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Comparing ibx/trunk/runtime/IBBlob.pas (file contents):
Revision 32 by tony, Sat Dec 28 19:22:24 2013 UTC vs.
Revision 33 by tony, Sat Jul 18 12:30:52 2015 UTC

#	Line 1 | Line 1
1	<	{************************************************************************}
2	<	{                                                                        }
3	<	{       Borland Delphi Visual Component Library                          }
4	<	{       InterBase Express core components                                }
5	<	{                                                                        }
6	<	{       Copyright (c) 1998-2000 Inprise Corporation                      }
7	<	{                                                                        }
8	<	{    InterBase Express is based in part on the product                   }
9	<	{    Free IB Components, written by Gregory H. Deatz for                 }
10	<	{    Hoagland, Longo, Moran, Dunst & Doukas Company.                     }
11	<	{    Free IB Components is used under license.                           }
12	<	{                                                                        }
13	<	{    The contents of this file are subject to the InterBase              }
14	<	{    Public License Version 1.0 (the "License"); you may not             }
15	<	{    use this file except in compliance with the License. You            }
16	<	{    may obtain a copy of the License at http://www.Inprise.com/IPL.html }
17	<	{    Software distributed under the License is distributed on            }
18	<	{    an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either              }
19	<	{    express or implied. See the License for the specific language       }
20	<	{    governing rights and limitations under the License.                 }
21	<	{    The Original Code was created by InterBase Software Corporation     }
22	<	{       and its successors.                                              }
23	<	{    Portions created by Inprise Corporation are Copyright (C) Inprise   }
24	<	{       Corporation. All Rights Reserved.                                }
25	<	{    Contributor(s): Jeff Overcash                                       }
26	<	{                                                                        }
27	<	{    IBX For Lazarus (Firebird Express)                                  }
28	<	{    Contributor: Tony Whyman, MWA Software http://www.mwasoftware.co.uk }
29	<	{    Portions created by MWA Software are copyright McCallum Whyman      }
30	<	{    Associates Ltd 2011                                                 }
31	<	{************************************************************************}
32	<
33	<	unit IBBlob;
34	<
35	<	{$Mode Delphi}
36	<
37	<	interface
38	<
39	<	uses
40	<	SysUtils, Classes, IBHeader, IBErrorCodes, IBExternals, DB, IB, IBDatabase;
41	<
42	<
43	<	const
44	<	DefaultBlobSegmentSize = 16 * 1024;
45	<
46	<	type
47	<	{ TIBBlobStream }
48	<	TIBBlobStream = class(TStream)
49	<	private
50	<	FBase: TIBBase;
51	<	FBlobID: TISC_QUAD;
52	<	FBlobMaxSegmentSize: Int64;
53	<	FBlobNumSegments: Int64;
54	<	FBlobSize: Int64;
55	<	FBlobType: Short;  { 0 = segmented, 1 = streamed }
56	<	FBuffer: PChar;
57	<	FBlobInitialized: Boolean;
58	<	FHandle: TISC_BLOB_HANDLE;
59	<	FMode: TBlobStreamMode;
60	<	FModified: Boolean;
61	<	FPosition: Int64;
62	<	protected
63	<	procedure CloseBlob;
64	<	procedure CreateBlob;
65	<	procedure EnsureBlobInitialized;
66	<	procedure GetBlobInfo;
67	<	function GetDatabase: TIBDatabase;
68	<	function GetDBHandle: PISC_DB_HANDLE;
69	<	function GetTransaction: TIBTransaction;
70	<	function GetTRHandle: PISC_TR_HANDLE;
71	<	procedure OpenBlob;
72	<	procedure SetBlobID(Value: TISC_QUAD);
73	<	procedure SetDatabase(Value: TIBDatabase);
