client/2.5/FB25Blob.pas

(*
 *  Firebird Interface (fbintf). The fbintf components provide a set of
 *  Pascal language bindings for the Firebird API. Although predominantly
 *  a new development they include source code taken from IBX and may be
 *  considered a derived product. This software thus also includes the copyright
 *  notice and license conditions from IBX.
 *
 *  Except for those parts dervied from IBX, 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): ______________________________________.
 *
*)
{************************************************************************}
{                                                                        }
{       Borland Delphi Visual Component Library                          }
{       InterBase Express core components                                }
{                                                                        }
{       Copyright (c) 1998-2000 Inprise Corporation                      }
{                                                                        }
{    InterBase Express is based in part on the product                   }
{    Free IB Components, written by Gregory H. Deatz for                 }
{    Hoagland, Longo, Moran, Dunst & Doukas Company.                     }
{    Free IB Components is used under license.                           }
{                                                                        }
{    The contents of this file are subject to the InterBase              }
{    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 at http://www.Inprise.com/IPL.html }
{    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 Original Code was created by InterBase Software Corporation     }
{       and its successors.                                              }
{    Portions created by Inprise Corporation are Copyright (C) Inprise   }
{       Corporation. All Rights Reserved.                                }
{    Contributor(s): Jeff Overcash                                       }
{                                                                        }
{    IBX For Lazarus (Firebird Express)                                  }
{    Contributor: Tony Whyman, MWA Software http://www.mwasoftware.co.uk }
{    Portions created by MWA Software are copyright McCallum Whyman      }
{    Associates Ltd 2011 - 2015                                                }
{                                                                        }
{************************************************************************}
unit FB25Blob;

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

interface

uses
  Classes, SysUtils, IB,  IBHeader,IBExternals, FBClientAPI, FB25ClientAPI, FB25Attachment,
  FB25Transaction, FBActivityMonitor, FBBlob;

type

   { TFB25BlobMetaData }

   TFB25BlobMetaData  = class(TFBBlobMetaData, IBlobMetaData)
   private
     FHasFullMetaData: boolean;
     FAttachment: TFB25Attachment;
     FTransaction: TFB25Transaction;
   protected
     procedure NeedFullMetadata; override;
   public
     constructor Create(Attachment: TFB25Attachment; Transaction: TFB25Transaction;
       RelationName, ColumnName: string); overload;
     constructor Create(Attachment: TFB25Attachment; Transaction: TFB25Transaction;
       RelationName, ColumnName: string; SubType: integer); overload;
  end;


  { TFB25Blob }

  TFB25Blob = class(TFBBlob,IBlob)
  private
    FHandle: TISC_BLOB_HANDLE;
    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: TFB25Attachment; Transaction: TFB25Transaction;
                       MetaData: IBlobMetaData; BPB: IBPB); overload;
    constructor Create(Attachment: TFB25Attachment; Transaction: TFB25Transaction;
                       SubType: integer; CharSetID: cardinal; BPB: IBPB); overload;
    constructor Create(Attachment: TFB25Attachment; Transaction: TFB25Transaction;
                       MetaData: IBlobMetaData; BlobID: TISC_QUAD; BPB: IBPB); overload;
    property Handle: TISC_BLOB_HANDLE read FHandle;

  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 IBErrorCodes, FBMessages, FBParamBlock;

{ TFB25BlobMetaData }

procedure TFB25BlobMetaData.NeedFullMetadata;
var
  BlobDesc: TISC_BLOB_DESC;
  Global: array [0..31] of char;
begin
  if FHasFullMetaData then Exit;

  FSegmentSize := 80;
  if (GetColumnName <> '') and (GetRelationName <> '') then
  begin
    with Firebird25ClientAPI do
      Call(isc_blob_lookup_desc(StatusVector,@(FAttachment.Handle),
                                            @(FTransaction.Handle),
                PChar(AnsiUpperCase(GetRelationName)),PChar(AnsiUpperCase(GetColumnName)),@BlobDesc,@Global));
    if FUnconfirmedCharacterSet then
      FCharSetID := BlobDesc.blob_desc_charset;
    FSubType := BlobDesc.blob_desc_subtype;
    FSegmentSize := BlobDesc.blob_desc_segment_size ;
  end;

