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 2, 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)
93 off = (long) GNUNET_CONTAINER_multihashmap_get (map, &pid->hashPubKey);
94 e = (off == 0) ? NULL : &table[off];
97 GNUNET_assert (e->rc > 0);
103 * Intern an peer identity. If the identity is already known, its
104 * reference counter will be increased by one.
106 * @param pid identity to intern
107 * @return the interned identity.
110 GNUNET_PEER_intern (const struct GNUNET_PeerIdentity *pid)
120 map = GNUNET_CONTAINER_multihashmap_create (32, GNUNET_YES);
121 off = (long) GNUNET_CONTAINER_multihashmap_get (map, &pid->hashPubKey);
122 e = (off == 0) ? NULL : &table[off];
125 GNUNET_assert (e->rc > 0);
129 ret = free_list_start;
132 GNUNET_array_grow (table, size, size + 16);
133 for (i = ret; i < size; i++)
134 table[i].pid = i + 1;
142 GNUNET_assert (ret < size);
143 GNUNET_assert (table[ret].rc == 0);
144 free_list_start = table[ret].pid;
145 table[ret].id = *pid;
147 table[ret].pid = ret;
148 GNUNET_break (GNUNET_OK ==
149 GNUNET_CONTAINER_multihashmap_put (map, &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 (table[id].rc == 0)
180 GNUNET_break (GNUNET_OK ==
181 GNUNET_CONTAINER_multihashmap_remove (map,
184 (void *) (long) id));
185 table[id].pid = free_list_start;
186 free_list_start = id;
193 * Change the reference counter of an interned PID.
195 * @param id identity to change the RC of
196 * @param delta how much to change the RC
199 GNUNET_PEER_change_rc (GNUNET_PEER_Id id, int delta)
203 GNUNET_assert (id < size);
204 GNUNET_assert (table[id].rc > 0);
205 GNUNET_assert ((delta >= 0) || (table[id].rc >= -delta));
206 table[id].rc += delta;
207 if (table[id].rc == 0)
209 GNUNET_break (GNUNET_OK ==
210 GNUNET_CONTAINER_multihashmap_remove (map,
213 (void *) (long) id));
214 table[id].pid = free_list_start;
215 free_list_start = id;
221 * Convert an interned PID to a normal peer identity.
223 * @param id interned PID to convert
224 * @param pid where to write the normal peer identity
227 GNUNET_PEER_resolve (GNUNET_PEER_Id id, struct GNUNET_PeerIdentity *pid)
231 memset (pid, 0, sizeof (struct GNUNET_PeerIdentity));
235 GNUNET_assert (id < size);
236 GNUNET_assert (table[id].rc > 0);