trunk/src/watch.c

/*
 *  ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
 *
 *  Copyright (c) 1997 Jukka Santala (Donwulff)
 *  Copyright (c) 2005-2018 ircd-hybrid development team
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
 *  USA
 */

/*! \file watch.c
 * \brief File including functions for WATCH support
 * \version $Id$
 */

#include "stdinc.h"
#include "list.h"
#include "memory.h"
#include "client.h"
#include "hash.h"
#include "irc_string.h"
#include "ircd.h"
#include "numeric.h"
#include "send.h"
#include "watch.h"


static dlink_list watchTable[HASHSIZE];


/*
 * Rough figure of the datastructures for watch:
 *
 * NOTIFY HASH          client_p1
 *   |                    |- nick1
 * nick1-|- client_p1     |- nick2
 *   |   |- client_p2                client_p3
 *   |   |- client_p3   client_p2      |- nick1
 *   |                    |- nick1
 * nick2-|- client_p2     |- nick2
 *       |- client_p1
 */

/*! \brief Counts up memory used by watch list headers
 */
void
watch_count_memory(unsigned int *const count, size_t *const bytes)
{
  for (unsigned int i = 0; i < HASHSIZE; ++i)
    (*count) += dlink_list_length(&watchTable[i]);

  (*bytes) = *count * sizeof(struct Watch);
}

/*! \brief Notifies all clients that have client_p's name on
 *         their watch list.
 * \param client_p Pointer to Client struct
 * \param reply Numeric to send. Either RPL_LOGON or RPL_LOGOFF
 */
void
watch_check_hash(const struct Client *client_p, const enum irc_numerics reply)
{
  struct Watch *watch = NULL;
  dlink_node *node = NULL;

  assert(IsClient(client_p));

  if ((watch = watch_find_hash(client_p->name)) == NULL)
    return;  /* This name isn't on watch */

  /* Update the time of last change to item */
  watch->lasttime = CurrentTime;

  /* Send notifies out to everybody on the list in header */
  DLINK_FOREACH(node, watch->watched_by.head)
    sendto_one_numeric(node->data, &me, reply, client_p->name,
                       client_p->username, client_p->host,
                       watch->lasttime, client_p->info);
}

/*! \brief Looks up the watch table for a given name
 * \param name Nick name to look up
 */
struct Watch *
watch_find_hash(const char *name)
{
  dlink_node *node = NULL;

  DLINK_FOREACH(node, watchTable[strhash(name)].head)
  {
    struct Watch *watch = node->data;

    if (irccmp(watch->name, name) == 0)
      return watch;
  }

  return NULL;
}

/*! \brief Adds a watch entry to client_p's watch list
 * \param name     Nick name to add
 * \param client_p Pointer to Client struct
 */
void
watch_add_to_hash_table(const char *name, struct Client *client_p)
{
  struct Watch *watch = NULL;
  dlink_node *node = NULL;

  /* If found NULL (no header for this name), make one... */
  if ((watch = watch_find_hash(name)) == NULL)
  {
    watch = xcalloc(sizeof(*watch));

    strlcpy(watch->name, name, sizeof(watch->name));
    watch->hash_value = strhash(watch->name);
    watch->lasttime = CurrentTime;

    dlinkAdd(watch, &watch->node, &watchTable[watch->hash_value]);
  }
  else
  {
    /* Is this client already on the watch-list? */
    node = dlinkFind(&watch->watched_by, client_p);
  }

  if (node == NULL)
  {
    /* No it isn't, so add it in the bucket and client adding it */
    dlinkAdd(client_p, make_dlink_node(), &watch->watched_by);
    dlinkAdd(watch, make_dlink_node(), &client_p->connection->watches);
  }
}

/*! \brief Removes a single entry from client_p's watch list
 * \param name     Name to remove
 * \param client_p Pointer to Client struct
 */
void
watch_del_from_hash_table(const char *name, struct Client *client_p)
{
  struct Watch *watch = NULL;
  dlink_node *node = NULL;

  if ((watch = watch_find_hash(name)) == NULL)
    return;  /* No header found for that name. i.e. it's not being watched */

  if ((node = dlinkFind(&watch->watched_by, client_p)) == NULL)
    return;  /* This name isn't being watched by client_p */

  dlinkDelete(node, &watch->watched_by);
  free_dlink_node(node);

  if ((node = dlinkFindDelete(&client_p->connection->watches, watch)))
    free_dlink_node(node);