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


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

constructor TFB25BlobMetaData.Create(Attachment: TFB25Attachment;
  Transaction: TFB25Transaction; RelationName, ColumnName: string);
begin
  inherited Create(Transaction,RelationName,ColumnName);
  FAttachment := Attachment;
  FTransaction := Transaction;
end;

constructor TFB25BlobMetaData.Create(Attachment: TFB25Attachment;
  Transaction: TFB25Transaction; RelationName, ColumnName: string;
  SubType: integer);
begin
  Create(Attachment,Transaction,RelationName,ColumnName);
  FSubType := SubType;
  FHasSubType := true;
end;

{ TFB25Blob }

procedure TFB25Blob.CheckReadable;
begin
  if FCreating or (FHandle = nil) then
    IBError(ibxeBlobCannotBeRead, [nil]);
end;

procedure TFB25Blob.CheckWritable;
begin
  if not FCreating or (FHandle = nil) then
    IBError(ibxeBlobCannotBeWritten, [nil]);
end;

function TFB25Blob.GetIntf: IBlob;
begin
  Result := self;
end;

procedure TFB25Blob.InternalClose(Force: boolean);
begin
  if FHandle = nil then
    Exit;
  with Firebird25ClientAPI do
    Call(isc_close_blob(StatusVector, @FHandle), not Force);
  FHandle := nil;
end;

procedure TFB25Blob.InternalCancel(Force: boolean);
begin
  if FHandle = nil then
    Exit;
  with Firebird25ClientAPI do
    Call(isc_cancel_blob(StatusVector,@FHandle),not Force);
  FHandle := nil;
end;

constructor TFB25Blob.Create(Attachment: TFB25Attachment; Transaction: TFB25Transaction;
  MetaData: IBlobMetaData; BPB: IBPB);
var DBHandle: TISC_DB_HANDLE;
    TRHandle: TISC_TR_HANDLE;
begin
  inherited Create(Attachment,Transaction,MetaData,BPB);
  DBHandle := Attachment.Handle;
  TRHandle := Transaction.Handle;
  with Firebird25ClientAPI do
  if BPB = nil then
    Call(isc_create_blob2(StatusVector, @DBHandle, @TRHandle, @FHandle, @FBlobID,
                           0, nil))
  else
  with BPB as TBPB do
    Call(isc_create_blob2(StatusVector, @DBHandle, @TRHandle, @FHandle, @FBlobID,
                         getDataLength, getBuffer));
end;

constructor TFB25Blob.Create(Attachment: TFB25Attachment;
  Transaction: TFB25Transaction; SubType: integer; CharSetID: cardinal;
  BPB: IBPB);
var DBHandle: TISC_DB_HANDLE;
    TRHandle: TISC_TR_HANDLE;
    MetaData: TFB25BlobMetaData;
begin
  MetaData := TFB25BlobMetaData.Create(Attachment,Transaction,'','',SubType);
  MetaData.FCharSetID := CharSetID;
  MetaData.FHasFullMetaData := true;
  inherited Create(Attachment,Transaction,MetaData,BPB);
  DBHandle := Attachment.Handle;
  TRHandle := Transaction.Handle;
  with Firebird25ClientAPI do
  if BPB = nil then
    Call(isc_create_blob2(StatusVector, @DBHandle, @TRHandle, @FHandle, @FBlobID,
                           0, nil))
  else
  with BPB as TBPB do
    Call(isc_create_blob2(StatusVector, @DBHandle, @TRHandle, @FHandle, @FBlobID,
                         getDataLength, getBuffer));
end;

constructor TFB25Blob.Create(Attachment: TFB25Attachment;
  Transaction: TFB25Transaction; MetaData: IBlobMetaData; BlobID: TISC_QUAD; BPB: IBPB);
var DBHandle: TISC_DB_HANDLE;
    TRHandle: TISC_TR_HANDLE;
begin
  inherited Create(Attachment,Transaction,MetaData,BlobID,BPB);
  DBHandle := Attachment.Handle;
  TRHandle := Transaction.Handle;
  if (BlobID.gds_quad_high = 0) and (BlobID.gds_quad_low = 0) then
    Exit;

  with Firebird25ClientAPI do
  if BPB = nil then
    Call(isc_open_blob2(StatusVector,  @DBHandle, @TRHandle, @FHandle,
                     @FBlobID, 0, nil))
  else
  with BPB as TBPB do
    Call(isc_open_blob2(StatusVector,  @DBHandle, @TRHandle, @FHandle,
                   @FBlobID, getDataLength, getBuffer));
end;

