2 This file is part of GNUnet
3 (C) 2006, 2008, 2009 Christian Grothoff (and other contributing authors)
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.
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.
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., 51 Franklin Street, Fifth Floor,
18 Boston, MA 02110-1301, USA.
23 * @brief peer-ID table that assigns integer IDs to peer-IDs to save memory
24 * @author Christian Grothoff
28 #include "gnunet_peer_lib.h"
30 #define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
36 * The identifier itself
38 struct GNUNET_PeerIdentity id;
41 * Short version of the identifier; if the RC==0, then index of next
42 * free slot in table, otherwise equal to this slot in the table.
47 * Reference counter, 0 if this slot is not used.
54 * Table with our interned peer IDs.
56 static struct PeerEntry **table;
59 * Hashmap of PeerIdentities to "struct PeerEntry"
60 * (for fast lookup). NULL until the library
61 * is actually being used.
63 static struct GNUNET_CONTAINER_MultiHashMap *map;
66 * Size of the "table".
68 static unsigned int size;
71 * Index of the beginning of the free list in the table; set to "size"
72 * if no slots are free in the table.
74 static unsigned int free_list_start;
78 * Search for a peer identity. The reference counter is not changed.
80 * @param pid identity to find
81 * @return the interned identity or 0.
84 GNUNET_PEER_search (const struct GNUNET_PeerIdentity *pid)
92 e = GNUNET_CONTAINER_multihashmap_get (map, &pid->hashPubKey);
95 GNUNET_assert (e->rc > 0);
101 * Intern an peer identity. If the identity is already known, its
102 * reference counter will be increased by one.
104 * @param pid identity to intern
105 * @return the interned identity.
108 GNUNET_PEER_intern (const struct GNUNET_PeerIdentity *pid)
117 map = GNUNET_CONTAINER_multihashmap_create (32, GNUNET_YES);
118 e = GNUNET_CONTAINER_multihashmap_get (map, &pid->hashPubKey);
121 GNUNET_assert (e->rc > 0);
125 ret = free_list_start;
128 GNUNET_array_grow (table, size, size + 16);
129 for (i = ret; i < size; i++)
131 table[i] = GNUNET_malloc (sizeof (struct PeerEntry));
132 table[i]->pid = i + 1;
141 GNUNET_assert (ret < size);
142 GNUNET_assert (0 == table[ret]->rc);
143 free_list_start = table[ret]->pid;
144 table[ret]->id = *pid;
146 table[ret]->pid = ret;
147 GNUNET_break (GNUNET_OK ==
148 GNUNET_CONTAINER_multihashmap_put (map,
149 &table[ret]->id.hashPubKey,
151 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
157 * Decrement multiple RCs of peer identities by one.
159 * @param ids array of PIDs to decrement the RCs of
160 * @param count size of the ids array
163 GNUNET_PEER_decrement_rcs (const GNUNET_PEER_Id *ids, unsigned int count)
170 for (i = count - 1; i >= 0; i--)
175 GNUNET_assert (id < size);
176 GNUNET_assert (table[id]->rc > 0);
178 if (0 == table[id]->rc)
180 GNUNET_break (GNUNET_OK ==
181 GNUNET_CONTAINER_multihashmap_remove (map,
182 &table[id]->id.hashPubKey,
184 table[id]->pid = free_list_start;
185 free_list_start = id;
192 * Change the reference counter of an interned PID.
194 * @param id identity to change the RC of
195 * @param delta how much to change the RC
198 GNUNET_PEER_change_rc (GNUNET_PEER_Id id, int delta)
202 GNUNET_assert (id < size);
203 GNUNET_assert (table[id]->rc > 0);
204 GNUNET_assert ((delta >= 0) || (table[id]->rc >= -delta));
205 table[id]->rc += delta;
206 if (0 == table[id]->rc)
208 GNUNET_break (GNUNET_OK ==
209 GNUNET_CONTAINER_multihashmap_remove (map,
210 &table[id]->id.hashPubKey,
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 return &table[id]->id;