  /* In case this header is now empty of notices, remove it */
  if (watch->watched_by.head == NULL)
  {
    assert(dlinkFind(&watchTable[watch->hash_value], watch));
    dlinkDelete(&watch->node, &watchTable[watch->hash_value]);
    xfree(watch);
  }
}

/*! \brief Removes all entries from client_p's watch list
 *         and deletes headers that are no longer being watched.
 * \param client_p Pointer to Client struct
 */
void
watch_del_watch_list(struct Client *client_p)
{
  dlink_node *node = NULL, *node_next = NULL;
  dlink_node *temp = NULL;

  DLINK_FOREACH_SAFE(node, node_next, client_p->connection->watches.head)
  {
    struct Watch *watch = node->data;

    assert(dlinkFind(&watch->watched_by, client_p));

    if ((temp = dlinkFindDelete(&watch->watched_by, client_p)))
      free_dlink_node(temp);

    /* If this leaves a header without notifies, remove it. */
    if (watch->watched_by.head == NULL)
    {
      assert(dlinkFind(&watchTable[watch->hash_value], watch));
      dlinkDelete(&watch->node, &watchTable[watch->hash_value]);

      xfree(watch);
    }

    dlinkDelete(node, &client_p->connection->watches);
    free_dlink_node(node);
  }

