How to query if there is cached data of a specified range?

NTFSD
1

Is there any way (any API call) to query if there is cached data of a
specified range?

2

Please reprahse !?

----- Original Message -----
From: “Eric Chan”
To: “File Systems Developers”
Sent: Wednesday, August 14, 2002 3:22 AM
Subject: [ntfsd] How to query if there is cached data of a specified range?

> Is there any way (any API call) to query if there is cached data of a
> specified range?
>
> —
> You are currently subscribed to ntfsd as: xxxxx@rdsor.ro
> To unsubscribe send a blank email to %%email.unsub%%
>

3

Is there any way to know if a file of particular offset and range is
cached?

Suppose I want to read a file from ByteOffset 4096 and Length 200, how can
I know if the cache has that range of data?

4

No API call for this.

Dan
----- Original Message -----
From: “Eric Chan”
To: “File Systems Developers”
Sent: Wednesday, August 14, 2002 3:22 AM
Subject: [ntfsd] How to query if there is cached data of a specified range?

> Is there any way (any API call) to query if there is cached data of a
> specified range?
>
> —
> You are currently subscribed to ntfsd as: xxxxx@rdsor.ro
> To unsubscribe send a blank email to %%email.unsub%%
>

5

Hi,

CcCopyRead with Wait parameter set to FALSE will return FALSE if data is
not in the cache, otherwise it will let you read the data.

If you don’t want to read data but want to check that if data already in
the cache it stays in the cache while you need it use CcPinData with flags
parameter 0 and use CcUnpinData when you done with it.

Just asking if data is in the cache right now doesn’t make any sense
because it can be removed from cache immediately after you had asked.

Suppose I want to read a file from ByteOffset 4096 and Length 200, how
can
I know if the cache has that range of data?

Alexei.