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;

{$IFDEF FPC}
{$mode objfpc}{$H+}
{$interfaces COM}
{$ENDIF}

interface

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

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: string); overload;
     constructor Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
       RelationName, ColumnName: string; 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 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
    procedure GetInfo(var NumSegments: Int64; var MaxSegmentSize, TotalSize: Int64;
      var BlobType: TBlobType); override;
    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: string);
begin
  inherited Create(Transaction,RelationName,ColumnName);
  FAttachment := Attachment;
  FTransaction := Transaction;
end;

constructor TFB30BlobMetaData.Create(Attachment: TFB30Attachment;
  Transaction: TFB30Transaction; RelationName, ColumnName: string;
  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.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;

procedure TFB30Blob.GetInfo(var NumSegments: Int64; var MaxSegmentSize,
  TotalSize: Int64; var BlobType: TBlobType);
var
  items: array[0..3] of Char;
  results: array[0..99] of Char;
  i, item_length: Integer;
  item: Integer;
begin
  if FBlobIntf = nil then
    IBError(ibxeBlobNotOpen,[nil]);

  items[0] := Char(isc_info_blob_num_segments);
  items[1] := Char(isc_info_blob_max_segment);
  items[2] := Char(isc_info_blob_total_length);
  items[3] := Char(isc_info_blob_type);

  with Firebird30ClientAPI do
  begin
    FBlobIntf.getInfo(StatusIntf,4,@items[0],SizeOf(results),@results[0]);
    Check4DataBaseError;
    SignalActivity;
    i := 0;
    while (i < SizeOf(results)) and (results[i] <> Char(isc_info_end)) do
    begin
      item := Integer(results[i]); Inc(i);
      item_length := DecodeInteger(@results[i], 2); Inc(i, 2);
      case item of
        isc_info_blob_num_segments:
          NumSegments := DecodeInteger(@results[i], item_length);
        isc_info_blob_max_segment:
          MaxSegmentSize := DecodeInteger(@results[i], item_length);
        isc_info_blob_total_length:
          TotalSize := DecodeInteger(@results[i], item_length);
        isc_info_blob_type:
          if DecodeInteger(@results[i], item_length) = 0 then
            BlobType := btSegmented
          else
            BlobType := btStream;
      end;
      Inc(i, item_length);
    end;
  end;
end;

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

  LocalBuffer := PChar(@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: PChar;
  localCount: uShort;
begin
  CheckWritable;
  Result := 0;
  if Count = 0 then Exit;

