, [nil]);
164	end;
165
166	procedure TFB30Blob.CheckWritable;
167	begin
168	if not FCreating or (FBlobIntf = nil) then
169	IBError(ibxeBlobCannotBeWritten, [nil]);
170	end;
171
172	function TFB30Blob.GetIntf: IBlob;
173	begin
174	Result := self;
175	end;
176
177	procedure TFB30Blob.GetInfo(Request: array of byte; Response: IBlobInfo);
178	begin
179	if FBlobIntf = nil then
180	IBError(ibxeBlobNotOpen,[nil]);
181
182	with Firebird30ClientAPI, Response as TBlobInfo do
183	begin
184	FBlobIntf.getInfo(StatusIntf,Length(Request),BytePtr(@Request),
185	GetBufSize, BytePtr(Buffer));
186	Check4DataBaseError;
187	SignalActivity;
188	end;
189	end;
190
191	procedure TFB30Blob.InternalClose(Force: boolean);
192	begin
193	if FBlobIntf = nil then
194	Exit;
195	with Firebird30ClientAPI do
196	begin
197	FBlobIntf.close(StatusIntf);
198	if not Force then Check4DataBaseError;
199	end;
200	FBlobIntf.release;
201	FBlobIntf := nil;
202	end;
203
204	procedure TFB30Blob.InternalCancel(Force: boolean);
205	begin
206	if FBlobIntf = nil then
207	Exit;
208	with Firebird30ClientAPI do
209	begin
210	FBlobIntf.cancel(StatusIntf);
211	if not Force then Check4DataBaseError;
212	end;
213	FBlobIntf.release;
214	FBlobIntf := nil;
215	end;
216
217	constructor TFB30Blob.Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
218	MetaData: IBlobMetaData; BPB: IBPB);
219	begin
220	inherited Create(Attachment,Transaction,MetaData,BPB);
221	with Firebird30ClientAPI do
222	begin
223	if BPB = nil then
224	FBlobIntf := Attachment.AttachmentIntf.createBlob(StatusIntf,Transaction.TransactionIntf,
225	@FBlobID,0,nil)
226	else
227	with BPB as TBPB do
228	FBlobIntf := Attachment.AttachmentIntf.createBlob(StatusIntf,Transaction.TransactionIntf,
229	@FBlobID,getDataLength, BytePtr(getBuffer));
230	Check4DataBaseError;
231	end;
232	end;
233
234	constructor TFB30Blob.Create(Attachment: TFB30Attachment;
235	Transaction: TFB30Transaction; SubType: integer; CharSetID: cardinal;
236	BPB: IBPB);
237	var MetaData: TFB30BlobMetaData;
238	begin
239	MetaData := TFB30BlobMetaData.Create(Attachment,Transaction,'','',SubType);
240	MetaData.FCharSetID := CharSetID;
241	MetaData.FHasFullMetaData := true;
242	inherited Create(Attachment,Transaction,MetaData,BPB);
243	with Firebird30ClientAPI do
244	begin
245	if BPB = nil then
246	FBlobIntf := Attachment.AttachmentIntf.createBlob(StatusIntf,Transaction.TransactionIntf,
247	@FBlobID,0,nil)
248	else
249	with BPB as TBPB do
250	FBlobIntf := Attachment.AttachmentIntf.createBlob(StatusIntf,Transaction.TransactionIntf,
251	@FBlobID,getDataLength, BytePtr(getBuffer));
252	Check4DataBaseError;
253	end;
254	end;
255
256	constructor TFB30Blob.Create(Attachment: TFB30Attachment;
257	Transaction: TFBTransaction; MetaData: IBlobMetaData; BlobID: TISC_QUAD; BPB: IBPB);
258	begin
259	inherited Create(Attachment,Transaction,MetaData,BlobID,BPB);
260	if (BlobID.gds_quad_high = 0) and (BlobID.gds_quad_low = 0) then
261	Exit;
262
263	with Firebird30ClientAPI do
264	begin
265	if BPB = nil then
266	FBlobIntf := Attachment.AttachmentIntf.openBlob(StatusIntf,(Transaction as TFB30Transaction).TransactionIntf,
267	@FBlobID, 0, nil)
268	else
269	with BPB as TBPB do
270	FBlobIntf := Attachment.AttachmentIntf.openBlob(StatusIntf,(Transaction as TFB30Transaction).TransactionIntf,
271	@FBlobID, getDataLength, BytePtr(getBuffer));
272	Check4DataBaseError;
273	end;
274	end;
275
276	function TFB30Blob.Read(var Buffer; Count: Longint): Longint;
277	var
278	BytesRead : cardinal;
279	LocalBuffer: PAnsiChar;
280	returnCode: integer;
281	localCount: uShort;
282	begin
283	CheckReadable;
284	Result := 0;
285	if FEOB then
286	Exit;
287
288	LocalBuffer := PAnsiChar(@Buffer);
289	repeat
290	localCount := Min(Count,MaxuShort);
291	with Firebird30ClientAPI do
292	returnCode := FBlobIntf.getSegment(StatusIntf,localCount, LocalBuffer, @BytesRead);
293	SignalActivity;
294	Inc(LocalBuffer,BytesRead);
295	Inc(Result,BytesRead);
296	Dec(Count,BytesRead);
297	until ((returncode <> Firebird.IStatus.Result_OK) and (returnCode <> Firebird.IStatus.Result_SEGMENT)) or (Count = 0);
298
299	FEOB := returnCode = Firebird.IStatus.RESULT_NO_DATA;
300	ClearStringCache;
301	if (returnCode <> Firebird.IStatus.Result_OK) and
302	(returnCode <> Firebird.IStatus.Result_SEGMENT) and
303	(returnCode <> Firebird.IStatus.RESULT_NO_DATA) then
304	Firebird30ClientAPI.IBDataBaseError
305	end;
306
307	function TFB30Blob.Write(const Buffer; Count: Longint): Longint;
308	var
309	LocalBuffer: PAnsiChar;
310	localCount: uShort;
311	begin
312	CheckWritable;
313	Result := 0;
314	if Count = 0 then Exit;
315
316	LocalBuffer := PAnsiChar(@Buffer);
317	repeat
318	localCount := Min(Count,MaxuShort);
319	with Firebird30ClientAPI do
320	begin
321	FBlobIntf.putSegment(StatusIntf,localCount,LocalBuffer);
322	Check4DataBaseError;
323	end;
324	Inc(LocalBuffer,localCount);
325	Inc(Result,localCount);
326	Dec(Count,localCount);
327	until Count = 0;
328	ClearStringCache;
329	SignalActivity;
330	end;
331
332	end.
333