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
     function Attachment: IAttachment; override;
     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, F.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(?)) ' +
  'UNION '+
  'Select F.RDB$FIELD_SUB_TYPE, F.RDB$SEGMENT_LENGTH, F.RDB$CHARACTER_SET_ID, F.RDB$FIELD_TYPE '+
  'From RDB$FIELDS F JOIN RDB$PROCEDURE_PARAMETERS P On P.RDB$FIELD_SOURCE = F.RDB$FIELD_NAME '+
    'Where Trim(P.RDB$PROCEDURE_NAME) = Upper(Trim(?)) and Trim(P.RDB$PARAMETER_NAME) = Upper(Trim(?)) ';

{ TFB30BlobMetaData }

function TFB30BlobMetaData.Attachment: IAttachment;
begin
  Result := FAttachment;
end;

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;
      SQLParams[2].AsString := GetRelationName;
      SQLParams[3].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:	109
Committed:	Thu Jan 18 14:37:48 2018 UTC (6 years, 3 months ago) by tony
Content type:	text/x-pascal
File size:	10552 byte(s)
Log Message:	Fixes Merged
#	User	Rev	Content
1	tony	45	(*
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	tony	56	{$IFDEF MSWINDOWS}
29			{$DEFINE WINDOWS}
30			{$ENDIF}
31	tony	45
32			{$IFDEF FPC}
33	tony	56	{$mode delphi}
34	tony	45	{$interfaces COM}
35			{$ENDIF}
36
37			interface
38
39			uses
40			Classes, SysUtils, Firebird, IB, IBHeader, IBExternals, FBClientAPI, FB30ClientAPI, FB30Attachment,
41	tony	56	FBTransaction, FB30Transaction, FBBlob, FBOutputBlock;
42	tony	45
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	tony	60	function Attachment: IAttachment; override;
54	tony	45	procedure NeedFullMetadata; override;
55			public
56			constructor Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
57	tony	56	RelationName, ColumnName: AnsiString); overload;
58	tony	45	constructor Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
59	tony	56	RelationName, ColumnName: AnsiString; SubType: integer); overload;
60	tony	45
61			end;
62
63
64			{ TFB30Blob }
65
66			TFB30Blob = class(TFBBlob,IBlob)
67			private
68			FBlobIntf: Firebird.IBlob;
69			FEOB: boolean;
70			protected
71			procedure CheckReadable; override;
72			procedure CheckWritable; override;
73			function GetIntf: IBlob; override;
74	tony	56	procedure GetInfo(Request: array of byte; Response: IBlobInfo); override;
75	tony	45	procedure InternalClose(Force: boolean); override;
76			procedure InternalCancel(Force: boolean); override;
77			public
78			constructor Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
79			MetaData: IBlobMetaData; BPB: IBPB); overload;
80			constructor Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
81			SubType: integer; CharSetID: cardinal; BPB: IBPB); overload;
82			constructor Create(Attachment: TFB30Attachment; Transaction: TFBTransaction;
83			MetaData: IBlobMetaData; BlobID: TISC_QUAD; BPB: IBPB); overload;
84			property BlobIntf: Firebird.IBlob read FBlobIntf;
85
86			{IBlob}
87			public
88			function Read(var Buffer; Count: Longint): Longint; override;
89			function Write(const Buffer; Count: Longint): Longint; override;
90			end;
91
92			implementation
93
94	tony	47	uses FBMessages, FB30Statement, FBParamBlock, Math;
95	tony	45
96			const
97	tony	109	sLookupBlobMetaData = 'Select F.RDB$FIELD_SUB_TYPE, F.RDB$SEGMENT_LENGTH, F.RDB$CHARACTER_SET_ID, F.RDB$FIELD_TYPE '+
98	tony	45	'From RDB$FIELDS F JOIN RDB$RELATION_FIELDS R On R.RDB$FIELD_SOURCE = F.RDB$FIELD_NAME '+
99	tony	109	'Where Trim(R.RDB$RELATION_NAME) = Upper(Trim(?)) and Trim(R.RDB$FIELD_NAME) = Upper(Trim(?)) ' +
100			'UNION '+
101			'Select F.RDB$FIELD_SUB_TYPE, F.RDB$SEGMENT_LENGTH, F.RDB$CHARACTER_SET_ID, F.RDB$FIELD_TYPE '+
102			'From RDB$FIELDS F JOIN RDB$PROCEDURE_PARAMETERS P On P.RDB$FIELD_SOURCE = F.RDB$FIELD_NAME '+
103			'Where Trim(P.RDB$PROCEDURE_NAME) = Upper(Trim(?)) and Trim(P.RDB$PARAMETER_NAME) = Upper(Trim(?)) ';
