RE: [eclipse-incubator-e4-dev] [resources]File systemlayer requirements

[John Arthorne <John_Arthorne@xxxxxxxxxx>]

Doug wrote on 10/15/2008 10:33:36 AM:

> > For me interesting part of JSR208 is WatchService API. I 
> > think that we could consider having file system notifications
> > in EFS, instead of RefreshProvider API available only on the
> > resource layer.
> 
> This is a good question. I don't think we've totally thought through
the
> delta notification mechanism yet. I think by default we're putting
it in
> the Project layer. I'll take a look at JSR 208 (or is it 203?) and
get a
> feel for what they are trying to accomplish.

To be clear, while file system level notification
is good (we have this today on Windows), it's not a replacement for delta
notification at the project layer. What deltas provide are *batched* notification
of changes to both physical files and corresponding resource *metadata*
(deltas are a description of everything that happened since you were last
notified).  File system level notification typically involves fine-grained,
unbatched notification of changes in the file system only (they describe
a moment in time rather than a span of time). So, while FS notification
can be used to reduce the notification lag on changes made directly in
the file system, it can't in any way replace the benefits clients are getting
from the resource delta mechanism today.

John