74	<	procedure SetMode(Value: TBlobStreamMode);
75	<	procedure SetTransaction(Value: TIBTransaction);
76	<	public
77	<	constructor Create;
78	<	destructor Destroy; override;
79	<	function Call(ErrCode: ISC_STATUS; RaiseError: Boolean): ISC_STATUS;
80	<	procedure CheckReadable;
81	<	procedure CheckWritable;
82	<	procedure Finalize;
83	<	procedure LoadFromFile(Filename: string);
84	<	procedure LoadFromStream(Stream: TStream);
85	<	function Read(var Buffer; Count: Longint): Longint; override;
86	<	procedure SaveToFile(Filename: string);
87	<	procedure SaveToStream(Stream: TStream);
88	<	function Seek(const Offset: Int64; Origin: TSeekOrigin): Int64; override;
89	<	procedure SetSize(const NewSize: Int64); override;
90	<	procedure SetSize(NewSize: Longint); override;
91	<	procedure Truncate;
92	<	function Write(const Buffer; Count: Longint): Longint; override;
93	<	property Handle: TISC_BLOB_HANDLE read FHandle;
94	<	property BlobID: TISC_QUAD read FBlobID write SetBlobID;
95	<	property BlobMaxSegmentSize: Int64 read FBlobMaxSegmentSize;
96	<	property BlobNumSegments: Int64 read FBlobNumSegments;
97	<	property BlobSize: Int64 read FBlobSize;
98	<	property BlobType: Short read FBlobType;
99	<	property Database: TIBDatabase read GetDatabase write SetDatabase;
100	<	property DBHandle: PISC_DB_HANDLE read GetDBHandle;
101	<	property Mode: TBlobStreamMode read FMode write SetMode;
102	<	property Modified: Boolean read FModified;
103	<	property Transaction: TIBTransaction read GetTransaction write SetTransaction;
104	<	property TRHandle: PISC_TR_HANDLE read GetTRHandle;
105	<	end;
106	<
107	<	procedure GetBlobInfo(hBlobHandle: PISC_BLOB_HANDLE; var NumSegments: Int64; var MaxSegmentSize,
108	<	TotalSize: Int64; var BlobType: Short);
109	<	procedure ReadBlob(hBlobHandle: PISC_BLOB_HANDLE; Buffer: PChar; BlobSize: Int64);
110	<	procedure WriteBlob(hBlobHandle: PISC_BLOB_HANDLE; Buffer: PChar; BlobSize: Int64);
111	<
112	<	implementation
113	<
114	<	uses IBIntf;
115	<
116	<	procedure GetBlobInfo(hBlobHandle: PISC_BLOB_HANDLE; var NumSegments: Int64; var MaxSegmentSize,
117	<	TotalSize: Int64; var BlobType: Short);
118	<	var
119	<	items: array[0..3] of Char;
120	<	results: array[0..99] of Char;
121	<	i, item_length: Integer;
122	<	item: Integer;
123	<	begin
124	<	items[0] := Char(isc_info_blob_num_segments);
125	<	items[1] := Char(isc_info_blob_max_segment);
126	<	items[2] := Char(isc_info_blob_total_length);
127	<	items[3] := Char(isc_info_blob_type);
128	<
129	<	if isc_blob_info(StatusVector, hBlobHandle, 4, @items[0], SizeOf(results),
130	<	@results[0]) > 0 then
131	<	IBDatabaseError;
132	<
133	<	i := 0;
134	<	while (i < SizeOf(results)) and (results[i] <> Char(isc_info_end)) do
135	<	begin
136	<	item := Integer(results[i]); Inc(i);
137	<	item_length := isc_vax_integer(@results[i], 2); Inc(i, 2);
138	<	case item of
139	<	isc_info_blob_num_segments:
140	<	NumSegments := isc_portable_integer(@results[i], item_length);
141	<	isc_info_blob_max_segment:
142	<	MaxSegmentSize := isc_portable_integer(@results[i], item_length);
143	<	isc_info_blob_total_length:
144	<	TotalSize := isc_portable_integer(@results[i], item_length);
145	<	isc_info_blob_type:
146	<	BlobType := isc_portable_integer(@results[i], item_length);
147	<	end;
148	<	Inc(i, item_length);
149	<	end;
150	<	end;
151	<
152	<	procedure ReadBlob(hBlobHandle: PISC_BLOB_HANDLE; Buffer: PChar; BlobSize: Int64);
153	<	var
154	<	CurPos: Int64;
155	<	BytesRead, SegLen: UShort;
156	<	LocalBuffer: PChar;
157	<	begin
158	<	CurPos := 0;
159	<	LocalBuffer := Buffer;
160	<	SegLen := UShort(DefaultBlobSegmentSize);
161	<	while (CurPos < BlobSize) do
162	<	begin
163	<	if (CurPos + SegLen > BlobSize) then
164	<	SegLen := BlobSize - CurPos;
165	<	if not ((isc_get_segment(StatusVector, hBlobHandle, @BytesRead, SegLen,
