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(ibxeMultiThreadRequired,['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:	221
Committed:	Mon Mar 19 09:48:37 2018 UTC (6 years, 8 months ago) by tony
Content type:	text/x-pascal
File size:	8885 byte(s)
Log Message:	Fixes merged
#	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	45	protected
87	tony	56	FEventBuffer: PByte;
88	tony	45	FEventBufferLen: integer;
89	tony	56	FResultBuffer: PByte;
90	tony	45	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	tony	47	procedure ProcessEventCounts;
98	tony	45	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	tony	56	procedure SetEvents(Event: AnsiString); overload;
106	tony	45	procedure Cancel;
107			function ExtractEventCounts: TEventCounts;
108			function GetAttachment: IAttachment;
109	tony	47	procedure AsyncWaitForEvent(EventHandler: TEventHandler); virtual; abstract;
110	tony	45	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	tony	56	EventNames: array of PAnsiChar;
126			EventName: AnsiString;
127	tony	45	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	tony	56	begin
141	tony	217	EventName := FEvents[i];
142	tony	56	EventNames[i] := PAnsiChar(EventName);
143			end;
144	tony	45
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	tony	47	Handler := nil;
168	tony	45	FCriticalSection.Enter;
169			try
170			if not FInWaitState then Exit;
171			FInWaitState := false;
172	tony	47	ProcessEventCounts;
173	tony	45	if assigned(FEventHandler) then
174			begin
175			Handler := FEventHandler;
176			FEventHandler := nil;
177			end;
178			finally
179	tony	47	FCriticalSection.Leave;
180	tony	45	end;
181	tony	47	if assigned(Handler) then
182			Handler(GetIEvents);
183	tony	45	end;
184
185	tony	47	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	tony	56	P := @EventCountList;
200	tony	47	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	tony	45	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	tony	217	if (EventNames.Count > 0) and not IsMultiThread then
250	tony	221	IBError(ibxeMultiThreadRequired,['Firebird Events Handling']);
251	tony	45	if EventNames.Text <> FEvents.Text then
252			begin
253			Cancel;
254			FEvents.Assign(EventNames);
255			CreateEventBlock;
256			end;
257			end;
258
259	tony	56	procedure TFBEvents.SetEvents(Event: AnsiString);
260	tony	45	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	tony	47	Result := FEventCounts;
280	tony	45	end;
281
282			function TFBEvents.GetAttachment: IAttachment;
283			begin
284			Result := FAttachment;
285			end;
286
287			end.
288