  LocalBuffer := PChar(@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:	47
Committed:	Mon Jan 9 15:31:51 2017 UTC (7 years, 3 months ago) by tony
Content type:	text/x-pascal
File size:	10956 byte(s)
Log Message:	Committing updates for Release R2-0-1
#	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
29	{$IFDEF FPC}
30	{$mode objfpc}{$H+}
31	{$interfaces COM}
32	{$ENDIF}
33
34	interface
35
36	uses
37	Classes, SysUtils, Firebird, IB, IBHeader, IBExternals, FBClientAPI, FB30ClientAPI, FB30Attachment,
38	FBTransaction, FB30Transaction, FBBlob;
39
40	type
41
42	{ TFB30BlobMetaData }
43
44	TFB30BlobMetaData = class(TFBBlobMetaData, IBlobMetaData)
45	private
46	FHasFullMetaData: boolean;
47	FAttachment: TFB30Attachment;
48	FTransaction: TFB30Transaction;
49	protected
50	procedure NeedFullMetadata; override;
51	public
52	constructor Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
53	RelationName, ColumnName: string); overload;
54	constructor Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
55	RelationName, ColumnName: string; SubType: integer); overload;
56
57	end;
58
59
60	{ TFB30Blob }
61
62	TFB30Blob = class(TFBBlob,IBlob)
63	private
64	FBlobIntf: Firebird.IBlob;
65	FEOB: boolean;
66	protected
67	procedure CheckReadable; override;
68	procedure CheckWritable; override;
69	function GetIntf: IBlob; override;
70	procedure InternalClose(Force: boolean); override;
71	procedure InternalCancel(Force: boolean); override;
72	public
73	constructor Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
74	MetaData: IBlobMetaData; BPB: IBPB); overload;
75	constructor Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
76	SubType: integer; CharSetID: cardinal; BPB: IBPB); overload;
77	constructor Create(Attachment: TFB30Attachment; Transaction: TFBTransaction;
78	MetaData: IBlobMetaData; BlobID: TISC_QUAD; BPB: IBPB); overload;
79	property BlobIntf: Firebird.IBlob read FBlobIntf;
80
81	{IBlob}
82	public
83	procedure GetInfo(var NumSegments: Int64; var MaxSegmentSize, TotalSize: Int64;
84	var BlobType: TBlobType); override;
85	function Read(var Buffer; Count: Longint): Longint; override;
86	function Write(const Buffer; Count: Longint): Longint; override;
87	end;
88
89	implementation
90
91	uses FBMessages, FB30Statement, FBParamBlock, Math;
92
93	const
94	sLookupBlobMetaData = 'Select F.RDB$FIELD_SUB_TYPE, F.RDB$SEGMENT_LENGTH, RDB$CHARACTER_SET_ID, F.RDB$FIELD_TYPE '+
95	'From RDB$FIELDS F JOIN RDB$RELATION_FIELDS R On R.RDB$FIELD_SOURCE = F.RDB$FIELD_NAME '+
96	'Where Trim(R.RDB$RELATION_NAME) = Upper(Trim(?)) and Trim(R.RDB$FIELD_NAME) = Upper(Trim(?))';
97
98	{ TFB30BlobMetaData }
99
100	procedure TFB30BlobMetaData.NeedFullMetadata;
101	var stmt: IStatement;
102	begin
103	if FHasFullMetaData then Exit;
104
105	FSegmentSize := 80;
106	if (GetColumnName <> '') and (GetRelationName <> '') then
107	begin
108	stmt := TFB30Statement.Create(FAttachment,FTransaction, sLookupBlobMetaData ,FAttachment.SQLDialect);
109	with stmt do
110	begin
111	SQLParams[0].AsString := GetRelationName;
112	SQLParams[1].AsString := GetColumnName;
113	with OpenCursor do
114	if FetchNext then
115	begin
116	if Data[3].AsInteger <> blr_blob then
117	IBError(ibxeInvalidBlobMetaData,[nil]);
118	FSubType := Data[0].AsInteger;
119	FSegmentSize := Data[1].AsInteger;
120	if FUnconfirmedCharacterSet then
121	FCharSetID := Data[2].AsInteger;
122	end
123	else
124	IBError(ibxeInvalidBlobMetaData,[nil]);
125
126	end;
127	end;
128
