fbintf/client/FBEvents.pas

(*
 *  Firebird Interface (fbintf). The fbintf components provide a set of
 *  Pascal language bindings for the Firebird API. Although predominantly
 *  a new development they include source code taken from IBX and may be
 *  considered a derived product. This software thus also includes the copyright
 *  notice and license conditions from IBX.
 *
 *  Except for those parts dervied from IBX, contents of this file are subject
 *  to the Initial Developer's 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 here:
 *
 *    http://www.firebirdsql.org/index.php?op=doc&id=idpl
 *
 *  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 Initial Developer of the Original Code is Tony Whyman.
 *
 *  The Original Code is (C) 2016 Tony Whyman, MWA Software
 *  (http://www.mwasoftware.co.uk).
 *
 *  All Rights Reserved.
 *
 *  Contributor(s): ______________________________________.
 *
*)
{************************************************************************}
{                                                                        }
{       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 - 2015                                                }
{                                                                        }
{************************************************************************}
unit FBEvents;
{$IFDEF MSWINDOWS} 
{$DEFINE WINDOWS} 
{$ENDIF}

{$IFDEF FPC}
{$mode delphi}
{$interfaces COM}
{$ENDIF}

interface

uses
  Classes, SysUtils, IB, FBClientAPI, syncobjs, FBActivityMonitor;

type

  { TFBEvents }

  TFBEvents = class(TActivityReporter)
  private
    FEvents: TStringList;
    FAttachment: IAttachment;
    FEventCounts: TEventCounts;
  protected
    FEventBuffer: PByte;
    FEventBufferLen: integer;
    FResultBuffer: PByte;
    FEventHandler: TEventHandler;
    FCriticalSection: TCriticalSection;
    FInWaitState: boolean;
    procedure CreateEventBlock;
    procedure CancelEvents(Force: boolean = false); virtual;
    procedure EventSignaled;
    function GetIEvents: IEvents; virtual; abstract;
    procedure ProcessEventCounts;
  public
    constructor Create(DBAttachment: IAttachment; aMonitor: IActivityMonitor; Events: TStrings);
    destructor Destroy; override;

    {IEvents}
    procedure GetEvents(EventNames: TStrings);
    procedure SetEvents(EventNames: TStrings); overload;
    procedure SetEvents(Event: AnsiString); overload;
    procedure Cancel;
    function ExtractEventCounts: TEventCounts;
    function GetAttachment: IAttachment;
    procedure AsyncWaitForEvent(EventHandler: TEventHandler); virtual; abstract;
  end;


implementation

uses FBMessages, IBExternals;

const
  MaxEvents = 15;

{ TFBEvents }

procedure TFBEvents.CreateEventBlock;
var
  i: integer;
  EventNames: array of PAnsiChar;
  EventName: AnsiString;
begin
  with FirebirdClientAPI do
  begin
    if FEventBuffer <> nil then
      isc_free( FEventBuffer);
    FEventBuffer := nil;
    if FResultBuffer <> nil then
      isc_free( FResultBuffer);
    FResultBuffer := nil;

    setlength(EventNames,MaxEvents);
    try
      for i := 0 to FEvents.Count-1 do
      begin
        EventName := FEvents[i];
        EventNames[i] := PAnsiChar(EventName);
      end;

      FEventBufferlen := isc_event_block(@FEventBuffer,@FResultBuffer,
                          FEvents.Count,
                          EventNames[0],EventNames[1],EventNames[2],
                          EventNames[3],EventNames[4],EventNames[5],
                          EventNames[6],EventNames[7],EventNames[8],
                          EventNames[9],EventNames[10],EventNames[11],
                          EventNames[12],EventNames[13],EventNames[14]
                          );
    finally
      SetLength(EventNames,0)
    end;
  end;
end;

procedure TFBEvents.CancelEvents(Force: boolean);
begin
  FEventHandler := nil;
end;

procedure TFBEvents.EventSignaled;
var Handler: TEventHandler;
begin
  Handler := nil;
  FCriticalSection.Enter;
  try
    if not FInWaitState then Exit;
    FInWaitState := false;
    ProcessEventCounts;
    if assigned(FEventHandler)  then
    begin
      Handler := FEventHandler;
      FEventHandler := nil;
    end;
  finally
    FCriticalSection.Leave;
  end;
  if assigned(Handler) then
    Handler(GetIEvents);
end;

procedure TFBEvents.ProcessEventCounts;
var P: PISC_LONG;
    EventCountList: array[0..19] of ISC_LONG;
    i: integer;
    j: integer;
begin
  SetLength(FEventCounts,0);
  if FResultBuffer = nil then Exit;