  assert(client_p->connection->watches.head == NULL);
  assert(client_p->connection->watches.tail == NULL);
}
Revision:	8590
Committed:	Sun Oct 21 15:44:08 2018 UTC (6 years, 10 months ago) by michael
Content type:	text/x-csrc
File size:	6046 byte(s)
Log Message:	- watch: cache hash values
#	Content
1	/*
2	* ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
3	*
4	* Copyright (c) 1997 Jukka Santala (Donwulff)
5	* Copyright (c) 2005-2018 ircd-hybrid development team
6	*
7	* This program is free software; you can redistribute it and/or modify
8	* it under the terms of the GNU General Public License as published by
9	* the Free Software Foundation; either version 2 of the License, or
10	* (at your option) any later version.
11	*
12	* This program is distributed in the hope that it will be useful,
13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15	* GNU General Public License for more details.
16	*
17	* You should have received a copy of the GNU General Public License
18	* along with this program; if not, write to the Free Software
19	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
20	* USA
21	*/
22
23	/*! \file watch.c
24	* \brief File including functions for WATCH support
25	* \version $Id$
26	*/
27
28	#include "stdinc.h"
29	#include "list.h"
30	#include "memory.h"
31	#include "client.h"
32	#include "hash.h"
33	#include "irc_string.h"
34	#include "ircd.h"
35	#include "numeric.h"
36	#include "send.h"
37	#include "watch.h"
38
39
40	static dlink_list watchTable[HASHSIZE];
41
42
43	/*
44	* Rough figure of the datastructures for watch:
45	*
46	* NOTIFY HASH client_p1
47	* \| \|- nick1
48	* nick1-\|- client_p1 \|- nick2
49	* \| \|- client_p2 client_p3
50	* \| \|- client_p3 client_p2 \|- nick1
51	* \| \|- nick1
52	* nick2-\|- client_p2 \|- nick2
53	* \|- client_p1
54	*/
55
56	/*! \brief Counts up memory used by watch list headers
57	*/
58	void
59	watch_count_memory(unsigned int const count, size_t const bytes)
60	{
61	for (unsigned int i = 0; i < HASHSIZE; ++i)
62	(*count) += dlink_list_length(&watchTable[i]);
63
64	(bytes) = count * sizeof(struct Watch);
65	}
66
67	/*! \brief Notifies all clients that have client_p's name on
68	* their watch list.
69	* \param client_p Pointer to Client struct
70	* \param reply Numeric to send. Either RPL_LOGON or RPL_LOGOFF
71	*/
72	void
73	watch_check_hash(const struct Client *client_p, const enum irc_numerics reply)
74	{
75	struct Watch *watch = NULL;
76	dlink_node *node = NULL;
77
78	assert(IsClient(client_p));
79
80	if ((watch = watch_find_hash(client_p->name)) == NULL)
81	return; /* This name isn't on watch */
82
83	/* Update the time of last change to item */
84	watch->lasttime = CurrentTime;
85
86	/* Send notifies out to everybody on the list in header */
87	DLINK_FOREACH(node, watch->watched_by.head)
88	sendto_one_numeric(node->data, &me, reply, client_p->name,
89	client_p->username, client_p->host,
90	watch->lasttime, client_p->info);
91	}
92
93	/*! \brief Looks up the watch table for a given name
94	* \param name Nick name to look up
95	*/
96	struct Watch *
97	watch_find_hash(const char *name)
98	{
99	dlink_node *node = NULL;
100
101	DLINK_FOREACH(node, watchTable[strhash(name)].head)
102	{
103	struct Watch *watch = node->data;
104
105	if (irccmp(watch->name, name) == 0)
106	return watch;
107	}
108
109	return NULL;
110	}
111
112	/*! \brief Adds a watch entry to client_p's watch list
113	* \param name Nick name to add
114	* \param client_p Pointer to Client struct
115	*/
116	void
117	watch_add_to_hash_table(const char name, struct Client client_p)
118	{
119	struct Watch *watch = NULL;
120	dlink_node *node = NULL;
121
122	/* If found NULL (no header for this name), make one... */
123	if ((watch = watch_find_hash(name)) == NULL)
124	{
125	watch = xcalloc(sizeof(*watch));
126
127	strlcpy(watch->name, name, sizeof(watch->name));
128	watch->hash_value = strhash(watch->name);
129	watch->lasttime = CurrentTime;
130
131	dlinkAdd(watch, &watch->node, &watchTable[watch->hash_value]);
132	}
133	else
134	{
135	/* Is this client already on the watch-list? */
136	node = dlinkFind(&watch->watched_by, client_p);
137	}
138
139	if (node == NULL)
140	{
141	/* No it isn't, so add it in the bucket and client adding it */
142	dlinkAdd(client_p, make_dlink_node(), &watch->watched_by);
143	dlinkAdd(watch, make_dlink_node(), &client_p->connection->watches);
144	}
145	}
146
147	/*! \brief Removes a single entry from client_p's watch list
148	* \param name Name to remove
149	* \param client_p Pointer to Client struct
150	*/
151	void
152	watch_del_from_hash_table(const char name, struct Client client_p)
153	{
154	struct Watch *watch = NULL;
155	dlink_node *node = NULL;
156
157	if ((watch = watch_find_hash(name)) == NULL)
158	return; /* No header found for that name. i.e. it's not being watched */
159
160	if ((node = dlinkFind(&watch->watched_by, client_p)) == NULL)
161	return; /* This name isn't being watched by client_p */
162
163	dlinkDelete(node, &watch->watched_by);
164	free_dlink_node(node);
165
166	if ((node = dlinkFindDelete(&client_p->connection->watches, watch)))
167	free_dlink_node(node);
168
169	/* In case this header is now empty of notices, remove it */
170	if (watch->watched_by.head == NULL)
171	{
172	assert(dlinkFind(&watchTable[watch->hash_value], watch));
173	dlinkDelete(&watch->node, &watchTable[watch->hash_value]);
174	xfree(watch);
175	}
176	}
177
178	/*! \brief Removes all entries from client_p's watch list
179	* and deletes headers that are no longer being watched.
180	* \param client_p Pointer to Client struct
181	*/
182	void
183	watch_del_watch_list(struct Client *client_p)
184	{
185	dlink_node node = NULL, node_next = NULL;
186	dlink_node *temp = NULL;
187
188	DLINK_FOREACH_SAFE(node, node_next, client_p->connection->watches.head)
189	{
190	struct Watch *watch = node->data;
191
192	assert(dlinkFind(&watch->watched_by, client_p));
193
194	if ((temp = dlinkFindDelete(&watch->watched_by, client_p)))
195	free_dlink_node(temp);
196
197	/* If this leaves a header without notifies, remove it. */
198	if (watch->watched_by.head == NULL)
199	{
200	assert(dlinkFind(&watchTable[watch->hash_value], watch));
201	dlinkDelete(&watch->node, &watchTable[watch->hash_value]);
202
203	xfree(watch);
204	}
205
206	dlinkDelete(node, &client_p->connection->watches);
207	free_dlink_node(node);
208	}
209
210	assert(client_p->connection->watches.head == NULL);
211	assert(client_p->connection->watches.tail == NULL);
212	}