166	<	LocalBuffer) = 0) or
167	<	(StatusVectorArray[1] = isc_segment)) then
168	<	IBDatabaseError;
169	<	Inc(LocalBuffer, BytesRead);
170	<	Inc(CurPos, BytesRead);
171	<	BytesRead := 0;
172	<	end;
173	<	end;
174	<
175	<	procedure WriteBlob(hBlobHandle: PISC_BLOB_HANDLE; Buffer: PChar;
176	<	BlobSize: Int64);
177	<	var
178	<	CurPos: Int64;
179	<	SegLen: Long;
180	<	begin
181	<	CurPos := 0;
182	<	SegLen := DefaultBlobSegmentSize;
183	<	while (CurPos < BlobSize) do
184	<	begin
185	<	if (CurPos + SegLen > BlobSize) then
186	<	SegLen := BlobSize - CurPos;
187	<	if isc_put_segment(StatusVector, hBlobHandle, SegLen,
188	<	PChar(@Buffer[CurPos])) > 0 then
189	<	IBDatabaseError;
190	<	Inc(CurPos, SegLen);
191	<	end;
192	<	end;
193	<
194	<
195	<	{ TIBBlobStream }
196	<	constructor TIBBlobStream.Create;
197	<	begin
198	<	inherited Create;
199	<	FBase := TIBBase.Create(Self);
200	<	FBuffer := nil;
201	<	FBlobSize := 0;
202	<	end;
203	<
204	<	destructor TIBBlobStream.Destroy;
205	<	begin
206	<	if (FHandle <> nil) and
207	<	(Call(isc_close_blob(StatusVector, @FHandle), False) > 0) then
208	<	IBDataBaseError;
209	<	FBase.Free;
210	<	SetSize(0);
211	<	inherited Destroy;
212	<	end;
213	<
214	<	function TIBBlobStream.Call(ErrCode: ISC_STATUS; RaiseError: Boolean): ISC_STATUS;
215	<	begin
216	<	result := 0;
217	<	if Transaction <> nil then
218	<	result := Transaction.Call(ErrCode, RaiseError)
219	<	else if RaiseError and (ErrCode > 0) then
220	<	IBDataBaseError;
221	<	end;
222	<
223	<	procedure TIBBlobStream.CheckReadable;
224	<	begin
225	<	if FMode = bmWrite then IBError(ibxeBlobCannotBeRead, [nil]);
226	<	end;
227	<
228	<	procedure TIBBlobStream.CheckWritable;
229	<	begin
230	<	if FMode = bmRead then IBError(ibxeBlobCannotBeWritten, [nil]);
231	<	end;
232	<
233	<	procedure TIBBlobStream.CloseBlob;
234	<	begin
235	<	Finalize;
236	<	if (FHandle <> nil) and
237	<	(Call(isc_close_blob(StatusVector, @FHandle), False) > 0) then
238	<	IBDataBaseError;
239	<	end;
240	<
241	<	procedure TIBBlobStream.CreateBlob;
242	<	begin
243	<	CheckWritable;
244	<	FBlobID.gds_quad_high := 0;
245	<	FBlobID.gds_quad_low := 0;
246	<	Truncate;
247	<	end;
248	<
249	<	procedure TIBBlobStream.EnsureBlobInitialized;
250	<	begin
251	<	if not FBlobInitialized then
252	<	case FMode of
253	<	bmWrite:
254	<	CreateBlob;
255	<	bmReadWrite: begin
256	<	if (FBlobID.gds_quad_high = 0) and
257	<	(FBlobID.gds_quad_low = 0) then
258	<	CreateBlob
259	<	else
260	<	OpenBlob;
261	<	end;
262	<	else
263	<	OpenBlob;
264	<	end;
265	<	FBlobInitialized := True;
266	<	end;
267	<
268	<	procedure TIBBlobStream.Finalize;
269	<	begin
270	<	if (not FBlobInitialized) or (FMode = bmRead) or (not FModified) then
271	<	exit;
272	<	{ need to start writing to a blob, create one }
273	<	Call(isc_create_blob2(StatusVector, DBHandle, TRHandle, @FHandle, @FBlobID,
274	<	0, nil), True);
275	<	IBBlob.WriteBlob(@FHandle, FBuffer, FBlobSize);
276	<	Call(isc_close_blob(StatusVector, @FHandle), True);
277	<	FModified := False;
278	<	end;
279	<
280	<	procedure TIBBlobStream.GetBlobInfo;
281	<	var
282	<	iBlobSize: Int64;
283	<	begin
284	<	IBBlob.GetBlobInfo(@FHandle, FBlobNumSegments, FBlobMaxSegmentSize,
285	<	iBlobSize, FBlobType);
286	<	SetSize(iBlobSize);
287	<	end;
288	<
289	<	function TIBBlobStream.GetDatabase: TIBDatabase;
290	<	begin
291	<	result := FBase.Database;
292	<	end;
293	<
294	<	function TIBBlobStream.GetDBHandle: PISC_DB_HANDLE;
295	<	begin
296	<	result := FBase.DBHandle;
297	<	end;
298	<
299	<	function TIBBlobStream.GetTransaction: TIBTransaction;
300	<	begin
301	<	result := FBase.Transaction;
302	<	end;
303	<
304	<	function TIBBlobStream.GetTRHandle: PISC_TR_HANDLE;
305	<	begin
306	<	result := FBase.TRHandle;
307	<	end;
308	<
309	<	procedure TIBBlobStream.LoadFromFile(Filename: string);
