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);
  function GetBlobCharSetID(hDB_Handle: TISC_DB_HANDLE; hTR_Handle: TISC_TR_HANDLE;
                      tableName, columnName: PChar): 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;

function GetBlobCharSetID(hDB_Handle: TISC_DB_HANDLE;
  hTR_Handle: TISC_TR_HANDLE; tableName, columnName: PChar): short;
var desc: TISC_BLOB_DESC;
    uGlobal: array [0..31] of char;
begin
  if isc_blob_lookup_desc(StatusVector,@hDB_Handle,@hTR_Handle,
                tableName,columnName,@desc,@uGlobal) > 0 then
    IBDatabaseError;

  Result := desc.blob_desc_charset;
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:	35
Committed:	Tue Jan 26 14:38:47 2016 UTC (8 years, 10 months ago) by tony
Content type:	text/x-pascal
File size:	13870 byte(s)
Log Message:	Committing updates for Release R1-3-2
#	User	Rev	Content
1	tony	33	{************************************************************************}
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	tony	35	function GetBlobCharSetID(hDB_Handle: TISC_DB_HANDLE; hTR_Handle: TISC_TR_HANDLE;
110			tableName, columnName: PChar): short;
111	tony	33	procedure ReadBlob(hBlobHandle: PISC_BLOB_HANDLE; Buffer: PChar; BlobSize: Int64);
112			procedure WriteBlob(hBlobHandle: PISC_BLOB_HANDLE; Buffer: PChar; BlobSize: Int64);
113
114			implementation
115
116			uses IBIntf;
117
118			procedure GetBlobInfo(hBlobHandle: PISC_BLOB_HANDLE; var NumSegments: Int64; var MaxSegmentSize,
119			TotalSize: Int64; var BlobType: Short);
120			var
121			items: array[0..3] of Char;
122			results: array[0..99] of Char;
123			i, item_length: Integer;
124			item: Integer;
125			begin
126			items[0] := Char(isc_info_blob_num_segments);
127			items[1] := Char(isc_info_blob_max_segment);
128			items[2] := Char(isc_info_blob_total_length);
129			items[3] := Char(isc_info_blob_type);
130
131			if isc_blob_info(StatusVector, hBlobHandle, 4, @items[0], SizeOf(results),
132			@results[0]) > 0 then
133			IBDatabaseError;
134
135			i := 0;
136			while (i < SizeOf(results)) and (results[i] <> Char(isc_info_end)) do
137			begin
138			item := Integer(results[i]); Inc(i);
139			item_length := isc_vax_integer(@results[i], 2); Inc(i, 2);
140			case item of
141			isc_info_blob_num_segments:
142			NumSegments := isc_portable_integer(@results[i], item_length);
143			isc_info_blob_max_segment:
144			MaxSegmentSize := isc_portable_integer(@results[i], item_length);
145			isc_info_blob_total_length:
146			TotalSize := isc_portable_integer(@results[i], item_length);
147			isc_info_blob_type:
148			BlobType := isc_portable_integer(@results[i], item_length);
149			end;
150			Inc(i, item_length);
151			end;
152			end;
153
154	tony	35	function GetBlobCharSetID(hDB_Handle: TISC_DB_HANDLE;
155			hTR_Handle: TISC_TR_HANDLE; tableName, columnName: PChar): short;
156			var desc: TISC_BLOB_DESC;
157			uGlobal: array [0..31] of char;
158			begin
159			if isc_blob_lookup_desc(StatusVector,@hDB_Handle,@hTR_Handle,
160			tableName,columnName,@desc,@uGlobal) > 0 then
161			IBDatabaseError;
162
163			Result := desc.blob_desc_charset;
164			end;
165
166	tony	33	procedure ReadBlob(hBlobHandle: PISC_BLOB_HANDLE; Buffer: PChar; BlobSize: Int64);
167			var
168			CurPos: Int64;
169			BytesRead, SegLen: UShort;
170			LocalBuffer: PChar;
171			begin
172			CurPos := 0;
173			LocalBuffer := Buffer;
174			SegLen := UShort(DefaultBlobSegmentSize);
175			while (CurPos < BlobSize) do
176			begin
177			if (CurPos + SegLen > BlobSize) then
178			SegLen := BlobSize - CurPos;
179			if not ((isc_get_segment(StatusVector, hBlobHandle, @BytesRead, SegLen,
180			LocalBuffer) = 0) or
181			(StatusVectorArray[1] = isc_segment)) then
