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root/public/ibx/trunk/fbintf/client/FBTransaction.pas
Revision: 380
Committed: Mon Jan 10 10:13:17 2022 UTC (2 years, 10 months ago) by tony
Content type: text/x-pascal
File size: 15523 byte(s)
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propset for eol-style

File Contents

# Content
1 (*
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 {************************************************************************}
31 { }
32 { Borland Delphi Visual Component Library }
33 { InterBase Express core components }
34 { }
35 { Copyright (c) 1998-2000 Inprise Corporation }
36 { }
37 { InterBase Express is based in part on the product }
38 { Free IB Components, written by Gregory H. Deatz for }
39 { Hoagland, Longo, Moran, Dunst & Doukas Company. }
40 { Free IB Components is used under license. }
41 { }
42 { The contents of this file are subject to the InterBase }
43 { Public License Version 1.0 (the "License"); you may not }
44 { use this file except in compliance with the License. You }
45 { may obtain a copy of the License at http://www.Inprise.com/IPL.html }
46 { Software distributed under the License is distributed on }
47 { an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either }
48 { express or implied. See the License for the specific language }
49 { governing rights and limitations under the License. }
50 { The Original Code was created by InterBase Software Corporation }
51 { and its successors. }
52 { Portions created by Inprise Corporation are Copyright (C) Inprise }
53 { Corporation. All Rights Reserved. }
54 { Contributor(s): Jeff Overcash }
55 { }
56 { IBX For Lazarus (Firebird Express) }
57 { Contributor: Tony Whyman, MWA Software http://www.mwasoftware.co.uk }
58 { Portions created by MWA Software are copyright McCallum Whyman }
59 { Associates Ltd 2011 - 2015 }
60 { }
61 {************************************************************************}
62 unit FBTransaction;
63 {$IFDEF MSWINDOWS}
64 {$DEFINE WINDOWS}
65 {$ENDIF}
66
67 {$IFDEF FPC}
68 {$mode delphi}
69 {$interfaces COM}
70 {$ENDIF}
71
72 interface
73
74 uses
75 Classes, SysUtils, IB, FBParamBlock, FBActivityMonitor, FBClientAPI, FBOutputBlock;
76
77 type
78 { TFBTransaction }
79
80 TFBTransaction = class(TActivityReporter, IActivityMonitor,ITransaction)
81 private
82 FFirebirdAPI: TFBClientAPI;
83 function GenerateTPB(sl: array of byte): ITPB;
84 protected
85 FTPB: ITPB;
86 FSeqNo: integer;
87 FDefaultCompletion: TTransactionAction;
88 FAttachments: array of IAttachment; {Keep reference to attachment - ensures
89 attachment cannot be freed before transaction}
90 procedure CheckHandle;
91 function GetActivityIntf(att: IAttachment): IActivityMonitor; virtual; abstract;
92 procedure SetInterface(api: TFBClientAPI); virtual;
93 function GetTrInfo(ReqBuffer: PByte; ReqBufLen: integer): ITrInformation; virtual; abstract;
94 public
95 constructor Create(api: TFBClientAPI; Attachments: array of IAttachment; Params: array of byte; DefaultCompletion: TTransactionAction); overload;
96 constructor Create(api: TFBClientAPI; Attachments: array of IAttachment; TPB: ITPB; DefaultCompletion: TTransactionAction); overload;
97 constructor Create(api: TFBClientAPI; Attachment: IAttachment; Params: array of byte; DefaultCompletion: TTransactionAction); overload;
98 constructor Create(api: TFBClientAPI; Attachment: IAttachment; TPB: ITPB; DefaultCompletion: TTransactionAction); overload;
99 destructor Destroy; override;
100 procedure DoDefaultTransactionEnd(Force: boolean);
101 property FirebirdAPI: TFBClientAPI read FFirebirdAPI;
102
103 public
104 {ITransaction}
105 function getTPB: ITPB;