310	<	var
311	<	Stream: TStream;
312	<	begin
313	<	Stream := TFileStream.Create(FileName, fmOpenRead);
314	<	try
315	<	LoadFromStream(Stream);
316	<	finally
317	<	Stream.Free;
318	<	end;
319	<	end;
320	<
321	<	procedure TIBBlobStream.LoadFromStream(Stream: TStream);
322	<	begin
323	<	CheckWritable;
324	<	EnsureBlobInitialized;
325	<	Stream.Position := 0;
326	<	SetSize(Stream.Size);
327	<	if FBlobSize <> 0 then
328	<	Stream.ReadBuffer(FBuffer^, FBlobSize);
329	<	FModified := True;
330	<	end;
331	<
332	<	procedure TIBBlobStream.OpenBlob;
333	<	begin
334	<	CheckReadable;
335	<	Call(isc_open_blob2(StatusVector, DBHandle, TRHandle, @FHandle,
336	<	@FBlobID, 0, nil), True);
337	<	try
338	<	GetBlobInfo;
339	<	SetSize(FBlobSize);
340	<	IBBlob.ReadBlob(@FHandle, FBuffer, FBlobSize);
341	<	except
342	<	Call(isc_close_blob(StatusVector, @FHandle), False);
343	<	raise;
344	<	end;
345	<	Call(isc_close_blob(StatusVector, @FHandle), True);
346	<	end;
347	<
348	<	function TIBBlobStream.Read(var Buffer; Count: Longint): Longint;
349	<	begin
350	<	CheckReadable;
351	<	EnsureBlobInitialized;
352	<	if (Count <= 0) then
353	<	begin
354	<	result := 0;
355	<	exit;
356	<	end;
357	<	if (FPosition + Count > FBlobSize) then
358	<	result := FBlobSize - FPosition
359	<	else
360	<	result := Count;
361	<	Move(FBuffer[FPosition], Buffer, result);
362	<	Inc(FPosition, Result);
363	<	end;
364	<
365	<	procedure TIBBlobStream.SaveToFile(Filename: string);
366	<	var
367	<	Stream: TStream;
368	<	begin
369	<	Stream := TFileStream.Create(FileName, fmCreate);
370	<	try
371	<	SaveToStream(Stream);
372	<	finally
373	<	Stream.Free;
374	<	end;
375	<	end;
376	<
377	<	procedure TIBBlobStream.SaveToStream(Stream: TStream);
378	<	begin
379	<	CheckReadable;
380	<	EnsureBlobInitialized;
381	<	if FBlobSize <> 0 then
382	<	begin
383	<	Seek(0, soFromBeginning);
384	<	Stream.WriteBuffer(FBuffer^, FBlobSize);
385	<	end;
386	<	end;
387	<
388	<	function TIBBlobStream.Seek(const Offset: Int64; Origin: TSeekOrigin): Int64;
389	<	begin
390	<	EnsureBlobInitialized;
391	<	case Origin of
392	<	soBeginning     : FPosition := Offset;
393	<	soCurrent       : Inc(FPosition, Offset);
394	<	soEnd           : FPosition := FBlobSize + Offset;
395	<	end;
396	<	result := FPosition;
397	<	end;
398	<
399	<	procedure TIBBlobStream.SetBlobID(Value: TISC_QUAD);
400	<	begin
401	<	System.Move(Value, FBlobID, SizeOf(TISC_QUAD));
402	<	FBlobInitialized := False;
403	<	end;
404	<
405	<	procedure TIBBlobStream.SetDatabase(Value: TIBDatabase);
406	<	begin
407	<	FBase.Database := Value;
408	<	FBlobInitialized := False;
409	<	end;
410	<
411	<	procedure TIBBlobStream.SetMode(Value: TBlobStreamMode);
412	<	begin
413	<	FMode := Value;
414	<	FBlobInitialized := False;
415	<	end;
416	<
417	<	procedure TIBBlobStream.SetSize(const NewSize: Int64);
418	<	begin
419	<	if (NewSize <> FBlobSize) then
420	<	begin
421	<	ReallocMem(FBuffer, NewSize);
422	<	FBlobSize := NewSize;
423	<	if NewSize = 0 then
424	<	FBuffer := nil;
425	<	end;
426	<	end;
427	<
428	<	procedure TIBBlobStream.SetSize(NewSize: Longint);
429	<	begin
430	<	SetSize(Int64(NewSize));
431	<	end;
432	<
433	<	procedure TIBBlobStream.SetTransaction(Value: TIBTransaction);
434	<	begin
435	<	FBase.Transaction := Value;
436	<	FBlobInitialized := False;
437	<	end;
438	<
439	<	procedure TIBBlobStream.Truncate;
440	<	begin
441	<	SetSize(0);
442	<	end;
443	<
444	<	function TIBBlobStream.Write(const Buffer; Count: Longint): Longint;
445	<	begin
446	<	CheckWritable;
447	<	EnsureBlobInitialized;
448	<	result := Count;
449	<	if Count <= 0 then
450	<	exit;
451	<	if (FPosition + Count > FBlobSize) then
452	<	SetSize(FPosition + Count);
453	<	Move(Buffer, FBuffer[FPosition], Count);
454	<	Inc(FPosition, Count);
455	<	FModified := True;
456	<	end;
457	<
458	<	end.
