skeleton for 'simple' ATS2 plugin

1 files changed, 408 insertions, 0 deletions

diff --git a/src/ats/plugin_ats2_simple.c b/src/ats/plugin_ats2_simple.c
new file mode 100644
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--- /dev/null
+++ b/src/ats/plugin_ats2_simple.c
@@ -0,0 +1,408 @@
+/*
+ This file is part of GNUnet.
+ Copyright (C) 2011-2015, 2018 GNUnet e.V.
+
+ 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/>.
+ */
+/**
+ * @file ats/plugin_ats2_simple.c
+ * @brief ATS simple solver
+ * @author Matthias Wachs
+ * @author Christian Grothoff
+ *
+ * TODO:
+ * - subscribe to PEERSTORE when short on HELLOs (given application preferences!)
+ * - keep track of HELLOs and when we tried them last => re-suggest 
+ * - sum up preferences per peer, keep totals! => PeerMap pid -> [preferences + sessions + addrs!]
+ * - sum up preferences overall, keep global sum => starting point for "proportional"
+ * - store DLL of available sessions per peer
+ */
+#include "platform.h"
+#include "gnunet_ats_plugin_new.h"
+#include "gnunet_peerstore_service.h"
+
+#define LOG(kind,...) GNUNET_log_from (kind, "ats-simple",__VA_ARGS__)
+
+
+/**
+ * Entry in list of addresses we could try per peer.
+ */
+struct Hello
+{
+
+  /**
+   * Kept in a DLL.
+   */
+  struct Hello *next;
+
+  /**
+   * Kept in a DLL.
+   */
+  struct Hello *prev;
+  
+  /**
+   * The address we could try.
+   */
+  const char *address;
+
+  /**
+   * When did we try it last?
+   */
+  struct GNUNET_TIME_Absolute last_attempt;
+
+  /**
+   * Current exponential backoff value.
+   */
+  struct GNUNET_TIME_Relative backoff;
+
+  /**
+   * Is a session with this address already up?
+   * If not, set to NULL.
+   */
+  struct GNUNET_ATS_SessionHandle *sh;
+
+};
+
+
+/**
+ * Internal representation of a session by the plugin.
+ * (If desired, plugin may just use NULL.)
+ */
+struct GNUNET_ATS_SessionHandle
+{
+
+  /**
+   * Kept in DLL per peer.
+   */
+  struct GNUNET_ATS_SessionHandle *next;
+
+  /**
+   * Kept in DLL per peer.
+   */
+  struct GNUNET_ATS_SessionHandle *prev;
+  
+  /**
+   * The session in the main ATS service.
+   */
+  struct GNUNET_ATS_Session *session;
+
+  /**
+   * Current performance data for this @e session
+   */
+  const struct GNUNET_ATS_SessionData *data;
+
+  /**
+   * Hello matching this session, or NULL for none.
+   */
+  struct Hello *hello;
+  
+  /**
+   * Address used by this session (largely for debugging).
+   */
+  const char *address;
+
+  /**
+   * Last BW-in allocation given to the transport service.
+   */
+  struct GNUNET_BANDWIDTH_Value32NBO bw_in;
+
+  /**
+   * Last BW-out allocation given to the transport service.
+   */
+  struct GNUNET_BANDWIDTH_Value32NBO bw_out;
+
+};
+
+
+/**
+ * Information about preferences and sessions we track
+ * per peer.
+ */
+struct Peer
+{
+
+  /**
+   * Kept in DLL per peer.
+   */
+  struct GNUNET_ATS_SessionHandle *sh_head;
+
+  /**
+   * Kept in DLL per peer.
+   */
+  struct GNUNET_ATS_SessionHandle *sh_tail;
+
+  /**
+   * Which peer is this for?
+   */
+  struct GNUNET_PeerIdentity pid;
+
+  /**
+   * Array where we sum up the bandwidth requests received indexed
+   * by preference kind (see `struct GNUNET_MQ_PreferenceKind`)
+   */
+  uint64_t bw_by_pk[GNUNET_MQ_PREFERENCE_COUNT];
+
+  /**
+   * Watch context where we are currently looking for HELLOs for
+   * this peer.
+   */
+  struct GNUNET_PEERSTORE_WatchContext *wc;
+
+  /**
+   * Task used to try again to suggest an address for this peer.
+   */
+  struct GNUNET_SCHEDULER_TaskHandle *task;  
+ 
+};
+
+
+/**
+ * Representation of a network (to be expanded...)
+ */
+struct Network
+{
+
+  /**
+   * Total inbound quota
+   */
+  unsigned long long total_quota_in;
+
+  /**
+   * Total outbound quota
+   */
+  unsigned long long total_quota_out;
+
+  /**
+   * ATS network type
+   */
+  enum GNUNET_NetworkType type;
+
+};
+
+
+/**
+ * A handle for the proportional solver
+ */
+struct SimpleHandle
+{
+
+  /**
+   * Our execution environment.
+   */
+  struct GNUNET_ATS_PluginEnvironment *env;
+
+  /**
+   * Information we track for each peer.
+   */
+  struct GNUNET_CONTAINER_MultiPeerMap *peers;
+
+  /**
+   * Information we track per network type (quotas).
+   */
+  struct Network networks[GNUNET_NT_COUNT];
+
+  /**
+   * Handle to the peerstore service.
+   */
+  struct GNUNET_PEERSTORE_Handle *ps;
+  
+};
+
+
+/**
+ * The world changed, recalculate our allocations.
