1 files changed, 294 insertions, 0 deletions

diff --git a/src/contrib/service/rps/gnunet-service-rps_view.c b/src/contrib/service/rps/gnunet-service-rps_view.c
new file mode 100644
index 000000000..d58b995a3
--- /dev/null
+++ b/src/contrib/service/rps/gnunet-service-rps_view.c
@@ -0,0 +1,294 @@
+/*
+     This file is part of GNUnet.
+     Copyright (C)
+
+     GNUnet is free software: you can redistribute it and/or modify it
+     under the terms of the GNU Affero General Public License as published
+     by the Free Software Foundation, either version 3 of the License,
+     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
+     Affero General Public License for more details.
+
+     You should have received a copy of the GNU Affero General Public License
+     along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+     SPDX-License-Identifier: AGPL3.0-or-later
+ */
+
+/**
+ * @file rps/gnunet-service-rps_view.c
+ * @brief wrapper around the "local view"
+ * @author Julius Bünger
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet-service-rps_view.h"
+#include <inttypes.h>
+
+struct View
+{
+  /**
+   * Array containing the peers
+   */
+  struct GNUNET_PeerIdentity *array;
+
+  /**
+   * (Maximum) length of the view
+   */
+  uint32_t length;
+
+  /**
+   * Multipeermap containing the peers
+   */
+  struct GNUNET_CONTAINER_MultiPeerMap *mpm;
+};
+
+
+/**
+ * Create an empty view.
+ *
+ * @param len the maximum length for the view
+ * @return The newly created view
+ */
+struct View *
+View_create (uint32_t len)
+{
+  struct View *view;
+
+  view = GNUNET_new (struct View);
+  view->length = len;
+  view->array = GNUNET_new_array (len, struct GNUNET_PeerIdentity);
+  view->mpm =
+    GNUNET_CONTAINER_multipeermap_create (len, GNUNET_NO);  /* might even be
+                                                           * set to _YES */
+  return view;
+}
+
+
+/**
+ * Change length of view
+ *
+ * If size is decreased, peers with higher indices are removed.
+ *
+ * @param view The view that is changed
+ * @param len the (maximum) length for the view
+ */
+void
+View_change_len (struct View *view,
+                 uint32_t len)
+{
+  uint32_t i;
+  uint32_t *index;
+
+  if (GNUNET_CONTAINER_multipeermap_size (view->mpm) < len)
+  {   /* Simply shrink */
+      /* We might simply clear and free the left over space */
+    GNUNET_array_grow (view->array, view->length, len);
+  }
+  else /* We have to remove elements */
+  {
+    /* TODO find a way to preserve indices */
+    for (i = 0; i < len; i++)
+    {
+      index = GNUNET_CONTAINER_multipeermap_get (view->mpm, &view->array[i]);
+      GNUNET_assert (NULL != index);
+      GNUNET_free (index);
+    }
+    GNUNET_array_grow (view->array, view->length, len);
+    GNUNET_CONTAINER_multipeermap_destroy (view->mpm);
+    view->mpm = GNUNET_CONTAINER_multipeermap_create (len, GNUNET_NO);
+    for (i = 0; i < len; i++)
+    {
+      index = GNUNET_new (uint32_t);
+      *index = i;
+      GNUNET_CONTAINER_multipeermap_put (view->mpm, &view->array[i], index,
+                                         GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST);
+    }
+  }
+  GNUNET_assert (view->length == len);
+}
+
+
+/**
+ * Get the view as an array
+ *
+ * @param view The view of which the array representation is of interest
+ * @return the view in array representation
+ */
+const struct GNUNET_PeerIdentity *
+View_get_as_array (const struct View *view)
+{
+  return view->array;
+}
+
+
+/**
+ * Get the size of the view
+ *
+ * @param view The view of which the size should be returned
+ * @return current number of actually contained peers
+ */
+unsigned int
+View_size (const struct View *view)
+{
+  return GNUNET_CONTAINER_multipeermap_size (view->mpm);
+}
+
+
+/**
+ * Insert peer into the view
+ *
+ * @param view The view to put the peer into
+ * @param peer the peer to insert