1	>	{************************************************************************}
2	>	{                                                                        }
3	>	{       Borland Delphi Visual Component Library                          }
4	>	{       InterBase Express core components                                }
5	>	{                                                                        }
6	>	{       Copyright (c) 1998-2000 Inprise Corporation                      }
7	>	{                                                                        }
8	>	{    InterBase Express is based in part on the product                   }
9	>	{    Free IB Components, written by Gregory H. Deatz for                 }
10	>	{    Hoagland, Longo, Moran, Dunst & Doukas Company.                     }
11	>	{    Free IB Components is used under license.                           }
12	>	{                                                                        }
13	>	{    The contents of this file are subject to the InterBase              }
14	>	{    Public License Version 1.0 (the "License"); you may not             }
15	>	{    use this file except in compliance with the License. You            }
16	>	{    may obtain a copy of the License at http://www.Inprise.com/IPL.html }
17	>	{    Software distributed under the License is distributed on            }
18	>	{    an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either              }
19	>	{    express or implied. See the License for the specific language       }
20	>	{    governing rights and limitations under the License.                 }
21	>	{    The Original Code was created by InterBase Software Corporation     }
22	>	{       and its successors.                                              }
23	>	{    Portions created by Inprise Corporation are Copyright (C) Inprise   }
24	>	{       Corporation. All Rights Reserved.                                }
25	>	{    Contributor(s): Jeff Overcash                                       }
26	>	{                                                                        }
27	>	{    IBX For Lazarus (Firebird Express)                                  }
28	>	{    Contributor: Tony Whyman, MWA Software http://www.mwasoftware.co.uk }
29	>	{    Portions created by MWA Software are copyright McCallum Whyman      }
30	>	{    Associates Ltd 2011                                                 }
31	>	{************************************************************************}
32	>
33	>	unit IBBlob;
34	>
35	>	{$Mode Delphi}
36	>
37	>	interface
38	>
39	>	uses
40	>	SysUtils, Classes, IBHeader, IBErrorCodes, IBExternals, DB, IB, IBDatabase;
41	>
42	>
43	>	const
44	>	DefaultBlobSegmentSize = 16 * 1024;
45	>
46	>	type
47	>	{ TIBBlobStream }
48	>	TIBBlobStream = class(TStream)
49	>	private
50	>	FBase: TIBBase;
51	>	FBlobID: TISC_QUAD;
52	>	FBlobMaxSegmentSize: Int64;
53	>	FBlobNumSegments: Int64;
54	>	FBlobSize: Int64;
55	>	FBlobType: Short;  { 0 = segmented, 1 = streamed }
56	>	FBuffer: PChar;
57	>	FBlobInitialized: Boolean;
58	>	FHandle: TISC_BLOB_HANDLE;
59	>	FMode: TBlobStreamMode;
60	>	FModified: Boolean;
61	>	FPosition: Int64;
62	>	protected
63	>	procedure CloseBlob;
64	>	procedure CreateBlob;
65	>	procedure EnsureBlobInitialized;
66	>	procedure GetBlobInfo;
67	>	function GetDatabase: TIBDatabase;
68	>	function GetDBHandle: PISC_DB_HANDLE;
69	>	function GetTransaction: TIBTransaction;
70	>	function GetTRHandle: PISC_TR_HANDLE;
71	>	procedure OpenBlob;
72	>	procedure SetBlobID(Value: TISC_QUAD);
73	>	procedure SetDatabase(Value: TIBDatabase);
74	>	procedure SetMode(Value: TBlobStreamMode);
75	>	procedure SetTransaction(Value: TIBTransaction);
76	>	public
77	>	constructor Create;
78	>	destructor Destroy; override;
