peerstore: watch functionality

1 files changed, 72 insertions, 22 deletions

diff --git a/src/peerstore/gnunet-service-peerstore.c b/src/peerstore/gnunet-service-peerstore.c
index 70d79ea5e..706fcaaae 100644
--- a/src/peerstore/gnunet-service-peerstore.c
+++ b/src/peerstore/gnunet-service-peerstore.c
@@ -73,6 +73,11 @@ static struct GNUNET_PEERSTORE_PluginFunctions *db;
 static struct GNUNET_CONTAINER_MultiHashMap *watchers;
 
 /**
+ * Our notification context.
+ */
+static struct GNUNET_SERVER_NotificationContext *nc;
+
+/**
  * Task run during shutdown.
  *
  * @param cls unused
@@ -88,8 +93,8 @@ shutdown_task (void *cls,
     GNUNET_free (db_lib_name);
     db_lib_name = NULL;
   }
-  if(NULL != watchers)
-    GNUNET_CONTAINER_multihashmap_destroy(watchers);
+  GNUNET_SERVER_notification_context_destroy(nc);
+  GNUNET_CONTAINER_multihashmap_destroy(watchers);
   GNUNET_SCHEDULER_shutdown();
 }
 
@@ -154,6 +159,60 @@ int record_iterator(void *cls,
 }
 
 /**
+ * Iterator over all watcher clients
+ * to notify them of a new record
+ *
+ * @param cls closuer, a 'struct GNUNET_PEERSTORE_Record *'
+ * @param key hash of record key
+ * @param value the watcher client, a 'struct GNUNET_SERVER_Client *'
+ * @return #GNUNET_YES to continue iterating
+ */
+int watch_notifier_it(void *cls,
+    const struct GNUNET_HashCode *key,
+    void *value)
+{
+  struct GNUNET_PEERSTORE_Record *record = cls;
+  struct GNUNET_SERVER_Client *client = value;
+  struct StoreRecordMessage *srm;
+
+  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Found a watcher to update.\n");
+  if(NULL == value)
+  {
+    GNUNET_CONTAINER_multihashmap_remove(watchers, key, value);
+    return GNUNET_YES;
+  }
+  srm = PEERSTORE_create_record_message(record->sub_system,
+      record->peer,
+      record->key,
+      record->value,
+      record->value_size,
+      record->expiry,
+      GNUNET_MESSAGE_TYPE_PEERSTORE_WATCH_RECORD);
+  GNUNET_SERVER_notification_context_unicast(nc, client,
+      (const struct GNUNET_MessageHeader *)srm, GNUNET_YES);
+  return GNUNET_YES;
+}
+
+/**
+ * Given a new record, notifies watchers
+ *
+ * @cls closure, a 'struct GNUNET_PEERSTORE_Record *'
+ * @tc unused
+ */
+void watch_notifier (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+  struct GNUNET_PEERSTORE_Record *record = cls;
+  struct GNUNET_HashCode keyhash;
+
+  GNUNET_log(GNUNET_ERROR_TYPE_INFO, "Sending update to any watchers.\n");
+  PEERSTORE_hash_key(record->sub_system,
+      record->peer,
+      record->key,
+      &keyhash);
+  GNUNET_CONTAINER_multihashmap_get_multiple(watchers, &keyhash, &watch_notifier_it, record);
+}
+
+/**
  * Handle a watch cancel request from client
  *
  * @param cls unused
@@ -167,13 +226,6 @@ void handle_watch_cancel (void *cls,
   struct StoreKeyHashMessage *hm;
 
