Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!psuvax1!psuvm!blekul11!gutest8
From: GUTEST8@cc1.kuleuven.ac.be (Ives Aerts)
Newsgroups: comp.sys.amiga.programmer
Subject: EXAMINE_NEXT problem, how does amigados do it ?
Message-ID: <91133.150111GUTEST8@cc1.kuleuven.ac.be>
Date: 13 May 91 14:59:11 GMT
Organization: K.U.Leuven - Academic Computing Center
Lines: 37

I have to implement an examine next function for my device
and can't find one that works efficiently.

From what I've read I conclude that I can only use the disk key
and filename information from the supplied FileInfoBlock to
determine what's the next directory entry to examine.
The supplied lock doesn't have to be the same as the one passed
in the previous examine or examine next call and the file info
block can be a new one with the diskkey and filename fields
copied from the previous FileInfoBlock. I allso can't store
any intermediate information in a structure or variable owned
by myself 'cos there's no way to find out when I can clear
this information (which would lead to an out of memory
situation after a number of examine/examine next calls)
Therefor only the diskkey and filename from the last
FileInfoBlock can be used. Correct me if this is wrong.

The solution I came up with is this one:
    Allways examine the directory entry with the smallest
    diskkey larger than the one in the FileInfoBlock.
This way I won't run into problems if the last diskkey
points to a file or directory that has been deleted since
the examine next call.
Trouble is that I have to traverse the whole directory
each time to find the smallest diskkey I can pass on.
This is quite an amount of overhead for large directories.
I allso won't catch any new files with a small diskkey
that appear while scanning the directory.

Anyone who came up with a better solution ? And to the
folx at commodore (I guess randell should know this) how
does amigados do this ?
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