glib/gio/inotify/inotify-helper.c
2014-01-31 14:31:55 +01:00

294 lines
7.5 KiB
C

/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 2; tab-width: 8 -*- */
/* inotify-helper.c - GVFS Monitor based on inotify.
Copyright (C) 2007 John McCutchan
The Gnome Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The Gnome Library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the Gnome Library; see the file COPYING.LIB. If not,
see <http://www.gnu.org/licenses/>.
Authors:
John McCutchan <john@johnmccutchan.com>
*/
#include "config.h"
#include <errno.h>
#include <time.h>
#include <string.h>
#include <sys/ioctl.h>
/* Just include the local header to stop all the pain */
#include <sys/inotify.h>
#include <gio/glocalfile.h>
#include <gio/gfilemonitor.h>
#include <gio/gfile.h>
#include "inotify-helper.h"
#include "inotify-missing.h"
#include "inotify-path.h"
static gboolean ih_debug_enabled = FALSE;
#define IH_W if (ih_debug_enabled) g_warning
static void ih_event_callback (ik_event_t *event,
inotify_sub *sub,
gboolean file_event);
static void ih_not_missing_callback (inotify_sub *sub);
/* We share this lock with inotify-kernel.c and inotify-missing.c
*
* inotify-kernel.c takes the lock when it reads events from
* the kernel and when it processes those events
*
* inotify-missing.c takes the lock when it is scanning the missing
* list.
*
* We take the lock in all public functions
*/
G_LOCK_DEFINE (inotify_lock);
static GFileMonitorEvent ih_mask_to_EventFlags (guint32 mask);
/**
* _ih_startup:
*
* Initializes the inotify backend. This must be called before
* any other functions in this module.
*
* Return value: #TRUE if initialization succeeded, #FALSE otherwise
*/
gboolean
_ih_startup (void)
{
static gboolean initialized = FALSE;
static gboolean result = FALSE;
G_LOCK (inotify_lock);
if (initialized == TRUE)
{
G_UNLOCK (inotify_lock);
return result;
}
result = _ip_startup (ih_event_callback);
if (!result)
{
G_UNLOCK (inotify_lock);
return FALSE;
}
_im_startup (ih_not_missing_callback);
IH_W ("started gvfs inotify backend\n");
initialized = TRUE;
G_UNLOCK (inotify_lock);
return TRUE;
}
/*
* Adds a subscription to be monitored.
*/
gboolean
_ih_sub_add (inotify_sub *sub)
{
G_LOCK (inotify_lock);
if (!_ip_start_watching (sub))
_im_add (sub);
G_UNLOCK (inotify_lock);
return TRUE;
}
/*
* Cancels a subscription which was being monitored.
*/
gboolean
_ih_sub_cancel (inotify_sub *sub)
{
G_LOCK (inotify_lock);
if (!sub->cancelled)
{
IH_W ("cancelling %s\n", sub->dirname);
sub->cancelled = TRUE;
_im_rm (sub);
_ip_stop_watching (sub);
}
G_UNLOCK (inotify_lock);
return TRUE;
}
static char *
_ih_fullpath_from_event (ik_event_t *event,
const char *dirname,
const char *filename)
{
char *fullpath;
if (filename)
fullpath = g_strdup_printf ("%s/%s", dirname, filename);
else if (event->name)
fullpath = g_strdup_printf ("%s/%s", dirname, event->name);
else
fullpath = g_strdup_printf ("%s/", dirname);
return fullpath;
}
static gboolean
ih_event_is_paired_move (ik_event_t *event)
{
if (event->pair)
{
ik_event_t *paired = event->pair;
/* intofiy(7): IN_MOVE == IN_MOVED_FROM | IN_MOVED_TO */
return (event->mask | paired->mask) & IN_MOVE;
}
return FALSE;
}
static void
ih_event_callback (ik_event_t *event,
inotify_sub *sub,
gboolean file_event)
{
gchar *fullpath;
GFileMonitorEvent eflags;
GFile* child;
GFile* other;
eflags = ih_mask_to_EventFlags (event->mask);
fullpath = _ih_fullpath_from_event (event, sub->dirname,
file_event ? sub->filename : NULL);
child = g_file_new_for_path (fullpath);
g_free (fullpath);
if (ih_event_is_paired_move (event) && sub->pair_moves)
{
const char *parent_dir = (char *) _ip_get_path_for_wd (event->pair->wd);
fullpath = _ih_fullpath_from_event (event->pair, parent_dir, NULL);
other = g_file_new_for_path (fullpath);
g_free (fullpath);
eflags = G_FILE_MONITOR_EVENT_MOVED;
event->pair = NULL; /* prevents the paired event to be emitted as well */
}
else
other = NULL;
g_file_monitor_emit_event (G_FILE_MONITOR (sub->user_data),
child, other, eflags);
/* For paired moves or moves whose mask has been changed from IN_MOVED_TO to
* IN_CREATE, notify also that it's probably the last change to the file,
* emitting CHANGES_DONE_HINT.