   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Received a watch cancel request from client.\n");
-  if(NULL == watchers)
-  {
-    GNUNET_log(GNUNET_ERROR_TYPE_WARNING,
-        "Received a watch cancel request when we don't have any watchers.\n");
-    GNUNET_SERVER_receive_done(client, GNUNET_SYSERR);
-    return;
-  }
   hm = (struct StoreKeyHashMessage *) message;
   GNUNET_CONTAINER_multihashmap_remove(watchers, &hm->keyhash, client);
   GNUNET_SERVER_receive_done(client, GNUNET_OK);
@@ -195,8 +247,7 @@ void handle_watch (void *cls,
   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Received a watch request from client.\n");
   hm = (struct StoreKeyHashMessage *) message;
   GNUNET_SERVER_client_mark_monitor(client);
-  if(NULL == watchers)
-    watchers = GNUNET_CONTAINER_multihashmap_create(10, GNUNET_NO);
+  GNUNET_SERVER_notification_context_add(nc, client);
   GNUNET_CONTAINER_multihashmap_put(watchers, &hm->keyhash,
      client, GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
   GNUNET_SERVER_receive_done(client, GNUNET_OK);
@@ -246,7 +297,7 @@ void handle_iterate (void *cls,
     GNUNET_free(tc);
     GNUNET_SERVER_receive_done(client, GNUNET_SYSERR);
   }
-  GNUNET_free(record);
+  GNUNET_free(record); /* FIXME: destroy record */
 }
 
 /**
@@ -261,7 +312,6 @@ void handle_store (void *cls,
     const struct GNUNET_MessageHeader *message)
 {
   struct GNUNET_PEERSTORE_Record *record;
-  uint16_t response_type;
   struct GNUNET_SERVER_TransmitContext *tc;
 
   record = PEERSTORE_parse_record_message(message);
@@ -275,6 +325,7 @@ void handle_store (void *cls,
       || NULL == record->peer
       || NULL == record->key)
   {
+    /* FIXME: Destroy record */
     GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Full key not supplied in client store request\n");
     GNUNET_SERVER_receive_done(client, GNUNET_SYSERR);
     return;
@@ -284,7 +335,7 @@ void handle_store (void *cls,
       record->sub_system,
       GNUNET_i2s (record->peer),
       record->key);
-  if(GNUNET_OK == db->store_record(db->cls,
+  if(GNUNET_OK != db->store_record(db->cls,
       record->sub_system,
       record->peer,
       record->key,
@@ -292,18 +343,15 @@ void handle_store (void *cls,
       record->value_size,
       *record->expiry))
   {
-    response_type = GNUNET_MESSAGE_TYPE_PEERSTORE_STORE_RESULT_OK;
-  }
-  else
-  {
+    /* FIXME: Destroy record */
     GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Failed to store requested value, sqlite database error.");
-    response_type = GNUNET_MESSAGE_TYPE_PEERSTORE_STORE_RESULT_FAIL;
+    GNUNET_SERVER_receive_done(client, GNUNET_SYSERR);
+    return;
   }
-
   tc = GNUNET_SERVER_transmit_context_create (client);
-  GNUNET_SERVER_transmit_context_append_data(tc, NULL, 0, response_type);
+  GNUNET_SERVER_transmit_context_append_data(tc, NULL, 0, GNUNET_MESSAGE_TYPE_PEERSTORE_STORE_RESULT_OK);
   GNUNET_SERVER_transmit_context_run (tc, GNUNET_TIME_UNIT_FOREVER_REL);
-  //TODO: notify watchers, if a client is disconnected, remove its watch entry
+  GNUNET_SCHEDULER_add_continuation(&watch_notifier, record, -1);
 }
 
 /**
@@ -343,6 +391,8 @@ run (void *cls,
           GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Could not load database backend `%s'\n", db_lib_name);
   else
   {
+    nc = GNUNET_SERVER_notification_context_create (server, 16);
+    watchers = GNUNET_CONTAINER_multihashmap_create(10, GNUNET_NO);
     GNUNET_SCHEDULER_add_now(&cleanup_expired_records, NULL);
     GNUNET_SERVER_add_handlers (server, handlers);
     GNUNET_SERVER_disconnect_notify (server,