[GNUnet-SVN] r17284 - gnunet/src/mesh

[gnunet]

Author: bartpolot
Date: 2011-10-07 15:05:48 +0200 (Fri, 07 Oct 2011)
New Revision: 17284

Modified:
   gnunet/src/mesh/gnunet-service-mesh.c
Log:
Refactored connection to peers, cancelation of transmissions

Modified: gnunet/src/mesh/gnunet-service-mesh.c
===================================================================
--- gnunet/src/mesh/gnunet-service-mesh.c       2011-10-07 11:37:13 UTC (rev 
17283)
+++ gnunet/src/mesh/gnunet-service-mesh.c       2011-10-07 13:05:48 UTC (rev 
17284)
@@ -320,6 +320,11 @@
    * Path itself
    */
   struct MeshPeerPath *path;
+  
+  /**
+   * Position in peer's transmit queue
+   */
+  unsigned int pos;
 };
 
 
@@ -621,12 +626,167 @@
 
/******************************************************************************/
 
 /**
+ * Check if client has registered with the service and has not disconnected
+ *
+ * @param client the client to check
+ *
+ * @return non-NULL if client exists in the global DLL
+ */
+static struct MeshClient *
+client_get (struct GNUNET_SERVER_Client *client)
+{
+  struct MeshClient *c;
+
+  c = clients;
+  while (NULL != c)
+  {
+    if (c->handle == client)
+      return c;
+    c = c->next;
+  }
+  return NULL;
+}
+
+
+/**
+ * Checks if a given client has subscribed to certain message type
+ *
+ * @param message_type Type of message to check
+ * @param c Client to check
+ *
+ * @return GNUNET_YES or GNUNET_NO, depending on subscription status
+ *
+ * TODO inline?
+ */
+static int
+client_is_subscribed (uint16_t message_type, struct MeshClient *c)
+{
+  GNUNET_HashCode hc;
+
+  GNUNET_CRYPTO_hash (&message_type, sizeof (uint16_t), &hc);
+  return GNUNET_CONTAINER_multihashmap_contains (c->types, &hc);
+}
+
+
+/**
+ * Send the message to all clients that have subscribed to its type
+ *
+ * @param msg Pointer to the message itself
+ * @return number of clients this message was sent to
+ */
+static unsigned int
+send_subscribed_clients (struct GNUNET_MessageHeader *msg)
+{
+  struct MeshClient *c;
+  unsigned int count;
+  uint16_t type;
+
+  type = ntohs (msg->type);
+  for (count = 0, c = clients; c != NULL; c = c->next)
+  {
+    if (client_is_subscribed (type, c))
+    {
+      count++;
+      GNUNET_SERVER_notification_context_unicast (nc, c->handle, msg,
+                                                  GNUNET_YES);
+    }
+  }
+  return count;
+}
+
+
+/**
+ * Notify the client that owns the tunnel that a peer has connected to it
+ * 
+ * @param t Tunnel whose owner to notify
+ * @param id Short id of the peer that has connected
+ */
+static void
+send_client_peer_connected (const struct MeshTunnel *t, const GNUNET_PEER_Id 
id)
+{
+  struct GNUNET_MESH_PeerControl pc;
+
+  pc.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_LOCAL_PEER_ADD);
+  pc.header.size = htons (sizeof (struct GNUNET_MESH_PeerControl));
+  pc.tunnel_id = htonl (t->local_tid);
+  GNUNET_PEER_resolve (id, &pc.peer);
+  GNUNET_SERVER_notification_context_unicast (nc, t->client->handle,
+                                              &pc.header, GNUNET_NO);
+}
+
+
+/**
+ * Cancel a core transmission that was already requested and free all resources
+ * associated to the request.
+ * 
+ * @param peer PeeInfo of the peer whose transmission is cancelled.
+ * @param i Position of the transmission to be cancelled.
+ */
+static void
+peer_info_cancel_transmission(struct MeshPeerInfo *peer, unsigned int i)
+{
+  if (peer->core_transmit[i])
+  {
+    struct MeshDataDescriptor *dd;
+    struct MeshPathInfo *path_info;
+    GNUNET_CORE_notify_transmit_ready_cancel (peer->core_transmit[i]);
+    /* TODO: notify that tranmission has failed */
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "MESH:   Cancelled data transmission at %u\n",
+                i);
+    switch (peer->types[i])
+    {
+      case GNUNET_MESSAGE_TYPE_MESH_MULTICAST:
+      case GNUNET_MESSAGE_TYPE_MESH_UNICAST:
+      case GNUNET_MESSAGE_TYPE_MESH_TO_ORIGIN:
+        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "MESH:    type payload\n");
+        dd = peer->infos[i];
+        if (0 == --(*dd->copies))
+        {
+          GNUNET_free (dd->copies);
+          GNUNET_free (dd->data);
+        }
+        break;
+      case GNUNET_MESSAGE_TYPE_MESH_PATH_CREATE:
+        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "MESH:    type create path\n");
+        path_info = peer->infos[i];
+        path_destroy(path_info->path);
+        break;
+    }
+    GNUNET_free (peer->infos[i]);
+  } 
+}
+
+
+/**
+ * 
+ */
+static unsigned int
+peer_info_transmit_position (struct MeshPeerInfo *peer)
+{
+  unsigned int i;
+
+  for (i = 0; peer->core_transmit[i]; i++)
+  {
+    if (i == (CORE_QUEUE_SIZE - 1))
+    {
+      /* All positions are taken! Overwriting! */
+      GNUNET_break (0);
+      peer_info_cancel_transmission(peer, 0);
+      return 0;
+    }
+  }
+  return i;
+}
+
+
+/**
  * Retrieve the MeshPeerInfo stucture associated with the peer, create one
  * and insert it in the appropiate structures if the peer is not known yet.
  *
- * @param peer Identity of the peer
+ * @param peer Full identity of the peer.
  *
- * @return Existing or newly created peer info
+ * @return Existing or newly created peer info.
  */
 static struct MeshPeerInfo *
 peer_info_get (const struct GNUNET_PeerIdentity *peer)
@@ -647,6 +807,113 @@
 }
 