procedure TFB25Blob.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 FHandle = 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 Firebird25ClientAPI do
  begin
    Call(isc_blob_info(StatusVector, @FHandle, 4, @items[0], SizeOf(results),
                    @results[0]));
    i := 0;
    while (i < SizeOf(results)) and (results[i] <> Char(isc_info_end)) do
    begin
      item := Integer(results[i]); Inc(i);
      item_length := isc_portable_integer(@results[i], 2); Inc(i, 2);
      case item of
        isc_info_blob_num_segments:
          NumSegments := isc_portable_integer(@results[i], item_length);
        isc_info_blob_max_segment:
          MaxSegmentSize := isc_portable_integer(@results[i], item_length);
        isc_info_blob_total_length:
          TotalSize := isc_portable_integer(@results[i], item_length);
        isc_info_blob_type:
          if isc_portable_integer(@results[i], item_length) = 0 then
            BlobType := btSegmented
          else
            BlobType := btStream;
      end;
      Inc(i, item_length);
    end;
  end;
end;

function TFB25Blob.Read(var Buffer; Count: Longint): Longint;
var
  BytesRead : UShort;
  LocalBuffer: PChar;
  returnCode: long;
  localCount: uShort;
begin
  CheckReadable;
  Result := 0;
  if FEOB then
    Exit;

  LocalBuffer := PChar(@Buffer);
  repeat
    if Count > MaxuShort then
      localCount := MaxuShort
    else
      localCount := Count;
    with Firebird25ClientAPI do
      returnCode := isc_get_segment(StatusVector, @FHandle, @BytesRead, localCount,
                           LocalBuffer);
    Inc(LocalBuffer,BytesRead);
    Inc(Result,BytesRead);
    Dec(Count,BytesRead);
  until ((returncode <> 0) and (returnCode <> isc_segment)) or (Count = 0);

  FEOB := returnCode = isc_segstr_eof;
  ClearStringCache;
  if (returnCode <> 0) and (returnCode <> isc_segment) and (returnCode <> isc_segstr_eof) then
    Firebird25ClientAPI.IBDataBaseError
end;

function TFB25Blob.Write(const Buffer; Count: Longint): Longint;
var
  LocalBuffer: PChar;
  localCount: uShort;
begin
  CheckWritable;
  LocalBuffer := PChar(@Buffer);
  Result := 0;
  if Count = 0 then Exit;

  repeat
    if Count > MaxuShort then
      localCount := MaxuShort
    else
      localCount := Count;
    with Firebird25ClientAPI do
      Call(isc_put_segment(StatusVector,@FHandle,localCount,LocalBuffer));
    Dec(Count,localCount);
    Inc(LocalBuffer,localCount);
    Inc(Result,localCount);
  until Count = 0;
  ClearStringCache;
end;


end.