  FillChar(EventCountList,sizeof(EventCountList),0);

  with FirebirdClientAPI do
     isc_event_counts( @EventCountList, FEventBufferLen, FEventBuffer, FResultBuffer);
  j := 0;
  P := @EventCountList;
  for i := 0 to FEvents.Count - 1 do
  begin
    if EventCountList[i] <> 0 then
    begin
      Inc(j);
      SetLength(FEventCounts,j);
      FEventCounts[j-1].EventName := FEvents[i];
      FEventCounts[j-1].Count := P^;
      Inc(P);
//      writeln('Event: ',FEventCounts[j-1].EventName,' Count = ',FEventCounts[j-1].Count);
    end;
  end;
end;

constructor TFBEvents.Create(DBAttachment: IAttachment;
  aMonitor: IActivityMonitor; Events: TStrings);
begin
  inherited Create(aMonitor);
  FAttachment := DBAttachment;
  if Events.Count > MaxEvents then
    IBError(ibxeMaximumEvents, [nil]);

  FCriticalSection := TCriticalSection.Create;
  FEvents := TStringList.Create;
  FEvents.Assign(Events);
  CreateEventBlock;
end;

destructor TFBEvents.Destroy;
begin
  if assigned(FCriticalSection) then FCriticalSection.Free;
  if assigned(FEvents) then FEvents.Free;
  with FirebirdClientAPI do
  begin
    if FEventBuffer <> nil then
      isc_free( FEventBuffer);
    if FResultBuffer <> nil then
      isc_free( FResultBuffer);
  end;
  inherited Destroy;
end;

procedure TFBEvents.GetEvents(EventNames: TStrings);
begin
  EventNames.Assign(FEvents)
end;

procedure TFBEvents.SetEvents(EventNames: TStrings);
begin
  if (EventNames.Count > 0) and not IsMultiThread then
    IBError(ibxMultiThreadRequired,['Firebird Events Handling']);
  if EventNames.Text <> FEvents.Text then
  begin
    Cancel;
    FEvents.Assign(EventNames);
    CreateEventBlock;
  end;
end;

procedure TFBEvents.SetEvents(Event: AnsiString);
var S: TStringList;
begin
  S := TStringList.Create;
  try
    S.Add(Event);
    SetEvents(S);
  finally
    S.Free;
  end;
end;

procedure TFBEvents.Cancel;
begin
  if assigned(FEventHandler) then
    CancelEvents;
end;

function TFBEvents.ExtractEventCounts: TEventCounts;
begin
  Result := FEventCounts;
end;

function TFBEvents.GetAttachment: IAttachment;
begin
  Result := FAttachment;
end;

end.

