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, 2 months ago) by tony
Content type:	text/x-pascal
File size:	13870 byte(s)
Log Message:	Committing updates for Release R1-3-2
#	Content
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	function GetBlobCharSetID(hDB_Handle: TISC_DB_HANDLE; hTR_Handle: TISC_TR_HANDLE;
110	tableName, columnName: PChar): short;
111	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	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	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.