mc/lib/vfs
Andrew Borodin 4a83daacc4 Ticket #4147: VFS timestamps: use g_get_real_time().
In the function vfs_expire(), curr_time and exp_time are declared
guint64. curr_time is initialised with a timestamp and exp_time
with this timestamp minus vfs_timeout seconds. Later there is if
(stamping->time <= exp_time). Prior to commit
a94dd7d2de curr_time was initialised with
a value larger than vfs_timeout seconds, so everything was fine. This
commit changed the initialisation to a timer starting when mc is
started. So for the first vfs_timeout seconds, the result of the
subtraction is negative, but it is a guint64, so we just get a VERY
large unsigned value and the if (stamping->time <= exp_time) is always
true. So mc thinks the vfs hasn't been used recently and goes into an
infinite loop.

If one opens a .rpm file with mc and goes into the CONTENTS.cpio and
then tries to go into the .tar.gz there (this is the usual structure of
a .rpm) after waiting vfs_timeout seconds, everything is fine. However,
before vfs_timeout seconds, mc hangs.

Solution: use g_get_real_time() instead of mc_timer_elapsed().

Thanks nvwarr at hotmail.com for finding out the reason for this bug.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
2020-12-12 20:39:01 +03:00
..
direntry.c Ticket #4147: VFS timestamps: use g_get_real_time(). 2020-12-12 20:39:01 +03:00
gc.c Ticket #4147: VFS timestamps: use g_get_real_time(). 2020-12-12 20:39:01 +03:00
gc.h VFS GC: reimplement using GSList. 2019-02-03 13:10:00 +03:00
HACKING VFS structure changes: 2011-03-21 11:48:26 +02:00
interface.c Ticket #4145: file names longer than 255 bytes are not supported. 2020-12-12 20:23:05 +03:00
Makefile.am Clarify usage of AM_CPPFLAGS. 2012-12-18 16:27:49 +04:00
netutil.c Ticket #4050: code cleanup before 4.8.25 release. 2020-02-29 19:10:17 +03:00
netutil.h Clarify of sig_atomic_t usage (got from Mutt). 2012-11-09 10:05:13 +04:00
parse_ls_vga.c lib/vfs/parse_ls_vga.c: refactoring. 2020-02-29 19:10:17 +03:00
path.c Ticket #4050: code cleanup before 4.8.25 release. 2020-02-29 19:10:17 +03:00
path.h lib/vfs/path.c: cleanup some -Wcast-qual warning. 2016-04-16 10:23:44 +03:00
README VFS structure changes: 2011-03-21 11:48:26 +02:00
utilvfs.c Ticket #4050: code cleanup before 4.8.25 release. 2020-02-29 19:10:17 +03:00
utilvfs.h Changed input parameters of mc_mkstemp() and mc_tempdir() functions 2012-03-06 11:41:26 +03:00
vfs.c Ticket #4145: file names longer than 255 bytes are not supported. 2020-12-12 20:23:05 +03:00
vfs.h Ticket #4145: file names longer than 255 bytes are not supported. 2020-12-12 20:23:05 +03:00
xdirentry.h Ticket #4147: VFS timestamps: use g_get_real_time(). 2020-12-12 20:39:01 +03:00

NOTE: Although vfs has been meant to be implemented as a separate
entity redistributable under the LGPL in its current implementation it
uses GPLed code from src/. So there are two possibilities if you want
to use vfs:

1. Distribute your copy of vfs under the GPL. Then you can freely
include the GPLed functions from the rest of the mc source code.

2. Distribute your copy of vfs under the LGPL. Then you cannot include
the functions outside the vfs subdirectory. You must then either
rewrite them or work around them in other ways.

========================================================================

Hi!

I'm midnight commander's vfs layer. Before you start hacking me,
please read this file. I'm integral part of midnight commander, but I
try to go out and live my life myself as a shared library, too. That
means that I should try to use as little functions from midnight as
possible (so I'm tiny, nice and people like me), that I should not
pollute name space by unnecessary symbols (so I do not crash fellow
programs) and that I should have a clean interface between myself and
midnight.

Because I'm rather close to midnight, try to:

* Keep the indentation as the rest of the code. Following could help
you with your friend emacs:

(defun mc-c-mode ()
	"C mode with adjusted defaults for use with the Midnight commander."
	(interactive)
	(c-mode)
	(c-set-style "K&R")
	(setq	c-indent-level 4
		c-continued-statement-offset 4
		c-brace-offset 0
		c-argdecl-indent 4
		c-label-offset -4
		c-brace-imaginary-offset 0
		c-continued-brace-offset 0
		c-tab-always-indent nil
		c-basic-offset 4
		tab-width 8
		comment-column 60))

(setq auto-mode-alist (cons '(".*/mc/.*\\.[ch]$" . mc-c-mode)
                       auto-mode-alist))

And because I'm trying to live life on my own as libvfs.so, try to:

* Make sure all exported symbols are defined in vfs.h and begin with
'vfs_'.

* Do not make any references from midnight into modules like tar. It
would probably pollute name space and midnight would depend on concrete
configuration of libvfs. mc_setctl() and mc_ctl() are your
friends. (And mine too :-).

							 Pavel Machek
							 pavel@ucw.cz

PS: If you'd like to use my features in whole operating system, you
might want to link me to rpc.nfsd. On
http://atrey.karlin.mff.cuni.cz/~pavel/podfuk/podfuk.html you'll find
how to do it.

PPS: I have a friend, shared library called avfs, which is LD_PRELOAD
capable. You can reach her at http://www.inf.bme.hu/~mszeredi/avfs.