autoreload_inotify.c (2710B)
1 /* Copyright 2017 Max Voit, Bert Muennich 2 * 3 * This file is part of sxiv. 4 * 5 * sxiv is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published 7 * by the Free Software Foundation; either version 2 of the License, 8 * or (at your option) any later version. 9 * 10 * sxiv is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with sxiv. If not, see <http://www.gnu.org/licenses/>. 17 */ 18 19 #include "sxiv.h" 20 21 #include <errno.h> 22 #include <stdlib.h> 23 #include <string.h> 24 #include <unistd.h> 25 #include <sys/inotify.h> 26 27 void arl_init(arl_t *arl) 28 { 29 arl->fd = inotify_init1(IN_CLOEXEC | IN_NONBLOCK); 30 arl->wd_dir = arl->wd_file = -1; 31 if (arl->fd == -1) 32 error(0, 0, "Could not initialize inotify, no automatic image reloading"); 33 } 34 35 CLEANUP void arl_cleanup(arl_t *arl) 36 { 37 if (arl->fd != -1) 38 close(arl->fd); 39 free(arl->filename); 40 } 41 42 static void rm_watch(int fd, int *wd) 43 { 44 if (*wd != -1) { 45 inotify_rm_watch(fd, *wd); 46 *wd = -1; 47 } 48 } 49 50 static void add_watch(int fd, int *wd, const char *path, uint32_t mask) 51 { 52 *wd = inotify_add_watch(fd, path, mask); 53 if (*wd == -1) 54 error(0, errno, "inotify: %s", path); 55 } 56 57 void arl_setup(arl_t *arl, const char *filepath) 58 { 59 char *base = strrchr(filepath, '/'); 60 61 if (arl->fd == -1) 62 return; 63 64 rm_watch(arl->fd, &arl->wd_dir); 65 rm_watch(arl->fd, &arl->wd_file); 66 67 add_watch(arl->fd, &arl->wd_file, filepath, IN_CLOSE_WRITE | IN_DELETE_SELF); 68 69 free(arl->filename); 70 arl->filename = estrdup(filepath); 71 72 if (base != NULL) { 73 arl->filename[++base - filepath] = '\0'; 74 add_watch(arl->fd, &arl->wd_dir, arl->filename, IN_CREATE | IN_MOVED_TO); 75 strcpy(arl->filename, base); 76 } 77 } 78 79 union { 80 char d[4096]; /* aligned buffer */ 81 struct inotify_event e; 82 } buf; 83 84 bool arl_handle(arl_t *arl) 85 { 86 bool reload = false; 87 char *ptr; 88 const struct inotify_event *e; 89 90 for (;;) { 91 ssize_t len = read(arl->fd, buf.d, sizeof(buf.d)); 92 93 if (len == -1) { 94 if (errno == EINTR) 95 continue; 96 break; 97 } 98 for (ptr = buf.d; ptr < buf.d + len; ptr += sizeof(*e) + e->len) { 99 e = (const struct inotify_event*) ptr; 100 if (e->wd == arl->wd_file && (e->mask & IN_CLOSE_WRITE)) { 101 reload = true; 102 } else if (e->wd == arl->wd_file && (e->mask & IN_DELETE_SELF)) { 103 rm_watch(arl->fd, &arl->wd_file); 104 } else if (e->wd == arl->wd_dir && (e->mask & (IN_CREATE | IN_MOVED_TO))) { 105 if (STREQ(e->name, arl->filename)) 106 reload = true; 107 } 108 } 109 } 110 return reload; 111 } 112