aboutsummaryrefslogtreecommitdiff
path: root/src/mesh/mesh_path.c
blob: 52f0c948a4495087d2420dddb733f83677ae8633 (plain) (blame)
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
/*
     This file is part of GNUnet.
     (C) 2001 - 2013 Christian Grothoff (and other contributing authors)

     GNUnet 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 3, or (at your
     option) any later version.

     GNUnet 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 GNUnet; see the file COPYING.  If not, write to the
     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
     Boston, MA 02111-1307, USA.
*/

/**
 * @file mesh/mesh_path.c
 * @brief Path handling functions
 * @author Bartlomiej Polot
 */

#include "mesh.h"
#include "mesh_path.h"


/**
 * Create a new path
 *
 * @param length How many hops will the path have.
 *
 * @return A newly allocated path with a peer array of the specified length.
 */
struct MeshPeerPath *
path_new (unsigned int length)
{
  struct MeshPeerPath *p;

  p = GNUNET_malloc (sizeof (struct MeshPeerPath));
  if (length > 0)
  {
    p->length = length;
    p->peers = GNUNET_malloc (length * sizeof (GNUNET_PEER_Id));
  }
  return p;
}


/**
 * Invert the path
 *
 * @param path the path to invert
 */
void
path_invert (struct MeshPeerPath *path)
{
  GNUNET_PEER_Id aux;
  unsigned int i;

  for (i = 0; i < path->length / 2; i++)
  {
    aux = path->peers[i];
    path->peers[i] = path->peers[path->length - i - 1];
    path->peers[path->length - i - 1] = aux;
  }
}


/**
 * Duplicate a path, incrementing short peer's rc.
 *
 * @param path The path to duplicate.
 */
struct MeshPeerPath *
path_duplicate (const struct MeshPeerPath *path)
{
  struct MeshPeerPath *aux;
  unsigned int i;

  aux = path_new (path->length);
  memcpy (aux->peers, path->peers, path->length * sizeof (GNUNET_PEER_Id));
  for (i = 0; i < aux->length; i++)
    GNUNET_PEER_change_rc (aux->peers[i], 1);
  return aux;
}


/**
 * Get the length of a path.
 *
 * @param path The path to measure, with the local peer at any point of it.
 *
 * @return Number of hops to reach destination.
 *         UINT_MAX in case the peer is not in the path.
 */
unsigned int
path_get_length (struct MeshPeerPath *path)
{
  if (NULL == path)
    return UINT_MAX;
  return path->length;
}


/**
 * Destroy the path and free any allocated resources linked to it
 *
 * @param p the path to destroy
 *
 * @return GNUNET_OK on success
 */
int
path_destroy (struct MeshPeerPath *p)
{
  if (NULL == p)
    return GNUNET_OK;
  GNUNET_PEER_decrement_rcs (p->peers, p->length);
  GNUNET_free_non_null (p->peers);
  GNUNET_free (p);
  return GNUNET_OK;
}

void
path_debug (struct MeshPeerPath *p)
{
  unsigned int i;

  fprintf (stderr, "PATH:"); 
  for (i = 0; i < p->length; i++)
    fprintf (stderr, "  %s", GNUNET_i2s (GNUNET_PEER_resolve2 (p->peers[i]))); 
  fprintf (stderr, " END\n"); 
}