 
+/**
+ * Retrieve the MeshPeerInfo stucture associated with the peer, create one
+ * and insert it in the appropiate structures if the peer is not known yet.
+ *
+ * @param peer Short identity of the peer.
+ *
+ * @return Existing or newly created peer info.
+ */
+static struct MeshPeerInfo *
+peer_info_get_short (const GNUNET_PEER_Id peer)
+{
+  struct GNUNET_PeerIdentity id;
+
+  GNUNET_PEER_resolve(peer, &id);
+  return peer_info_get(&id);
+}
+
+
+/**
+ * Function called to notify a client about the socket
+ * being ready to queue more data.  "buf" will be
+ * NULL and "size" zero if the socket was closed for
+ * writing in the meantime.
+ *
+ * @param cls closure
+ * @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
+send_core_create_path (void *cls, size_t size, void *buf);
+
+
+/**
+ * Try to establish a new connection to this peer.
+ * Use the best path for the given tunnel.
+ * If the peer doesn't have any path to it yet, try to get one. 
+ * If the peer already has some path, send a CREATE PATH towards it.
+ *
+ * @param peer PeerInfo of the peer.
+ * @param t Tunnel for which to create the path, if possible.
+ */
+static void
+peer_info_connect (struct MeshPeerInfo *peer, struct MeshTunnel *t)
+{
+  struct MeshPeerPath *p;
+  struct MeshPathInfo *path_info;
+  struct MeshPeerInfo *neighbor;
+
+  if (NULL != peer->path_head)
+  {
+    p = tree_get_path_to_peer(t->tree, peer->id);
+    if (p->length > 1)
+    {
+      struct GNUNET_PeerIdentity *id;
+
+      path_info = GNUNET_malloc (sizeof (struct MeshPathInfo));
+      path_info->path = p;
+      path_info->peer = peer;
+      path_info->t = t;
+      id = path_get_first_hop(t->tree, peer->id);
+      neighbor = peer_info_get(id);
+      path_info->pos = peer_info_transmit_position(neighbor);
+      neighbor->types[path_info->pos] = GNUNET_MESSAGE_TYPE_MESH_PATH_CREATE;
+      neighbor->infos[path_info->pos] = path_info;
+      neighbor->core_transmit[path_info->pos] = 
+          GNUNET_CORE_notify_transmit_ready (
+              core_handle, /* handle */
+              0, /* cork */
+              0, /* priority */
+              GNUNET_TIME_UNIT_FOREVER_REL, /* timeout */
+              id, /* target */
+              sizeof (struct GNUNET_MESH_ManipulatePath)
+              + (p->length * sizeof (struct GNUNET_PeerIdentity)), /*size */
+              &send_core_create_path, /* callback */
+              path_info);        /* cls */
+    }
+    else
+    {
+      send_client_peer_connected(t, myid);
+    }
+  }
+  else if (NULL == peer->dhtget)
+  {
+    struct GNUNET_PeerIdentity id;
+
+    GNUNET_PEER_resolve(peer->id, &id);
+    path_info = GNUNET_malloc(sizeof(struct MeshPathInfo));
+    path_info->peer = peer;
+    path_info->t = t;
+    peer->dhtget =
+        GNUNET_DHT_get_start(dht_handle,       /* handle */
+                             GNUNET_TIME_UNIT_FOREVER_REL,     /* timeout */
+                             GNUNET_BLOCK_TYPE_TEST,   /* type */
+                             &id.hashPubKey,       /* key to search */
+                             4,         /* replication level */
+                             GNUNET_DHT_RO_RECORD_ROUTE |
+                               GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE,
+                             NULL,     /* xquery */
+                             0,        /* xquery bits */
+                             &dht_get_id_handler,
+                             path_info);
+  }
+  /* Otherwise, there is no path but the DHT get is already started. */
+}
+
+
 #if LATER
 /**
  * Destroy the peer_info and free any allocated resources linked to it
@@ -749,8 +1016,7 @@
      * Trivial immiediate fix: try to reconnect to the disconnected node. All
      * its children will be reachable trough him.
      */
-    GNUNET_PEER_resolve(d, &id);
-    peer_d = peer_info_get(&id);
+    peer_d = peer_info_get_short(d);
     best = UINT_MAX;
     aux = NULL;
     for (p = peer_d->path_head; NULL != p; p = p->next)
@@ -817,6 +1083,11 @@
   }
 