* The first (first part of the if's guard below) is the case of a normal
* move within the monitored tree and in the same mounted volume.
* The latter (second part of the guard) is the case of a move within the
* same mounted volume, but from a not monitored directory.
*
* It's not needed in cases like moves across mounted volumes as the IN_CREATE
* will be followed by a IN_MODIFY and IN_CLOSE_WRITE events.
* Also not needed if sub->pair_moves is set as EVENT_MOVED will be emitted
* instead of EVENT_CREATED which implies no further modification will be
* applied to the file
* See: https://bugzilla.gnome.org/show_bug.cgi?id=640077
*/
if ((!sub->pair_moves &&
event->is_second_in_pair && (event->mask & IN_MOVED_TO)) ||
(!ih_event_is_paired_move (event) &&
(event->original_mask & IN_MOVED_TO) && (event->mask & IN_CREATE)))
{
g_file_monitor_emit_event (G_FILE_MONITOR (sub->user_data),
child, NULL, G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT);
}
g_object_unref (child);
if (other)
g_object_unref (other);
}
static void
ih_not_missing_callback (inotify_sub *sub)
{
gchar *fullpath;
GFileMonitorEvent eflags;
guint32 mask;
GFile* child;
if (sub->filename)
{
fullpath = g_strdup_printf ("%s/%s", sub->dirname, sub->filename);
g_warning ("Missing callback called fullpath = %s\n", fullpath);
if (!g_file_test (fullpath, G_FILE_TEST_EXISTS))
{
g_free (fullpath);
return;
}
mask = IN_CREATE;
}
else
{
fullpath = g_strdup_printf ("%s", sub->dirname);
mask = IN_CREATE|IN_ISDIR;
}
eflags = ih_mask_to_EventFlags (mask);
child = g_file_new_for_path (fullpath);
g_free (fullpath);
g_file_monitor_emit_event (G_FILE_MONITOR (sub->user_data),
child, NULL, eflags);
g_object_unref (child);
}
/* Transforms a inotify event to a GVFS event. */
static GFileMonitorEvent
ih_mask_to_EventFlags (guint32 mask)
{
mask &= ~IN_ISDIR;
switch (mask)
{
case IN_MODIFY:
return G_FILE_MONITOR_EVENT_CHANGED;
case IN_CLOSE_WRITE:
return G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT;
case IN_ATTRIB:
return G_FILE_MONITOR_EVENT_ATTRIBUTE_CHANGED;
case IN_MOVE_SELF:
case IN_MOVED_FROM:
case IN_DELETE:
case IN_DELETE_SELF:
return G_FILE_MONITOR_EVENT_DELETED;
case IN_CREATE:
case IN_MOVED_TO:
return G_FILE_MONITOR_EVENT_CREATED;
case IN_UNMOUNT:
return G_FILE_MONITOR_EVENT_UNMOUNTED;
case IN_Q_OVERFLOW:
case IN_OPEN:
case IN_CLOSE_NOWRITE:
case IN_ACCESS:
case IN_IGNORED:
default:
return -1;
}
}