106 procedure PrepareForCommit;virtual; abstract;
107 procedure Commit(Force: boolean=false); virtual; abstract;
108 procedure CommitRetaining; virtual; abstract;
109 function GetInTransaction: boolean; virtual; abstract;
110 function GetIsReadOnly: boolean;
111 function GetTransactionID: integer;
112 function GetAttachmentCount: integer;
113 function GetAttachment(index: integer): IAttachment;
114 procedure Rollback(Force: boolean=false); virtual; abstract;
115 procedure RollbackRetaining; virtual; abstract;
116 procedure Start(DefaultCompletion: TTransactionCompletion=taCommit); overload; virtual; abstract;
117 procedure Start(TPB: ITPB; DefaultCompletion: TTransactionCompletion=taCommit); overload;
118 function GetTrInformation(Requests: array of byte): ITrInformation; overload;
119 function GetTrInformation(Request: byte): ITrInformation; overload;
120
121 property InTransaction: boolean read GetInTransaction;
122 property TransactionSeqNo: integer read FSeqNo;
123 end;
124
125 {The transaction user interface is used to force an action on the end of the
126 transaction.}
127
128 ITransactionUser = interface
129 ['{156fcdc9-a326-44b3-a82d-f23c6fb9f97c}']
130 procedure TransactionEnding(aTransaction: ITransaction; Force: boolean);
131 end;
132
133 { TTPBItem }
134
135 TTPBItem = class(TParamBlockItem,ITPBItem)
136 public
137 function getParamTypeName: AnsiString; override;
138 end;
139
140 { TTPB }
141
142 TTPB = class (TCustomParamBlock<TTPBItem,ITPBItem>, ITPB)
143 protected
144 function LookupItemType(ParamTypeName: AnsiString): byte; override;
145 public
146 constructor Create(api: TFBClientAPI);
147 function GetParamTypeName(ParamType: byte): Ansistring;
148 {$IFDEF FPC}
149 function ITPB.GetDPBParamTypeName = GetParamTypeName;
150 {$ELSE}
151 function GetDPBParamTypeName(ParamType: byte): Ansistring;
152 {$ENDIF}
153 end;
154
155 {$IFDEF FPC}
156 TTrInfoItem = class;
157
158 { TTrInfoItem }
159
160 TTrInfoItem = class(TOutputBlockItemGroup<TTrInfoItem,ITrInfoItem>,ITrInfoItem)
161 {$ELSE}
162 TTransInfoItem = class(TOutputBlockItemGroup<TOutputBlockItem,ITransInfoItem>,ITransInfoItem)
163 {$ENDIF}
164 public
165 procedure DecodeTraIsolation(var IsolationType, RecVersion: byte);
166 end;
167
168 { TTrInformation }
169
170 TTrInformation = class(TCustomOutputBlock<TTrInfoItem,ITrInfoItem>, ITrInformation)
171 protected
172 procedure DoParseBuffer; override;
173 public
174 constructor Create(api: TFBClientAPI; aSize: integer = DefaultBufferSize);
175 {$IFNDEF FPC}
176 function Find(ItemType: byte): ITransInfoItem;
177 {$ENDIF}
178 end;
179
180 implementation
181
182 uses FBMessages;
183
184 const
185 isc_tpb_last_tpb_constant = isc_tpb_at_snapshot_number;
186
187 TPBConstantNames: array[1..isc_tpb_last_tpb_constant] of string = (
188 'consistency',
189 'concurrency',
190 'shared',
191 'protected',
192 'exclusive',
193 'wait',
194 'nowait',
195 'read',
196 'write',
197 'lock_read',
198 'lock_write',
199 'verb_time',
200 'commit_time',
201 'ignore_limbo',
202 'read_committed',
203 'autocommit',
204 'rec_version',
205 'no_rec_version',
206 'restart_requests',
207 'no_auto_undo',
208 'lock_timeout',
209 'read_consistency',
210 'at_snapshot_number'
211 );
212
213 { TFBTransaction }
214
215 function TFBTransaction.GenerateTPB(sl: array of byte): ITPB;
216 var
217 i: Integer;
218 begin
219 Result := TTPB.Create(FFirebirdAPI);
220 for i := 0 to Length(sl) - 1 do
221 Result.Add(sl[i]);
222 end;
223
224 procedure TFBTransaction.CheckHandle;
225 begin
226 if not InTransaction then
227 IBError(ibxeNotInTransaction,[]);
228 end;
229
230 procedure TFBTransaction.SetInterface(api: TFBClientAPI);
