trunk/runtime/IBBlob.pas

{************************************************************************}
{                                                                        }
{       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                                                 }
{************************************************************************}

unit IBBlob;

{$Mode Delphi}

interface

uses
  SysUtils, Classes, IBHeader, IBErrorCodes, IBExternals, DB, IB, IBDatabase;


const
  DefaultBlobSegmentSize = 16 * 1024; 

type
  { TIBBlobStream }
  TIBBlobStream = class(TStream)
  private
    FBase: TIBBase;
    FBlobID: TISC_QUAD;
    FBlobMaxSegmentSize: Int64;
    FBlobNumSegments: Int64;
    FBlobSize: Int64;
    FBlobType: Short;  { 0 = segmented, 1 = streamed }
    FBuffer: PChar;
    FBlobInitialized: Boolean;
    FHandle: TISC_BLOB_HANDLE;
    FMode: TBlobStreamMode;
    FModified: Boolean;
    FPosition: Int64;
  protected
    procedure CloseBlob;
    procedure CreateBlob;
    procedure EnsureBlobInitialized;
    procedure GetBlobInfo;
    function GetDatabase: TIBDatabase;
    function GetDBHandle: PISC_DB_HANDLE;
    function GetTransaction: TIBTransaction;
    function GetTRHandle: PISC_TR_HANDLE;
    procedure OpenBlob;
    procedure SetBlobID(Value: TISC_QUAD);
    procedure SetDatabase(Value: TIBDatabase);
    procedure SetMode(Value: TBlobStreamMode);
    procedure SetTransaction(Value: TIBTransaction);
  public
    constructor Create;
    destructor Destroy; override;
    function Call(ErrCode: ISC_STATUS; RaiseError: Boolean): ISC_STATUS;
    procedure CheckReadable;
    procedure CheckWritable;
    procedure Finalize;
    procedure LoadFromFile(Filename: string);
    procedure LoadFromStream(Stream: TStream);
    function Read(var Buffer; Count: Longint): Longint; override;
    procedure SaveToFile(Filename: string);
    procedure SaveToStream(Stream: TStream);
    function Seek(const Offset: Int64; Origin: TSeekOrigin): Int64; override;
    procedure SetSize(const NewSize: Int64); override;
    procedure SetSize(NewSize: Longint); override;
    procedure Truncate;
    function Write(const Buffer; Count: Longint): Longint; override;
    property Handle: TISC_BLOB_HANDLE read FHandle;
    property BlobID: TISC_QUAD read FBlobID write SetBlobID;
    property BlobMaxSegmentSize: Int64 read FBlobMaxSegmentSize;
    property BlobNumSegments: Int64 read FBlobNumSegments;
    property BlobSize: Int64 read FBlobSize;
    property BlobType: Short read FBlobType;
    property Database: TIBDatabase read GetDatabase write SetDatabase;
    property DBHandle: PISC_DB_HANDLE read GetDBHandle;
    property Mode: TBlobStreamMode read FMode write SetMode;
    property Modified: Boolean read FModified;
    property Transaction: TIBTransaction read GetTransaction write SetTransaction;
    property TRHandle: PISC_TR_HANDLE read GetTRHandle;
  end;

  procedure GetBlobInfo(hBlobHandle: PISC_BLOB_HANDLE; var NumSegments: Int64; var MaxSegmentSize,
                      TotalSize: Int64; var BlobType: Short);
  procedure ReadBlob(hBlobHandle: PISC_BLOB_HANDLE; Buffer: PChar; BlobSize: Int64);
  procedure WriteBlob(hBlobHandle: PISC_BLOB_HANDLE; Buffer: PChar; BlobSize: Int64);

implementation

uses IBIntf;

procedure GetBlobInfo(hBlobHandle: PISC_BLOB_HANDLE; var NumSegments: Int64; var MaxSegmentSize,
                      TotalSize: Int64; var BlobType: Short);
var
  items: array[0..3] of Char;
  results: array[0..99] of Char;
  i, item_length: Integer;
  item: Integer;
begin
  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);

  if isc_blob_info(StatusVector, hBlobHandle, 4, @items[0], SizeOf(results),
                    @results[0]) > 0 then
    IBDatabaseError;

  i := 0;
  while (i < SizeOf(results)) and (results[i] <> Char(isc_info_end)) do
  begin
    item := Integer(results[i]); Inc(i);
    item_length := isc_vax_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:
        BlobType := isc_portable_integer(@results[i], item_length);
    end;
    Inc(i, item_length);
  end;
end;

