udr/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 }

  {Firebird Event and Result buffer syntax is:

    record
      version: byte;
      event: array of packed record
        strlen: byte;
        strchars: array of AnsiChar; //no of chars given by strlen
        EventCounts: long;
      end;
    end;

  }

  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
    const EPB_version1 = 1;
  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 }

(* Original Firebird 'C' code

SLONG API_ROUTINE_VARARG isc_event_block(UCHAR** event_buffer,
  UCHAR** result_buffer,
  USHORT count, ...)
{
/**************************************
 *
 *      i s c _ e v e n t _ b l o c k
 *
 **************************************
 *
 * Functional description
 *      Create an initialized event parameter block from a
 *      variable number of input arguments.
 *      Return the size of the block.
 *
 *      Return 0 if any error occurs.
 *
 **************************************/
        va_list ptr;

        va_start(ptr, count);

        // calculate length of event parameter block, setting initial length to include version
        // and counts for each argument

        SLONG length = 1;
        USHORT i = count;
        while (i--)
        {
                const char* q = va_arg(ptr, SCHAR * );
                length += static_cast<SLONG>(strlen(q)) + 5;
        }
        va_end(ptr);

        UCHAR* p = *event_buffer = (UCHAR * ) gds__alloc((SLONG) length);
        // FREE: apparently never freed
        if (!*event_buffer)                     // NOMEM:
                return 0;
        if ((*result_buffer = (UCHAR * ) gds__alloc((SLONG) length)) == NULL)
        {
                // NOMEM:
                // FREE: apparently never freed
                gds__free(*event_buffer);
                *event_buffer = NULL;
                return 0;
        }

        // initialize the block with event names and counts

        *p++ = EPB_version1;

        va_start(ptr, count);

        i = count;
        while (i--)
        {
                const char* q = va_arg(ptr, SCHAR * );

                // Strip the blanks from the ends
                const char* end = q + strlen(q);
                while (--end >= q && *end == ' ')
                        ;
                *p++ = end - q + 1;
                while (q <= end)
                        *p++ = *q++;
                *p++ = 0;
                *p++ = 0;
                *p++ = 0;
                *p++ = 0;
        }
        va_end(ptr);

        return static_cast<SLONG>(p - *event_buffer);
}
*)

{CreateEventBlock effectively replaces isc_event_block}

procedure TFBEvents.CreateEventBlock;
var i: integer;
    P: PByte;
begin
  {calculate length of event parameter block, setting initial length to include version
   and counts for each argument}

  FEventBufferLen := 1;
  for i := 0 to FEvents.Count - 1 do
    FEventBufferLen := FEventBufferLen + length(FEvents[i]) + 1 + sizeof(Long);

  with FFirebirdClientAPI do
  begin
    IBAlloc(FEventBuffer,0,FEventBufferLen);
    if FEventBuffer = nil then Exit;
    {$if declared(FillByte)}
    FillByte(FEventBuffer^,FEventBufferLen,0);
    {$else}
    FillChar(FEventBuffer^,FEventBufferLen,0);
    {$ifend}
    IBAlloc(FResultBuffer,0,FEventBufferLen);
    if FResultBuffer = nil then
    begin
      FreeMem(FEventBuffer);
      Exit;
    end;

    P := FEventBuffer;
    P^ := EPB_version1;
    Inc(P);
    SetLength(FEventCounts,FEvents.Count);

    for i := 0 to FEvents.Count - 1 do
    begin
      P^ := Length(FEvents[i]);
      Inc(P);
      Move(FEvents[i][1],P^,Length(FEvents[i]));
      Inc(P,Length(FEvents[i])+sizeof(Long));
      FEventCounts[i].EventName := FEvents[i];
    end;
  end;

{  for i := 0 to FEventBufferLen - 1 do
  write(Format('%x ', [FEventBuffer[i]]));
   writeln;}
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;

(*
  Original Firebird 'C' code for isc_event_counts

void API_ROUTINE isc_event_counts(ULONG* result_vector,
                                                                  SSHORT buffer_length,
                                                                  UCHAR* event_buffer,
                                                                  const UCHAR* result_buffer)
{
/**************************************
 *
 *      g d s _ $ e v e n t _ c o u n t s
 *
 **************************************
 *
 * Functional description
 *      Get the delta between two events in an event
 *      parameter block.  Used to update gds_events
 *      for GPRE support of events.
 *
 **************************************/
        ULONG* vec = result_vector;
        const UCHAR* p = event_buffer;
        const UCHAR* q = result_buffer;
        USHORT length = buffer_length;
        const UCHAR* const end = p + length;

        // analyze the event blocks, getting the delta for each event

        p++;
        q++;
        while (p < end)
        {
                // skip over the event name

                const USHORT i = (USHORT)* p++;
                p += i;
                q += i + 1;