   l = path_get_length (path);
+  if (0 == l)
+  {
+    GNUNET_free (path);
+    return;
+  }
 
   for (aux = peer_info->path_head; aux != NULL; aux = aux->next)
   {
@@ -963,49 +1234,6 @@
 
 
 /**
- * Check if client has registered with the service and has not disconnected
- *
- * @param client the client to check
- *
- * @return non-NULL if client exists in the global DLL
- */
-static struct MeshClient *
-client_get (struct GNUNET_SERVER_Client *client)
-{
-  struct MeshClient *c;
-
-  c = clients;
-  while (NULL != c)
-  {
-    if (c->handle == client)
-      return c;
-    c = c->next;
-  }
-  return NULL;
-}
-
-
-/**
- * Checks if a given client has subscribed to certain message type
- *
- * @param message_type Type of message to check
- * @param c Client to check
- *
- * @return GNUNET_YES or GNUNET_NO, depending on subscription status
- *
- * TODO inline?
- */
-static int
-client_is_subscribed (uint16_t message_type, struct MeshClient *c)
-{
-  GNUNET_HashCode hc;
-
-  GNUNET_CRYPTO_hash (&message_type, sizeof (uint16_t), &hc);
-  return GNUNET_CONTAINER_multihashmap_contains (c->types, &hc);
-}
-
-
-/**
  * Search for a tunnel among the tunnels for a client
  *
  * @param c the client whose tunnels to search in
@@ -1069,24 +1297,27 @@
 void
 notify_peer_disconnected (const struct MeshTunnelTreeNode *n)
 {
-  struct GNUNET_MESH_PeerControl msg;
+  struct MeshPeerInfo *peer;
 
-  if (NULL == n->t->client || NULL == nc)
-    return;
-
-  msg.header.size = htons (sizeof (msg));
-  msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_LOCAL_PEER_DEL);
-  msg.tunnel_id = htonl (n->t->local_tid);
-  GNUNET_PEER_resolve (n->peer, &msg.peer);
-  GNUNET_SERVER_notification_context_unicast (nc, n->t->client->handle,
-                                              &msg.header, GNUNET_NO);
+  if (NULL != n->t->client && NULL != nc)
+  {
+    struct GNUNET_MESH_PeerControl msg;
+    msg.header.size = htons (sizeof (msg));
+    msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_LOCAL_PEER_DEL);
+    msg.tunnel_id = htonl (n->t->local_tid);
+    GNUNET_PEER_resolve (n->peer, &msg.peer);
+    GNUNET_SERVER_notification_context_unicast (nc, n->t->client->handle,
+                                                &msg.header, GNUNET_NO);
+  }
+  peer = peer_info_get_short(n->peer);
+  peer_info_connect(peer, n->t);
 }
 
