summaryrefslogtreecommitdiff
path: root/libfshelp/translator-list.c
blob: 99a858f473d53336a031f42d35e275a879163d9f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
/* A list of active translators.

   Copyright (C) 2013 Free Software Foundation, Inc.

   Written by Justus Winter <4winter@informatik.uni-hamburg.de>

   This file is part of the GNU Hurd.

   The GNU Hurd 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, or (at
   your option) any later version.

   The GNU Hurd 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 the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.  */

#include <argz.h>
#include <hurd/fsys.h>
#include <hurd/ihash.h>
#include <mach.h>
#include <mach/notify.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <libgen.h>

#include "fshelp.h"

struct translator
{
  char *name;
  mach_port_t active;
};

/* The list of active translators.  */
static struct hurd_ihash translator_ihash
  = HURD_IHASH_INITIALIZER (HURD_IHASH_NO_LOCP);

/* The lock protecting the translator_ihash.  */
static pthread_mutex_t translator_ihash_lock = PTHREAD_MUTEX_INITIALIZER;

static void
translator_ihash_cleanup (void *element, void *arg)
{
  /* No need to deallocate port, we only keep the name of the
     port, not a reference.  */
  free (element);
}

/* Record an active translator being bound to the given file name
   NAME.  ACTIVE is the control port of the translator.  */
error_t
fshelp_set_active_translator (const char *name, mach_port_t active)
{
  error_t err = 0;
  pthread_mutex_lock (&translator_ihash_lock);

  if (! translator_ihash.cleanup)
    hurd_ihash_set_cleanup (&translator_ihash, translator_ihash_cleanup, NULL);

  struct translator *t = NULL;
  HURD_IHASH_ITERATE (&translator_ihash, value)
    {
      t = value;
      if (strcmp (name, t->name) == 0)
	goto update; /* Entry exists.  */
    }

  t = malloc (sizeof (struct translator));
  if (! t)
    return ENOMEM;

  t->active = MACH_PORT_NULL;
  t->name = strdup (name);
  if (! t->name)
    {
      err = errno;
      free (t);
      goto out;
    }

  err = hurd_ihash_add (&translator_ihash, (hurd_ihash_key_t) t, t);
  if (err)
    goto out;

 update:
  if (active)
    /* No need to increment the reference count, we only keep the
       name, not a reference.  */
    t->active = active;
  else
    hurd_ihash_remove (&translator_ihash, (hurd_ihash_key_t) t);

 out:
  pthread_mutex_unlock (&translator_ihash_lock);
  return err;
}

/* Remove the active translator specified by its control port ACTIVE.
   If there is no active translator with the given control port, this
   does nothing.  */
error_t
fshelp_remove_active_translator (mach_port_t active)
{
  error_t err = 0;
  pthread_mutex_lock (&translator_ihash_lock);

  struct translator *t = NULL;
  HURD_IHASH_ITERATE (&translator_ihash, value)
    {
      struct translator *v = value;
      if (active == v->active)
	{
	  t = v;
	  break;
	}
    }

  if (t)
    hurd_ihash_remove (&translator_ihash, (hurd_ihash_key_t) t);

  pthread_mutex_unlock (&translator_ihash_lock);
  return err;
}

/* Records the list of active translators into the argz vector
   specified by TRANSLATORS filtered by FILTER.  */
error_t
fshelp_get_active_translators (char **translators,
			       size_t *translators_len,
			       fshelp_filter filter)
{
  error_t err = 0;
  pthread_mutex_lock (&translator_ihash_lock);

  HURD_IHASH_ITERATE (&translator_ihash, value)
    {
      struct translator *t = value;
      if (filter)
	{
	  char *dir = strdup (t->name);
	  if (! dir)
	    {
	      err = ENOMEM;
	      break;
	    }

	  err = filter (dirname (dir));
	  free (dir);
	  if (err)
	    {
	      err = 0;
	      continue; /* Skip this entry.  */
	    }
	}

      err = argz_add (translators, translators_len,
		      t->name);
      if (err)
	break;
    }

  pthread_mutex_unlock (&translator_ihash_lock);
  return err;
}