Revision:	217
Committed:	Fri Mar 16 10:27:26 2018 UTC (6 years, 8 months ago) by tony
Content type:	text/x-pascal
File size:	8884 byte(s)
Log Message:	Fixes Merged
#	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 FBEvents;
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, FBClientAPI, syncobjs, FBActivityMonitor;
76
77	type
78
79	{ TFBEvents }
80
81	TFBEvents = class(TActivityReporter)
82	private
83	FEvents: TStringList;
84	FAttachment: IAttachment;
85	FEventCounts: TEventCounts;
86	protected
87	FEventBuffer: PByte;
88	FEventBufferLen: integer;
89	FResultBuffer: PByte;
90	FEventHandler: TEventHandler;
91	FCriticalSection: TCriticalSection;
92	FInWaitState: boolean;
93	procedure CreateEventBlock;
94	procedure CancelEvents(Force: boolean = false); virtual;
95	procedure EventSignaled;
96	function GetIEvents: IEvents; virtual; abstract;
97	procedure ProcessEventCounts;
98	public
99	constructor Create(DBAttachment: IAttachment; aMonitor: IActivityMonitor; Events: TStrings);
100	destructor Destroy; override;
101
102	{IEvents}
103	procedure GetEvents(EventNames: TStrings);
104	procedure SetEvents(EventNames: TStrings); overload;
105	procedure SetEvents(Event: AnsiString); overload;
106	procedure Cancel;
107	function ExtractEventCounts: TEventCounts;
108	function GetAttachment: IAttachment;
109	procedure AsyncWaitForEvent(EventHandler: TEventHandler); virtual; abstract;
110	end;
111
112
113	implementation
114
115	uses FBMessages, IBExternals;
116
117	const
118	MaxEvents = 15;
119
120	{ TFBEvents }
121
122	procedure TFBEvents.CreateEventBlock;
123	var
124	i: integer;
125	EventNames: array of PAnsiChar;
126	EventName: AnsiString;
127	begin
128	with FirebirdClientAPI do
129	begin
130	if FEventBuffer <> nil then
131	isc_free( FEventBuffer);
132	FEventBuffer := nil;
133	if FResultBuffer <> nil then
134	isc_free( FResultBuffer);
135	FResultBuffer := nil;
136
137	setlength(EventNames,MaxEvents);
138	try
139	for i := 0 to FEvents.Count-1 do
140	begin
141	EventName := FEvents[i];
142	EventNames[i] := PAnsiChar(EventName);
143	end;
144
145	FEventBufferlen := isc_event_block(@FEventBuffer,@FResultBuffer,
146	FEvents.Count,
147	EventNames[0],EventNames[1],EventNames[2],
148	EventNames[3],EventNames[4],EventNames[5],
149	EventNames[6],EventNames[7],EventNames[8],
150	EventNames[9],EventNames[10],EventNames[11],
151	EventNames[12],EventNames[13],EventNames[14]
152	);
153	finally
154	SetLength(EventNames,0)
155	end;
156	end;
157	end;
158
159	procedure TFBEvents.CancelEvents(Force: boolean);
160	begin
161	FEventHandler := nil;
162	end;
163
164	procedure TFBEvents.EventSignaled;
165	var Handler: TEventHandler;
166	begin
167	Handler := nil;
168	FCriticalSection.Enter;
169	try
170	if not FInWaitState then Exit;
171	FInWaitState := false;
172	ProcessEventCounts;
173	if assigned(FEventHandler) then
174	begin
175	Handler := FEventHandler;
176	FEventHandler := nil;
177	end;
178	finally
179	FCriticalSection.Leave;
180	end;
181	if assigned(Handler) then
182	Handler(GetIEvents);
183	end;
184
185	procedure TFBEvents.ProcessEventCounts;
186	var P: PISC_LONG;
187	EventCountList: array[0..19] of ISC_LONG;
188	i: integer;
189	j: integer;
190	begin
191	SetLength(FEventCounts,0);
192	if FResultBuffer = nil then Exit;
193
194	FillChar(EventCountList,sizeof(EventCountList),0);
195
196	with FirebirdClientAPI do
197	isc_event_counts( @EventCountList, FEventBufferLen, FEventBuffer, FResultBuffer);
198	j := 0;
199	P := @EventCountList;
200	for i := 0 to FEvents.Count - 1 do
201	begin
202	if EventCountList[i] <> 0 then
203	begin
204	Inc(j);
205	SetLength(FEventCounts,j);
206	FEventCounts[j-1].EventName := FEvents[i];
207	FEventCounts[j-1].Count := P^;
208	Inc(P);
209	// writeln('Event: ',FEventCounts[j-1].EventName,' Count = ',FEventCounts[j-1].Count);
210	end;
211	end;
212	end;
213
214	constructor TFBEvents.Create(DBAttachment: IAttachment;
215	aMonitor: IActivityMonitor; Events: TStrings);
216	begin
217	inherited Create(aMonitor);
218	FAttachment := DBAttachment;
219	if Events.Count > MaxEvents then
220	IBError(ibxeMaximumEvents, [nil]);
221
222	FCriticalSection := TCriticalSection.Create;
223	FEvents := TStringList.Create;
224	FEvents.Assign(Events);
225	CreateEventBlock;
226	end;
227
228	destructor TFBEvents.Destroy;
229	begin
230	if assigned(FCriticalSection) then FCriticalSection.Free;
231	if assigned(FEvents) then FEvents.Free;
232	with FirebirdClientAPI do
233	begin
234	if FEventBuffer <> nil then
235	isc_free( FEventBuffer);
236	if FResultBuffer <> nil then
237	isc_free( FResultBuffer);
238	end;
239	inherited Destroy;
240	end;
241
242	procedure TFBEvents.GetEvents(EventNames: TStrings);
243	begin
244	EventNames.Assign(FEvents)
245	end;
246
247	procedure TFBEvents.SetEvents(EventNames: TStrings);
248	begin
249	if (EventNames.Count > 0) and not IsMultiThread then
250	IBError(ibxMultiThreadRequired,['Firebird Events Handling']);
251	if EventNames.Text <> FEvents.Text then
252	begin
253	Cancel;
254	FEvents.Assign(EventNames);
255	CreateEventBlock;
256	end;
257	end;
258
259	procedure TFBEvents.SetEvents(Event: AnsiString);
260	var S: TStringList;
261	begin
262	S := TStringList.Create;
263	try
264	S.Add(Event);
265	SetEvents(S);
266	finally
267	S.Free;
268	end;
269	end;
270
271	procedure TFBEvents.Cancel;
272	begin
273	if assigned(FEventHandler) then
274	CancelEvents;
275	end;
276
277	function TFBEvents.ExtractEventCounts: TEventCounts;
278	begin
279	Result := FEventCounts;
280	end;
281
282	function TFBEvents.GetAttachment: IAttachment;
283	begin
284	Result := FAttachment;
285	end;
286
287	end.
288