129	if FUnconfirmedCharacterSet and (FCharSetID > 1) and FAttachment.HasDefaultCharSet then
130	begin
131	FCharSetID := FAttachment.CharSetID;
132	FUnconfirmedCharacterSet := false;
133	end;
134
135	FHasFullMetaData := true;
136	FHasSubType := true;
137	end;
138
139	constructor TFB30BlobMetaData.Create(Attachment: TFB30Attachment;
140	Transaction: TFB30Transaction; RelationName, ColumnName: string);
141	begin
142	inherited Create(Transaction,RelationName,ColumnName);
143	FAttachment := Attachment;
144	FTransaction := Transaction;
145	end;
146
147	constructor TFB30BlobMetaData.Create(Attachment: TFB30Attachment;
148	Transaction: TFB30Transaction; RelationName, ColumnName: string;
149	SubType: integer);
150	begin
151	Create(Attachment,Transaction,RelationName,ColumnName);
152	FSubType := SubType;
153	FHasSubType := true;
154	end;
155
156	{ TFB30Blob }
157
158	procedure TFB30Blob.CheckReadable;
159	begin
160	if FCreating or (FBlobIntf = nil) then
161	IBError(ibxeBlobCannotBeRead, [nil]);
162	end;
163
164	procedure TFB30Blob.CheckWritable;
165	begin
166	if not FCreating or (FBlobIntf = nil) then
167	IBError(ibxeBlobCannotBeWritten, [nil]);
168	end;
169
170	function TFB30Blob.GetIntf: IBlob;
171	begin
172	Result := self;
173	end;
174
175	procedure TFB30Blob.InternalClose(Force: boolean);
176	begin
177	if FBlobIntf = nil then
178	Exit;
179	with Firebird30ClientAPI do
180	begin
181	FBlobIntf.close(StatusIntf);
182	if not Force then Check4DataBaseError;
183	end;
184	FBlobIntf.release;
185	FBlobIntf := nil;
186	end;
187
188	procedure TFB30Blob.InternalCancel(Force: boolean);
189	begin
190	if FBlobIntf = nil then
191	Exit;
192	with Firebird30ClientAPI do
193	begin
194	FBlobIntf.cancel(StatusIntf);
195	if not Force then Check4DataBaseError;
196	end;
197	FBlobIntf.release;
198	FBlobIntf := nil;
199	end;
200
201	constructor TFB30Blob.Create(Attachment: TFB30Attachment; Transaction: TFB30Transaction;
202	MetaData: IBlobMetaData; BPB: IBPB);
203	begin
204	inherited Create(Attachment,Transaction,MetaData,BPB);
205	with Firebird30ClientAPI do
206	begin
207	if BPB = nil then
208	FBlobIntf := Attachment.AttachmentIntf.createBlob(StatusIntf,Transaction.TransactionIntf,
209	@FBlobID,0,nil)
210	else
211	with BPB as TBPB do
212	FBlobIntf := Attachment.AttachmentIntf.createBlob(StatusIntf,Transaction.TransactionIntf,
213	@FBlobID,getDataLength, BytePtr(getBuffer));
214	Check4DataBaseError;
215	end;
216	end;
217
218	constructor TFB30Blob.Create(Attachment: TFB30Attachment;
219	Transaction: TFB30Transaction; SubType: integer; CharSetID: cardinal;
220	BPB: IBPB);
221	var MetaData: TFB30BlobMetaData;
222	begin
223	MetaData := TFB30BlobMetaData.Create(Attachment,Transaction,'','',SubType);
224	MetaData.FCharSetID := CharSetID;
225	MetaData.FHasFullMetaData := true;
226	inherited Create(Attachment,Transaction,MetaData,BPB);
227	with Firebird30ClientAPI do
228	begin
229	if BPB = nil then
230	FBlobIntf := Attachment.AttachmentIntf.createBlob(StatusIntf,Transaction.TransactionIntf,
231	@FBlobID,0,nil)
232	else
233	with BPB as TBPB do
234	FBlobIntf := Attachment.AttachmentIntf.createBlob(StatusIntf,Transaction.TransactionIntf,
235	@FBlobID,getDataLength, BytePtr(getBuffer));
236	Check4DataBaseError;
237	end;
238	end;
239
240	constructor TFB30Blob.Create(Attachment: TFB30Attachment;
241	Transaction: TFBTransaction; MetaData: IBlobMetaData; BlobID: TISC_QUAD; BPB: IBPB);
242	begin
243	inherited Create(Attachment,Transaction,MetaData,BlobID,BPB);
