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/*
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 "mesh2.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 (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 < path->length; i++)
GNUNET_PEER_change_rc (path->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;
}
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