#include "gnunet_time_lib.h"
+#define DEBUG_SERVER_NC GNUNET_NO
+
+/**
+ * Entry in list of messages pending to be transmitted.
+ */
struct PendingMessageList
{
+ /**
+ * This is a linked list.
+ */
struct PendingMessageList *next;
+ /**
+ * Message to transmit (allocated at the end of this
+ * struct, do not free)
+ */
const struct GNUNET_MessageHeader *msg;
+ /**
+ * Can this message be dropped?
+ */
int can_drop;
};
+/**
+ * Lists of clients we manage for notifications.
+ */
struct ClientList
{
+ /**
+ * This is a linked list.
+ */
struct ClientList *next;
+ /**
+ * Overall context this client belongs to.
+ */
+ struct GNUNET_SERVER_NotificationContext *nc;
+
+ /**
+ * Handle to the client.
+ */
struct GNUNET_SERVER_Client *client;
+ /**
+ * Handle for pending transmission request to the client (or NULL).
+ */
struct GNUNET_CONNECTION_TransmitHandle *th;
- struct PendingMessageList *pending;
+ /**
+ * Head of linked list of requests queued for transmission.
+ */
+ struct PendingMessageList *pending_head;
+ /**
+ * Tail of linked list of requests queued for transmission.
+ */
+ struct PendingMessageList *pending_tail;
+
+ /**
+ * Number of messages currently in the list.
+ */
unsigned int num_pending;
};
struct GNUNET_SERVER_NotificationContext
{
+ /**
+ * Server we do notifications for.
+ */
struct GNUNET_SERVER_Handle *server;
+ /**
+ * List of clients receiving notifications.
+ */
struct ClientList *clients;
+ /**
+ * Maximum number of optional messages to queue per client.
+ */
unsigned int queue_length;
};
+/**
+ * Client has disconnected, clean up.
+ *
+ * @param cls our 'struct GNUNET_SERVER_NotificationContext *'
+ * @param client handle of client that disconnected
+ */
static void
handle_client_disconnect (void *cls,
struct GNUNET_SERVER_Client *client)
struct ClientList *prev;
struct PendingMessageList *pml;
+ if (client == NULL)
+ {
+ nc->server = NULL;
+ return;
+ }
prev = NULL;
pos = nc->clients;
while (NULL != pos)
nc->clients = pos->next;
else
prev->next = pos->next;
- while (NULL != (pml = pos->pending))
+ while (NULL != (pml = pos->pending_head))
{
- pos->pending = pml->next;
+ pos->pending_head = pml->next;
GNUNET_free (pml);
}
+ GNUNET_SERVER_client_drop (client);
+ if (pos->th != NULL)
+ {
+ GNUNET_CONNECTION_notify_transmit_ready_cancel (pos->th);
+ pos->th = NULL;
+ }
GNUNET_free (pos);
}
while (NULL != (pos = nc->clients))
{
nc->clients = pos->next;
- GNUNET_SERVER_receive_done (pos->client, GNUNET_NO);
GNUNET_SERVER_client_drop (pos->client);
- while (NULL != (pml = pos->pending))
+ GNUNET_SERVER_receive_done (pos->client, GNUNET_NO);
+ while (NULL != (pml = pos->pending_head))
{
- pos->pending = pml->next;
+ pos->pending_head = pml->next;
GNUNET_free (pml);
}
GNUNET_free (pos);
}
- GNUNET_SERVER_disconnect_notify_cancel (nc->server,
- &handle_client_disconnect,
- nc);
+ if (nc->server != NULL)
+ GNUNET_SERVER_disconnect_notify_cancel (nc->server,
+ &handle_client_disconnect,
+ nc);
GNUNET_free (nc);
}
GNUNET_SERVER_notification_context_add (struct GNUNET_SERVER_NotificationContext *nc,
struct GNUNET_SERVER_Client *client)
{
+ struct ClientList *cl;
+
+ cl = GNUNET_malloc (sizeof (struct ClientList));
+ cl->next = nc->clients;
+ cl->nc = nc;
+ cl->client = client;
+ GNUNET_SERVER_client_keep (client);
+ nc->clients = cl;
+}
+
+
+/**
+ * Function called to notify a client about the socket begin ready to
+ * queue more data. "buf" will be NULL and "size" zero if the socket
+ * was closed for writing in the meantime.