Revision:	47
Committed:	Mon Jan 9 15:31:51 2017 UTC (7 years, 10 months ago) by tony
Content type:	text/x-pascal
Original Path:	*ibx/trunk/fbintf/client/2.5/FB25Blob.pas*
File size:	13034 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. Although predominantly
4	* a new development they include source code taken from IBX and may be
5	* considered a derived product. This software thus also includes the copyright
6	* notice and license conditions from IBX.
7	*
8	* Except for those parts dervied from IBX, contents of this file are subject
9	* to the Initial Developer's Public License Version 1.0 (the "License"); you
10	* may not use this file except in compliance with the License. You may obtain a
11	* copy of the License here:
12	*
13	* http://www.firebirdsql.org/index.php?op=doc&id=idpl
14	*
15	* Software distributed under the License is distributed on an "AS
16	* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
17	* implied. See the License for the specific language governing rights
18	* and limitations under the License.
19	*
20	* The Initial Developer of the Original Code is Tony Whyman.
21	*
22	* The Original Code is (C) 2016 Tony Whyman, MWA Software
23	* (http://www.mwasoftware.co.uk).
24	*
25	* All Rights Reserved.
26	*
27	* Contributor(s): ______________________________________.
28	*
29	*)
30	{************************************************************************}
31	{ }
32	{ Borland Delphi Visual Component Library }
33	{ InterBase Express core components }
34	{ }
35	{ Copyright (c) 1998-2000 Inprise Corporation }
36	{ }
37	{ InterBase Express is based in part on the product }
38	{ Free IB Components, written by Gregory H. Deatz for }
39	{ Hoagland, Longo, Moran, Dunst & Doukas Company. }
40	{ Free IB Components is used under license. }
41	{ }
42	{ The contents of this file are subject to the InterBase }
43	{ Public License Version 1.0 (the "License"); you may not }
44	{ use this file except in compliance with the License. You }
45	{ may obtain a copy of the License at http://www.Inprise.com/IPL.html }
46	{ Software distributed under the License is distributed on }
47	{ an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either }
48	{ express or implied. See the License for the specific language }
49	{ governing rights and limitations under the License. }
50	{ The Original Code was created by InterBase Software Corporation }
51	{ and its successors. }
52	{ Portions created by Inprise Corporation are Copyright (C) Inprise }
53	{ Corporation. All Rights Reserved. }
54	{ Contributor(s): Jeff Overcash }
55	{ }
56	{ IBX For Lazarus (Firebird Express) }
57	{ Contributor: Tony Whyman, MWA Software http://www.mwasoftware.co.uk }
58	{ Portions created by MWA Software are copyright McCallum Whyman }
59	{ Associates Ltd 2011 - 2015 }
60	{ }
61	{************************************************************************}
62	unit FB25Blob;
63
64	{$IFDEF FPC}
65	{$mode objfpc}{$H+}
66	{$interfaces COM}
67	{$ENDIF}
68
69	interface
70
71	uses
72	Classes, SysUtils, IB, IBHeader,IBExternals, FBClientAPI, FB25ClientAPI, FB25Attachment,
73	FB25Transaction, FBActivityMonitor, FBBlob;
74
75	type
76
77	{ TFB25BlobMetaData }
78
79	TFB25BlobMetaData = class(TFBBlobMetaData, IBlobMetaData)
80	private
81	FHasFullMetaData: boolean;
82	FAttachment: TFB25Attachment;
83	FTransaction: TFB25Transaction;
84	protected
85	procedure NeedFullMetadata; override;
86	public
87	constructor Create(Attachment: TFB25Attachment; Transaction: TFB25Transaction;
88	RelationName, ColumnName: string); overload;
89	constructor Create(Attachment: TFB25Attachment; Transaction: TFB25Transaction;
90	RelationName, ColumnName: string; SubType: integer); overload;
91	end;
92
93
94	{ TFB25Blob }
95
96	TFB25Blob = class(TFBBlob,IBlob)
97	private
98	FHandle: TISC_BLOB_HANDLE;
99	FEOB: boolean;
100	protected
101	procedure CheckReadable; override;
102	procedure CheckWritable; override;
103	function GetIntf: IBlob; override;
104	procedure InternalClose(Force: boolean); override;
105	procedure InternalCancel(Force: boolean); override;
106	public
107	constructor Create(Attachment: TFB25Attachment; Transaction: TFB25Transaction;