104	tony	45
105			{ TFB30BlobMetaData }
106
107	tony	60	function TFB30BlobMetaData.Attachment: IAttachment;
108			begin
109			Result := FAttachment;
110			end;
111
112	tony	45	procedure TFB30BlobMetaData.NeedFullMetadata;
113			var stmt: IStatement;
114			begin
115			if FHasFullMetaData then Exit;
116
117			FSegmentSize := 80;
118			if (GetColumnName <> '') and (GetRelationName <> '') then
119			begin
120			stmt := TFB30Statement.Create(FAttachment,FTransaction, sLookupBlobMetaData ,FAttachment.SQLDialect);
121			with stmt do
122			begin
123			SQLParams[0].AsString := GetRelationName;
124			SQLParams[1].AsString := GetColumnName;
125	tony	109	SQLParams[2].AsString := GetRelationName;
126			SQLParams[3].AsString := GetColumnName;
127	tony	45	with OpenCursor do
128			if FetchNext then
129			begin
130			if Data[3].AsInteger <> blr_blob then
131			IBError(ibxeInvalidBlobMetaData,[nil]);
132			FSubType := Data[0].AsInteger;
133			FSegmentSize := Data[1].AsInteger;
134	tony	47	if FUnconfirmedCharacterSet then
135			FCharSetID := Data[2].AsInteger;
136	tony	45	end
137			else
138			IBError(ibxeInvalidBlobMetaData,[nil]);
139
140			end;
141	tony	47	end;
142	tony	45
143	tony	47	if FUnconfirmedCharacterSet and (FCharSetID > 1) and FAttachment.HasDefaultCharSet then
144	tony	45	begin
145			FCharSetID := FAttachment.CharSetID;
146			FUnconfirmedCharacterSet := false;
147			end;
148
149			FHasFullMetaData := true;
150			FHasSubType := true;
151			end;
152
153			constructor TFB30BlobMetaData.Create(Attachment: TFB30Attachment;
154	tony	56	Transaction: TFB30Transaction; RelationName, ColumnName: AnsiString);
155	tony	45	begin
156			inherited Create(Transaction,RelationName,ColumnName);
157			FAttachment := Attachment;
158			FTransaction := Transaction;
159			end;
160
161			constructor TFB30BlobMetaData.Create(Attachment: TFB30Attachment;
162	tony	56	Transaction: TFB30Transaction; RelationName, ColumnName: AnsiString;
163	tony	45	SubType: integer);
164			begin
165			Create(Attachment,Transaction,RelationName,ColumnName);
166			FSubType := SubType;
167			FHasSubType := true;
168			end;
169
170			{ TFB30Blob }
171
172			procedure TFB30Blob.CheckReadable;
173			begin
174			if FCreating or (FBlobIntf = nil) then
175			IBError(ibxeBlobCannotBeRead, [nil]);
176			end;
177
178			procedure TFB30Blob.CheckWritable;
179			begin
180			if not FCreating or (FBlobIntf = nil) then
181			IBError(ibxeBlobCannotBeWritten, [nil]);
182			end;
183
184			function TFB30Blob.GetIntf: IBlob;
185			begin
186			Result := self;
187			end;
188
189	tony	56	procedure TFB30Blob.GetInfo(Request: array of byte; Response: IBlobInfo);
190			begin
191			if FBlobIntf = nil then
192			IBError(ibxeBlobNotOpen,[nil]);
193
194			with Firebird30ClientAPI, Response as TBlobInfo do
195			begin
196			FBlobIntf.getInfo(StatusIntf,Length(Request),BytePtr(@Request),
197			GetBufSize, BytePtr(Buffer));
198			Check4DataBaseError;
199			SignalActivity;
200			end;
201			end;
202
203	tony	45	procedure TFB30Blob.InternalClose(Force: boolean);
204			begin
205			if FBlobIntf = nil then
206			Exit;
207			with Firebird30ClientAPI do
208			begin
209			FBlobIntf.close(StatusIntf);
210			if not Force then Check4DataBaseError;
211			end;
212			FBlobIntf.release;
213			FBlobIntf := nil;
214			end;
215
216			procedure TFB30Blob.InternalCancel(Force: boolean);
217			begin
218			if FBlobIntf = nil then
219			Exit;
220			with Firebird30ClientAPI do
221			begin
222			FBlobIntf.cancel(StatusIntf);
223			if not Force then Check4DataBaseError;
224			end;
225			FBlobIntf.release;
226			FBlobIntf := nil;
227			end;
228
229			constructor TFB30Blob.Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
230			MetaData: IBlobMetaData; BPB: IBPB);
231			begin
232			inherited Create(Attachment,Transaction,MetaData,BPB);
233			with Firebird30ClientAPI do