79	>	function Call(ErrCode: ISC_STATUS; RaiseError: Boolean): ISC_STATUS;
80	>	procedure CheckReadable;
81	>	procedure CheckWritable;
82	>	procedure Finalize;
83	>	procedure LoadFromFile(Filename: string);
84	>	procedure LoadFromStream(Stream: TStream);
85	>	function Read(var Buffer; Count: Longint): Longint; override;
86	>	procedure SaveToFile(Filename: string);
87	>	procedure SaveToStream(Stream: TStream);
88	>	function Seek(const Offset: Int64; Origin: TSeekOrigin): Int64; override;
89	>	procedure SetSize(const NewSize: Int64); override;
90	>	procedure SetSize(NewSize: Longint); override;
91	>	procedure Truncate;
92	>	function Write(const Buffer; Count: Longint): Longint; override;
93	>	property Handle: TISC_BLOB_HANDLE read FHandle;
94	>	property BlobID: TISC_QUAD read FBlobID write SetBlobID;
95	>	property BlobMaxSegmentSize: Int64 read FBlobMaxSegmentSize;
96	>	property BlobNumSegments: Int64 read FBlobNumSegments;
97	>	property BlobSize: Int64 read FBlobSize;
98	>	property BlobType: Short read FBlobType;
99	>	property Database: TIBDatabase read GetDatabase write SetDatabase;
100	>	property DBHandle: PISC_DB_HANDLE read GetDBHandle;
101	>	property Mode: TBlobStreamMode read FMode write SetMode;
102	>	property Modified: Boolean read FModified;
103	>	property Transaction: TIBTransaction read GetTransaction write SetTransaction;
104	>	property TRHandle: PISC_TR_HANDLE read GetTRHandle;
105	>	end;
106	>
107	>	procedure GetBlobInfo(hBlobHandle: PISC_BLOB_HANDLE; var NumSegments: Int64; var MaxSegmentSize,
108	>	TotalSize: Int64; var BlobType: Short);
109	>	procedure ReadBlob(hBlobHandle: PISC_BLOB_HANDLE; Buffer: PChar; BlobSize: Int64);
110	>	procedure WriteBlob(hBlobHandle: PISC_BLOB_HANDLE; Buffer: PChar; BlobSize: Int64);
111	>
112	>	implementation
113	>
114	>	uses IBIntf;
115	>
116	>	procedure GetBlobInfo(hBlobHandle: PISC_BLOB_HANDLE; var NumSegments: Int64; var MaxSegmentSize,
117	>	TotalSize: Int64; var BlobType: Short);
118	>	var
119	>	items: array[0..3] of Char;
120	>	results: array[0..99] of Char;
121	>	i, item_length: Integer;
122	>	item: Integer;
123	>	begin
124	>	items[0] := Char(isc_info_blob_num_segments);
125	>	items[1] := Char(isc_info_blob_max_segment);
126	>	items[2] := Char(isc_info_blob_total_length);
127	>	items[3] := Char(isc_info_blob_type);
128	>
129	>	if isc_blob_info(StatusVector, hBlobHandle, 4, @items[0], SizeOf(results),
130	>	@results[0]) > 0 then
131	>	IBDatabaseError;
132	>
133	>	i := 0;
134	>	while (i < SizeOf(results)) and (results[i] <> Char(isc_info_end)) do
135	>	begin
136	>	item := Integer(results[i]); Inc(i);
137	>	item_length := isc_vax_integer(@results[i], 2); Inc(i, 2);
138	>	case item of
139	>	isc_info_blob_num_segments:
140	>	NumSegments := isc_portable_integer(@results[i], item_length);
141	>	isc_info_blob_max_segment:
142	>	MaxSegmentSize := isc_portable_integer(@results[i], item_length);
143	>	isc_info_blob_total_length:
144	>	TotalSize := isc_portable_integer(@results[i], item_length);
145	>	isc_info_blob_type:
146	>	BlobType := isc_portable_integer(@results[i], item_length);
147	>	end;
148	>	Inc(i, item_length);
149	>	end;
150	>	end;
151	>
152	>	procedure ReadBlob(hBlobHandle: PISC_BLOB_HANDLE; Buffer: PChar; BlobSize: Int64);
153	>	var
154	>	CurPos: Int64;
155	>	BytesRead, SegLen: UShort;
156	>	LocalBuffer: PChar;
157	>	begin
158	>	CurPos := 0;
159	>	LocalBuffer := Buffer;
160	>	SegLen := UShort(DefaultBlobSegmentSize);
161	>	while (CurPos < BlobSize) do
162	>	begin
163	>	if (CurPos + SegLen > BlobSize) then
164	>	SegLen := BlobSize - CurPos;
165	>	if not ((isc_get_segment(StatusVector, hBlobHandle, @BytesRead, SegLen,
166	>	LocalBuffer) = 0) or
167	>	(StatusVectorArray[1] = isc_segment)) then
168	>	IBDatabaseError;
169	>	Inc(LocalBuffer, BytesRead);
