> Or, you know, double the size of the buffer and call it again starting at
zero
Although not elegant, that is what I would do. I have to do the same when
getting retrieval pointers of a file.
On Tue, Jul 10, 2018 at 12:40 PM xxxxx@osr.com wrote:
> From the MSDN documentation: > >
> > It says “…to retrieve the remaining bitmap”… so, you start with the > NEXT LCN, I would think. > > Or, you know, double the size of the buffer and call it again starting at > zero > > Peter > OSR > @OSRDrivers > > > — > NTDEV is sponsored by OSR > > Visit the list online at: < > http://www.osronline.com/showlists.cfm?list=ntdev> > > MONTHLY seminars on crash dump analysis, WDF, Windows internals and > software drivers! > Details at http: > > To unsubscribe, visit the List Server section of OSR Online at < > http://www.osronline.com/page.cfm?name=ListServer> >
– Jamey Kirby Disrupting the establishment since 1964
This is a personal email account and as such, emails are not subject to archiving. Nothing else really matters.</http:>
And with a little math, you can figure out how large the buffer needs to be
for the entire volume (or pretty darn close).
On Tue, Jul 10, 2018 at 12:47 PM Jamey Kirby wrote:
> > Or, you know, double the size of the buffer and call it again starting > at zero > > Although not elegant, that is what I would do. I have to do the same when > getting retrieval pointers of a file. > > On Tue, Jul 10, 2018 at 12:40 PM xxxxx@osr.com > wrote: > >> From the MSDN documentation: >> >>
>> >> It says “…to retrieve the remaining bitmap”… so, you start with the >> NEXT LCN, I would think. >> >> Or, you know, double the size of the buffer and call it again starting at >> zero >> >> Peter >> OSR >> @OSRDrivers >> >> >> — >> NTDEV is sponsored by OSR >> >> Visit the list online at: < >> http://www.osronline.com/showlists.cfm?list=ntdev> >> >> MONTHLY seminars on crash dump analysis, WDF, Windows internals and >> software drivers! >> Details at http: >> >> To unsubscribe, visit the List Server section of OSR Online at < >> http://www.osronline.com/page.cfm?name=ListServer> >> > > > – > Jamey Kirby > Disrupting the establishment since 1964 > > This is a personal email account and as such, emails are not subject to > archiving. Nothing else really matters. >
– Jamey Kirby Disrupting the establishment since 1964
This is a personal email account and as such, emails are not subject to archiving. Nothing else really matters.</http:>
If you mean “How do I CALCULATE the next LCN” the answer is: You take the number of bytes returned to you and multiple by 8. That’s the NEXT LCN number.
Just for testing purposes, you can validate that you’re computing the next LCN correctly by retrieving the bitmap for a few clusters BEFORE that next LCN, and comparing the contents of the two buffers. That is, let’s say you get clusters 1 through 16 in your first request (you’ll get a lot more than this, but this is an example). You then get 17 through 32 in your SECOND request. You can validate that you’re calculating things correctly by retrieving the bitmap for clusters 8 through 24 and comparing the bits at the end of the first buffer you had previous retrieved and at the beginning of the second buffer you previously retrieved.