2 This file is part of GNUnet
3 Copyright (C) 2006, 2008, 2009 GNUnet e.V.
5 GNUnet is free software: you can redistribute it and/or modify it
6 under the terms of the GNU Affero General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
8 or (at your option) any later version.
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 Affero General Public License for more details.
15 You should have received a copy of the GNU Affero General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
18 SPDX-License-Identifier: AGPL3.0-or-later
23 * @brief peer-ID table that assigns integer IDs to peer-IDs to save memory
24 * @author Christian Grothoff
27 #include "gnunet_peer_lib.h"
29 #define LOG(kind, ...) GNUNET_log_from(kind, "util-peer", __VA_ARGS__)
34 * The identifier itself
36 struct GNUNET_PeerIdentity id;
39 * Short version of the identifier; if the RC==0, then index of next
40 * free slot in table, otherwise equal to this slot in the table.
45 * Reference counter, 0 if this slot is not used.
52 * Table with our interned peer IDs.
54 static struct PeerEntry **table;
57 * Peermap of PeerIdentities to "struct PeerEntry"
58 * (for fast lookup). NULL until the library
59 * is actually being used.
61 static struct GNUNET_CONTAINER_MultiPeerMap *map;
64 * Size of the "table".
66 static unsigned int size;
69 * Index of the beginning of the free list in the table; set to "size"
70 * if no slots are free in the table.
72 static unsigned int free_list_start;
76 * Search for a peer identity. The reference counter is not changed.
78 * @param pid identity to find
79 * @return the interned identity or 0.
82 GNUNET_PEER_search(const struct GNUNET_PeerIdentity *pid)
90 e = GNUNET_CONTAINER_multipeermap_get(map, pid);
93 GNUNET_assert(e->rc > 0);
99 * Intern an peer identity. If the identity is already known, its
100 * reference counter will be increased by one.
102 * @param pid identity to intern
103 * @return the interned identity.
106 GNUNET_PEER_intern(const struct GNUNET_PeerIdentity *pid)
115 map = GNUNET_CONTAINER_multipeermap_create(32, GNUNET_YES);
116 e = GNUNET_CONTAINER_multipeermap_get(map, pid);
119 GNUNET_assert(e->rc > 0);
123 ret = free_list_start;
126 GNUNET_array_grow(table, size, size + 16);
127 for (i = ret; i < size; i++)
129 table[i] = GNUNET_new(struct PeerEntry);
130 table[i]->pid = i + 1;
135 memset(&table[0]->id, 0, sizeof(struct GNUNET_PeerIdentity));
140 GNUNET_assert(ret < size);
141 GNUNET_assert(0 == table[ret]->rc);
142 free_list_start = table[ret]->pid;
143 table[ret]->id = *pid;
145 table[ret]->pid = ret;
146 GNUNET_break(GNUNET_OK ==
147 GNUNET_CONTAINER_multipeermap_put(map,
150 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
156 * Decrement multiple RCs of peer identities by one.
158 * @param ids array of PIDs to decrement the RCs of
159 * @param count size of the ids array
162 GNUNET_PEER_decrement_rcs(const GNUNET_PEER_Id *ids, unsigned int count)
169 for (i = count - 1; i >= 0; i--)
174 GNUNET_assert(id < size);
175 GNUNET_assert(table[id]->rc > 0);
177 if (0 == table[id]->rc)
179 GNUNET_break(GNUNET_OK ==
180 GNUNET_CONTAINER_multipeermap_remove(map,
183 table[id]->pid = free_list_start;
184 free_list_start = id;
191 * Change the reference counter of an interned PID.
193 * @param id identity to change the RC of
194 * @param delta how much to change the RC
197 GNUNET_PEER_change_rc(GNUNET_PEER_Id id, int delta)
201 GNUNET_assert(id < size);
202 GNUNET_assert(table[id]->rc > 0);
203 GNUNET_assert((delta >= 0) ||
204 (table[id]->rc >= (unsigned int)(-delta)));
205 table[id]->rc += delta;
206 if (0 == table[id]->rc)
208 GNUNET_break(GNUNET_OK ==
209 GNUNET_CONTAINER_multipeermap_remove(map,
212 table[id]->pid = free_list_start;
213 free_list_start = id;
219 * Convert an interned PID to a normal peer identity.
221 * @param id interned PID to convert
222 * @param pid where to write the normal peer identity
225 GNUNET_PEER_resolve(GNUNET_PEER_Id id, struct GNUNET_PeerIdentity *pid)
229 memset(pid, 0, sizeof(struct GNUNET_PeerIdentity));
232 GNUNET_assert(id < size);
233 GNUNET_assert(table[id]->rc > 0);
234 *pid = table[id]->id;
239 * Convert an interned PID to a normal peer identity.
241 * @param id interned PID to convert
242 * @return pointer to peer identity, valid as long 'id' is valid
244 const struct GNUNET_PeerIdentity *
245 GNUNET_PEER_resolve2(GNUNET_PEER_Id id)
247 GNUNET_assert(id < size);
248 GNUNET_assert(table[id]->rc > 0);
249 return &table[id]->id;