170	>	Inc(CurPos, BytesRead);
171	>	BytesRead := 0;
172	>	end;
173	>	end;
174	>
175	>	procedure WriteBlob(hBlobHandle: PISC_BLOB_HANDLE; Buffer: PChar;
176	>	BlobSize: Int64);
177	>	var
178	>	CurPos: Int64;
179	>	SegLen: Long;
180	>	begin
181	>	CurPos := 0;
182	>	SegLen := DefaultBlobSegmentSize;
183	>	while (CurPos < BlobSize) do
184	>	begin
185	>	if (CurPos + SegLen > BlobSize) then
186	>	SegLen := BlobSize - CurPos;
187	>	if isc_put_segment(StatusVector, hBlobHandle, SegLen,
188	>	PChar(@Buffer[CurPos])) > 0 then
189	>	IBDatabaseError;
190	>	Inc(CurPos, SegLen);
191	>	end;
192	>	end;
193	>
194	>
195	>	{ TIBBlobStream }
196	>	constructor TIBBlobStream.Create;
197	>	begin
198	>	inherited Create;
199	>	FBase := TIBBase.Create(Self);
200	>	FBuffer := nil;
201	>	FBlobSize := 0;
202	>	end;
203	>
204	>	destructor TIBBlobStream.Destroy;
205	>	begin
206	>	if (FHandle <> nil) and
207	>	(Call(isc_close_blob(StatusVector, @FHandle), False) > 0) then
208	>	IBDataBaseError;
209	>	FBase.Free;
210	>	SetSize(0);
211	>	inherited Destroy;
212	>	end;
213	>
214	>	function TIBBlobStream.Call(ErrCode: ISC_STATUS; RaiseError: Boolean): ISC_STATUS;
215	>	begin
216	>	result := 0;
217	>	if Transaction <> nil then
218	>	result := Transaction.Call(ErrCode, RaiseError)
219	>	else if RaiseError and (ErrCode > 0) then
220	>	IBDataBaseError;
221	>	end;
222	>
223	>	procedure TIBBlobStream.CheckReadable;
224	>	begin
225	>	if FMode = bmWrite then IBError(ibxeBlobCannotBeRead, [nil]);
226	>	end;
227	>
228	>	procedure TIBBlobStream.CheckWritable;
229	>	begin
230	>	if FMode = bmRead then IBError(ibxeBlobCannotBeWritten, [nil]);
231	>	end;
232	>
233	>	procedure TIBBlobStream.CloseBlob;
234	>	begin
235	>	Finalize;
236	>	if (FHandle <> nil) and
237	>	(Call(isc_close_blob(StatusVector, @FHandle), False) > 0) then
238	>	IBDataBaseError;
239	>	end;
240	>
241	>	procedure TIBBlobStream.CreateBlob;
242	>	begin
243	>	CheckWritable;
244	>	FBlobID.gds_quad_high := 0;
245	>	FBlobID.gds_quad_low := 0;
246	>	Truncate;
247	>	end;
248	>
249	>	procedure TIBBlobStream.EnsureBlobInitialized;
250	>	begin
251	>	if not FBlobInitialized then
252	>	case FMode of
253	>	bmWrite:
254	>	CreateBlob;
255	>	bmReadWrite: begin
256	>	if (FBlobID.gds_quad_high = 0) and
257	>	(FBlobID.gds_quad_low = 0) then
258	>	CreateBlob
259	>	else
260	>	OpenBlob;
261	>	end;
262	>	else
263	>	OpenBlob;
264	>	end;
265	>	FBlobInitialized := True;
266	>	end;
267	>
268	>	procedure TIBBlobStream.Finalize;
269	>	begin
270	>	if (not FBlobInitialized) or (FMode = bmRead) or (not FModified) then
271	>	exit;
272	>	{ need to start writing to a blob, create one }
273	>	Call(isc_create_blob2(StatusVector, DBHandle, TRHandle, @FHandle, @FBlobID,
274	>	0, nil), True);
275	>	IBBlob.WriteBlob(@FHandle, FBuffer, FBlobSize);
276	>	Call(isc_close_blob(StatusVector, @FHandle), True);
277	>	FModified := False;
278	>	end;
279	>
280	>	procedure TIBBlobStream.GetBlobInfo;
281	>	var
282	>	iBlobSize: Int64;
283	>	begin
284	>	IBBlob.GetBlobInfo(@FHandle, FBlobNumSegments, FBlobMaxSegmentSize,
285	>	iBlobSize, FBlobType);
286	>	SetSize(iBlobSize);
287	>	end;
288	>
289	>	function TIBBlobStream.GetDatabase: TIBDatabase;
290	>	begin
291	>	result := FBase.Database;
292	>	end;
293	>
294	>	function TIBBlobStream.GetDBHandle: PISC_DB_HANDLE;
295	>	begin
296	>	result := FBase.DBHandle;
297	>	end;
298	>
299	>	function TIBBlobStream.GetTransaction: TIBTransaction;
300	>	begin
301	>	result := FBase.Transaction;
302	>	end;
303	>
304	>	function TIBBlobStream.GetTRHandle: PISC_TR_HANDLE;
305	>	begin
306	>	result := FBase.TRHandle;
307	>	end;
308	>
309	>	procedure TIBBlobStream.LoadFromFile(Filename: string);
310	>	var
311	>	Stream: TStream;
312	>	begin
313	>	Stream := TFileStream.Create(FileName, fmOpenRead);
