trying to make KX logic slightly more readable
[oweals/gnunet.git] / src / cadet / gnunet-service-cadet-new_paths.c
index 1c648462d37f846d21588277078d1bb930a63847..685656ec31e3d5ffb66960cd733c58ccba941fcb 100644 (file)
@@ -25,7 +25,6 @@
  *
  * TODO:
  * - path desirability score calculations are not done
- *   (and will be tricky to have during path changes)
  */
 #include "platform.h"
 #include "gnunet-service-cadet-new_connection.h"
@@ -54,13 +53,6 @@ struct CadetPeerPath
    */
   struct GNUNET_CONTAINER_HeapNode *hn;
 
-  /**
-   * Connections using this path, by destination peer
-   * (each hop of the path could correspond to an
-   * active connection).
-   */
-  struct GNUNET_CONTAINER_MultiPeerMap *connections;
-
   /**
    * Desirability of the path. How unique is it for the various peers
    * on it?
@@ -75,6 +67,19 @@ struct CadetPeerPath
 };
 
 
+/**
+ * Calculate the path's desirability score.
+ *
+ * @param path path to calculate the score for
+ */
+static void
+recalculate_path_desirability (struct CadetPeerPath *path)
+{
+  /* FIXME: update path desirability! */
+  GNUNET_break (0); // not implemented
+}
+
+
 /**
  * Return how much we like keeping the path.  This is an aggregate
  * score based on various factors, including the age of the path
@@ -185,9 +190,6 @@ path_destroy (struct CadetPeerPath *path)
   LOG (GNUNET_ERROR_TYPE_DEBUG,
        "Destroying path %s\n",
        GCPP_2s (path));
-  GNUNET_assert (0 ==
-                 GNUNET_CONTAINER_multipeermap_size (path->connections));
-  GNUNET_CONTAINER_multipeermap_destroy (path->connections);
   for (unsigned int i=0;i<path->entries_length;i++)
     GNUNET_free (path->entries[i]);
   GNUNET_free (path->entries);
@@ -214,10 +216,7 @@ GCPP_release (struct CadetPeerPath *path)
   entry = path->entries[path->entries_length - 1];
   while (1)
   {
-    /* cut 'off' end of path, verifying it is not in use */
-    GNUNET_assert (NULL ==
-                   GNUNET_CONTAINER_multipeermap_get (path->connections,
-                                                      GCP_get_id (entry->peer)));
+    /* cut 'off' end of path */
     GCP_path_entry_remove (entry->peer,
                            entry,
                            path->entries_length - 1);
@@ -231,7 +230,7 @@ GCPP_release (struct CadetPeerPath *path)
     entry = path->entries[path->entries_length - 1];
     path->hn = GCP_attach_path (entry->peer,
                                 path,
-                                path->entries_length,
+                                path->entries_length - 1,
                                 GNUNET_NO);
     if (NULL != path->hn)
       return; /* yep, got attached, we are done. */
@@ -275,8 +274,7 @@ GCPP_update_score (struct CadetPeerPath *path,
     else
       entry->score += delta;
   }
-
-  /* FIXME: update path desirability! */
+  recalculate_path_desirability (path);
 }
 
 
@@ -324,12 +322,29 @@ check_match (void *cls,
   GNUNET_assert (path->entries_length > off);
   if ( (path->entries_length != off + 1) &&
        (off + 1 != cm_ctx->cpath_length) )
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "check_match missmatch because path %s is too long (%u vs. %u vs. %u)\n",
+         GCPP_2s (path),
+         path->entries_length,
+         off + 1,
+         cm_ctx->cpath_length);
     return GNUNET_YES; /* too long, goes somewhere else already, thus cannot be useful */
+  }
   for (unsigned int i=0;i<off;i++)
     if (cm_ctx->cpath[i] !=
         GCPP_get_peer_at_offset (path,
                                  i))
+    {
+      LOG (GNUNET_ERROR_TYPE_DEBUG,
+           "check_match path %s missmatches at offset %u\n",
+           GCPP_2s (path),
+           i);
       return GNUNET_YES; /* missmatch, ignore */
+    }
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "check_match found match with path %s\n",
+       GCPP_2s (path));
   cm_ctx->match = path;
   return GNUNET_NO; /* match, we are done! */
 }
@@ -355,39 +370,61 @@ extend_path (struct CadetPeerPath *path,
   struct GNUNET_CONTAINER_HeapNode *hn;
   int i;
 
