3 * tailing reliable realtime streaming feeder for inn
4 * filemon.c - file monitoring (inotify, kqueue, poll, etc.)
6 * Copyright (C) 2010 Ian Jackson <ijackson@chiark.greenend.org.uk>
8 * This program is free software: you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation, either version 3 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program. If not, see <http://www.gnu.org/licenses/>.
21 * (I believe that when you compile and link this as part of the inn2
22 * build, with the Makefile runes I have provided, all the libraries
23 * and files which end up included in innduct are licence-compatible
24 * with GPLv3. If not then please let me know. -Ian Jackson.)
29 /*---------- filemon implemented with inotify ----------*/
31 #if defined(HAVE_SYS_INOTIFY_H) && !defined(HAVE_FILEMON)
34 #include <sys/inotify.h>
36 DEFLIST(Filemon_Perfile);
38 struct Filemon_Perfile {
39 ISNODE(Filemon_Perfile);
44 static int filemon_inotify_fd;
45 static Filemon_PerfileList filemon_inotify_watches;
47 static void filemon_method_startfile(InputFile *ipf, Filemon_Perfile *pf) {
50 pf->wd= inotify_add_watch(filemon_inotify_fd, ipf->path, IN_MODIFY);
51 if (pf->wd < 0) sysdie("inotify_add_watch %s", ipf->path);
53 LIST_ADDHEAD(filemon_inotify_watches, pf);
54 dbg("filemon inotify startfile %p wd=%d pf=%p", ipf, pf->wd, pf);
57 static void filemon_method_stopfile(InputFile *ipf, Filemon_Perfile *pf) {
58 dbg("filemon inotify stopfile %p wd=%d pf=%p", ipf, pf->wd, pf);
59 int r= inotify_rm_watch(filemon_inotify_fd, pf->wd);
60 if (r) syscrash("inotify_rm_watch");
61 LIST_REMOVE(filemon_inotify_watches, pf);
64 static void *filemon_inotify_readable(oop_source *lp, int fd,
65 oop_event e, void *u) {
66 struct inotify_event iev;
69 int r= read(filemon_inotify_fd, &iev, sizeof(iev));
71 if (isewouldblock(errno)) break;
72 syscrash("read from inotify master");
73 } else if (r!=sizeof(iev)) {
74 crash("inotify read %d bytes wanted struct of %d", r, (int)sizeof(iev));
77 FOR_LIST_NODE(pf, filemon_inotify_watches)
78 if (pf->wd == iev.wd) goto found;
79 /* Linux seems to remember events and can produce them even after
80 * you've removed the watch. This means that we can't spot bugs
81 * where we lose track of our watches and have to just regard
82 * unexpected random watch events as normal. It's not a
83 * correctness problem as the watch is just a prod to read a file,
84 * which is harmless if it does not need to be read. */
85 dbg("inotify read event on unknown wd=%d", iev.wd);
90 /*dbg("filemon inotify readable read %p wd=%d", ipf, iev.wd);*/
91 tailing_make_readable(ipf);
96 int filemon_method_init(void) {
97 LIST_INIT(filemon_inotify_watches);
98 filemon_inotify_fd= inotify_init();
99 if (filemon_inotify_fd<0) {
100 syswarn("filemon/inotify: inotify_init failed");
103 xsetnonblock(filemon_inotify_fd, 1);
104 loop->on_fd(loop, filemon_inotify_fd, OOP_READ, filemon_inotify_readable, 0);
106 dbg("filemon inotify init filemon_inotify_fd=%d", filemon_inotify_fd);
110 void filemon_method_dump_info(FILE *f) {
111 fprintf(f,"inotify");
112 DUMPV("%d",,filemon_inotify_fd);
113 DUMPV("%d",filemon_inotify_watches.,count);
116 FOR_LIST_NODE(pf, filemon_inotify_watches)
117 fprintf(f," watching %p wd=%d pf=%p\n", pf->ipf, pf->wd, pf);
120 #endif /* HAVE_INOTIFY && !HAVE_FILEMON */
122 /*---------- filemon dummy implementation ----------*/
124 #if !defined(HAVE_FILEMON)
126 struct Filemon_Perfile { int dummy; };
128 int filemon_method_init(void) {
129 warn("filemon/dummy: no filemon method compiled in");
132 static void filemon_method_startfile(InputFile *ipf, Filemon_Perfile *pf) { }
133 static void filemon_method_stopfile(InputFile *ipf, Filemon_Perfile *pf) { }
134 void filemon_method_dump_info(FILE *f) { fprintf(f,"dummy\n"); }
136 #endif /* !HAVE_FILEMON */
138 /*---------- filemon generic interface ----------*/
140 void filemon_start(InputFile *ipf) {
141 assert(!ipf->filemon);
144 filemon_method_startfile(ipf, ipf->filemon);
147 void filemon_stop(InputFile *ipf) {
148 if (!ipf->filemon) return;
149 filemon_method_stopfile(ipf, ipf->filemon);