towards a new conveniance API

1 files changed, 218 insertions, 0 deletions

diff --git a/src/util/server_nc.c b/src/util/server_nc.c
new file mode 100644
index 000000000..89e59b799
--- /dev/null
+++ b/src/util/server_nc.c
@@ -0,0 +1,218 @@
+/*
+     This file is part of GNUnet.
+     (C) 2010 Christian Grothoff (and other contributing authors)
+
+     GNUnet 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, or (at your
+     option) any later version.
+
+     GNUnet 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 GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+
+/**
+ * @file util/server_nc.c
+ * @brief convenience functions for transmission of
+ *        a notification stream 
+ * @author Christian Grothoff
+ */
+
+#include "platform.h"
+#include "gnunet_common.h"
+#include "gnunet_connection_lib.h"
+#include "gnunet_scheduler_lib.h"
+#include "gnunet_server_lib.h"
+#include "gnunet_time_lib.h"
+
+
+struct PendingMessageList
+{
+
+  struct PendingMessageList *next;
+
+  const struct GNUNET_MessageHeader *msg;
+
+  int can_drop;
+
+};
+
+
+struct ClientList
+{
+
+  struct ClientList *next;
+
+  struct GNUNET_SERVER_Client *client;
+
+  struct GNUNET_CONNECTION_TransmitHandle *th;
+
+  struct PendingMessageList *pending;
+
+  unsigned int num_pending;
+
+};
+
+
+/**
+ * The notification context is the key datastructure for a conveniance
+ * API used for transmission of notifications to the client until the
+ * client disconnects (or the notification context is destroyed, in
+ * which case we disconnect these clients).  Essentially, all
+ * (notification) messages are queued up until the client is able to
+ * read them.
+ */
+struct GNUNET_SERVER_NotificationContext
+{
+
+  struct GNUNET_SERVER_Handle *server;
+
+  struct ClientList *clients;
+
+  unsigned int queue_length;
+
+};
+
+
+static void
+handle_client_disconnect (void *cls,
+                          struct GNUNET_SERVER_Client *client)
+{
+  struct GNUNET_SERVER_NotificationContext *nc = cls;
+  struct ClientList *pos;
+  struct ClientList *prev;
+  struct PendingMessageList *pml;
+
+  prev = NULL;
+  pos = nc->clients;
+  while (NULL != pos)
+    {
+      if (pos->client == client)
+        break;
+      prev = pos;
+      pos = pos->next;
+    }
+  if (pos == NULL)
+    return;
+  if (prev == NULL)
+    nc->clients = pos->next;
+  else
+    prev->next = pos->next;
+  while (NULL != (pml = pos->pending))
+    {
+      pos->pending = pml->next;
+      GNUNET_free (pml);
+    }
+  GNUNET_free (pos);
+}
+
+
+/**
+ * Create a new notification context.
+ *
+ * @param server server for which this function creates the context
+ * @param queue_length maximum number of messages to keep in
+ *        the notification queue; optional messages are dropped
+ *        it the queue gets longer than this number of messages
+ * @return handle to the notification context
+ */
+struct GNUNET_SERVER_NotificationContext *
+GNUNET_SERVER_notification_context_create (struct GNUNET_SERVER_Handle *server,
+                                           unsigned int queue_length)
+{
+  struct GNUNET_SERVER_NotificationContext *ret;
+
+  ret = GNUNET_malloc (sizeof (struct GNUNET_SERVER_NotificationContext));
+  ret->server = server;
+  ret->queue_length = queue_length;
+  GNUNET_SERVER_disconnect_notify (server,
+                                   &handle_client_disconnect,
+                                   ret);
+  return ret;
+}
+
+
+/**
+ * Destroy the context, force disconnect for all clients.
+ *
+ * @param nc context to destroy.
+ */
+void
+GNUNET_SERVER_notification_context_destroy (struct GNUNET_SERVER_NotificationContext *nc)
+{
+  struct ClientList *pos;
+  struct PendingMessageList *pml;
+
+  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))
+        {
+          pos->pending = pml->next;
+          GNUNET_free (pml);
+        }
+      GNUNET_free (pos);
+    }
+  GNUNET_SERVER_disconnect_notify_cancel (nc->server,
+                                          &handle_client_disconnect,
+                                          nc);
+  GNUNET_free (nc);
+}
+
+
+/**
+ * Add a client to the notification context.
+ *
+ * @param nc context to modify
+ * @param client client to add
+ */
+void
+GNUNET_SERVER_notification_context_add (struct GNUNET_SERVER_NotificationContext *nc,
+                                        struct GNUNET_SERVER_Client *client)
+{
+}
+
+
+/**
+ * Send a message to a particular client; must have
+ * already been added to the notification context.
+ *
+ * @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
+ */
+void
+GNUNET_SERVER_notification_context_unicast (struct GNUNET_SERVER_NotificationContext *nc,
+                                            struct GNUNET_SERVER_Client *client,
+                                            const struct GNUNET_MessageHeader *msg,
+                                            int can_drop)
+{
+}
+
+
+/**
+ * Send a message to all clients of this context.
+ *
+ * @param nc context to modify
+ * @param msg message to send
+ * @param can_drop can this message be dropped due to queue length limitations
+ */
+void
+GNUNET_SERVER_notification_context_broadcast (struct GNUNET_SERVER_NotificationContext *nc,
+                                              const struct GNUNET_MessageHeader *msg,
+                                              int can_drop)
+{
+}
+
+
+/* end of server_nc.c */