Subject: Re: [RFC][PATCH] inotify 0.9.2
From: Ray Lee <ray-lk@madrabbit.org>
To: John McCutchan <ttb@tentacle.dhs.org>
Cc: Chris Friesen <cfriesen@nortelnetworks.com>, Edgar Toernig <froese@gmx.de>,
       Robert Love <rml@novell.com>,
       Linux Kernel <linux-kernel@vger.kernel.org>,
       viro@parcelfarce.linux.theplanet.co.uk
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Date: Wed, 22 Sep 2004 18:46:53 -0700
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On Tue, 2004-09-21 at 19:27, John McCutchan wrote:
> On Tue, 2004-09-21 at 11:43, Chris Friesen wrote:
> > Edgar Toernig wrote:
> > > Robert Love wrote:
> > > 
> > >> struct inotify_event {
> > >> 	int wd;
> > >> 	int mask;
> > >>-	char filename[256];
> > >>+	char filename[PATH_MAX];
> > >> };
> > > 
> > > 
> > > You really want to shove >4kB per event to userspace???
> > 
> > Ouch.
> > 
> > Maybe make it variable-size?  On average it would likely be shorter.
> > 
> > struct inotify_event {
> > 	int wd;
> > 	int mask;
> > 	short namelen;
> > 	char filename[0];
> > };
> 
> This makes reading events from inotify a pain, first you need to read up
> to namelen, then read namelen more bytes. 
> 

Not the case. A mildly smarter userspace program would merely read
everything outstanding (or everything up to a fixed buffer length), and
then unserialize the events based on the boundaries it can figure out
from the first portion of the structure.

This is a way common technique.

At least in code I write, anyway :-).

Ray

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