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-rw-r--r--src/mesh/mesh_path.c125
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diff --git a/src/mesh/mesh_path.c b/src/mesh/mesh_path.c
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1/*
2 This file is part of GNUnet.
3 (C) 2001 - 2013 Christian Grothoff (and other contributing authors)
4
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
9
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
19*/
20
21/**
22 * @file mesh/mesh_path.c
23 * @brief Path handling functions
24 * @author Bartlomiej Polot
25 */
26
27#include "mesh2.h"
28#include "mesh_path.h"
29
30
31/**
32 * Create a new path
33 *
34 * @param length How many hops will the path have.
35 *
36 * @return A newly allocated path with a peer array of the specified length.
37 */
38struct MeshPeerPath *
39path_new (unsigned int length)
40{
41 struct MeshPeerPath *p;
42
43 p = GNUNET_malloc (sizeof (struct MeshPeerPath));
44 if (length > 0)
45 {
46 p->length = length;
47 p->peers = GNUNET_malloc (length * sizeof (GNUNET_PEER_Id));
48 }
49 return p;
50}
51
52
53/**
54 * Invert the path
55 *
56 * @param path the path to invert
57 */
58void
59path_invert (struct MeshPeerPath *path)
60{
61 GNUNET_PEER_Id aux;
62 unsigned int i;
63
64 for (i = 0; i < path->length / 2; i++)
65 {
66 aux = path->peers[i];
67 path->peers[i] = path->peers[path->length - i - 1];
68 path->peers[path->length - i - 1] = aux;
69 }
70}
71
72
73/**
74 * Duplicate a path, incrementing short peer's rc.
75 *
76 * @param path The path to duplicate.
77 */
78struct MeshPeerPath *
79path_duplicate (struct MeshPeerPath *path)
80{
81 struct MeshPeerPath *aux;
82 unsigned int i;
83
84 aux = path_new (path->length);
85 memcpy (aux->peers, path->peers, path->length * sizeof (GNUNET_PEER_Id));
86 for (i = 0; i < path->length; i++)
87 GNUNET_PEER_change_rc (path->peers[i], 1);
88 return aux;
89}
90
91
92/**
93 * Get the length of a path.
94 *
95 * @param path The path to measure, with the local peer at any point of it.
96 *
97 * @return Number of hops to reach destination.
98 * UINT_MAX in case the peer is not in the path.
99 */
100unsigned int
101path_get_length (struct MeshPeerPath *path)
102{
103 if (NULL == path)
104 return UINT_MAX;
105 return path->length;
106}
107
108
109/**
110 * Destroy the path and free any allocated resources linked to it
111 *
112 * @param p the path to destroy
113 *
114 * @return GNUNET_OK on success
115 */
116int
117path_destroy (struct MeshPeerPath *p)
118{
119 if (NULL == p)
120 return GNUNET_OK;
121 GNUNET_PEER_decrement_rcs (p->peers, p->length);
122 GNUNET_free_non_null (p->peers);
123 GNUNET_free (p);
124 return GNUNET_OK;
125}