                // get the change in count

                const ULONG initial_count = gds__vax_integer(p, sizeof(SLONG));
                p += sizeof(SLONG);
                const ULONG new_count = gds__vax_integer(q, sizeof(SLONG));
                q += sizeof(SLONG);
                *vec++ = new_count - initial_count;
        }

        // copy over the result to the initial block to prepare
        // for the next call to gds__event_wait

        memcpy(event_buffer, result_buffer, length);
}
*)

{ProcessEventCounts effectively replaces isc_event_counts}

procedure TFBEvents.ProcessEventCounts;

var i: integer;
    P, Q: PByte;
    initial_count: Long;
    new_count: Long;
    len: byte;
begin
  P := FEventBuffer;
  Q := FResultBuffer;
  Inc(P); {skip past version byte}
  Inc(Q);
  for i := 0 to Length(FEventCounts) - 1 do
  with FFirebirdClientAPI do
  begin
    {skip over the event name}
    len := P^;
    P := P + len + 1;
    Q := Q + len + 1; {event name length in P^}
    initial_count := DecodeInteger(P,sizeof(Long));
    Inc(P,sizeof(Long));
    new_count := DecodeInteger(Q,sizeof(Long));
    Inc(Q,sizeof(Long));
    FEventCounts[i].Count := new_count - initial_count;
  end;
  Move(FResultBuffer^,FEventBuffer^,FEventBufferLen);
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
      FreeMem( FEventBuffer);
    if FResultBuffer <> nil then
      FreeMem( FResultBuffer);
  end;
  inherited Destroy;
end;

