Mark,
I have had good success lately using file-based databases as the overhead of
database connections is avoided. I currently favour DBISAM for this. When I
have used Interbase in the past I implemented connection pooling. Each
thread instantiates a new tsession and tquery and sets the matching session
names accross these components and the pooled tdatabase.
I prefer not to use Web Broker components - mainly because I have been doing
this ISAPI stuff since long before they appeared and have found little
reason to change. Although with Kylix I may have to.
regards,
Steve
The following is a simple straight ISAPI app without using a webmodule or
datamodule and compiles to a 831k dll most of which is the complete DBISAM
engine. With the database stuff commented out it becomes a 42k dll: (many
things omitted obviously for this demo)
library hello;
uses
windows,
sysutils,
Isapi2,
DBISAMTb;
const
CR = #13#10;
DataDir = 'c:\inetpub\wwwroot\test\data\';
function GetExtensionVersion( var Ver: THSE_VERSION_INFO ): BOOL; stdcall;
begin
Ver.dwExtensionVersion := $00010000; // Version 1.0
Ver.lpszExtensionDesc := 'blah';
Result := True;
end;
function HttpExtensionProc( var ECB: TEXTENSION_CONTROL_BLOCK ): DWORD;
stdcall;
var
ResStr : string;
StrLen : Integer;
rc : Integer;
begin
IsMultiThread := true; // for thread-safe VCL memory management
ECB.dwHTTPStatusCode := 200;
ECB.lpszLogData := 'Delphi DLL Log';
ResStr := '<HTML><body>';
ResStr := ResStr + '<H1 ALIGN=CENTER>Hello World.</H1>';
Sessions.OpenSession( IntToStr( GetCurrentThreadID ) );
Sessions.CurrentSession.PrivateDir := DataDir;
rc := 0 ;
try
with TDBISAMTable.create( nil ) do try
SessionName := IntToStr( GetCurrentThreadID );
DatabaseName := DataDir;
TableName := 'test.dat';
Open;
rc := RecordCount ;
close ;
finally
free ;
end ;
finally
with Sessions.FindSession( IntToStr( GetCurrentThreadID ) )
do
close;
ResStr := ResStr + '<p>There are '+IntToStr(rc)+' records in the table';
end ;
ResStr := ResStr + '</body></HTML>';
ResStr := Format( 'HTTP/1.0 200 OK' + CR +
'Content-Type: text/html' + CR +
'Content-Length: %d' + CR +
'Content:' + CR + CR + '%s', [Length(ResStr), ResStr]);
StrLen := Length(ResStr);
ECB.WriteClient(ECB.ConnID, Pointer(ResStr), DWORD(StrLen), 0);
Result := HSE_STATUS_SUCCESS;
end;
exports
GetExtensionVersion,
HttpExtensionProc;
begin
// you could do your connection pool setup here
end.
> -----Original Message-----
> From: Gary T. Benner [mailto:[EMAIL PROTECTED]]
> Sent: Monday, 2 April 2001 12:50
> To: Multiple recipients of list delphi
> Subject: RE: Re: [DUG]: ISAPI dlls...
>
>
> [Reply]
>
> HI all,
>
> For ISAPI stuff the best site for tutorials is
> www.matlus.com. The guy who writes the articles is called
> Shriv Kumar, and he's quite
> good. Some of his articles are also on the Delphi Informant website.
>
> Re using the TSession component, you need this when you use
> the BDE to access the database. From experience, if you are
> using IB as a backend, then use IBO or IBX, not the BDE. If
> you are using local files, use TClientDatasets or other non-BDE
> types. I believe DBISAM (?) works well.
>
> I've been working on connection pooling techniques,and it is
> possible, and does help manage connections well.
>
> Kind Regards
>
>
> Gary
>
>
>
>
> At 12:10 on 2/04/2001 you wrote
>
> >To :
> >CC :
> >From: Mark Derricutt, [EMAIL PROTECTED]
> >Hey guys, I'm still trying to get this ISAPI working. Well,
> it works, just
> >not under load. Someone mentioned putting a TSession
> component on my
> >webmodule and use that to allow the reuse of an existing
> connection, but
> >no, that doesn't work, IIS just doesn't run the app at all then.
> >
> >If theres anyone here whose done alot of ISAPI stuff before,
> are you able
> >to lend a hand, maybe blat up a simple demo project showing
> how I should be
> >handling multiple threads talking t the same connection (I
> tried putting
> >the TDatabase in its own TDataModule but that didn't wanna
> run either).
> >
> >*mutter*
> >
> >Any help out there?
> >
> >
> >--On Friday, March 30, 2001 12:56 PM +1200 Mark Derricutt
> ><[EMAIL PROTECTED]> wrote:
> >
> >> What would cause the DB to no longer be connected.... mmmmm
> >
> >--
> >There are exceptions, I'm sure, but the Windows 2000 on-line
> community
> >seems to have, in general, the moral and spiritual qualities of your
> >average porn site. (c) Bryan Pfaffenberger, Linux Journal, Jan 2001.
> >-------------------------------------------------------------
> --------------
> > New Zealand Delphi Users group - Delphi List -
> [EMAIL PROTECTED]
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>
>
>
> ========================================================
>
> Gary Benner - Software Developer
> [EMAIL PROTECTED]
> Corporate Software New Zealand Limited Auckland - New Zealand
> tel: +64-9 846-6067 (24hr) fax: +64-9 846-6152 mob:
> (021)-966-992
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>
> Ref#: 41006
>
>
>
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