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root/public/ibx/trunk/fbintf/client/FBBlob.pas
Revision: 60
Committed: Mon Mar 27 15:21:02 2017 UTC (7 years, 1 month ago) by tony
Content type: text/x-pascal
File size: 11440 byte(s)
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File Contents

# User Rev Content
1 tony 45 (*
2     * Firebird Interface (fbintf). The fbintf components provide a set of
3     * Pascal language bindings for the Firebird API. Although predominantly
4     * a new development they include source code taken from IBX and may be
5     * considered a derived product. This software thus also includes the copyright
6     * notice and license conditions from IBX.
7     *
8     * Except for those parts dervied from IBX, contents of this file are subject
9     * to the Initial Developer's Public License Version 1.0 (the "License"); you
10     * may not use this file except in compliance with the License. You may obtain a
11     * copy of the License here:
12     *
13     * http://www.firebirdsql.org/index.php?op=doc&id=idpl
14     *
15     * Software distributed under the License is distributed on an "AS
16     * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
17     * implied. See the License for the specific language governing rights
18     * and limitations under the License.
19     *
20     * The Initial Developer of the Original Code is Tony Whyman.
21     *
22     * The Original Code is (C) 2016 Tony Whyman, MWA Software
23     * (http://www.mwasoftware.co.uk).
24     *
25     * All Rights Reserved.
26     *
27     * Contributor(s): ______________________________________.
28     *
29     *)
30     unit FBBlob;
31 tony 56 {$IFDEF MSWINDOWS}
32     {$DEFINE WINDOWS}
33     {$ENDIF}
34 tony 45
35     {$IFDEF FPC}
36 tony 56 {$mode delphi}
37 tony 45 {$interfaces COM}
38     {$ENDIF}
39    
40     interface
41    
42     uses
43 tony 56 Classes, SysUtils, IB, FBActivityMonitor, FBTransaction, FBClientAPI,
44     FBOutputBlock;
45 tony 45
46     type
47    
48     { TFBBlobMetaData }
49    
50     TFBBlobMetaData = class(TActivityReporter)
51     private
52 tony 56 FRelationName: AnsiString;
53     FColumnName: AnsiString;
54 tony 45 protected
55     FUnconfirmedCharacterSet: boolean;
56     FHasSubType: boolean;
57     FSubType: integer;
58     FCharSetID: cardinal;
59     FSegmentSize: cardinal;
60 tony 60 function Attachment: IAttachment; virtual; abstract;
61 tony 45 procedure NeedFullMetadata; virtual; abstract;
62     procedure NeedSubType;
63     public
64 tony 56 constructor Create(Transaction: TFBTransaction; RelationName, ColumnName: AnsiString
65 tony 45 );
66 tony 47 procedure SetCharSetID(aValue: integer);
67 tony 45
68     public
69     {IBlobMetaData}
70     function GetSubType: integer;
71     function GetCharSetID: cardinal;
72     function GetCodePage: TSystemCodePage;
73     function GetSegmentSize: cardinal;
74 tony 56 function GetRelationName: AnsiString;
75     function GetColumnName: AnsiString;
76 tony 45 function GetUnconfirmedCharacterSet: boolean;
77     end;
78    
79     TFBBlob = class(TActivityReporter)
80     private
81     FMetaData: IBlobMetaData;
82     FAttachment: IAttachment;
83     FTransaction: ITransaction;
84     FBPB: IBPB;
85     FStringData: rawbytestring;
86     FStringCached: boolean;
87     protected
88     FCreating: boolean;
89     FBlobID: TISC_QUAD;
90     procedure CheckReadable; virtual; abstract;
91     procedure CheckWritable; virtual; abstract;
92     procedure ClearStringCache;
93     function GetIntf: IBlob; virtual; abstract;
94 tony 56 procedure GetInfo(Request: array of byte; Response: IBlobInfo); overload; virtual; abstract;