234			begin
235			if BPB = nil then
236			FBlobIntf := Attachment.AttachmentIntf.createBlob(StatusIntf,Transaction.TransactionIntf,
237			@FBlobID,0,nil)
238			else
239			with BPB as TBPB do
240			FBlobIntf := Attachment.AttachmentIntf.createBlob(StatusIntf,Transaction.TransactionIntf,
241			@FBlobID,getDataLength, BytePtr(getBuffer));
242			Check4DataBaseError;
243			end;
244			end;
245
246			constructor TFB30Blob.Create(Attachment: TFB30Attachment;
247			Transaction: TFB30Transaction; SubType: integer; CharSetID: cardinal;
248			BPB: IBPB);
249			var MetaData: TFB30BlobMetaData;
250			begin
251			MetaData := TFB30BlobMetaData.Create(Attachment,Transaction,'','',SubType);
252			MetaData.FCharSetID := CharSetID;
253			MetaData.FHasFullMetaData := true;
254			inherited Create(Attachment,Transaction,MetaData,BPB);
255			with Firebird30ClientAPI do
256			begin
257			if BPB = nil then
258			FBlobIntf := Attachment.AttachmentIntf.createBlob(StatusIntf,Transaction.TransactionIntf,
259			@FBlobID,0,nil)
260			else
261			with BPB as TBPB do
262			FBlobIntf := Attachment.AttachmentIntf.createBlob(StatusIntf,Transaction.TransactionIntf,
263			@FBlobID,getDataLength, BytePtr(getBuffer));
264			Check4DataBaseError;
265			end;
266			end;
267
268			constructor TFB30Blob.Create(Attachment: TFB30Attachment;
269			Transaction: TFBTransaction; MetaData: IBlobMetaData; BlobID: TISC_QUAD; BPB: IBPB);
270			begin
271			inherited Create(Attachment,Transaction,MetaData,BlobID,BPB);
272			if (BlobID.gds_quad_high = 0) and (BlobID.gds_quad_low = 0) then
273			Exit;
274
275			with Firebird30ClientAPI do
276			begin
277			if BPB = nil then
278			FBlobIntf := Attachment.AttachmentIntf.openBlob(StatusIntf,(Transaction as TFB30Transaction).TransactionIntf,
279			@FBlobID, 0, nil)
280			else
281			with BPB as TBPB do
282			FBlobIntf := Attachment.AttachmentIntf.openBlob(StatusIntf,(Transaction as TFB30Transaction).TransactionIntf,
283			@FBlobID, getDataLength, BytePtr(getBuffer));
284			Check4DataBaseError;
285			end;
286			end;
287
288			function TFB30Blob.Read(var Buffer; Count: Longint): Longint;
289			var
290			BytesRead : cardinal;
291	tony	56	LocalBuffer: PAnsiChar;
292	tony	45	returnCode: integer;
293			localCount: uShort;
294			begin
295			CheckReadable;
296			Result := 0;
297			if FEOB then
298			Exit;
299
300	tony	56	LocalBuffer := PAnsiChar(@Buffer);
301	tony	45	repeat
302	tony	47	localCount := Min(Count,MaxuShort);
303	tony	45	with Firebird30ClientAPI do
304			returnCode := FBlobIntf.getSegment(StatusIntf,localCount, LocalBuffer, @BytesRead);
305			SignalActivity;
306			Inc(LocalBuffer,BytesRead);
307			Inc(Result,BytesRead);
308			Dec(Count,BytesRead);
309			until ((returncode <> Firebird.IStatus.Result_OK) and (returnCode <> Firebird.IStatus.Result_SEGMENT)) or (Count = 0);
310
311			FEOB := returnCode = Firebird.IStatus.RESULT_NO_DATA;
312			ClearStringCache;
313			if (returnCode <> Firebird.IStatus.Result_OK) and
314			(returnCode <> Firebird.IStatus.Result_SEGMENT) and
315			(returnCode <> Firebird.IStatus.RESULT_NO_DATA) then
316			Firebird30ClientAPI.IBDataBaseError
317			end;
318
319			function TFB30Blob.Write(const Buffer; Count: Longint): Longint;
320	tony	47	var
321	tony	56	LocalBuffer: PAnsiChar;
322	tony	47	localCount: uShort;
323	tony	45	begin
324			CheckWritable;
325			Result := 0;
326			if Count = 0 then Exit;
327
328	tony	56	LocalBuffer := PAnsiChar(@Buffer);
329	tony	47	repeat
330			localCount := Min(Count,MaxuShort);
331			with Firebird30ClientAPI do
332			begin
333			FBlobIntf.putSegment(StatusIntf,localCount,LocalBuffer);
334			Check4DataBaseError;
335			end;
336			Inc(LocalBuffer,localCount);
337			Inc(Result,localCount);
338			Dec(Count,localCount);
339			until Count = 0;
340	tony	45	ClearStringCache;
341			SignalActivity;
342			end;
343
344			end.
345