+  /* Expand path */
+  GNUNET_array_grow (path->entries,
+                     path->entries_length,
+                     old_len + num_peers);
+  for (i=num_peers-1;i >= 0;i--)
+  {
+    struct CadetPeerPathEntry *entry = GNUNET_new (struct CadetPeerPathEntry);
+
+    path->entries[old_len + i] = entry;
+    entry->peer = peers[i];
+    entry->path = path;
+  }
+  for (i=num_peers-1;i >= 0;i--)
+  {
+    struct CadetPeerPathEntry *entry = path->entries[old_len + i];
+
+    GCP_path_entry_add (entry->peer,
+                        entry,
+                        old_len + i);
+  }
+
   /* If we extend an existing path, detach it from the
      old owner and re-attach to the new one */
   hn = NULL;
   for (i=num_peers-1;i>=0;i--)
   {
-    /* FIXME: note that path->desirability is used, but not yet updated here! */
+    struct CadetPeerPathEntry *entry = path->entries[old_len + i];
+
+    path->entries_length = old_len + i + 1;
+    recalculate_path_desirability (path);
     hn = GCP_attach_path (peers[i],
                           path,
                           old_len + (unsigned int) i,
                           GNUNET_YES);
     if (NULL != hn)
       break;
+    GCP_path_entry_remove (entry->peer,
+                           entry,
+                           old_len + i);
+    GNUNET_free (entry);
+    path->entries[old_len + i] = NULL;
   }
   if (NULL == hn)
-    return; /* none of the peers is interested in this path */
+  {
+    /* none of the peers is interested in this path;
+       shrink path back */
+    GNUNET_array_grow (path->entries,
+                       path->entries_length,
+                       old_len);
+    return;
+  }
   GCP_detach_path (path->entries[old_len-1]->peer,
                    path,
                    path->hn);
   path->hn = hn;
-  GNUNET_array_grow (path->entries,
-                     path->entries_length,
-                     old_len + i);
-  for (;i >= 0;i--)
-  {
-    struct CadetPeerPathEntry *entry = GNUNET_new (struct CadetPeerPathEntry);
-
-    path->entries[old_len + i] = entry;
-    entry->peer = peers[i];
-    entry->path = path;
-    GCP_path_entry_add (entry->peer,
-                        entry,
-                        old_len + i);
-  }
   LOG (GNUNET_ERROR_TYPE_DEBUG,
        "Extended path %s\n",
        GCPP_2s (path));
@@ -467,43 +504,60 @@ GCPP_try_path_from_dht (const struct GNUNET_PeerIdentity *get_path,
 
   /* No match at all, create completely new path */
   path = GNUNET_new (struct CadetPeerPath);
+  path->entries_length = get_path_length + put_path_length;
+  path->entries = GNUNET_new_array (path->entries_length,
+                                    struct CadetPeerPathEntry *);
+  for (i=path->entries_length-1;i>=0;i--)
+  {
+    struct CadetPeerPathEntry *entry = GNUNET_new (struct CadetPeerPathEntry);
+
+    path->entries[i] = entry;
+    entry->peer = cpath[i];
+    entry->path = path;
+  }
+  for (i=path->entries_length-1;i>=0;i--)
+  {
+    struct CadetPeerPathEntry *entry = path->entries[i];
+
+    GCP_path_entry_add (entry->peer,
+                        entry,
+                        i);
+  }
 
-  /* First, try to attach it */
+  /* Finally, try to attach it */
   hn = NULL;
   for (i=get_path_length + put_path_length-1;i>=0;i--)
   {
+    struct CadetPeerPathEntry *entry = path->entries[i];
+
     path->entries_length = i + 1;
-    /* FIXME: note that path->desirability is used, but not yet initialized here! */
+    recalculate_path_desirability (path);
     hn = GCP_attach_path (cpath[i],
                           path,
                           (unsigned int) i,
                           GNUNET_NO);
     if (NULL != hn)
       break;
+    GCP_path_entry_remove (entry->peer,
+                           entry,
+                           i);
+    GNUNET_free (entry);
+    path->entries[i] = NULL;
   }
   if (NULL == hn)
   {
     /* None of the peers on the path care about it. */
     LOG (GNUNET_ERROR_TYPE_DEBUG,
          "Path discovered from DHT is not interesting to us\n");
+    GNUNET_free (path->entries);
     GNUNET_free (path);
     return;
   }
   path->hn = hn;
-  path->entries_length = i + 1;
-  path->entries = GNUNET_new_array (path->entries_length,
-                                    struct CadetPeerPathEntry *);
-  for (;i>=0;i--)
-  {
-    struct CadetPeerPathEntry *entry = GNUNET_new (struct CadetPeerPathEntry);
-
-    path->entries[i] = entry;
-    entry->peer = cpath[i];
-    entry->path = path;
-    GCP_path_entry_add (entry->peer,
-                        entry,
-                        i);
-  }
+  /* Shrink path to actual useful length */
+  GNUNET_array_grow (path->entries,
+                     path->entries_length,
+                     i + 1);
   LOG (GNUNET_ERROR_TYPE_DEBUG,
        "Created new path %s based on information from DHT\n",
        GCPP_2s (path));
@@ -583,10 +637,16 @@ GCPP_get_path_from_route (unsigned int path_length,
     path->entries[i] = entry;
     entry->peer = cpath[i];
     entry->path = path;
+  }
+  for (int i=path_length-1;i>=0;i--)
+  {
+    struct CadetPeerPathEntry *entry = path->entries[i];
+
     GCP_path_entry_add (entry->peer,
                         entry,
                         i);
   }
+  recalculate_path_desirability (path);
   LOG (GNUNET_ERROR_TYPE_DEBUG,
        "Created new path %s to create inverse for incoming connection\n",
        GCPP_2s (path));