95 tony 45 procedure InternalClose(Force: boolean); virtual; abstract;
96     procedure InternalCancel(Force: boolean); virtual; abstract;
97     public
98     constructor Create(Attachment: IAttachment; Transaction: TFBTransaction;
99     MetaData: IBlobMetaData; BPB: IBPB); overload;
100     constructor Create(Attachment: IAttachment; Transaction: TFBTransaction;
101     MetaData: IBlobMetaData; BlobID: TISC_QUAD; BPB: IBPB); overload;
102     destructor Destroy; override;
103     procedure TransactionEnding(aTransaction: TFBTransaction; Force: boolean);
104    
105     public
106     {IBlobMetaData}
107     function GetSubType: integer;
108     function GetCharSetID: cardinal;
109     function GetCodePage: TSystemCodePage;
110     function GetSegmentSize: cardinal;
111 tony 56 function GetRelationName: AnsiString;
112     function GetColumnName: AnsiString;
113 tony 45 function GetUnconfirmedCharacterSet: boolean;
114    
115     {IBlob}
116     function GetBPB: IBPB;
117     procedure Cancel;
118     procedure Close;
119     function GetBlobSize: Int64;
120     procedure GetInfo(var NumSegments: Int64; var MaxSegmentSize, TotalSize: Int64;
121 tony 56 var BlobType: TBlobType); overload;
122 tony 45 function GetBlobID: TISC_QUAD;
123     function GetBlobMode: TFBBlobMode;
124     function Read(var Buffer; Count: Longint): Longint; virtual; abstract;
125     function Write(const Buffer; Count: Longint): Longint; virtual; abstract;
126 tony 56 function LoadFromFile(Filename: AnsiString): IBlob;
127 tony 45 function LoadFromStream(S: TStream) : IBlob;
128 tony 56 function SaveToFile(Filename: AnsiString): IBlob;
129 tony 45 function SaveToStream(S: TStream): IBlob;
130     function GetAttachment: IAttachment;
131     function GetTransaction: ITransaction;
132     function GetAsString: rawbytestring;
133     procedure SetAsString(aValue: rawbytestring);
134     function SetString(aValue: rawbytestring): IBlob;
135     end;
136    
137    
138    
139     implementation
140    
141     uses FBMessages;
142    
143     { TFBBlob }
144    
145     procedure TFBBlob.ClearStringCache;
146     begin
147     FStringData := '';
148     FStringCached := false;
149     end;
150    
151     constructor TFBBlob.Create(Attachment: IAttachment;
152     Transaction: TFBTransaction; MetaData: IBlobMetaData; BPB: IBPB);
153     begin
154     inherited Create(Transaction);
155     FAttachment := Attachment;
156     FTransaction := Transaction;
157     FMetaData := MetaData;
158     FBPB := BPB;
159     FCreating := true;
160     end;
161    
162     constructor TFBBlob.Create(Attachment: IAttachment;
163     Transaction: TFBTransaction; MetaData: IBlobMetaData; BlobID: TISC_QUAD; BPB: IBPB);
164     begin
165     Create(Attachment,Transaction,MetaData,BPB);
166     FBlobID := BlobID;
167     FCreating := false;
168     end;
169    
170     destructor TFBBlob.Destroy;
171     begin
172     if FCreating then
173     Cancel
174     else
175     Close;
176     inherited Destroy;
177     end;
178    
179     procedure TFBBlob.TransactionEnding(aTransaction: TFBTransaction;
180     Force: boolean);
181     begin
182 tony 56 if aTransaction <> (FTransaction as TFBTransaction) then
183 tony 45 Exit;
184     if FCreating then
185     InternalCancel(Force)
186     else
187     InternalClose(Force);
188     end;
189    
190     function TFBBlob.GetSubType: integer;
191     begin
192     Result := FMetaData.GetSubType;
193     end;
194    
195     function TFBBlob.GetCharSetID: cardinal;
196     begin
197     Result := FMetaData.GetCharSetID;
198     end;
199    
200     function TFBBlob.GetCodePage: TSystemCodePage;
201     begin
202     Result := FMetaData.GetCodePage;
