GNUnet  0.11.x
nc.c
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1 /*
2  This file is part of GNUnet.
3  Copyright (C) 2010, 2016 GNUnet e.V.
4 
5  GNUnet is free software: you can redistribute it and/or modify it
6  under the terms of the GNU Affero General Public License as published
7  by the Free Software Foundation, either version 3 of the License,
8  or (at your option) any later version.
9 
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  Affero General Public License for more details.
14 
15  You should have received a copy of the GNU Affero General Public License
16  along with this program. If not, see <http://www.gnu.org/licenses/>.
17 
18  SPDX-License-Identifier: AGPL3.0-or-later
19  */
20 
28 #include "platform.h"
29 #include "gnunet_util_lib.h"
30 
31 #define LOG(kind, ...) GNUNET_log_from (kind, "util-nc", __VA_ARGS__)
32 
33 
38 {
43 
48 
53 
59 
64 };
65 
66 
76 {
81 
86 
90  unsigned int queue_length;
91 };
92 
93 
99 static void
100 handle_mq_destroy (void *cls)
101 {
102  struct SubscriberList *pos = cls;
103  struct GNUNET_NotificationContext *nc = pos->nc;
104 
106  nc->subscribers_tail,
107  pos);
108  GNUNET_free (pos);
109 }
110 
111 
122 {
124 
127  return nc;
128 }
129 
130 
136 void
138 {
139  struct SubscriberList *pos;
140 
141  while (NULL != (pos = nc->subscribers_head))
142  {
144  nc->subscribers_tail,
145  pos);
147  GNUNET_free (pos);
148  }
149  GNUNET_free (nc);
150 }
151 
152 
159 void
161  struct GNUNET_MQ_Handle *mq)
162 {
163  struct SubscriberList *cl;
164 
165  for (cl = nc->subscribers_head; NULL != cl; cl = cl->next)
166  if (cl->mq == mq)
167  return;
168  /* already present */
169  cl = GNUNET_new (struct SubscriberList);
171  nc->subscribers_tail,
172  cl);
173  cl->nc = nc;
174  cl->mq = mq;
175  cl->mq_nh = GNUNET_MQ_destroy_notify (cl->mq,
177  cl);
178 }
179 
180 
188 void
190  const struct GNUNET_MessageHeader *msg,
191  int can_drop)
192 {
193  struct SubscriberList *pos;
194  struct GNUNET_MQ_Envelope *env;
195 
196  for (pos = nc->subscribers_head; NULL != pos; pos = pos->next)
197  {
198  if ((GNUNET_YES == can_drop) &&
199  (GNUNET_MQ_get_length (pos->mq) > nc->queue_length))
200  continue;
201  env = GNUNET_MQ_msg_copy (msg);
202  GNUNET_MQ_send (pos->mq,
203  env);
204  }
205 }
206 
207 
214 unsigned int
216 {
217  unsigned int num;
218  struct SubscriberList *pos;
219 
220  num = 0;
221  for (pos = nc->subscribers_head; NULL != pos; pos = pos->next)
222  num++;
223  return num;
224 }
225 
226 
227 /* end of nc.c */
#define GNUNET_CONTAINER_DLL_remove(head, tail, element)
Remove an element from a DLL.
Handle we return for callbacks registered to be notified when GNUNET_MQ_destroy() is called on a queu...
Definition: mq.c:789
struct GNUNET_MQ_Envelope * GNUNET_MQ_msg_copy(const struct GNUNET_MessageHeader *hdr)
Create a new envelope by copying an existing message.
Definition: mq.c:653
The notification context is the key datastructure for a convenience API used for transmission of noti...
Definition: nc.c:75
struct GNUNET_MessageHeader * msg
Definition: 005.c:2
struct GNUNET_MQ_DestroyNotificationHandle * GNUNET_MQ_destroy_notify(struct GNUNET_MQ_Handle *mq, GNUNET_SCHEDULER_TaskCallback cb, void *cb_cls)
Register function to be called whenever mq is being destroyed.
Definition: mq.c:1109
#define GNUNET_CONTAINER_DLL_insert(head, tail, element)
Insert an element at the head of a DLL.
struct GNUNET_NotificationContext * nc
Overall context this subscriber belongs to.
Definition: nc.c:52
struct SubscriberList * prev
This is a doubly linked list.
Definition: nc.c:47
unsigned int queue_length
Maximum number of optional messages to queue per subscriber.
Definition: nc.c:90
#define GNUNET_new(type)
Allocate a struct or union of the given type.
struct SubscriberList * next
This is a doubly linked list.
Definition: nc.c:42
static void handle_mq_destroy(void *cls)
Subscriber has disconnected, clean up.
Definition: nc.c:100
void GNUNET_notification_context_add(struct GNUNET_NotificationContext *nc, struct GNUNET_MQ_Handle *mq)
Add a subscriber to the notification context.
Definition: nc.c:160
struct SubscriberList * subscribers_tail
Tail of list of subscribers receiving notifications.
Definition: nc.c:85
unsigned int GNUNET_MQ_get_length(struct GNUNET_MQ_Handle *mq)
Obtain the current length of the message queue.
Definition: mq.c:335
unsigned int GNUNET_notification_context_get_size(struct GNUNET_NotificationContext *nc)
Return active number of subscribers in this context.
Definition: nc.c:215
Lists of subscribers we manage for notifications.
Definition: nc.c:37
struct SubscriberList * subscribers_head
Head of list of subscribers receiving notifications.
Definition: nc.c:80
struct GNUNET_MQ_Envelope * env
Definition: 005.c:1
struct GNUNET_NotificationContext * GNUNET_notification_context_create(unsigned int queue_length)
Create a new notification context.
Definition: nc.c:121
Handle to a message queue.
Definition: mq.c:85
void GNUNET_notification_context_broadcast(struct GNUNET_NotificationContext *nc, const struct GNUNET_MessageHeader *msg, int can_drop)
Send a message to all subscribers of this context.
Definition: nc.c:189
struct GNUNET_MQ_Handle * mq
Message queue for the subscriber.
Definition: nc.c:63
void GNUNET_MQ_destroy_notify_cancel(struct GNUNET_MQ_DestroyNotificationHandle *dnh)
Cancel registration from GNUNET_MQ_destroy_notify().
Definition: mq.c:1130
Header for all communications.
#define GNUNET_YES
Definition: gnunet_common.h:77
void GNUNET_notification_context_destroy(struct GNUNET_NotificationContext *nc)
Destroy the context, force disconnect for all subscribers.
Definition: nc.c:137
void GNUNET_MQ_send(struct GNUNET_MQ_Handle *mq, struct GNUNET_MQ_Envelope *ev)
Send a message with the given message queue.
Definition: mq.c:353
struct GNUNET_MQ_DestroyNotificationHandle * mq_nh
Handle where we registered with mq to be told about the MQ&#39;s destruction.
Definition: nc.c:58
#define GNUNET_free(ptr)
Wrapper around free.