Current File : //proc/self/root/usr/src/node-v0.10.4/deps/uv/src/unix/linux-inotify.c
/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include "uv.h"
#include "tree.h"
#include "internal.h"
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <sys/types.h>
#include <unistd.h>
struct watcher_list {
RB_ENTRY(watcher_list) entry;
ngx_queue_t watchers;
char* path;
int wd;
};
struct watcher_root {
struct watcher_list* rbh_root;
};
#define CAST(p) ((struct watcher_root*)(p))
/* Don't look aghast, this is exactly how glibc's basename() works. */
static char* basename_r(const char* path) {
char* s = strrchr(path, '/');
return s ? (s + 1) : (char*)path;
}
static int compare_watchers(const struct watcher_list* a,
const struct watcher_list* b) {
if (a->wd < b->wd) return -1;
if (a->wd > b->wd) return 1;
return 0;
}
RB_GENERATE_STATIC(watcher_root, watcher_list, entry, compare_watchers)
static void uv__inotify_read(uv_loop_t* loop,
uv__io_t* w,
unsigned int revents);
static int new_inotify_fd(void) {
int fd;
fd = uv__inotify_init1(UV__IN_NONBLOCK | UV__IN_CLOEXEC);
if (fd != -1)
return fd;
if (errno != ENOSYS)
return -1;
if ((fd = uv__inotify_init()) == -1)
return -1;
if (uv__cloexec(fd, 1) || uv__nonblock(fd, 1)) {
SAVE_ERRNO(close(fd));
return -1;
}
return fd;
}
static int init_inotify(uv_loop_t* loop) {
if (loop->inotify_fd != -1)
return 0;
loop->inotify_fd = new_inotify_fd();
if (loop->inotify_fd == -1) {
uv__set_sys_error(loop, errno);
return -1;
}
uv__io_init(&loop->inotify_read_watcher, uv__inotify_read, loop->inotify_fd);
uv__io_start(loop, &loop->inotify_read_watcher, UV__POLLIN);
return 0;
}
static struct watcher_list* find_watcher(uv_loop_t* loop, int wd) {
struct watcher_list w;
w.wd = wd;
return RB_FIND(watcher_root, CAST(&loop->inotify_watchers), &w);
}
static void uv__inotify_read(uv_loop_t* loop,
uv__io_t* dummy,
unsigned int events) {
const struct uv__inotify_event* e;
struct watcher_list* w;
uv_fs_event_t* h;
ngx_queue_t* q;
const char* path;
ssize_t size;
const char *p;
/* needs to be large enough for sizeof(inotify_event) + strlen(filename) */
char buf[4096];
while (1) {
do
size = read(loop->inotify_fd, buf, sizeof(buf));
while (size == -1 && errno == EINTR);
if (size == -1) {
assert(errno == EAGAIN || errno == EWOULDBLOCK);
break;
}
assert(size > 0); /* pre-2.6.21 thing, size=0 == read buffer too small */
/* Now we have one or more inotify_event structs. */
for (p = buf; p < buf + size; p += sizeof(*e) + e->len) {
e = (const struct uv__inotify_event*)p;
events = 0;
if (e->mask & (UV__IN_ATTRIB|UV__IN_MODIFY))
events |= UV_CHANGE;
if (e->mask & ~(UV__IN_ATTRIB|UV__IN_MODIFY))
events |= UV_RENAME;
w = find_watcher(loop, e->wd);
if (w == NULL)
continue; /* Stale event, no watchers left. */
/* inotify does not return the filename when monitoring a single file
* for modifications. Repurpose the filename for API compatibility.
* I'm not convinced this is a good thing, maybe it should go.
*/
path = e->len ? (const char*) (e + 1) : basename_r(w->path);
ngx_queue_foreach(q, &w->watchers) {
h = ngx_queue_data(q, uv_fs_event_t, watchers);
h->cb(h, path, events, 0);
}
}
}
}
int uv_fs_event_init(uv_loop_t* loop,
uv_fs_event_t* handle,
const char* path,
uv_fs_event_cb cb,
int flags) {
struct watcher_list* w;
int events;
int wd;
if (init_inotify(loop)) return -1;
events = UV__IN_ATTRIB
| UV__IN_CREATE
| UV__IN_MODIFY
| UV__IN_DELETE
| UV__IN_DELETE_SELF
| UV__IN_MOVE_SELF
| UV__IN_MOVED_FROM
| UV__IN_MOVED_TO;
wd = uv__inotify_add_watch(loop->inotify_fd, path, events);
if (wd == -1)
return uv__set_sys_error(loop, errno);
w = find_watcher(loop, wd);
if (w)
goto no_insert;
w = malloc(sizeof(*w) + strlen(path) + 1);
if (w == NULL)
return uv__set_sys_error(loop, ENOMEM);
w->wd = wd;
w->path = strcpy((char*)(w + 1), path);
ngx_queue_init(&w->watchers);
RB_INSERT(watcher_root, CAST(&loop->inotify_watchers), w);
no_insert:
uv__handle_init(loop, (uv_handle_t*)handle, UV_FS_EVENT);
uv__handle_start(handle); /* FIXME shouldn't start automatically */
ngx_queue_insert_tail(&w->watchers, &handle->watchers);
handle->filename = w->path;
handle->cb = cb;
handle->wd = wd;
return 0;
}
void uv__fs_event_close(uv_fs_event_t* handle) {
struct watcher_list* w;
w = find_watcher(handle->loop, handle->wd);
assert(w != NULL);
handle->wd = -1;
handle->filename = NULL;
uv__handle_stop(handle);
ngx_queue_remove(&handle->watchers);
if (ngx_queue_empty(&w->watchers)) {
/* No watchers left for this path. Clean up. */
RB_REMOVE(watcher_root, CAST(&handle->loop->inotify_watchers), w);
uv__inotify_rm_watch(handle->loop->inotify_fd, w->wd);
free(w);
}
}
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