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;
    FFirebirdClientAPI: TFBClientAPI;
  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 FFirebirdClientAPI 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 FFirebirdClientAPI 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;
  FFirebirdClientAPI := DBAttachment.getFirebirdAPI as TFBClientAPI;
  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 FFirebirdClientAPI 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
  {$ifdef Unix}
  if (EventNames.Count > 0) and not IsMultiThread then
    IBError(ibxeMultiThreadRequired,['Firebird Events Handling']);
  {$endif}
  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:	263
Committed:	Thu Dec 6 15:55:01 2018 UTC (6 years ago) by tony
Content type:	text/x-pascal
Original Path:	*ibx/trunk/fbintf/client/FBEvents.pas*
File size:	9022 byte(s)
Log Message:	Release 2.3.2 committed
#	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			{************************************************************************}
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	tony	56	{$IFDEF MSWINDOWS}
64			{$DEFINE WINDOWS}
65			{$ENDIF}
66	tony	45
67			{$IFDEF FPC}
68	tony	56	{$mode delphi}
69	tony	45	{$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	tony	47	FEventCounts: TEventCounts;
86	tony	263	FFirebirdClientAPI: TFBClientAPI;
87	tony	45	protected
88	tony	56	FEventBuffer: PByte;
89	tony	45	FEventBufferLen: integer;
90	tony	56	FResultBuffer: PByte;
91	tony	45	FEventHandler: TEventHandler;
92			FCriticalSection: TCriticalSection;
93			FInWaitState: boolean;
94			procedure CreateEventBlock;
95			procedure CancelEvents(Force: boolean = false); virtual;
96			procedure EventSignaled;
97			function GetIEvents: IEvents; virtual; abstract;
98	tony	47	procedure ProcessEventCounts;
99	tony	45	public
100			constructor Create(DBAttachment: IAttachment; aMonitor: IActivityMonitor; Events: TStrings);
101			destructor Destroy; override;
102
103			{IEvents}
104			procedure GetEvents(EventNames: TStrings);
105			procedure SetEvents(EventNames: TStrings); overload;
106	tony	56	procedure SetEvents(Event: AnsiString); overload;
107	tony	45	procedure Cancel;
108			function ExtractEventCounts: TEventCounts;
109			function GetAttachment: IAttachment;
110	tony	47	procedure AsyncWaitForEvent(EventHandler: TEventHandler); virtual; abstract;
111	tony	45	end;
112
113
114			implementation
115
116			uses FBMessages, IBExternals;
117
118			const
119			MaxEvents = 15;
120
121			{ TFBEvents }
122
123			procedure TFBEvents.CreateEventBlock;
124			var
125			i: integer;
126	tony	56	EventNames: array of PAnsiChar;
127			EventName: AnsiString;
128	tony	45	begin
129	tony	263	with FFirebirdClientAPI do
130	tony	45	begin
131			if FEventBuffer <> nil then
132			isc_free( FEventBuffer);
133			FEventBuffer := nil;
134			if FResultBuffer <> nil then
135			isc_free( FResultBuffer);
136			FResultBuffer := nil;
137
138			setlength(EventNames,MaxEvents);
139			try
140			for i := 0 to FEvents.Count-1 do
141	tony	56	begin
142	tony	217	EventName := FEvents[i];
143	tony	56	EventNames[i] := PAnsiChar(EventName);
144			end;
145	tony	45
146			FEventBufferlen := isc_event_block(@FEventBuffer,@FResultBuffer,
147			FEvents.Count,
148			EventNames[0],EventNames[1],EventNames[2],
149			EventNames[3],EventNames[4],EventNames[5],
150			EventNames[6],EventNames[7],EventNames[8],
151			EventNames[9],EventNames[10],EventNames[11],
152			EventNames[12],EventNames[13],EventNames[14]
153			);
154			finally
155			SetLength(EventNames,0)
156			end;
157			end;
158			end;
159
