On Thu, Oct 23, 2008 at 3:33 PM, Andreas Masur <amasur@gmx.de> wrote:
On Oct 23, 2008, at 9:14 AM, Giovanni Piero Deretta wrote:
On Thu, Oct 23, 2008 at 2:45 PM, Carlos Rafael Giani <e0325834@student.tuwien.ac.at> wrote:
Hi,
is a file monitor feature planned for boost.filesystem? I have been looking for a platform independent solution, but there is none (except in toolkits like Qt). Also, so far only inotify (a subsystem in the Linux kernel) can tell me when a file is closed after writing, which is absolutely necessary when watching a plugins/ directory, for example (you don't want to touch the plugins when they're only halfway copied). Several tools watch the plugin directory, but don't care if the plugins are being written or are fully there already. This can lead to instabilities.
I think it is only logical to add this to boost.filesystem, something like set_monitor_callback(pathname, function_object);
On the contrary, I think that the logical place to add this is boost.asio. In fact it should be relatively easy to add there. I think someone already implemented it. You might want to ask in the Asio mailing list.
May I ask why? As far as I understand boost.asio, it deals with the I/O of external systems (networking, serial etc.). A file monitoring feature in my eyes rather deals with the filesystem.
Asio doesn't just deal with I/O, but can be used as a general multiplexer for asynchronous system events. For example it supports timer expiration events and asynchronous DNS name resolution. In fact I do not see how boost file system could support an event callback without replicating large parts of asio. Please, let's not add another event loop to boost. -- gpd