+ *
+ * @return GNUNET_OK if peer was actually inserted
+ *         GNUNET_NO if peer was not inserted
+ */
+int
+View_put (struct View *view,
+          const struct GNUNET_PeerIdentity *peer)
+{
+  uint32_t *index;
+
+  if ((view->length <= View_size (view)) ||  /* If array is 'full' */
+      (GNUNET_YES == View_contains_peer (view, peer)))
+  {
+    return GNUNET_NO;
+  }
+  else
+  {
+    index = GNUNET_new (uint32_t);
+    *index = (uint32_t) View_size (view);
+    view->array[*index] = *peer;
+    GNUNET_CONTAINER_multipeermap_put (view->mpm, peer, index,
+                                       GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST);
+    return GNUNET_OK;
+  }
+}
+
+
+/**
+ * Check whether view contains a peer
+ *
+ * @param view The which is checked for a peer
+ * @param peer the peer to check for
+ *
+ * @return GNUNET_OK if view contains peer
+ *         GNUNET_NO otherwise
+ */
+int
+View_contains_peer (const struct View *view,
+                    const struct GNUNET_PeerIdentity *peer)
+{
+  return GNUNET_CONTAINER_multipeermap_contains (view->mpm, peer);
+}
+
+
+/**
+ * Remove peer from view
+ *
+ * @param view The view of which to remove the peer
+ * @param peer the peer to remove
+ *
+ * @return GNUNET_OK if view contained peer and removed it successfully
+ *         GNUNET_NO if view does not contain peer
+ */
+int
+View_remove_peer (struct View *view,
+                  const struct GNUNET_PeerIdentity *peer)
+{
+  uint32_t *index;
+  uint32_t *swap_index;
+  uint32_t last_index;
+
+  if (GNUNET_NO == View_contains_peer (view, peer))
+  {
+    return GNUNET_NO;
+  }
+  index = GNUNET_CONTAINER_multipeermap_get (view->mpm, peer);
+  GNUNET_assert (NULL != index);
+  last_index = View_size (view) - 1;
+  if (*index < last_index)
+  {   /* Fill the 'gap' in the array with the last peer */
+    view->array[*index] = view->array[last_index];
+    GNUNET_assert (GNUNET_YES == View_contains_peer (view,
+                                                     &view->array[last_index]));
+    swap_index = GNUNET_CONTAINER_multipeermap_get (view->mpm,
+                                                    &view->array[last_index]);
+    GNUNET_assert (NULL != swap_index);
+    *swap_index = *index;
+    GNUNET_free (index);
+  }
+  GNUNET_CONTAINER_multipeermap_remove_all (view->mpm, peer);
+  return GNUNET_OK;
+}
+
+
+/**
+ * Get a peer by index
+ *
+ * @param view the view of which to get the peer
+ * @param index the index of the peer to get
+ *
+ * @return peer to the corresponding index.
+ *         NULL if this index is not known
+ */
+const struct GNUNET_PeerIdentity *
+View_get_peer_by_index (const struct View *view,
+                        uint32_t index)
+{
+  if (index < GNUNET_CONTAINER_multipeermap_size (view->mpm))
+  {
+    return &view->array[index];
+  }
+  else
+  {
+    return NULL;
+  }
+}
+
+
+/**
+ * Clear the view
+ *
+ * @param view The view to clear
+ */
+void
+View_clear (struct View *view)
+{
+  for (uint32_t i = 0; 0 < View_size (view); i++)
+  {   /* Need to free indices stored at peers */
+    uint32_t *index;
+
+    GNUNET_assert (GNUNET_YES ==
+                   GNUNET_CONTAINER_multipeermap_contains (view->mpm,
+                                                           &view->array[i]));
+    index = GNUNET_CONTAINER_multipeermap_get (view->mpm, &view->array[i]);
+    GNUNET_assert (NULL != index);
+    GNUNET_free (index);
+    GNUNET_CONTAINER_multipeermap_remove_all (view->mpm, &view->array[i]);
+  }
+  GNUNET_assert (0 == View_size (view));
+}
+
+
+/**
+ * Destroy view.
+ *
+ * @param view the view to destroy
+ */
+void
+View_destroy (struct View *view)
+{
+  View_clear (view);
+  GNUNET_free (view->array);
+  view->array = NULL;
+  GNUNET_CONTAINER_multipeermap_destroy (view->mpm);
+  GNUNET_free (view);
+}
+
+
+/* end of gnunet-service-rps_view.c */