244	if (BlobID.gds_quad_high = 0) and (BlobID.gds_quad_low = 0) then
245	Exit;
246
247	with Firebird30ClientAPI do
248	begin
249	if BPB = nil then
250	FBlobIntf := Attachment.AttachmentIntf.openBlob(StatusIntf,(Transaction as TFB30Transaction).TransactionIntf,
251	@FBlobID, 0, nil)
252	else
253	with BPB as TBPB do
254	FBlobIntf := Attachment.AttachmentIntf.openBlob(StatusIntf,(Transaction as TFB30Transaction).TransactionIntf,
255	@FBlobID, getDataLength, BytePtr(getBuffer));
256	Check4DataBaseError;
257	end;
258	end;
259
260	procedure TFB30Blob.GetInfo(var NumSegments: Int64; var MaxSegmentSize,
261	TotalSize: Int64; var BlobType: TBlobType);
262	var
263	items: array[0..3] of Char;
264	results: array[0..99] of Char;
265	i, item_length: Integer;
266	item: Integer;
267	begin
268	if FBlobIntf = nil then
269	IBError(ibxeBlobNotOpen,[nil]);
270
271	items[0] := Char(isc_info_blob_num_segments);
272	items[1] := Char(isc_info_blob_max_segment);
273	items[2] := Char(isc_info_blob_total_length);
274	items[3] := Char(isc_info_blob_type);
275
276	with Firebird30ClientAPI do
277	begin
278	FBlobIntf.getInfo(StatusIntf,4,@items[0],SizeOf(results),@results[0]);
279	Check4DataBaseError;
280	SignalActivity;
281	i := 0;
282	while (i < SizeOf(results)) and (results[i] <> Char(isc_info_end)) do
283	begin
284	item := Integer(results[i]); Inc(i);
285	item_length := DecodeInteger(@results[i], 2); Inc(i, 2);
286	case item of
287	isc_info_blob_num_segments:
288	NumSegments := DecodeInteger(@results[i], item_length);
289	isc_info_blob_max_segment:
290	MaxSegmentSize := DecodeInteger(@results[i], item_length);
291	isc_info_blob_total_length:
292	TotalSize := DecodeInteger(@results[i], item_length);
293	isc_info_blob_type:
294	if DecodeInteger(@results[i], item_length) = 0 then
295	BlobType := btSegmented
296	else
297	BlobType := btStream;
298	end;
299	Inc(i, item_length);
300	end;
301	end;
302	end;
303
304	function TFB30Blob.Read(var Buffer; Count: Longint): Longint;
305	var
306	BytesRead : cardinal;
307	LocalBuffer: PChar;
308	returnCode: integer;
309	localCount: uShort;
310	begin
311	CheckReadable;
312	Result := 0;
313	if FEOB then
314	Exit;
315
316	LocalBuffer := PChar(@Buffer);
317	repeat
318	localCount := Min(Count,MaxuShort);
319	with Firebird30ClientAPI do
320	returnCode := FBlobIntf.getSegment(StatusIntf,localCount, LocalBuffer, @BytesRead);
321	SignalActivity;
322	Inc(LocalBuffer,BytesRead);
323	Inc(Result,BytesRead);
324	Dec(Count,BytesRead);
325	until ((returncode <> Firebird.IStatus.Result_OK) and (returnCode <> Firebird.IStatus.Result_SEGMENT)) or (Count = 0);
326
327	FEOB := returnCode = Firebird.IStatus.RESULT_NO_DATA;
328	ClearStringCache;
329	if (returnCode <> Firebird.IStatus.Result_OK) and
330	(returnCode <> Firebird.IStatus.Result_SEGMENT) and
331	(returnCode <> Firebird.IStatus.RESULT_NO_DATA) then
332	Firebird30ClientAPI.IBDataBaseError
333	end;
334
335	function TFB30Blob.Write(const Buffer; Count: Longint): Longint;
336	var
337	LocalBuffer: PChar;
338	localCount: uShort;
339	begin
340	CheckWritable;
341	Result := 0;
342	if Count = 0 then Exit;
343
344	LocalBuffer := PChar(@Buffer);
345	repeat
346	localCount := Min(Count,MaxuShort);
347	with Firebird30ClientAPI do
348	begin
349	FBlobIntf.putSegment(StatusIntf,localCount,LocalBuffer);
350	Check4DataBaseError;
351	end;
352	Inc(LocalBuffer,localCount);
353	Inc(Result,localCount);
354	Dec(Count,localCount);
355	until Count = 0;
356	ClearStringCache;
357	SignalActivity;
358	end;
359
360	end.
361