231 begin
232 FFirebirdAPI := api;
233 end;
234
235 constructor TFBTransaction.Create(api: TFBClientAPI; Attachments: array of IAttachment;
236 Params: array of byte; DefaultCompletion: TTransactionAction);
237 begin
238 Create(api, Attachments,GenerateTPB(Params), DefaultCompletion);
239 end;
240
241 constructor TFBTransaction.Create(api: TFBClientAPI; Attachments: array of IAttachment; TPB: ITPB;
242 DefaultCompletion: TTransactionAction);
243 var
244 i: Integer;
245 begin
246 inherited Create(nil);
247 SetInterface(api);
248 if Length(Attachments) = 0 then
249 IBError(ibxeEmptyAttachmentsList,[nil]);
250
251 {make sure all attachments use same Firebird API}
252 for i := 0 to Length(Attachments) - 1 do
253 if Attachments[i].getFirebirdAPI.GetFBLibrary.GetHandle <> FFirebirdAPI.GetFBLibrary.GetHandle then
254 IBError(ibxeDifferentAPIs,[nil]);
255
256 SetLength(FAttachments,Length(Attachments));
257 for i := 0 to Length(Attachments) - 1 do
258 begin
259 AddMonitor(GetActivityIntf(Attachments[i]));
260 FAttachments[i] := Attachments[i];
261 end;
262 FTPB := TPB;
263 Start(DefaultCompletion);
264 end;
265
266 constructor TFBTransaction.Create(api: TFBClientAPI; Attachment: IAttachment;
267 Params: array of byte; DefaultCompletion: TTransactionAction);
268 begin
269 Create(api,Attachment,GenerateTPB(Params),DefaultCompletion);
270 end;
271
272 constructor TFBTransaction.Create(api: TFBClientAPI; Attachment: IAttachment; TPB: ITPB;
273 DefaultCompletion: TTransactionAction);
274 begin
275 inherited Create(nil);
276 SetInterface(api);
277 AddMonitor(GetActivityIntf(Attachment));
278 SetLength(FAttachments,1);
279 FAttachments[0] := Attachment;
280 FTPB := TPB;
281 Start(DefaultCompletion);
282 end;
283
284 destructor TFBTransaction.Destroy;
285 begin
286 DoDefaultTransactionEnd(false);
287 inherited Destroy;
288 end;
289
290 procedure TFBTransaction.DoDefaultTransactionEnd(Force: boolean);
291 var i: integer;
292 intf: IUnknown;
293 user: ITransactionUser;
294 begin
295 if InTransaction then
296 begin
297 for i := 0 to InterfaceCount - 1 do
298 begin
299 intf := GetInterface(i);
300 if (intf <> nil) and (intf.QueryInterface(ITransactionUser,user) = S_OK) then
301 user.TransactionEnding(self,Force);
302 end;
303 case FDefaultCompletion of
304 taRollback:
305 Rollback(Force);
306 taCommit:
307 Commit(Force);
308 end;
309 end;
310 end;
311
312 function TFBTransaction.getTPB: ITPB;
313 begin
314 Result := FTPB;
315 end;
316
317 function TFBTransaction.GetIsReadOnly: boolean;
318 var Info: ITrInformation;
319 begin
320 Info := GetTrInformation(isc_info_tra_access);
321 if (Info.Count > 0) and (Info[0].getItemType = isc_info_tra_access) then
322 Result := Info[0].getAsInteger = isc_info_tra_readonly
323 else
324 Result := false;
325 end;
326
327 function TFBTransaction.GetTransactionID: integer;
328 var Info: ITrInformation;
329 begin
330 Result := -1;
331 Info := GetTrInformation(isc_info_tra_id);
332 if (Info.Count > 0) and (Info[0].getItemType = isc_info_tra_id) then
333 Result := Info[0].getAsInteger;
334 end;
335
336 function TFBTransaction.GetAttachmentCount: integer;
337 begin
338 Result := Length(FAttachments);
339 end;
340
341 function TFBTransaction.GetAttachment(index: integer): IAttachment;
342 begin
343 if (index >= 0) and (index < Length(FAttachments)) then
344 Result := FAttachments[index]
345 else
346 IBError(ibxeAttachmentListIndexError,[index]);
347 end;
348
349 procedure TFBTransaction.Start(TPB: ITPB; DefaultCompletion: TTransactionCompletion
350 );
351 begin
352 FTPB := TPB;
353 Start(DefaultCompletion);
354 end;
355
356 function TFBTransaction.GetTrInformation(Requests: array of byte