108	MetaData: IBlobMetaData; BPB: IBPB); overload;
109	constructor Create(Attachment: TFB25Attachment; Transaction: TFB25Transaction;
110	SubType: integer; CharSetID: cardinal; BPB: IBPB); overload;
111	constructor Create(Attachment: TFB25Attachment; Transaction: TFB25Transaction;
112	MetaData: IBlobMetaData; BlobID: TISC_QUAD; BPB: IBPB); overload;
113	property Handle: TISC_BLOB_HANDLE read FHandle;
114
115	public
116	procedure GetInfo(var NumSegments: Int64; var MaxSegmentSize, TotalSize: Int64;
117	var BlobType: TBlobType); override;
118	function Read(var Buffer; Count: Longint): Longint; override;
119	function Write(const Buffer; Count: Longint): Longint; override;
120	end;
121
122	implementation
123
124	uses IBErrorCodes, FBMessages, FBParamBlock;
125
126	{ TFB25BlobMetaData }
127
128	procedure TFB25BlobMetaData.NeedFullMetadata;
129	var
130	BlobDesc: TISC_BLOB_DESC;
131	Global: array [0..31] of char;
132	begin
133	if FHasFullMetaData then Exit;
134
135	FSegmentSize := 80;
136	if (GetColumnName <> '') and (GetRelationName <> '') then
137	begin
138	with Firebird25ClientAPI do
139	Call(isc_blob_lookup_desc(StatusVector,@(FAttachment.Handle),
140	@(FTransaction.Handle),
141	PChar(AnsiUpperCase(GetRelationName)),PChar(AnsiUpperCase(GetColumnName)),@BlobDesc,@Global));
142	if FUnconfirmedCharacterSet then
143	FCharSetID := BlobDesc.blob_desc_charset;
144	FSubType := BlobDesc.blob_desc_subtype;
145	FSegmentSize := BlobDesc.blob_desc_segment_size ;
146	end;
147
148	if FUnconfirmedCharacterSet and (FCharSetID > 1) and FAttachment.HasDefaultCharSet then
149	begin
150	FCharSetID := FAttachment.CharSetID;
151	FUnconfirmedCharacterSet := false;
152	end;
153
154
155	FHasFullMetaData := true;
156	FHasSubType := true;
157	end;
158
159	constructor TFB25BlobMetaData.Create(Attachment: TFB25Attachment;
160	Transaction: TFB25Transaction; RelationName, ColumnName: string);
161	begin
162	inherited Create(Transaction,RelationName,ColumnName);
163	FAttachment := Attachment;
164	FTransaction := Transaction;
165	end;
166
167	constructor TFB25BlobMetaData.Create(Attachment: TFB25Attachment;
168	Transaction: TFB25Transaction; RelationName, ColumnName: string;
169	SubType: integer);
170	begin
171	Create(Attachment,Transaction,RelationName,ColumnName);
172	FSubType := SubType;
173	FHasSubType := true;
174	end;
175
176	{ TFB25Blob }
177
178	procedure TFB25Blob.CheckReadable;
179	begin
180	if FCreating or (FHandle = nil) then
181	IBError(ibxeBlobCannotBeRead, [nil]);
182	end;
183
184	procedure TFB25Blob.CheckWritable;
185	begin
186	if not FCreating or (FHandle = nil) then
187	IBError(ibxeBlobCannotBeWritten, [nil]);
188	end;
189
190	function TFB25Blob.GetIntf: IBlob;
191	begin
192	Result := self;
193	end;
194
195	procedure TFB25Blob.InternalClose(Force: boolean);
196	begin
197	if FHandle = nil then
198	Exit;
199	with Firebird25ClientAPI do
200	Call(isc_close_blob(StatusVector, @FHandle), not Force);
201	FHandle := nil;
202	end;
203
204	procedure TFB25Blob.InternalCancel(Force: boolean);
205	begin
206	if FHandle = nil then
207	Exit;
208	with Firebird25ClientAPI do
209	Call(isc_cancel_blob(StatusVector,@FHandle),not Force);
210	FHandle := nil;
211	end;
212
213	constructor TFB25Blob.Create(Attachment: TFB25Attachment; Transaction: TFB25Transaction;
214	MetaData: IBlobMetaData; BPB: IBPB);
215	var DBHandle: TISC_DB_HANDLE;
216	TRHandle: TISC_TR_HANDLE;
217	begin
218	inherited Create(Attachment,Transaction,MetaData,BPB);
219	DBHandle := Attachment.Handle;
220	TRHandle := Transaction.Handle;
221	with Firebird25ClientAPI do
222	if BPB = nil then
223	Call(isc_create_blob2(StatusVector, @DBHandle, @TRHandle, @FHandle, @FBlobID,
224	0, nil))
225	else
226	with BPB as TBPB do
227	Call(isc_create_blob2(StatusVector, @DBHandle, @TRHandle, @FHandle, @FBlobID,
228	getDataLength, getBuffer));
229	end;
230
231	constructor TFB25Blob.Create(Attachment: TFB25Attachment;
232	Transaction: TFB25Transaction; SubType: integer; CharSetID: cardinal;
233	BPB: IBPB);
234	var DBHandle: TISC_DB_HANDLE;
235	TRHandle: TISC_TR_HANDLE;
236	MetaData: TFB25BlobMetaData;
237	begin
238	MetaData := TFB25BlobMetaData.Create(Attachment,Transaction,'','',SubType);