160			procedure TFBEvents.CancelEvents(Force: boolean);
161			begin
162			FEventHandler := nil;
163			end;
164
165			procedure TFBEvents.EventSignaled;
166			var Handler: TEventHandler;
167			begin
168	tony	47	Handler := nil;
169	tony	45	FCriticalSection.Enter;
170			try
171			if not FInWaitState then Exit;
172			FInWaitState := false;
173	tony	47	ProcessEventCounts;
174	tony	45	if assigned(FEventHandler) then
175			begin
176			Handler := FEventHandler;
177			FEventHandler := nil;
178			end;
179			finally
180	tony	47	FCriticalSection.Leave;
181	tony	45	end;
182	tony	47	if assigned(Handler) then
183			Handler(GetIEvents);
184	tony	45	end;
185
186	tony	47	procedure TFBEvents.ProcessEventCounts;
187			var P: PISC_LONG;
188			EventCountList: array[0..19] of ISC_LONG;
189			i: integer;
190			j: integer;
191			begin
192			SetLength(FEventCounts,0);
193			if FResultBuffer = nil then Exit;
194
195			FillChar(EventCountList,sizeof(EventCountList),0);
196
197	tony	263	with FFirebirdClientAPI do
198	tony	47	isc_event_counts( @EventCountList, FEventBufferLen, FEventBuffer, FResultBuffer);
199			j := 0;
200	tony	56	P := @EventCountList;
201	tony	47	for i := 0 to FEvents.Count - 1 do
202			begin
203			if EventCountList[i] <> 0 then
204			begin
205			Inc(j);
206			SetLength(FEventCounts,j);
207			FEventCounts[j-1].EventName := FEvents[i];
208			FEventCounts[j-1].Count := P^;
209			Inc(P);
210			// writeln('Event: ',FEventCounts[j-1].EventName,' Count = ',FEventCounts[j-1].Count);
211			end;
212			end;
213			end;
214
215	tony	45	constructor TFBEvents.Create(DBAttachment: IAttachment;
216			aMonitor: IActivityMonitor; Events: TStrings);
217			begin
218			inherited Create(aMonitor);
219			FAttachment := DBAttachment;
220	tony	263	FFirebirdClientAPI := DBAttachment.getFirebirdAPI as TFBClientAPI;
221	tony	45	if Events.Count > MaxEvents then
222			IBError(ibxeMaximumEvents, [nil]);
223
224			FCriticalSection := TCriticalSection.Create;
225			FEvents := TStringList.Create;
226			FEvents.Assign(Events);
227			CreateEventBlock;
228			end;
229
230			destructor TFBEvents.Destroy;
231			begin
232			if assigned(FCriticalSection) then FCriticalSection.Free;
233			if assigned(FEvents) then FEvents.Free;
234	tony	263	with FFirebirdClientAPI do
235	tony	45	begin
236			if FEventBuffer <> nil then
237			isc_free( FEventBuffer);
238			if FResultBuffer <> nil then
239			isc_free( FResultBuffer);
240			end;
241			inherited Destroy;
242			end;
243
244			procedure TFBEvents.GetEvents(EventNames: TStrings);
245			begin
246			EventNames.Assign(FEvents)
247			end;
248
249			procedure TFBEvents.SetEvents(EventNames: TStrings);
250			begin
251	tony	263	{$ifdef Unix}
252	tony	217	if (EventNames.Count > 0) and not IsMultiThread then
253	tony	221	IBError(ibxeMultiThreadRequired,['Firebird Events Handling']);
254	tony	263	{$endif}
255	tony	45	if EventNames.Text <> FEvents.Text then
256			begin
257			Cancel;
258			FEvents.Assign(EventNames);
259			CreateEventBlock;
260			end;
261			end;
262
263	tony	56	procedure TFBEvents.SetEvents(Event: AnsiString);
264	tony	45	var S: TStringList;
265			begin
266			S := TStringList.Create;
267			try
268			S.Add(Event);
269			SetEvents(S);
270			finally
271			S.Free;
272			end;
273			end;
274
275			procedure TFBEvents.Cancel;
276			begin
277			if assigned(FEventHandler) then
278			CancelEvents;
279			end;
280
281			function TFBEvents.ExtractEventCounts: TEventCounts;
282			begin
283	tony	47	Result := FEventCounts;
284	tony	45	end;
285
286			function TFBEvents.GetAttachment: IAttachment;
287			begin
288			Result := FAttachment;
289			end;
290
291			end.
292