/*
This file is part of GNUnet.
Copyright (C)
GNUnet is free software: you can redistribute it and/or modify it
under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License,
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
Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see .
SPDX-License-Identifier: AGPL3.0-or-later
*/
/**
* @file rps/gnunet-service-rps_view.c
* @brief wrapper around the "local view"
* @author Julius Bünger
*/
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet-service-rps_view.h"
#include
struct View
{
/**
* Array containing the peers
*/
struct GNUNET_PeerIdentity *array;
/**
* (Maximum) length of the view
*/
uint32_t length;
/**
* Multipeermap containing the peers
*/
struct GNUNET_CONTAINER_MultiPeerMap *mpm;
};
/**
* Create an empty view.
*
* @param len the maximum length for the view
* @return The newly created view
*/
struct View *
View_create (uint32_t len)
{
struct View *view;
view = GNUNET_new (struct View);
view->length = len;
view->array = GNUNET_new_array (len, struct GNUNET_PeerIdentity);
view->mpm =
GNUNET_CONTAINER_multipeermap_create (len, GNUNET_NO); /* might even be
* set to _YES */
return view;
}
/**
* Change length of view
*
* If size is decreased, peers with higher indices are removed.
*
* @param view The view that is changed
* @param len the (maximum) length for the view
*/
void
View_change_len (struct View *view,
uint32_t len)
{
uint32_t i;
uint32_t *index;
if (GNUNET_CONTAINER_multipeermap_size (view->mpm) < len)
{ /* Simply shrink */
/* We might simply clear and free the left over space */
GNUNET_array_grow (view->array, view->length, len);
}
else /* We have to remove elements */
{
/* TODO find a way to preserve indices */
for (i = 0; i < len; i++)
{
index = GNUNET_CONTAINER_multipeermap_get (view->mpm, &view->array[i]);
GNUNET_assert (NULL != index);
GNUNET_free (index);
}
GNUNET_array_grow (view->array, view->length, len);
GNUNET_CONTAINER_multipeermap_destroy (view->mpm);
view->mpm = GNUNET_CONTAINER_multipeermap_create (len, GNUNET_NO);
for (i = 0; i < len; i++)
{
index = GNUNET_new (uint32_t);
*index = i;
GNUNET_CONTAINER_multipeermap_put (view->mpm, &view->array[i], index,
GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST);
}
}
GNUNET_assert (view->length == len);
}
/**
* Get the view as an array
*
* @param view The view of which the array representation is of interest
* @return the view in array representation
*/
const struct GNUNET_PeerIdentity *
View_get_as_array (const struct View *view)
{
return view->array;
}
/**
* Get the size of the view
*
* @param view The view of which the size should be returned
* @return current number of actually contained peers
*/
unsigned int
View_size (const struct View *view)
{
return GNUNET_CONTAINER_multipeermap_size (view->mpm);
}
/**
* Insert peer into the view
*
* @param view The view to put the peer into
* @param peer the peer to insert
*
* @return GNUNET_OK if peer was actually inserted
* GNUNET_NO if peer was not inserted
*/
int
View_put (struct View *view,
const struct GNUNET_PeerIdentity *peer)
{
uint32_t *index;
if ((view->length <= View_size (view)) || /* If array is 'full' */
(GNUNET_YES == View_contains_peer (view, peer)))
{
return GNUNET_NO;
}
else
{
index = GNUNET_new (uint32_t);
*index = (uint32_t) View_size (view);
view->array[*index] = *peer;
GNUNET_CONTAINER_multipeermap_put (view->mpm, peer, index,
GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST);
return GNUNET_OK;
}
}
/**
* Check whether view contains a peer
*
* @param view The which is checked for a peer
* @param peer the peer to check for
*
* @return GNUNET_OK if view contains peer
* GNUNET_NO otherwise
*/
int
View_contains_peer (const struct View *view,
const struct GNUNET_PeerIdentity *peer)
{
return GNUNET_CONTAINER_multipeermap_contains (view->mpm, peer);
}
/**
* Remove peer from view
*
* @param view The view of which to remove the peer
* @param peer the peer to remove
*
* @return GNUNET_OK if view contained peer and removed it successfully
* GNUNET_NO if view does not contain peer
*/
int
View_remove_peer (struct View *view,
const struct GNUNET_PeerIdentity *peer)
{
uint32_t *index;
uint32_t *swap_index;
uint32_t last_index;
if (GNUNET_NO == View_contains_peer (view, peer))
{
return GNUNET_NO;
}
index = GNUNET_CONTAINER_multipeermap_get (view->mpm, peer);
GNUNET_assert (NULL != index);
last_index = View_size (view) - 1;
if (*index < last_index)
{ /* Fill the 'gap' in the array with the last peer */
view->array[*index] = view->array[last_index];
GNUNET_assert (GNUNET_YES == View_contains_peer (view,
&view->array[last_index]));
swap_index = GNUNET_CONTAINER_multipeermap_get (view->mpm,
&view->array[last_index]);
GNUNET_assert (NULL != swap_index);
*swap_index = *index;
GNUNET_free (index);
}
GNUNET_CONTAINER_multipeermap_remove_all (view->mpm, peer);
return GNUNET_OK;
}
/**
* Get a peer by index
*
* @param view the view of which to get the peer
* @param index the index of the peer to get
*
* @return peer to the corresponding index.
* NULL if this index is not known
*/
const struct GNUNET_PeerIdentity *
View_get_peer_by_index (const struct View *view,
uint32_t index)
{
if (index < GNUNET_CONTAINER_multipeermap_size (view->mpm))
{
return &view->array[index];
}
else
{
return NULL;
}
}
/**
* Clear the view
*
* @param view The view to clear
*/
void
View_clear (struct View *view)
{
for (uint32_t i = 0; 0 < View_size (view); i++)
{ /* Need to free indices stored at peers */
uint32_t *index;
GNUNET_assert (GNUNET_YES ==
GNUNET_CONTAINER_multipeermap_contains (view->mpm, &view->array[i]));
index = GNUNET_CONTAINER_multipeermap_get (view->mpm, &view->array[i]);
GNUNET_assert (NULL != index);
GNUNET_free (index);
GNUNET_CONTAINER_multipeermap_remove_all (view->mpm, &view->array[i]);
}
GNUNET_assert (0 == View_size (view));
}
/**
* Destroy view.
*
* @param view the view to destroy
*/
void
View_destroy (struct View *view)
{
View_clear (view);
GNUNET_free (view->array);
view->array = NULL;
GNUNET_CONTAINER_multipeermap_destroy (view->mpm);
GNUNET_free (view);
}
/* end of gnunet-service-rps_view.c */