357 ): ITrInformation;
358 var ReqBuffer: PByte;
359 i: integer;
360 begin
361 CheckHandle;
362 if Length(Requests) = 1 then
363 Result := GetTrInformation(Requests[0])
364 else
365 begin
366 GetMem(ReqBuffer,Length(Requests));
367 try
368 for i := 0 to Length(Requests) - 1 do
369 ReqBuffer[i] := Requests[i];
370
371 Result := GetTrInfo(ReqBuffer,Length(Requests));
372
373 finally
374 FreeMem(ReqBuffer);
375 end;
376 end;
377 end;
378
379 function TFBTransaction.GetTrInformation(Request: byte): ITrInformation;
380 begin
381 CheckHandle;
382 Result := GetTrInfo(@Request,1);
383 end;
384
385 { TTPBItem }
386
387 function TTPBItem.getParamTypeName: AnsiString;
388 begin
389 Result := TPBPrefix + TPBConstantNames[getParamType];
390 end;
391
392
393 {TTPB}
394
395 constructor TTPB.Create(api: TFBClientAPI);
396 begin
397 inherited Create(api);
398 FDataLength := 1;
399 FBuffer^ := isc_tpb_version3;
400 end;
401
402 function TTPB.GetParamTypeName(ParamType: byte): Ansistring;
403 begin
404 if ParamType <= isc_tpb_last_tpb_constant then
405 Result := TPBConstantNames[ParamType]
406 else
407 Result := '';
408 end;
409
410 {$IFNDEF FPC}
411 function TTPB.GetDPBParamTypeName(ParamType: byte): Ansistring;
412 begin
413 Result := GetParamTypeName(ParamType);
414 end;
415 {$ENDIF}
416
417
418 function TTPB.LookupItemType(ParamTypeName: AnsiString): byte;
419 var i: byte;
420 begin
421 Result := 0;
422 ParamTypeName := LowerCase(ParamTypeName);
423 if (Pos(TPBPrefix, ParamTypeName) = 1) then
424 Delete(ParamTypeName, 1, Length(TPBPrefix));
425
426 for i := 1 to isc_tpb_last_tpb_constant do
427 if (ParamTypeName = TPBConstantNames[i]) then
428 begin
429 Result := i;
430 break;
431 end;
432 end;
433
434 { TTrInfoItem }
435
436 procedure TTrInfoItem.DecodeTraIsolation(var IsolationType, RecVersion: byte);
437 begin
438 with FFirebirdClientAPI, ItemData^ do
439 if getItemType = isc_info_tra_isolation then
440 begin
441 if FDataLength = 1 then
442 begin
443 IsolationType := getAsInteger;
444 RecVersion := 0;
445 end
446 else
447 begin
448 IsolationType := (FBufPtr + 3)^;
449 RecVersion := (FBufPtr + 4)^;
450 end
451 end
452 else
453 IBError(ibxeInfoBufferTypeError,[integer(FBufPtr^)]);
454 end;
455
456 { TTrInformation }
457
458 procedure TTrInformation.DoParseBuffer;
459 var P: PByte;
460 index: integer;
461 begin
462 P := Buffer;
463 index := 0;
464 SetLength(FItems,0);
465 while (P^ <> isc_info_end) and (P < Buffer + getBufSize) do
466 begin
467 SetLength(FItems,index+1);
468 case byte(P^) of
469 isc_info_tra_id,
470 isc_info_tra_oldest_interesting,
471 isc_info_tra_oldest_active,
472 isc_info_tra_oldest_snapshot,
473 fb_info_tra_snapshot_number,
474 isc_info_tra_lock_timeout:
475 FItems[index] := AddIntegerItem(P);
476
477 isc_info_tra_isolation,
478 {return transaction isolation mode of current transaction.
479 format of returned clumplets is following:
480
481 isc_info_tra_isolation,
482 1, isc_info_tra_consistency | isc_info_tra_concurrency
483 |
484 2, isc_info_tra_read_committed,
485 isc_info_tra_no_rec_version | isc_info_tra_rec_version
486
487 i.e. for read committed transactions returned 2 items while for
488 other transactions returned 1 item}
489
490 isc_info_tra_access:
491 FItems[index] := AddIntegerItem(P);
492 fb_info_tra_dbpath:
493 FItems[index] := AddStringItem(P);
494 else
495 FItems[index] := AddItem(P);
496 end;
497 P := P + FItems[index]^.FSize;
498 Inc(index);
499 end;
500 end;
501
502 constructor TTrInformation.Create(api: TFBClientAPI; aSize: integer);
503 begin
504 inherited Create(api,aSize);
505 FIntegerType := dtInteger;
506 end;
507
508 end.
509

Properties

Name Value
svn:eol-style native