+ */
+static void
+update (struct SimpleHandle *h)
+{
+  // recalculate allocations
+  // notify transport if it makes sense (delta significant)
+}
+
+
+/**
+ * The plugin should begin to respect a new preference.
+ *
+ * @param cls the closure
+ * @param pref the preference to add
+ * @return plugin's internal representation, or NULL
+ */
+static struct GNUNET_ATS_PreferenceHandle *
+simple_preference_add (void *cls,
+                       const struct GNUNET_ATS_Preference *pref)
+{
+  struct SimpleHandle *h = cls;
+  // Setup peer if necessary (-> including HELLO triggers!)
+  // add pref to bw_by_pk
+  // trigger update
+  return NULL;
+}
+
+
+/**
+ * The plugin should end respecting a preference.
+ *
+ * @param cls the closure
+ * @param ph whatever @e preference_add returned 
+ * @param pref the preference to delete
+ * @return plugin's internal representation, or NULL
+ */
+static void
+simple_preference_del (void *cls,                   
+                       struct GNUNET_ATS_PreferenceHandle *ph,
+                       const struct GNUNET_ATS_Preference *pref)
+{
+  struct SimpleHandle *h = cls;
+  // find peer
+  // subtract pref from bw_by_pk
+  // remove peer if otherwise dead
+  // trigger update
+}
+
+
+/**
+ * Transport established a new session with performance
+ * characteristics given in @a data.
+ *
+ * @param cls closure
+ * @param data performance characteristics of @a sh
+ * @param address address information (for debugging)
+ * @return handle by which the plugin will identify this session
+ */
+static struct GNUNET_ATS_SessionHandle *
+simple_session_add (void *cls,
+                    const struct GNUNET_ATS_SessionData *data,
+                    const char *address)
+{
+  struct SimpleHandle *h = cls;
+
+  // find or add peer if necessary
+  // setup session
+  // match HELLO
+  // trigger update
+  return NULL;
+}
+
+
+/**
+ * @a data changed for a given @a sh, solver should consider
+ * the updated performance characteristics.
+ *
+ * @param cls closure
+ * @param sh session this is about
+ * @param data performance characteristics of @a sh
+ */
+static void
+simple_session_update (void *cls,
+                       struct GNUNET_ATS_SessionHandle *sh,
+                       const struct GNUNET_ATS_SessionData *data)
+{
+  struct SimpleHandle *h = cls;
+  // trigger update
+}
+
+
+/**
+ * A session went away. Solver should update accordingly.
+ *
+ * @param cls closure
+ * @param sh session this is about
+ * @param data (last) performance characteristics of @a sh
+ */
+static void
+simple_session_del (void *cls,
+                    struct GNUNET_ATS_SessionHandle *sh,
+                    const struct GNUNET_ATS_SessionData *data)
+{
+  struct SimpleHandle *h = cls;
+  // tear down session
+  // del peer if otherwise dead
+  // trigger update
+}
+
+
+#include "plugin_ats2_common.c"
+
+
+/**
+ * Function invoked when the plugin is loaded.
+ *
+ * @param[in,out] cls the `struct GNUNET_ATS_PluginEnvironment *` to use;
+ *            modified to return the API functions (ugh).
+ * @return the `struct SimpleHandle` to pass as a closure
+ */
+void *
+libgnunet_plugin_ats2_simple_init (void *cls)
+{
+  static struct GNUNET_ATS_SolverFunctions sf;
+  struct GNUNET_ATS_PluginEnvironment *env = cls;
+  struct SimpleHandle *s;
+
+  s = GNUNET_new (struct SimpleHandle);
+  s->env = env;
+  s->peers = GNUNET_CONTAINER_multipeermap_create (128,
+                                                   GNUNET_YES);
+  s->ps = GNUNET_PEERSTORE_connect (env->cfg);
+  sf.cls = s;
+  sf.preference_add = &simple_preference_add;
+  sf.preference_del = &simple_preference_del;
+  sf.session_add = &simple_session_add;
+  sf.session_update = &simple_session_update;
+  sf.session_del = &simple_session_del;
+  for (enum GNUNET_NetworkType nt = 0;
+       nt < GNUNET_NT_COUNT;
+       nt++)
+  {
+    const char *name = GNUNET_NT_to_string (nt);
+
+    if (NULL == name)
+    {
+      GNUNET_break (0);
+      break;
+    }
+    get_quota (env->cfg,
+               name,
+               "IN",
+               &s->networks[nt].total_quota_in);
+    get_quota (env->cfg,
+               name,
+               "OUT",
+               &s->networks[nt].total_quota_out);
+    s->networks[nt].type = nt;
+  }
+  return &sf;
+}
+
+
+/**
+ * Function used to unload the plugin.
+ *
+ * @param cls return value from #libgnunet_plugin_ats_proportional_init()
+ */
+void *
+libgnunet_plugin_ats2_simple_done (void *cls)
+{
+  struct GNUNET_ATS_SolverFunctions *sf = cls;
+  struct SimpleHandle *s = sf->cls;
+
+  // FIXME: iterate over peers and clean up!
+  GNUNET_CONTAINER_multipeermap_destroy (s->peers);
+  GNUNET_PEERSTORE_disconnect (s->ps,
+                               GNUNET_NO);
+  GNUNET_free (s);
+  return NULL;
+}
+
+
+/* end of plugin_ats2_simple.c */