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"
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 * Hashmap of PeerIdentities to "struct PeerEntry"
58 * (for fast lookup). NULL until the library
59 * is actually being used.
61 static struct GNUNET_CONTAINER_MultiHashMap *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)
91 off = (long) GNUNET_CONTAINER_multihashmap_get (map, &pid->hashPubKey);
92 e = (off == 0) ? NULL : &table[off];
95 GNUNET_assert (e->rc > 0);
105 * Intern an peer identity. If the identity is already known, its
106 * reference counter will be increased by one.
108 * @param pid identity to intern
109 * @return the interned identity.
112 GNUNET_PEER_intern (const struct GNUNET_PeerIdentity *pid)
122 map = GNUNET_CONTAINER_multihashmap_create (32);
123 off = (long) GNUNET_CONTAINER_multihashmap_get (map, &pid->hashPubKey);
124 e = (off == 0) ? NULL : &table[off];
127 GNUNET_assert (e->rc > 0);
131 ret = free_list_start;
134 GNUNET_array_grow (table, size, size + 16);
135 for (i = ret; i < size; i++)
136 table[i].pid = i + 1;
144 GNUNET_assert (ret < size);
145 GNUNET_assert (table[ret].rc == 0);
146 free_list_start = table[ret].pid;
147 table[ret].id = *pid;
149 table[ret].pid = ret;
150 GNUNET_break (GNUNET_OK ==
151 GNUNET_CONTAINER_multihashmap_put (map, &pid->hashPubKey,
153 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
159 * Decrement multiple RCs of peer identities by one.
161 * @param ids array of PIDs to decrement the RCs of
162 * @param count size of the ids array
165 GNUNET_PEER_decrement_rcs (const GNUNET_PEER_Id *ids, unsigned int count)
172 for (i = count - 1; i >= 0; i--)
177 GNUNET_assert (id < size);
178 GNUNET_assert (table[id].rc > 0);
180 if (table[id].rc == 0)
182 GNUNET_break (GNUNET_OK ==
183 GNUNET_CONTAINER_multihashmap_remove (map,
186 (void *) (long) id));
187 table[id].pid = free_list_start;
188 free_list_start = id;
195 * Change the reference counter of an interned PID.
197 * @param id identity to change the RC of
198 * @param delta how much to change the RC
201 GNUNET_PEER_change_rc (GNUNET_PEER_Id id, int delta)
205 GNUNET_assert (id < size);
206 GNUNET_assert (table[id].rc > 0);
207 GNUNET_assert ((delta >= 0) || (table[id].rc >= -delta));
208 table[id].rc += delta;
209 if (table[id].rc == 0)
211 GNUNET_break (GNUNET_OK ==
212 GNUNET_CONTAINER_multihashmap_remove (map,
215 (void *) (long) id));
216 table[id].pid = free_list_start;
217 free_list_start = id;
223 * Convert an interned PID to a normal peer identity.
225 * @param id interned PID to convert
226 * @param pid where to write the normal peer identity
229 GNUNET_PEER_resolve (GNUNET_PEER_Id id, struct GNUNET_PeerIdentity *pid)
233 memset (pid, 0, sizeof (struct GNUNET_PeerIdentity));
237 GNUNET_assert (id < size);
238 GNUNET_assert (table[id].rc > 0);