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

procedure TFBEvents.SetEvents(EventNames: TStrings);
var i: integer;
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;
    for i := 0 to EventNames.Count - 1 do
      FEvents[i] := Trim(EventNames[i]);
    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:	371
Committed:	Wed Jan 5 15:21:22 2022 UTC (2 years, 10 months ago) by tony
Content type:	text/x-pascal
File size:	12469 byte(s)
Log Message:	Beta Release 0.1
#	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	tony	371	{Firebird Event and Result buffer syntax is:
82
83			record
84			version: byte;
85			event: array of packed record
86			strlen: byte;
87			strchars: array of AnsiChar; //no of chars given by strlen
88			EventCounts: long;
89			end;
90			end;
91
92			}
93
94	tony	45	TFBEvents = class(TActivityReporter)
95			private
96			FEvents: TStringList;
97			FAttachment: IAttachment;
98	tony	47	FEventCounts: TEventCounts;
99	tony	263	FFirebirdClientAPI: TFBClientAPI;
100	tony	45	protected
101	tony	56	FEventBuffer: PByte;
102	tony	45	FEventBufferLen: integer;
103	tony	56	FResultBuffer: PByte;
104	tony	45	FEventHandler: TEventHandler;
105			FCriticalSection: TCriticalSection;
106			FInWaitState: boolean;
107			procedure CreateEventBlock;
108			procedure CancelEvents(Force: boolean = false); virtual;
109			procedure EventSignaled;
110			function GetIEvents: IEvents; virtual; abstract;
111	tony	47	procedure ProcessEventCounts;
112	tony	45	public
113	tony	371	const EPB_version1 = 1;
114			public
115	tony	45	constructor Create(DBAttachment: IAttachment; aMonitor: IActivityMonitor; Events: TStrings);
116			destructor Destroy; override;
117
118			{IEvents}
119			procedure GetEvents(EventNames: TStrings);
120			procedure SetEvents(EventNames: TStrings); overload;
121	tony	56	procedure SetEvents(Event: AnsiString); overload;
122	tony	45	procedure Cancel;
123			function ExtractEventCounts: TEventCounts;
124			function GetAttachment: IAttachment;
125	tony	47	procedure AsyncWaitForEvent(EventHandler: TEventHandler); virtual; abstract;
126	tony	45	end;
127
128
129			implementation
130
131			uses FBMessages, IBExternals;
132
133			const
134			MaxEvents = 15;
135
136			{ TFBEvents }
137
138	tony	371	(* Original Firebird 'C' code
139
140			SLONG API_ROUTINE_VARARG isc_event_block(UCHAR** event_buffer,
141			UCHAR** result_buffer,
142			USHORT count, ...)
143			{
144			/**************************************
145			*
146			* i s c _ e v e n t _ b l o c k
147			*
148			**************************************
149			*
150			* Functional description
151			* Create an initialized event parameter block from a
152			* variable number of input arguments.
153			* Return the size of the block.
154			*
155			* Return 0 if any error occurs.
156			*
157			**************************************/
158			va_list ptr;
159
160			va_start(ptr, count);
161
162			// calculate length of event parameter block, setting initial length to include version
163			// and counts for each argument
164
165			SLONG length = 1;
166			USHORT i = count;
167			while (i--)
168			{
169			const char* q = va_arg(ptr, SCHAR * );
170			length += static_cast<SLONG>(strlen(q)) + 5;
171			}
172			va_end(ptr);
173
174			UCHAR* p = event_buffer = (UCHAR ) gds__alloc((SLONG) length);
175			// FREE: apparently never freed
176			if (!*event_buffer) // NOMEM:
177			return 0;
178			if ((result_buffer = (UCHAR ) gds__alloc((SLONG) length)) == NULL)
179			{
180			// NOMEM:
181			// FREE: apparently never freed
182			gds__free(*event_buffer);
183			*event_buffer = NULL;
184			return 0;
185			}
186
187			// initialize the block with event names and counts
188
189			*p++ = EPB_version1;
190
191			va_start(ptr, count);
192
193			i = count;
194			while (i--)
195			{
196			const char* q = va_arg(ptr, SCHAR * );
197
198			// Strip the blanks from the ends
199			const char* end = q + strlen(q);
200			while (--end >= q && *end == ' ')
201			;
202			*p++ = end - q + 1;
203			while (q <= end)
204			p++ = q++;
205			*p++ = 0;
206			*p++ = 0;
207			*p++ = 0;
208			*p++ = 0;
209			}
210			va_end(ptr);
211
212			return static_cast<SLONG>(p - *event_buffer);
213			}
214			*)
215
216			{CreateEventBlock effectively replaces isc_event_block}
217
218	tony	45	procedure TFBEvents.CreateEventBlock;
219	tony	371	var i: integer;
220			P: PByte;
221	tony	45	begin
222	tony	371	{calculate length of event parameter block, setting initial length to include version
223			and counts for each argument}
224
225			FEventBufferLen := 1;
226			for i := 0 to FEvents.Count - 1 do
227			FEventBufferLen := FEventBufferLen + length(FEvents[i]) + 1 + sizeof(Long);
228
229	tony	263	with FFirebirdClientAPI do
230	tony	45	begin
231	tony	371	IBAlloc(FEventBuffer,0,FEventBufferLen);
232			if FEventBuffer = nil then Exit;
233			{$if declared(FillByte)}
234			FillByte(FEventBuffer^,FEventBufferLen,0);
235			{$else}
236			FillChar(FEventBuffer^,FEventBufferLen,0);
237			{$ifend}
238			IBAlloc(FResultBuffer,0,FEventBufferLen);
239			if FResultBuffer = nil then
240			begin
241			FreeMem(FEventBuffer);
242			Exit;
243			end;
244	tony	45
245	tony	371	P := FEventBuffer;
246			P^ := EPB_version1;
247			Inc(P);
248			SetLength(FEventCounts,FEvents.Count);
249	tony	45
250	tony	371	for i := 0 to FEvents.Count - 1 do
251			begin
252			P^ := Length(FEvents[i]);
253			Inc(P);
254			Move(FEvents[i][1],P^,Length(FEvents[i]));
255			Inc(P,Length(FEvents[i])+sizeof(Long));
256			FEventCounts[i].EventName := FEvents[i];