182			IBDatabaseError;
183			Inc(LocalBuffer, BytesRead);
184			Inc(CurPos, BytesRead);
185			BytesRead := 0;
186			end;
187			end;
188
189			procedure WriteBlob(hBlobHandle: PISC_BLOB_HANDLE; Buffer: PChar;
190			BlobSize: Int64);
191			var
192			CurPos: Int64;
193			SegLen: Long;
194			begin
195			CurPos := 0;
196			SegLen := DefaultBlobSegmentSize;
197			while (CurPos < BlobSize) do
198			begin
199			if (CurPos + SegLen > BlobSize) then
200			SegLen := BlobSize - CurPos;
201			if isc_put_segment(StatusVector, hBlobHandle, SegLen,
202			PChar(@Buffer[CurPos])) > 0 then
203			IBDatabaseError;
204			Inc(CurPos, SegLen);
205			end;
206			end;
207
208
209			{ TIBBlobStream }
210			constructor TIBBlobStream.Create;
211			begin
212			inherited Create;
213			FBase := TIBBase.Create(Self);
214			FBuffer := nil;
215			FBlobSize := 0;
216			end;
217
218			destructor TIBBlobStream.Destroy;
219			begin
220			if (FHandle <> nil) and
221			(Call(isc_close_blob(StatusVector, @FHandle), False) > 0) then
222			IBDataBaseError;
223			FBase.Free;
224			SetSize(0);
225			inherited Destroy;
226			end;
227
228			function TIBBlobStream.Call(ErrCode: ISC_STATUS; RaiseError: Boolean): ISC_STATUS;
229			begin
230			result := 0;
231			if Transaction <> nil then
232			result := Transaction.Call(ErrCode, RaiseError)
233			else if RaiseError and (ErrCode > 0) then
234			IBDataBaseError;
235			end;
236
237			procedure TIBBlobStream.CheckReadable;
238			begin
239			if FMode = bmWrite then IBError(ibxeBlobCannotBeRead, [nil]);
240			end;
241
242			procedure TIBBlobStream.CheckWritable;
243			begin
244			if FMode = bmRead then IBError(ibxeBlobCannotBeWritten, [nil]);
245			end;
246
247			procedure TIBBlobStream.CloseBlob;
248			begin
249			Finalize;
250			if (FHandle <> nil) and
251			(Call(isc_close_blob(StatusVector, @FHandle), False) > 0) then
252			IBDataBaseError;
253			end;
254
255			procedure TIBBlobStream.CreateBlob;
256			begin
257			CheckWritable;
258			FBlobID.gds_quad_high := 0;
259			FBlobID.gds_quad_low := 0;
260			Truncate;
261			end;
262
263			procedure TIBBlobStream.EnsureBlobInitialized;
264			begin
265			if not FBlobInitialized then
266			case FMode of
267			bmWrite:
268			CreateBlob;
269			bmReadWrite: begin
270			if (FBlobID.gds_quad_high = 0) and
271			(FBlobID.gds_quad_low = 0) then
272			CreateBlob
273			else
274			OpenBlob;
275			end;
276			else
277			OpenBlob;
278			end;
279			FBlobInitialized := True;
280			end;
281
282			procedure TIBBlobStream.Finalize;
283			begin
284			if (not FBlobInitialized) or (FMode = bmRead) or (not FModified) then
285			exit;
286			{ need to start writing to a blob, create one }
287			Call(isc_create_blob2(StatusVector, DBHandle, TRHandle, @FHandle, @FBlobID,
288			0, nil), True);
289			IBBlob.WriteBlob(@FHandle, FBuffer, FBlobSize);
290			Call(isc_close_blob(StatusVector, @FHandle), True);
291			FModified := False;
292			end;
293
294			procedure TIBBlobStream.GetBlobInfo;
295			var
296			iBlobSize: Int64;
297			begin
298			IBBlob.GetBlobInfo(@FHandle, FBlobNumSegments, FBlobMaxSegmentSize,
299			iBlobSize, FBlobType);
300			SetSize(iBlobSize);
301			end;
302
303			function TIBBlobStream.GetDatabase: TIBDatabase;
304			begin
305			result := FBase.Database;
306			end;
307
308			function TIBBlobStream.GetDBHandle: PISC_DB_HANDLE;
309			begin
310			result := FBase.DBHandle;
311			end;
312
313			function TIBBlobStream.GetTransaction: TIBTransaction;
314			begin
315			result := FBase.Transaction;
316			end;
317
318			function TIBBlobStream.GetTRHandle: PISC_TR_HANDLE;
319			begin
320			result := FBase.TRHandle;
321			end;
322
323			procedure TIBBlobStream.LoadFromFile(Filename: string);
324			var
325			Stream: TStream;
