ISAPI How to maintain conenction between client and web serv
Mark A Gregory -- m.gregory@rmit.edu.au
Friday, May 17, 1996
[Moderator's note: Environment completely unknown, and I still don't
see why this is an MFC question, but I'm tired of dealing with this.]
----------
Hi,
I would like to know how long a connection to a Web server is
maintained from the point when a client first accesses one of the pages
on the server.
I want to allow the client to do a number of things, and to store the
result of these actions in a temp file. I need to access the file
every time the client sends a new request.
I want to know if I can use the HCONN connID member of the
EXTENSION_CONTROL_BLOCK for this purpose and how long does it remain
valid.
thank you Mark A Gregory
Steve Dunn -- steved@globalnet.co.uk
Sunday, May 19, 1996
Mark A Gregory wrote:
> I would like to know how long a connection to a Web server is
> maintained from the point when a client first accesses one of the pages
> on the server.
>
> I want to allow the client to do a number of things, and to store the
> result of these actions in a temp file. I need to access the file
> every time the client sends a new request.
>
> I want to know if I can use the HCONN connID member of the
> EXTENSION_CONTROL_BLOCK for this purpose and how long does it remain
> valid.
As I understand, you simply call the ISAPI app and it remains
permanently 'connected' (ie. does not re-instantiate itself, just
starts another thread) every time it is called. Stick your code in
C(whateverclass)::Default(CHttpServerContext* pCtxt)
Remember to call Enter/Leave CriticalSection as it is possible for more
than one thread to access shared resources at the same time.
Hope this was of help. (PS. Files (ie. counters) need only be written
once when the ISAPI app shuts down)
Larry Helber -- lhelber@targetvision.com
Monday, May 20, 1996
> I would like to know how long a connection to a Web server is
> maintained from the point when a client first accesses one of the pages
> on the server.
The length of time you are connected to a Web server is the amount of time
required to transfer the request. For example to receive a full HTML document
with graphics the process looks like this:
client connects to server and request an html file, the server then sends the
file to the client and terminates the connection. The client then parses through
the html document looking for graphic links and repeats the process for each
grpahic.
> I want to allow the client to do a number of things, and to store the
> result of these actions in a temp file. I need to access the file
> every time the client sends a new request.
This is the problem of a lot of Webmasters. The most common way of handling this
task is to include some for of process ID along with the request. If you see a
URL that looks like "http://www.shopping.com/computers/system.html?23540-9120354"
The long number is a process state for filling a shopping cart. I have seen
several libraries availible to handle this for you or you can try and roll your
that handles your own specific needs.
> I want to know if I can use the HCONN connID member of the
> EXTENSION_CONTROL_BLOCK for this purpose and how long does it remain
> valid.No. See above explanation
Mark A Gregory -- m.gregory@rmit.edu.au
Tuesday, May 21, 1996
[Mini-digest: 2 responses]
Hi Larry,
you suggested that you knew of a code scheme that would help me with my problem, I
would really appreciate more info on this.
I created an ISA extension and changed Default. I have tried fopen, ofstream, CreateFile, etc.
and I cannot write to a file, yet two examples that I have which are .exe (from a book, written in
Visual C++) read/write to a file.
Are you able to help, can you please tell me what is wrong with the code shown here.
I find that yet again Microsoft has provided a really great tool and have not provided enough info
for someone to use it.
Thank you
Mark A Gregory
------------------------------------------------
void CTobasketExtension::Default(CHttpServerContext* pCtxt)
{
StartContent(pCtxt);
WriteTitle(pCtxt);
*pCtxt << _T("This default message was produced by the Internet");
*pCtxt << _T(" Server DLL Wizard. Edit your CTobasketExtension::Default()");
*pCtxt << _T(" implementation to change it.\r\n");
EndContent(pCtxt);
char szArgs[1024];
char szFileName[1024];
strcpy (szArgs, "This is a test");
strcpy (szFileName, "ABC.TMP");
ofstream *pfileout;
pfileout = new ofstream(szFileName,ios::app);
*pfileout << szArgs <<"\n";
delete pfileout;
FILE* log=fopen("ABC.LOG","a");
fprintf(log,szArgs);
fprintf(log,"\n");
fclose (log);
}
-----From: "David W. Gillett"
> > I would like to know how long a connection to a Web server is
> > maintained from the point when a client first accesses one of the pages
> > on the server.
>
> The length of time you are connected to a Web server is the amount
> of time required to transfer the request. For example to receive a
> full HTML document with graphics the process looks like this:
> client connects to server and request an html file, the server
> then sends the file to the client and terminates the connection.
> The client then parses through the html document looking for
> graphic links and repeats the process for each graphic.
This is a concept that many people find difficult. Once the client
has received the "page", that connection is closed.
> > I want to allow the client to do a number of things, and to store the
> > result of these actions in a temp file. I need to access the file
> > every time the client sends a new request.
>
> This is the problem of a lot of Webmasters. The most common way of
> handling this task is to include some for of process ID along with
> the request. If you see a URL that looks like
> "http://www.shopping.com/computers/system.html?23540-9120354" The
> long number is a process state for filling a shopping cart. I
> have seen several libraries availible to handle this for you or
> you can try and roll your that handles your own specific needs.
This perhaps needs to be elaborated upon just a little. In sending
back the initial "page", you want to insert some context info into
(some of) the links on the page, so that a subsequent request
(generated by the user following one of those links) carries enough
context with it to either re-attach-to or re-create the previous
context. (And understand that the user you just sent a page to might
not come back for more, so saved contexts should have a limited
lifetime. If you need to establish a long-term context for this
user, consider using a cookie instead.)
> > I want to know if I can use the HCONN connID member of the
> > EXTENSION_CONTROL_BLOCK for this purpose and how long does it remain
> > valid.
>
> No. See above explanation
Dave
| Вернуться в корень Архива
|