procedure ReadBlob(hBlobHandle: PISC_BLOB_HANDLE; Buffer: PChar; BlobSize: Int64);
var
  CurPos: Int64;
  BytesRead, SegLen: UShort;
  LocalBuffer: PChar;
begin
  CurPos := 0;
  LocalBuffer := Buffer;
  SegLen := UShort(DefaultBlobSegmentSize);
  while (CurPos < BlobSize) do
  begin
    if (CurPos + SegLen > BlobSize) then
      SegLen := BlobSize - CurPos;
    if not ((isc_get_segment(StatusVector, hBlobHandle, @BytesRead, SegLen,
                             LocalBuffer) = 0) or
            (StatusVectorArray[1] = isc_segment)) then
      IBDatabaseError;
    Inc(LocalBuffer, BytesRead);
    Inc(CurPos, BytesRead);
    BytesRead := 0;
  end;
end;

procedure WriteBlob(hBlobHandle: PISC_BLOB_HANDLE; Buffer: PChar;
  BlobSize: Int64);
var
  CurPos: Int64;
  SegLen: Long;
begin
  CurPos := 0;
  SegLen := DefaultBlobSegmentSize;
  while (CurPos < BlobSize) do
  begin
    if (CurPos + SegLen > BlobSize) then
      SegLen := BlobSize - CurPos;
    if isc_put_segment(StatusVector, hBlobHandle, SegLen,
         PChar(@Buffer[CurPos])) > 0 then
      IBDatabaseError;
    Inc(CurPos, SegLen);
  end;
end;


{ TIBBlobStream }
constructor TIBBlobStream.Create;
begin
  inherited Create;
  FBase := TIBBase.Create(Self);
  FBuffer := nil;
  FBlobSize := 0;
end;

destructor TIBBlobStream.Destroy;
begin
  if (FHandle <> nil) and
     (Call(isc_close_blob(StatusVector, @FHandle), False) > 0) then
    IBDataBaseError;
  FBase.Free;
  SetSize(0);
  inherited Destroy;
end;

function TIBBlobStream.Call(ErrCode: ISC_STATUS; RaiseError: Boolean): ISC_STATUS;
begin
  result := 0;
  if Transaction <> nil then
    result := Transaction.Call(ErrCode, RaiseError)
  else if RaiseError and (ErrCode > 0) then
    IBDataBaseError;
end;

procedure TIBBlobStream.CheckReadable;
begin
  if FMode = bmWrite then IBError(ibxeBlobCannotBeRead, [nil]);
end;

procedure TIBBlobStream.CheckWritable;
begin
  if FMode = bmRead then IBError(ibxeBlobCannotBeWritten, [nil]);
end;

procedure TIBBlobStream.CloseBlob;
begin
  Finalize;
  if (FHandle <> nil) and
     (Call(isc_close_blob(StatusVector, @FHandle), False) > 0) then
    IBDataBaseError;
end;

procedure TIBBlobStream.CreateBlob;
begin
  CheckWritable;
  FBlobID.gds_quad_high := 0;
  FBlobID.gds_quad_low := 0;
  Truncate;
end;

procedure TIBBlobStream.EnsureBlobInitialized;
begin
  if not FBlobInitialized then
    case FMode of
      bmWrite:
        CreateBlob;
      bmReadWrite: begin
        if (FBlobID.gds_quad_high = 0) and
           (FBlobID.gds_quad_low = 0) then
          CreateBlob
        else
          OpenBlob;
      end;
      else
        OpenBlob;
    end;
  FBlobInitialized := True;
end;

procedure TIBBlobStream.Finalize;
begin
  if (not FBlobInitialized) or (FMode = bmRead) or (not FModified) then
    exit;
  { need to start writing to a blob, create one }
  Call(isc_create_blob2(StatusVector, DBHandle, TRHandle, @FHandle, @FBlobID,
                       0, nil), True);
  IBBlob.WriteBlob(@FHandle, FBuffer, FBlobSize);
  Call(isc_close_blob(StatusVector, @FHandle), True);
  FModified := False;
end;

procedure TIBBlobStream.GetBlobInfo;
var
  iBlobSize: Int64;
begin
  IBBlob.GetBlobInfo(@FHandle, FBlobNumSegments, FBlobMaxSegmentSize,
    iBlobSize, FBlobType);
  SetSize(iBlobSize);
end;

function TIBBlobStream.GetDatabase: TIBDatabase;
begin
  result := FBase.Database;
end;

function TIBBlobStream.GetDBHandle: PISC_DB_HANDLE;
begin
  result := FBase.DBHandle;
end;

function TIBBlobStream.GetTransaction: TIBTransaction;
begin
  result := FBase.Transaction;
end;