326			begin
327			Stream := TFileStream.Create(FileName, fmOpenRead);
328			try
329			LoadFromStream(Stream);
330			finally
331			Stream.Free;
332			end;
333			end;
334
335			procedure TIBBlobStream.LoadFromStream(Stream: TStream);
336			begin
337			CheckWritable;
338			EnsureBlobInitialized;
339			Stream.Position := 0;
340			SetSize(Stream.Size);
341			if FBlobSize <> 0 then
342			Stream.ReadBuffer(FBuffer^, FBlobSize);
343			FModified := True;
344			end;
345
346			procedure TIBBlobStream.OpenBlob;
347			begin
348			CheckReadable;
349			Call(isc_open_blob2(StatusVector, DBHandle, TRHandle, @FHandle,
350			@FBlobID, 0, nil), True);
351			try
352			GetBlobInfo;
353			SetSize(FBlobSize);
354			IBBlob.ReadBlob(@FHandle, FBuffer, FBlobSize);
355			except
356			Call(isc_close_blob(StatusVector, @FHandle), False);
357			raise;
358			end;
359			Call(isc_close_blob(StatusVector, @FHandle), True);
360			end;
361
362			function TIBBlobStream.Read(var Buffer; Count: Longint): Longint;
363			begin
364			CheckReadable;
365			EnsureBlobInitialized;
366			if (Count <= 0) then
367			begin
368			result := 0;
369			exit;
370			end;
371			if (FPosition + Count > FBlobSize) then
372			result := FBlobSize - FPosition
373			else
374			result := Count;
375			Move(FBuffer[FPosition], Buffer, result);
376			Inc(FPosition, Result);
377			end;
378
379			procedure TIBBlobStream.SaveToFile(Filename: string);
380			var
381			Stream: TStream;
382			begin
383			Stream := TFileStream.Create(FileName, fmCreate);
384			try
385			SaveToStream(Stream);
386			finally
387			Stream.Free;
388			end;
389			end;
390
391			procedure TIBBlobStream.SaveToStream(Stream: TStream);
392			begin
393			CheckReadable;
394			EnsureBlobInitialized;
395			if FBlobSize <> 0 then
396			begin
397			Seek(0, soFromBeginning);
398			Stream.WriteBuffer(FBuffer^, FBlobSize);
399			end;
400			end;
401
402			function TIBBlobStream.Seek(const Offset: Int64; Origin: TSeekOrigin): Int64;
403			begin
404			EnsureBlobInitialized;
405			case Origin of
406			soBeginning : FPosition := Offset;
407			soCurrent : Inc(FPosition, Offset);
408			soEnd : FPosition := FBlobSize + Offset;
409			end;
410			result := FPosition;
411			end;
412
413			procedure TIBBlobStream.SetBlobID(Value: TISC_QUAD);
414			begin
415			System.Move(Value, FBlobID, SizeOf(TISC_QUAD));
416			FBlobInitialized := False;
417			end;
418
419			procedure TIBBlobStream.SetDatabase(Value: TIBDatabase);
420			begin
421			FBase.Database := Value;
422			FBlobInitialized := False;
423			end;
424
425			procedure TIBBlobStream.SetMode(Value: TBlobStreamMode);
426			begin
427			FMode := Value;
428			FBlobInitialized := False;
429			end;
430
431			procedure TIBBlobStream.SetSize(const NewSize: Int64);
432			begin
433			if (NewSize <> FBlobSize) then
434			begin
435			ReallocMem(FBuffer, NewSize);
436			FBlobSize := NewSize;
437			if NewSize = 0 then
438			FBuffer := nil;
439			end;
440			end;
441
442			procedure TIBBlobStream.SetSize(NewSize: Longint);
443			begin
444			SetSize(Int64(NewSize));
445			end;
446
447			procedure TIBBlobStream.SetTransaction(Value: TIBTransaction);
448			begin
449			FBase.Transaction := Value;
450			FBlobInitialized := False;
451			end;
452
453			procedure TIBBlobStream.Truncate;
454			begin
455			SetSize(0);
456			end;
457
458			function TIBBlobStream.Write(const Buffer; Count: Longint): Longint;
459			begin
460			CheckWritable;
461			EnsureBlobInitialized;
462			result := Count;
463			if Count <= 0 then
464			exit;
465			if (FPosition + Count > FBlobSize) then
466			SetSize(FPosition + Count);
467			Move(Buffer, FBuffer[FPosition], Count);
468			Inc(FPosition, Count);
469			FModified := True;
470			end;
471
472			end.