257	tony	45	end;
258			end;
259	tony	371
260			{ for i := 0 to FEventBufferLen - 1 do
261			write(Format('%x ', [FEventBuffer[i]]));
262			writeln;}
263	tony	45	end;
264
265			procedure TFBEvents.CancelEvents(Force: boolean);
266			begin
267			FEventHandler := nil;
268			end;
269
270			procedure TFBEvents.EventSignaled;
271			var Handler: TEventHandler;
272			begin
273	tony	47	Handler := nil;
274	tony	45	FCriticalSection.Enter;
275			try
276			if not FInWaitState then Exit;
277			FInWaitState := false;
278	tony	47	ProcessEventCounts;
279	tony	45	if assigned(FEventHandler) then
280			begin
281			Handler := FEventHandler;
282			FEventHandler := nil;
283			end;
284			finally
285	tony	47	FCriticalSection.Leave;
286	tony	45	end;
287	tony	47	if assigned(Handler) then
288			Handler(GetIEvents);
289	tony	45	end;
290
291	tony	371	(*
292			Original Firebird 'C' code for isc_event_counts
293
294			void API_ROUTINE isc_event_counts(ULONG* result_vector,
295			SSHORT buffer_length,
296			UCHAR* event_buffer,
297			const UCHAR* result_buffer)
298			{
299			/**************************************
300			*
301			* g d s _ $ e v e n t _ c o u n t s
302			*
303			**************************************
304			*
305			* Functional description
306			* Get the delta between two events in an event
307			* parameter block. Used to update gds_events
308			* for GPRE support of events.
309			*
310			**************************************/
311			ULONG* vec = result_vector;
312			const UCHAR* p = event_buffer;
313			const UCHAR* q = result_buffer;
314			USHORT length = buffer_length;
315			const UCHAR* const end = p + length;
316
317			// analyze the event blocks, getting the delta for each event
318
319			p++;
320			q++;
321			while (p < end)
322			{
323			// skip over the event name
324
325			const USHORT i = (USHORT)* p++;
326			p += i;
327			q += i + 1;
328
329			// get the change in count
330
331			const ULONG initial_count = gds__vax_integer(p, sizeof(SLONG));
332			p += sizeof(SLONG);
333			const ULONG new_count = gds__vax_integer(q, sizeof(SLONG));
334			q += sizeof(SLONG);
335			*vec++ = new_count - initial_count;
336			}
337
338			// copy over the result to the initial block to prepare
339			// for the next call to gds__event_wait
340
341			memcpy(event_buffer, result_buffer, length);
342			}
343			*)
344
345			{ProcessEventCounts effectively replaces isc_event_counts}
346
347	tony	47	procedure TFBEvents.ProcessEventCounts;
348	tony	371
349			var i: integer;
350			P, Q: PByte;
351			initial_count: Long;
352			new_count: Long;
353			len: byte;
354	tony	47	begin
355	tony	371	P := FEventBuffer;
356			Q := FResultBuffer;
357			Inc(P); {skip past version byte}
358			Inc(Q);
359			for i := 0 to Length(FEventCounts) - 1 do
360	tony	263	with FFirebirdClientAPI do
361	tony	47	begin
362	tony	371	{skip over the event name}
363			len := P^;
364			P := P + len + 1;
365			Q := Q + len + 1; {event name length in P^}
366			initial_count := DecodeInteger(P,sizeof(Long));
367			Inc(P,sizeof(Long));
368			new_count := DecodeInteger(Q,sizeof(Long));
369			Inc(Q,sizeof(Long));
370			FEventCounts[i].Count := new_count - initial_count;
371	tony	47	end;
372	tony	371	Move(FResultBuffer^,FEventBuffer^,FEventBufferLen);
373	tony	47	end;
374
375	tony	45	constructor TFBEvents.Create(DBAttachment: IAttachment;
376			aMonitor: IActivityMonitor; Events: TStrings);
377			begin
378			inherited Create(aMonitor);
379			FAttachment := DBAttachment;
380	tony	263	FFirebirdClientAPI := DBAttachment.getFirebirdAPI as TFBClientAPI;
381	tony	45	if Events.Count > MaxEvents then
382			IBError(ibxeMaximumEvents, [nil]);
383
384			FCriticalSection := TCriticalSection.Create;
385			FEvents := TStringList.Create;
386			FEvents.Assign(Events);
387			CreateEventBlock;
388			end;
389
390			destructor TFBEvents.Destroy;
391			begin
392			if assigned(FCriticalSection) then FCriticalSection.Free;
393			if assigned(FEvents) then FEvents.Free;
394	tony	263	with FFirebirdClientAPI do
395	tony	45	begin
396			if FEventBuffer <> nil then
397	tony	371	FreeMem( FEventBuffer);
398	tony	45	if FResultBuffer <> nil then
399	tony	371	FreeMem( FResultBuffer);
400	tony	45	end;
401			inherited Destroy;
402			end;
403
404			procedure TFBEvents.GetEvents(EventNames: TStrings);
405			begin
406			EventNames.Assign(FEvents)
407			end;
408
409			procedure TFBEvents.SetEvents(EventNames: TStrings);
410	tony	371	var i: integer;
411	tony	45	begin
412	tony	263	{$ifdef Unix}
413	tony	217	if (EventNames.Count > 0) and not IsMultiThread then
414	tony	221	IBError(ibxeMultiThreadRequired,['Firebird Events Handling']);
415	tony	263	{$endif}
416	tony	45	if EventNames.Text <> FEvents.Text then
417			begin
418			Cancel;
419	tony	371	for i := 0 to EventNames.Count - 1 do
420			FEvents[i] := Trim(EventNames[i]);
421	tony	45	CreateEventBlock;
422			end;
423			end;
424
425	tony	56	procedure TFBEvents.SetEvents(Event: AnsiString);
426	tony	45	var S: TStringList;
427			begin
428			S := TStringList.Create;
429			try
430			S.Add(Event);
431			SetEvents(S);
432			finally
433			S.Free;
434			end;
435			end;
436
437			procedure TFBEvents.Cancel;
438			begin
439			if assigned(FEventHandler) then
440			CancelEvents;
441			end;
442
443			function TFBEvents.ExtractEventCounts: TEventCounts;
444			begin
445	tony	47	Result := FEventCounts;
446	tony	45	end;
447
448			function TFBEvents.GetAttachment: IAttachment;
449			begin
450			Result := FAttachment;
451			end;
452
453			end.
454