function TIBBlobStream.GetTRHandle: PISC_TR_HANDLE;
begin
  result := FBase.TRHandle;
end;

procedure TIBBlobStream.LoadFromFile(Filename: string);
var
  Stream: TStream;
begin
  Stream := TFileStream.Create(FileName, fmOpenRead);
  try
    LoadFromStream(Stream);
  finally
    Stream.Free;
  end;
end;

procedure TIBBlobStream.LoadFromStream(Stream: TStream);
begin
  CheckWritable;
  EnsureBlobInitialized;
  Stream.Position := 0;
  SetSize(Stream.Size);
  if FBlobSize <> 0 then
    Stream.ReadBuffer(FBuffer^, FBlobSize);
  FModified := True;
end;

procedure TIBBlobStream.OpenBlob;
begin
  CheckReadable;
  Call(isc_open_blob2(StatusVector, DBHandle, TRHandle, @FHandle,
                     @FBlobID, 0, nil), True);
  try
    GetBlobInfo;
    SetSize(FBlobSize);
    IBBlob.ReadBlob(@FHandle, FBuffer, FBlobSize);
  except
    Call(isc_close_blob(StatusVector, @FHandle), False);
    raise;
  end;
  Call(isc_close_blob(StatusVector, @FHandle), True);
end;

function TIBBlobStream.Read(var Buffer; Count: Longint): Longint;
begin
  CheckReadable;
  EnsureBlobInitialized;
  if (Count <= 0) then
  begin
    result := 0;
    exit;
  end;
  if (FPosition + Count > FBlobSize) then
    result := FBlobSize - FPosition
  else
    result := Count;
  Move(FBuffer[FPosition], Buffer, result);
  Inc(FPosition, Result);
end;

procedure TIBBlobStream.SaveToFile(Filename: string);
var
  Stream: TStream;
begin
  Stream := TFileStream.Create(FileName, fmCreate);
  try
    SaveToStream(Stream);
  finally
    Stream.Free;
  end;
end;

procedure TIBBlobStream.SaveToStream(Stream: TStream);
begin
  CheckReadable;
  EnsureBlobInitialized;
  if FBlobSize <> 0 then
  begin
    Seek(0, soFromBeginning);
    Stream.WriteBuffer(FBuffer^, FBlobSize);
  end;
end;

function TIBBlobStream.Seek(const Offset: Int64; Origin: TSeekOrigin): Int64;
begin
  EnsureBlobInitialized;
  case Origin of
    soBeginning     : FPosition := Offset;
    soCurrent       : Inc(FPosition, Offset);
    soEnd           : FPosition := FBlobSize + Offset;
  end;
  result := FPosition;
end;

procedure TIBBlobStream.SetBlobID(Value: TISC_QUAD);
begin
  System.Move(Value, FBlobID, SizeOf(TISC_QUAD));
  FBlobInitialized := False;
end;

procedure TIBBlobStream.SetDatabase(Value: TIBDatabase);
begin
  FBase.Database := Value;
  FBlobInitialized := False;
end;

procedure TIBBlobStream.SetMode(Value: TBlobStreamMode);
begin
  FMode := Value;
  FBlobInitialized := False;
end;

procedure TIBBlobStream.SetSize(const NewSize: Int64);
begin
  if (NewSize <> FBlobSize) then
  begin
    ReallocMem(FBuffer, NewSize);
    FBlobSize := NewSize;
    if NewSize = 0 then
      FBuffer := nil;
  end;
end;

procedure TIBBlobStream.SetSize(NewSize: Longint);
begin
  SetSize(Int64(NewSize));
end;

procedure TIBBlobStream.SetTransaction(Value: TIBTransaction);
begin
  FBase.Transaction := Value;
  FBlobInitialized := False;
end;

procedure TIBBlobStream.Truncate;
begin
  SetSize(0);
end;

function TIBBlobStream.Write(const Buffer; Count: Longint): Longint;
begin
  CheckWritable;
  EnsureBlobInitialized;
  result := Count;
  if Count <= 0 then
    exit;
  if (FPosition + Count > FBlobSize) then
    SetSize(FPosition + Count);
  Move(Buffer, FBuffer[FPosition], Count);
  Inc(FPosition, Count);
  FModified := True;
end;

end.
Revision:	17
Committed:	Sat Dec 28 19:22:24 2013 UTC (10 years, 11 months ago) by tony
Content type:	text/x-pascal
File size:	13804 byte(s)
Log Message:	Committing updates for Release R1-0-5
#	User	Rev	Content
1	tony	17	{************************************************************************}
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.