nsxiv/autoreload_inotify.c
2017-05-17 20:12:22 +02:00

136 lines
3.5 KiB
C

/* Copyright 2017 Max Voit
*
* This file is part of sxiv.
*
* sxiv is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2 of the License,
* or (at your option) any later version.
*
* sxiv is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with sxiv. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/inotify.h>
#include <libgen.h>
#include "util.h"
#include "autoreload.h"
CLEANUP void arl_cleanup(arl_t *arl)
{
if (arl->fd != -1 && arl->wd != -1) {
if (inotify_rm_watch(arl->fd, arl->wd))
error(0, 0, "Failed to remove inotify watch.");
}
}
static void arl_setup_dir(arl_t *arl, const char *filepath)
{
char *dntmp, *dn;
if (arl->fd == -1) {
error(0, 0, "Uninitialized, could not add inotify watch on directory.");
return;
}
/* get dirname */
dntmp = (char*) strdup(filepath);
dn = (char*) dirname(dntmp);
/* this is not one-shot as other stuff may be created too
* note: we won't handle deletion of the directory itself,
* this is a design decision
*/
arl->wd = inotify_add_watch(arl->fd, dn, IN_CREATE);
if (arl->wd == -1)
error(0, 0, "Failed to add inotify watch on directory '%s'.", dn);
else
arl->watching_dir = true;
free(dntmp);
}
bool arl_handle(arl_t *arl, const char *filepath)
{
bool reload = false;
char buf[4096] __attribute__ ((aligned(__alignof__(struct inotify_event))));
char *ptr;
const struct inotify_event *event;
ssize_t len = read(arl->fd, buf, sizeof(buf));
if (len == -1) {
error(0, 0, "Failed to read inotify events.");
return false;
}
for (ptr = buf; ptr < buf + len; ptr += sizeof(*event) + event->len) {
event = (const struct inotify_event*) ptr;
/* events from watching the file itself */
if (event->mask & IN_CLOSE_WRITE) {
reload = true;
}
if (event->mask & IN_DELETE_SELF)
arl_setup_dir(arl, filepath);
/* events from watching the file's directory */
if (event->mask & IN_CREATE) {
char *fntmp = strdup(filepath);
char *fn = basename(fntmp);
if (STREQ(event->name, fn)) {
/* this is the file we're looking for */
/* cleanup, this has not been one-shot */
if (arl->watching_dir) {
if (inotify_rm_watch(arl->fd, arl->wd))
error(0, 0, "Failed to remove inotify watch.");
arl->watching_dir = false;
}
reload = true;
}
free(fntmp);
}
}
return reload;
}
void arl_init(arl_t *arl)
{
/* this needs to be done only once */
arl->fd = inotify_init();
arl->watching_dir = false;
if (arl->fd == -1)
error(0, 0, "Could not initialize inotify.");
}
void arl_setup(arl_t *arl, const char *filepath)
{
if (arl->fd == -1) {
error(0, 0, "Uninitialized, could not add inotify watch.");
return;
}
/* may have switched from a deleted to another image */
if (arl->watching_dir) {
if (inotify_rm_watch(arl->fd, arl->wd))
error(0, 0, "Failed to remove inotify watch.");
arl->watching_dir = false;
}
arl->wd = inotify_add_watch(arl->fd, filepath,
IN_ONESHOT | IN_CLOSE_WRITE | IN_DELETE_SELF);
if (arl->wd == -1)
error(0, 0, "Failed to add inotify watch on file '%s'.", filepath);
}