+ *
+ * @param cls the 'struct ClientList *'
+ * @param size number of bytes available in buf
+ * @param buf where the callee should write the message
+ * @return number of bytes written to buf
+ */
+static size_t
+transmit_message (void *cls,
+ size_t size,
+ void *buf)
+{
+ struct ClientList *cl = cls;
+ char *cbuf = buf;
+ struct PendingMessageList *pml;
+ uint16_t msize;
+ size_t ret;
+
+ cl->th = NULL;
+ if (buf == NULL)
+ {
+ /* 'cl' should be freed via disconnect notification shortly */
+ return 0;
+ }
+ ret = 0;
+ while (cl->pending_head != NULL)
+ {
+ pml = cl->pending_head;
+ msize = ntohs (pml->msg->size);
+ if (size < msize)
+ break;
+ cl->pending_head = pml->next;
+ if (pml->next == NULL)
+ cl->pending_tail = NULL;
+#if DEBUG_SERVER_NC
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Copying message of type %u and size %u from pending queue to transmission buffer\n",
+ ntohs (pml->msg->type),
+ msize);
+#endif
+ memcpy (&cbuf[ret], pml->msg, msize);
+ ret += msize;
+ size -= msize;
+ GNUNET_free (pml);
+ cl->num_pending--;
+ }
+ if (cl->pending_head != NULL)
+ cl->th = GNUNET_SERVER_notify_transmit_ready (cl->client,
+ ntohs (cl->pending_head->msg->size),
+ GNUNET_TIME_UNIT_FOREVER_REL,
+ &transmit_message,
+ cl);
+ return ret;
}
+/**
+ * Send a message to a particular client.
+ *
+ * @param nc context to modify
+ * @param client client to transmit to
+ * @param msg message to send
+ * @param can_drop can this message be dropped due to queue length limitations
+ */
+static void
+do_unicast (struct GNUNET_SERVER_NotificationContext *nc,
+ struct ClientList *client,
+ const struct GNUNET_MessageHeader *msg,
+ int can_drop)
+{
+ struct PendingMessageList *pml;
+ uint16_t size;
+
+ if ( (client->num_pending > nc->queue_length) &&
+ (GNUNET_YES == can_drop) )
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+ "Dropping message of type %u and size %u due to full queue (%u entries)\n",
+ ntohs (msg->type),
+ ntohs (msg->size),
+ (unsigned int) nc->queue_length);
+ return; /* drop! */
+ }
+ if (client->num_pending > nc->queue_length)
+ {
+ /* FIXME: consider checking for other messages in the
+ queue that are 'droppable' */
+ }
+ client->num_pending++;
+ size = ntohs (msg->size);
+ pml = GNUNET_malloc (sizeof (struct PendingMessageList) + size);
+ pml->msg = (const struct GNUNET_MessageHeader*) &pml[1];
+ pml->can_drop = can_drop;
+#if DEBUG_SERVER_NC
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Adding message of type %u and size %u to pending queue (which has %u entries)\n",
+ ntohs (msg->type),
+ ntohs (msg->size),
+ (unsigned int) nc->queue_length);
+#endif
+ memcpy (&pml[1], msg, size);
+ /* append */
+ if (client->pending_tail != NULL)
+ client->pending_tail->next = pml;
+ else
+ client->pending_head = pml;
+ client->pending_tail = pml;
+ if (client->th == NULL)
+ client->th = GNUNET_SERVER_notify_transmit_ready (client->client,
+ ntohs (client->pending_head->msg->size),
+ GNUNET_TIME_UNIT_FOREVER_REL,
+ &transmit_message,
+ client);
+}
+
+
/**
* Send a message to a particular client; must have
* already been added to the notification context.
const struct GNUNET_MessageHeader *msg,
int can_drop)
{
+ struct ClientList *pos;
+
+ pos = nc->clients;
+ while (NULL != pos)
+ {
+ if (pos->client == client)
+ break;
+ pos = pos->next;
+ }
+ GNUNET_assert (pos != NULL);
+ do_unicast (nc, pos, msg, can_drop);
}
const struct GNUNET_MessageHeader *msg,
int can_drop)
{
+ struct ClientList *pos;
+
+ pos = nc->clients;
+ while (NULL != pos)
+ {
+ do_unicast (nc, pos, msg, can_drop);
+ pos = pos->next;
+ }
}
projects / oweals / gnunet.git / blobdiff