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);
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)
118 map = GNUNET_CONTAINER_multihashmap_create (32);
119 off = (long) GNUNET_CONTAINER_multihashmap_get (map, &pid->hashPubKey);
120 e = (off == 0) ? NULL : &table[off];
123 GNUNET_assert (e->rc > 0);
127 ret = free_list_start;
130 GNUNET_array_grow (table, size, size + 16);
131 for (i = ret; i < size; i++)
132 table[i].pid = i + 1;
140 GNUNET_assert (ret < size);
141 GNUNET_assert (table[ret].rc == 0);
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_multihashmap_put (map, &pid->hashPubKey,
149 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
155 * Decrement multiple RCs of peer identities by one.
157 * @param ids array of PIDs to decrement the RCs of
158 * @param count size of the ids array
161 GNUNET_PEER_decrement_rcs (const GNUNET_PEER_Id *ids, unsigned int count)
168 for (i = count - 1; i >= 0; i--)
173 GNUNET_assert (id < size);
174 GNUNET_assert (table[id].rc > 0);
176 if (table[id].rc == 0)
178 GNUNET_break (GNUNET_OK ==
179 GNUNET_CONTAINER_multihashmap_remove (map,
182 (void *) (long) id));
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) || (table[id].rc >= -delta));
204 table[id].rc += delta;
205 if (table[id].rc == 0)
207 GNUNET_break (GNUNET_OK ==
208 GNUNET_CONTAINER_multihashmap_remove (map,
211 (void *) (long) id));
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));
233 GNUNET_assert (id < size);
234 GNUNET_assert (table[id].rc > 0);