314	>	try
315	>	LoadFromStream(Stream);
316	>	finally
317	>	Stream.Free;
318	>	end;
319	>	end;
320	>
321	>	procedure TIBBlobStream.LoadFromStream(Stream: TStream);
322	>	begin
323	>	CheckWritable;
324	>	EnsureBlobInitialized;
325	>	Stream.Position := 0;
326	>	SetSize(Stream.Size);
327	>	if FBlobSize <> 0 then
328	>	Stream.ReadBuffer(FBuffer^, FBlobSize);
329	>	FModified := True;
330	>	end;
331	>
332	>	procedure TIBBlobStream.OpenBlob;
333	>	begin
334	>	CheckReadable;
335	>	Call(isc_open_blob2(StatusVector, DBHandle, TRHandle, @FHandle,
336	>	@FBlobID, 0, nil), True);
337	>	try
338	>	GetBlobInfo;
339	>	SetSize(FBlobSize);
340	>	IBBlob.ReadBlob(@FHandle, FBuffer, FBlobSize);
341	>	except
342	>	Call(isc_close_blob(StatusVector, @FHandle), False);
343	>	raise;
344	>	end;
345	>	Call(isc_close_blob(StatusVector, @FHandle), True);
346	>	end;
347	>
348	>	function TIBBlobStream.Read(var Buffer; Count: Longint): Longint;
349	>	begin
350	>	CheckReadable;
351	>	EnsureBlobInitialized;
352	>	if (Count <= 0) then
353	>	begin
354	>	result := 0;
355	>	exit;
356	>	end;
357	>	if (FPosition + Count > FBlobSize) then
358	>	result := FBlobSize - FPosition
359	>	else
360	>	result := Count;
361	>	Move(FBuffer[FPosition], Buffer, result);
362	>	Inc(FPosition, Result);
363	>	end;
364	>
365	>	procedure TIBBlobStream.SaveToFile(Filename: string);
366	>	var
367	>	Stream: TStream;
368	>	begin
369	>	Stream := TFileStream.Create(FileName, fmCreate);
370	>	try
371	>	SaveToStream(Stream);
372	>	finally
373	>	Stream.Free;
374	>	end;
375	>	end;
376	>
377	>	procedure TIBBlobStream.SaveToStream(Stream: TStream);
378	>	begin
379	>	CheckReadable;
380	>	EnsureBlobInitialized;
381	>	if FBlobSize <> 0 then
382	>	begin
383	>	Seek(0, soFromBeginning);
384	>	Stream.WriteBuffer(FBuffer^, FBlobSize);
385	>	end;
386	>	end;
387	>
388	>	function TIBBlobStream.Seek(const Offset: Int64; Origin: TSeekOrigin): Int64;
389	>	begin
390	>	EnsureBlobInitialized;
391	>	case Origin of
392	>	soBeginning     : FPosition := Offset;
393	>	soCurrent       : Inc(FPosition, Offset);
394	>	soEnd           : FPosition := FBlobSize + Offset;
395	>	end;
396	>	result := FPosition;
397	>	end;
398	>
399	>	procedure TIBBlobStream.SetBlobID(Value: TISC_QUAD);
400	>	begin
401	>	System.Move(Value, FBlobID, SizeOf(TISC_QUAD));
402	>	FBlobInitialized := False;
403	>	end;
404	>
405	>	procedure TIBBlobStream.SetDatabase(Value: TIBDatabase);
406	>	begin
407	>	FBase.Database := Value;
408	>	FBlobInitialized := False;
409	>	end;
410	>
411	>	procedure TIBBlobStream.SetMode(Value: TBlobStreamMode);
412	>	begin
413	>	FMode := Value;
414	>	FBlobInitialized := False;
415	>	end;
416	>
417	>	procedure TIBBlobStream.SetSize(const NewSize: Int64);
418	>	begin
419	>	if (NewSize <> FBlobSize) then
420	>	begin
421	>	ReallocMem(FBuffer, NewSize);
422	>	FBlobSize := NewSize;
423	>	if NewSize = 0 then
424	>	FBuffer := nil;
425	>	end;
426	>	end;
427	>
428	>	procedure TIBBlobStream.SetSize(NewSize: Longint);
429	>	begin
430	>	SetSize(Int64(NewSize));
431	>	end;
432	>
433	>	procedure TIBBlobStream.SetTransaction(Value: TIBTransaction);
434	>	begin
435	>	FBase.Transaction := Value;
436	>	FBlobInitialized := False;
437	>	end;
438	>
439	>	procedure TIBBlobStream.Truncate;
440	>	begin
441	>	SetSize(0);
442	>	end;
443	>
444	>	function TIBBlobStream.Write(const Buffer; Count: Longint): Longint;
445	>	begin
446	>	CheckWritable;
447	>	EnsureBlobInitialized;
448	>	result := Count;
449	>	if Count <= 0 then
450	>	exit;
451	>	if (FPosition + Count > FBlobSize) then
452	>	SetSize(FPosition + Count);
453	>	Move(Buffer, FBuffer[FPosition], Count);
454	>	Inc(FPosition, Count);
455	>	FModified := True;
456	>	end;
457	>
458	>	end.

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