 
 /**
  * Add a peer to a tunnel, accomodating paths accordingly and initializing all
  * needed rescources.
- * If peer already exists, do nothing.
+ * If peer already exists, reevaluate shortest path and change if different.
  *
  * @param t Tunnel we want to add a new peer to
  * @param peer PeerInfo of the peer being added
@@ -1095,40 +1326,48 @@
 static void
 tunnel_add_peer (struct MeshTunnel *t, struct MeshPeerInfo *peer)
 {
+  struct GNUNET_PeerIdentity id;
+  struct MeshPeerPath *best_p;
   struct MeshPeerPath *p;
-  struct MeshPeerPath *best_p;
   unsigned int best_cost;
   unsigned int cost;
 
-  if (NULL != tree_find_peer(t->tree->root, peer->id))
+  GNUNET_PEER_resolve(peer->id, &id);
+  if (GNUNET_NO ==
+      GNUNET_CONTAINER_multihashmap_contains(t->peers, &id.hashPubKey))
   {
-    /* Already have it, nothing to do. */
-    return;
+    t->peers_total++;
+    GNUNET_array_append (peer->tunnels, peer->ntunnels, t);
+    GNUNET_CONTAINER_multihashmap_put(
+      t->peers,
+      &id.hashPubKey,
+      peer,
+      GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST);
   }
 
-  t->peers_total++;
-  GNUNET_array_append (peer->tunnels, peer->ntunnels, t);
-  if (NULL == (p = peer->path_head))
+  if (NULL != (p = peer->path_head))
   {
-    GNUNET_break (0);
-    return;
-  }
-
-  best_p = p;
-  best_cost = UINT_MAX;
-  while (NULL != p)
-  {
-    if ((cost = path_get_cost (t->tree, p)) < best_cost)
+    best_p = p;
+    best_cost = UINT_MAX;
+    while (NULL != p)
     {
-      best_cost = cost;
-      best_p = p;
+      if ((cost = path_get_cost (t->tree, p)) < best_cost)
+      {
+        best_cost = cost;
+        best_p = p;
+      }
+      p = p->next;
     }
-    p = p->next;
+    tree_add_path (t->tree, best_p, &notify_peer_disconnected);
+    if (GNUNET_SCHEDULER_NO_TASK == t->path_refresh_task)
+      t->path_refresh_task =
+          GNUNET_SCHEDULER_add_delayed (t->tree->refresh, &path_refresh, t);
   }
-  tree_add_path (t->tree, best_p, &notify_peer_disconnected);
-  if (GNUNET_SCHEDULER_NO_TASK == t->path_refresh_task)
-    t->path_refresh_task =
-        GNUNET_SCHEDULER_add_delayed (t->tree->refresh, &path_refresh, t);
+  else
+  {
+    /* Start a DHT get if necessary */
+    peer_info_connect(peer, t);
+  }
 }
 
 
@@ -1240,7 +1479,6 @@
 /****************      MESH NETWORK HANDLER HELPERS     
***********************/
 
/******************************************************************************/
 
-
 /**
  * Function called to notify a client about the socket
  * being ready to queue more data.  "buf" will be
@@ -1519,54 +1757,6 @@
 #endif
 
 
-/**
- * Send the message to all clients that have subscribed to its type
- *
- * @param msg Pointer to the message itself
- * @return number of clients this message was sent to
- */
-static unsigned int
-send_subscribed_clients (struct GNUNET_MessageHeader *msg)
-{
-  struct MeshClient *c;
-  unsigned int count;
-  uint16_t type;
-
-  type = ntohs (msg->type);
-  for (count = 0, c = clients; c != NULL; c = c->next)
-  {
-    if (client_is_subscribed (type, c))
-    {
-      count++;
-      GNUNET_SERVER_notification_context_unicast (nc, c->handle, msg,
-                                                  GNUNET_YES);
-    }
-  }
-  return count;
-}
-
-
-
-/**
- * Notify the client that owns the tunnel that a peer has connected to it
- * 
- * @param t Tunnel whose owner to notify
- * @param id Short id of the peer that has connected
- */
-static void
-send_client_peer_connected (const struct MeshTunnel *t, const GNUNET_PEER_Id 
id)
-{
-  struct GNUNET_MESH_PeerControl pc;
-
-  pc.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_LOCAL_PEER_ADD);
-  pc.header.size = htons (sizeof (struct GNUNET_MESH_PeerControl));
-  pc.tunnel_id = htonl (t->local_tid);
-  GNUNET_PEER_resolve (id, &pc.peer);
-  GNUNET_SERVER_notification_context_unicast (nc, t->client->handle,
-                                              &pc.header, GNUNET_NO);
-}
-
-
 
/******************************************************************************/
 /********************      MESH NETWORK HANDLERS     
**************************/
 