203     end;
204    
205     function TFBBlob.GetSegmentSize: cardinal;
206     begin
207     Result := FMetaData.GetSegmentSize;
208     end;
209    
210 tony 56 function TFBBlob.GetRelationName: AnsiString;
211 tony 45 begin
212     Result := FMetaData.GetRelationName;
213     end;
214    
215 tony 56 function TFBBlob.GetColumnName: AnsiString;
216 tony 45 begin
217     Result := FMetaData.GetColumnName;
218     end;
219    
220     function TFBBlob.GetUnconfirmedCharacterSet: boolean;
221     begin
222     Result := (FMetadata as TFBBlobMetadata).GetUnconfirmedCharacterSet;
223     end;
224    
225     function TFBBlob.GetBPB: IBPB;
226     begin
227     Result := FBPB;
228     end;
229    
230     procedure TFBBlob.Cancel;
231     begin
232     InternalCancel(false);
233     end;
234    
235     procedure TFBBlob.Close;
236     begin
237     InternalClose(false);
238     end;
239    
240     function TFBBlob.GetBlobSize: Int64;
241     var NumSegments: Int64;
242     MaxSegmentSize: Int64;
243     BlobType: TBlobType;
244     begin
245     GetInfo(NumSegments,MaxSegmentSize,Result,BlobType);
246     end;
247    
248 tony 56 procedure TFBBlob.GetInfo(var NumSegments: Int64; var MaxSegmentSize,
249     TotalSize: Int64; var BlobType: TBlobType);
250     var BlobInfo: IBlobInfo;
251     i: integer;
252     begin
253     NumSegments := 0;
254     MaxSegmentSize := 0;
255     TotalSize := 0;
256     BlobType := btSegmented;
257    
258     BlobInfo := TBlobInfo.Create;
259     GetInfo([isc_info_blob_num_segments,
260     isc_info_blob_max_segment,
261     isc_info_blob_total_length,
262     isc_info_blob_type],BlobInfo);
263    
264     for i := 0 to BlobInfo.Count - 1 do
265     with BlobInfo[i] do
266     case getItemType of
267     isc_info_blob_num_segments:
268     NumSegments := GetAsInteger;
269     isc_info_blob_max_segment:
270     MaxSegmentSize := GetAsInteger;
271     isc_info_blob_total_length:
272     TotalSize := GetAsInteger;
273     isc_info_blob_type:
274     if GetAsInteger = 0 then
275     BlobType := btSegmented
276     else
277     BlobType := btStream;
278     end;
279     end;
280    
281 tony 45 function TFBBlob.GetBlobID: TISC_QUAD;
282     begin
283     Result := FBlobID;
284     end;
285    
286     function TFBBlob.GetBlobMode: TFBBlobMode;
287     begin
288     if FCreating then
289     Result := fbmWrite
290     else
291     Result := fbmRead;
292     end;
293    
294 tony 56 function TFBBlob.LoadFromFile(Filename: AnsiString): IBlob;
295 tony 45 var
296     Stream: TStream;
297     begin
298     Stream := TFileStream.Create(FileName, fmOpenRead);
299     try
300     Result := LoadFromStream(Stream);
301     finally
302     Stream.Free;
303     end;
304     end;
305    
306     const BufSize = 8 * 1024;
307    
308     function TFBBlob.LoadFromStream(S: TStream): IBlob;
309     var Buffer: array [0..BufSize-1] of char;
310     BytesRead: integer;
311     begin
312     CheckWritable;
313     S.Position := 0;
314     repeat
315     BytesRead := S.Read(Buffer,BufSize);
316     Write(Buffer,BytesRead);
317     until BytesRead = 0;
318     Close;
319     Result := GetIntf;
320     end;
321    
322 tony 56 function TFBBlob.SaveToFile(Filename: AnsiString): IBlob;
323 tony 45 var
324     Stream: TStream;
325     begin
326     Stream := TFileStream.Create(FileName, fmCreate);
327     try
328     Result := SaveToStream(Stream);
329     finally
330     Stream.Free;
331     end;
332     end;
333    
334     function TFBBlob.SaveToStream(S: TStream): IBlob;
335     var Buffer: array [0..BufSize-1] of char;
336     BytesRead: integer;
337     begin
338     CheckReadable;
339     repeat