239	MetaData.FCharSetID := CharSetID;
240	MetaData.FHasFullMetaData := true;
241	inherited Create(Attachment,Transaction,MetaData,BPB);
242	DBHandle := Attachment.Handle;
243	TRHandle := Transaction.Handle;
244	with Firebird25ClientAPI do
245	if BPB = nil then
246	Call(isc_create_blob2(StatusVector, @DBHandle, @TRHandle, @FHandle, @FBlobID,
247	0, nil))
248	else
249	with BPB as TBPB do
250	Call(isc_create_blob2(StatusVector, @DBHandle, @TRHandle, @FHandle, @FBlobID,
251	getDataLength, getBuffer));
252	end;
253
254	constructor TFB25Blob.Create(Attachment: TFB25Attachment;
255	Transaction: TFB25Transaction; MetaData: IBlobMetaData; BlobID: TISC_QUAD; BPB: IBPB);
256	var DBHandle: TISC_DB_HANDLE;
257	TRHandle: TISC_TR_HANDLE;
258	begin
259	inherited Create(Attachment,Transaction,MetaData,BlobID,BPB);
260	DBHandle := Attachment.Handle;
261	TRHandle := Transaction.Handle;
262	if (BlobID.gds_quad_high = 0) and (BlobID.gds_quad_low = 0) then
263	Exit;
264
265	with Firebird25ClientAPI do
266	if BPB = nil then
267	Call(isc_open_blob2(StatusVector, @DBHandle, @TRHandle, @FHandle,
268	@FBlobID, 0, nil))
269	else
270	with BPB as TBPB do
271	Call(isc_open_blob2(StatusVector, @DBHandle, @TRHandle, @FHandle,
272	@FBlobID, getDataLength, getBuffer));
273	end;
274
275	procedure TFB25Blob.GetInfo(var NumSegments: Int64; var MaxSegmentSize,
276	TotalSize: Int64; var BlobType: TBlobType);
277	var
278	items: array[0..3] of Char;
279	results: array[0..99] of Char;
280	i, item_length: Integer;
281	item: Integer;
282	begin
283	if FHandle = nil then
284	IBError(ibxeBlobNotOpen,[nil]);
285
286	items[0] := Char(isc_info_blob_num_segments);
287	items[1] := Char(isc_info_blob_max_segment);
288	items[2] := Char(isc_info_blob_total_length);
289	items[3] := Char(isc_info_blob_type);
290
291	with Firebird25ClientAPI do
292	begin
293	Call(isc_blob_info(StatusVector, @FHandle, 4, @items[0], SizeOf(results),
294	@results[0]));
295	i := 0;
296	while (i < SizeOf(results)) and (results[i] <> Char(isc_info_end)) do
297	begin
298	item := Integer(results[i]); Inc(i);
299	item_length := isc_portable_integer(@results[i], 2); Inc(i, 2);
300	case item of
301	isc_info_blob_num_segments:
302	NumSegments := isc_portable_integer(@results[i], item_length);
303	isc_info_blob_max_segment:
304	MaxSegmentSize := isc_portable_integer(@results[i], item_length);
305	isc_info_blob_total_length:
306	TotalSize := isc_portable_integer(@results[i], item_length);
307	isc_info_blob_type:
308	if isc_portable_integer(@results[i], item_length) = 0 then
309	BlobType := btSegmented
310	else
311	BlobType := btStream;
312	end;
313	Inc(i, item_length);
314	end;
315	end;
316	end;
317
318	function TFB25Blob.Read(var Buffer; Count: Longint): Longint;
319	var
320	BytesRead : UShort;
321	LocalBuffer: PChar;
322	returnCode: long;
323	localCount: uShort;
324	begin
325	CheckReadable;
326	Result := 0;
327	if FEOB then
328	Exit;
329
330	LocalBuffer := PChar(@Buffer);
331	repeat
332	if Count > MaxuShort then
333	localCount := MaxuShort
334	else
335	localCount := Count;
336	with Firebird25ClientAPI do
337	returnCode := isc_get_segment(StatusVector, @FHandle, @BytesRead, localCount,
338	LocalBuffer);
339	Inc(LocalBuffer,BytesRead);
340	Inc(Result,BytesRead);
341	Dec(Count,BytesRead);
342	until ((returncode <> 0) and (returnCode <> isc_segment)) or (Count = 0);
343
344	FEOB := returnCode = isc_segstr_eof;
345	ClearStringCache;
346	if (returnCode <> 0) and (returnCode <> isc_segment) and (returnCode <> isc_segstr_eof) then
347	Firebird25ClientAPI.IBDataBaseError
348	end;
349
350	function TFB25Blob.Write(const Buffer; Count: Longint): Longint;
351	var
352	LocalBuffer: PChar;
353	localCount: uShort;
354	begin
355	CheckWritable;
356	LocalBuffer := PChar(@Buffer);
357	Result := 0;
358	if Count = 0 then Exit;
359
360	repeat
361	if Count > MaxuShort then
362	localCount := MaxuShort
363	else
364	localCount := Count;
365	with Firebird25ClientAPI do
366	Call(isc_put_segment(StatusVector,@FHandle,localCount,LocalBuffer));
367	Dec(Count,localCount);
368	Inc(LocalBuffer,localCount);
369	Inc(Result,localCount);
370	until Count = 0;
371	ClearStringCache;
372	end;
373
374
375	end.
376