/******************************************************************************/
@@ -2185,9 +2375,7 @@
                     enum GNUNET_BLOCK_Type type, size_t size, const void *data)
 {
   struct MeshPathInfo *path_info = cls;
-  struct MeshPathInfo *path_info_aux;
   struct MeshPeerPath *p;
-  struct MeshPeerPath *aux;
   struct GNUNET_PeerIdentity pi;
   int i;
 
@@ -2197,63 +2385,14 @@
              GNUNET_h2s_full(&pi.hashPubKey));
   GNUNET_DHT_get_stop(path_info->peer->dhtget);
   path_info->peer->dhtget = NULL;
-  if (NULL == get_path || NULL == put_path)
-  {
-    if (NULL == path_info->peer->path_head)
-    {
-      // Find ourselves some alternate initial path to the destination: retry
-      GNUNET_PEER_resolve(path_info->peer->id, &pi);
-      path_info->peer->dhtget =
-          GNUNET_DHT_get_start(dht_handle,       /* handle */
-                               GNUNET_TIME_UNIT_FOREVER_REL,     /* timeout */
-                               GNUNET_BLOCK_TYPE_TEST,   /* type */
-                               &pi.hashPubKey,   /*key to search */
-                               4,        /* replication level */
-                               GNUNET_DHT_RO_RECORD_ROUTE |
-                                 GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE,
-                               NULL,     /* xquery */
-                               0,        /* xquery bits */
-                               &dht_get_id_handler,
-                               (void *) path_info);
-      return;
-    }
-  }
 
-  p = path_build_from_dht (get_path, get_path_length, put_path, 
put_path_length);
+  p = path_build_from_dht (get_path, get_path_length,
+                           put_path, put_path_length);
   path_add_to_peer (path_info->peer, p);
   for (i = 0; i < path_info->peer->ntunnels; i++)
   {
     tunnel_add_peer (path_info->peer->tunnels[i], path_info->peer);
-    aux = tree_get_path_to_peer(path_info->peer->tunnels[i]->tree,
-                                path_info->peer->id);
-    if (aux->length > 1)
-    {
-      struct GNUNET_PeerIdentity id;
-
-      path_info_aux = GNUNET_malloc (sizeof (struct MeshPathInfo));
-      path_info_aux->path = aux;
-      path_info_aux->peer = path_info->peer;
-      path_info_aux->t = path_info->t;
-      GNUNET_PEER_resolve (p->peers[1], &id);
-      GNUNET_CORE_notify_transmit_ready (core_handle, /* handle */
-                                      0, /* cork */
-                                      0, /* priority */
-                                      GNUNET_TIME_UNIT_FOREVER_REL,
-                                      /* timeout */
-                                      &id, /* target */
-                                      sizeof (struct 
GNUNET_MESH_ManipulatePath)
-                                      +
-                                      (aux->length *
-                                        sizeof (struct GNUNET_PeerIdentity)),
-                                      /*size */
-                                      &send_core_create_path,
-                                      /* callback */
-                                      path_info_aux);        /* cls */
-    }
-    else
-    {
-      send_client_peer_connected(path_info->t, myid);
-    }
+    peer_info_connect(path_info->peer, path_info->t);
   }
   GNUNET_free (path_info);
 
@@ -3214,34 +3353,7 @@
   }
   for (i = 0; i < CORE_QUEUE_SIZE; i++)
   {
-    if (pi->core_transmit[i])
-    {
-      struct MeshDataDescriptor *dd;
-      struct MeshPathInfo *path_info;
-      GNUNET_CORE_notify_transmit_ready_cancel (pi->core_transmit[i]);
-      /* TODO: notify that tranmission has failed */
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "MESH:   data at %u\n", i);
-      switch (pi->types[i])
-      {
-        case GNUNET_MESSAGE_TYPE_MESH_MULTICAST:
-        case GNUNET_MESSAGE_TYPE_MESH_UNICAST:
-        case GNUNET_MESSAGE_TYPE_MESH_TO_ORIGIN:
-          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "MESH:    type payload\n");
-          dd = pi->infos[i];
-          if (0 == --(*dd->copies))
-          {
-            GNUNET_free (dd->copies);
-            GNUNET_free (dd->data);
-          }
-          break;
-        case GNUNET_MESSAGE_TYPE_MESH_PATH_CREATE:
-          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "MESH:    type create path\n");
-          path_info = pi->infos[i];
-          path_destroy(path_info->path);
-          break;
-      }
-      GNUNET_free (pi->infos[i]);
-    }
+    peer_info_cancel_transmission(pi, i);
   }
   path_remove_from_peer (pi, pi->id, myid);
   if (myid == pi->id)