340     BytesRead := Read(Buffer,BufSize);
341     S.Write(Buffer,BytesRead);
342     until BytesRead = 0;
343     Close;
344     Result := GetIntf;
345     end;
346    
347     function TFBBlob.GetAttachment: IAttachment;
348     begin
349     Result := FAttachment;
350     end;
351    
352     function TFBBlob.GetTransaction: ITransaction;
353     begin
354     Result := FTransaction;
355     end;
356    
357     function TFBBlob.GetAsString: rawbytestring;
358     var ss: TStringStream;
359     begin
360     if FStringCached then
361     begin
362     Result := FStringData;
363     Exit;
364     end;
365    
366     ss := TStringStream.Create('');
367     try
368     SaveToStream(ss);
369     Result := ss.DataString;
370     if (GetSubType = 1) and (FBPB = nil) then
371     SetCodePage(Result,GetCodePage,false);
372     finally
373     ss.Free;
374     end;
375     FStringData := Result;
376     FStringCached := true;
377     end;
378    
379     procedure TFBBlob.SetAsString(aValue: rawbytestring);
380     var
381     ss: TStringStream;
382     begin
383     {if GetUnconfirmedCharacterSet then
384     IBError(ibxeNoDefaultCharacterSet,[nil]);}
385    
386     if (GetSubType = 1) and (StringCodePage(aValue) <> GetCodePage) and
387     (GetCodePage <> CP_NONE) and (FBPB = nil) then
388     SetCodePage(aValue,GetCodePage,true);
389     ss := TStringStream.Create(aValue);
390     try
391     LoadFromStream(ss);
392     finally
393     ss.Free;
394     end;
395     FStringData := aValue;
396     FStringCached := true;
397     end;
398    
399     function TFBBlob.SetString(aValue: rawbytestring): IBlob;
400     begin
401     SetAsString(aValue);
402     Result := GetIntf;
403     end;
404    
405     {TFBBlobMetaData}
406    
407     procedure TFBBlobMetaData.NeedSubType;
408     begin
409     if not FHasSubType then
410     begin
411     NeedFullMetadata;
412     FHasSubType := true;
413     end;
414     end;
415    
416     constructor TFBBlobMetaData.Create(Transaction: TFBTransaction; RelationName,
417 tony 56 ColumnName: AnsiString);
418 tony 45 begin
419     inherited Create(Transaction);
420     // if (RelationName = '') or (ColumnName = '') then
421     // IBError(ibxeMissingColumnName,[]);
422     FRelationName := RelationName;
423     FColumnName := ColumnName;
424     FSegmentSize := 80;
425 tony 47 FUnconfirmedCharacterSet := true;
426     FCharSetID := 0;
427 tony 45 end;
428    
429 tony 47 procedure TFBBlobMetaData.SetCharSetID(aValue: integer);
430     begin
431     FCharSetID := aValue;
432     FUnconfirmedCharacterSet := false;
433     end;
434    
435 tony 45 function TFBBlobMetaData.GetSubType: integer;
436     begin
437     NeedSubType;
438     Result := FSubType;
439     end;
440    
441     function TFBBlobMetaData.GetCharSetID: cardinal;
442     begin
443     NeedFullMetadata;
444     Result := FCharSetID;
445     end;
446    
447     function TFBBlobMetaData.GetCodePage: TSystemCodePage;
448     begin
449 tony 60 Attachment.CharSetID2CodePage(GetCharSetID,Result);
450 tony 45 end;
451    
452     function TFBBlobMetaData.GetSegmentSize: cardinal;
453     begin
454     NeedFullMetadata;
455     Result := FSegmentSize;
456     end;
457    
458 tony 56 function TFBBlobMetaData.GetRelationName: AnsiString;
459 tony 45 begin
460     Result := FRelationName;
461     end;
462    
463 tony 56 function TFBBlobMetaData.GetColumnName: AnsiString;
464 tony 45 begin
465     Result := FColumnName;
466     end;
467    
468     function TFBBlobMetaData.GetUnconfirmedCharacterSet: boolean;
469     begin
470     NeedFullMetadata;
471     Result := FUnconfirmedCharacterSet;
472     end;
473    
474    
475     end.
476