On Sat, 12 Aug 2000, Michal Jaegermann wrote:
>Proponent of Rube Goldberg-like contraptions for storing "extendent
>information" about files claim that an obvious answer of using
>directories for such purpose is "brittle". A long real-life experies
>from NeXTSTEP does not support that.
>
>On NeXT various "NeXT Apps" are simply directory tries and command line
>tools do not even try to hide that fact. If you are using graphical
>file tools then by default they will show up as a single entity but an
>extra command, not hidden very deeply :-), will allow you to open such
>unit as a directory and get to components separately. This is,
>actually, a _good thing_ as a user can, for example, adjust and
>customize various interface elements using Interface Builder. After
>many years when NeXTSTEP is around I do not recall serious complaints
>that this leads to a breakage and if somebody will acutally mess
>something up then things are easily fixable.
>
>OTOH various other complicated schemes for storing a meta-information
>invariably turn out to be a major PITA and _really brittle_ outside
>their very narrowly defined "native environments" and break regularly
>when somebody will do something "unexpected" (read - use some standard
>and universal tool).
>
>With all this evidence in mind I watch pretty amazed when this
>discussion periodically flares up and various kludges are proposed
>as if nobody tried something like that in the past.
I agree. Trying to do an FSCK on such a beast must be REALLY fun.
The old UNISYS had similar things to track file revisions. Half the
time the file got really screwed when there was a crash - the same
line of fortran would be repeated (once for every change made to it).
It also made the filesystem very slow.
The only support I can think of would be a flag on a "directory" to
indicate to an underlying file system that the file is complex. That
way when a unix tar, cpio, dump ... (they have to carry the bit) copies
files out, the mkdir would recieve the flag. The underlying FS could
impliment it as either a simple directory (plus flag), or a complex file
with native streams. Tar and cpio copying from a filesystem with the
native streams would see a directory with the bit.
No changes to open or anything but the directory functions to pass
the flag back and forth.
-- ------------------------------------------------------------------------- Jesse I Pollard, II Email: pollard@cats-chateau.netAny opinions expressed are solely my own.
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