FILELEN() Function slow to update?

Re: FILELEN() Function slow to update?


"Keith Elkin" <keith@keithelk in.com> wrote in message
news:d%AQb.1452 3$O22.8858790@n ews4.srv.hcvlny .cv.net...[color=blue]
> I'm having a strange problem using random file access and was[/color]
wondering if[color=blue]
> anyone is aware of why this might be happening. When I write new[/color]
records to[color=blue]
> the file, it seems to take a few seconds before the FILELEN() function[/color]
to[color=blue]
> update with the accurate length. As a test I did the following:
>
> Sub test()
> Dim inta As Integer
>
> For inta = 1 To 5
>
> Raffle.TicketsP urchased = inta
> Put #20, inta, Raffle
> Get #20, inta, Raffle
> 'Delay (2) Notice this is commented out)
> intNumRows = FileLen(App.Pat h & "\herosraffle.d at") / Len(Raffle)
> Say (Str(intNumRows ) + " " + Str(Raffle.Tick etsPurchased))
> Next inta
> End Sub
>
>
> This gave me the following results
>
> 1 1
> 1 2
> 2 3
> 3 4
> 4 5
>
>
> If I re-run the code with the 2 second delay added in I get
>
> 1 1
> 2 2
> 3 3
> 4 4
> 5 5
>
>
> Why does it take so long for FILELEN() to update? Is there another[/color]
way I[color=blue]
> can check for how many records are in the file using a different[/color]
command?[color=blue]
> Adding a delay slows down the process this program is performing.[/color]
Thanks in[color=blue]
> advance,
> -Keith
>
>[/color]
Use LOF(#) to get the length of an open file (in your case, LOF(20).
FileLen(Path) is for closed files. You also might want to use FreeFile
to get a file number, instead of using a hard coded value.

Re: FILELEN() Function slow to update?

Data written to disk is a buffered action, which Windows does when it can.

BTW, the proper formula for calculating the number of records in a random
access file, once it has been opened, is:

totalrecords = LOF(#hfile) \ Len(YourUDT)

Notice too that the division is Integer division, not Floating Point, as
there will never be a decimal.

And conversely, FYI, the next new record for a random access file is always
totalrecords + 1


--

Randy Birch
MVP Visual Basic

Please respond only to the newsgroups so all can benefit.

There's no place like 127.0.0.1


"Keith Elkin" <keith@keithelk in.com> wrote in message
news:d%AQb.1452 3$O22.8858790@n ews4.srv.hcvlny .cv.net...
: I'm having a strange problem using random file access and was wondering if
: anyone is aware of why this might be happening. When I write new records
to
: the file, it seems to take a few seconds before the FILELEN() function to
: update with the accurate length. As a test I did the following:
:
: Sub test()
: Dim inta As Integer
:
: For inta = 1 To 5
:
: Raffle.TicketsP urchased = inta
: Put #20, inta, Raffle
: Get #20, inta, Raffle
: 'Delay (2) Notice this is commented out)
: intNumRows = FileLen(App.Pat h & "\herosraffle.d at") / Len(Raffle)
: Say (Str(intNumRows ) + " " + Str(Raffle.Tick etsPurchased))
: Next inta
: End Sub
:
:
: This gave me the following results
:
: 1 1
: 1 2
: 2 3
: 3 4
: 4 5
:
:
: If I re-run the code with the 2 second delay added in I get
:
: 1 1
: 2 2
: 3 3
: 4 4
: 5 5
:
:
: Why does it take so long for FILELEN() to update? Is there another way I
: can check for how many records are in the file using a different command?
: Adding a delay slows down the process this program is performing. Thanks
in
: advance,
: -Keith
:
: