sensor: fixes for proof-of-work, test passes now
[oweals/gnunet.git] / src / sensor / sensor_util_lib.c
index 90befe6af3537b55965e9671569183997512d8a4..d3ed8c408696c78a9217b8d03189df56f4b7d204 100644 (file)
 
 /**
  * @file sensor/sensor_util_lib.c
- * @brief senor utilities
+ * @brief sensor utilities
  * @author Omar Tarabai
  */
 #include <inttypes.h>
 #include "platform.h"
 #include "gnunet_util_lib.h"
 #include "gnunet_sensor_util_lib.h"
+#include "gnunet_statistics_service.h"
 
 #define LOG(kind,...) GNUNET_log_from (kind, "sensor-util",__VA_ARGS__)
 
@@ -51,28 +52,28 @@ static const char *datatypes[] = { "numeric", "string", NULL };
  * @param version full version string
  * @param major pointer to parsed major value
  * @param minor pointer to parsed minor value
- * @return #GNUNET_OK if parsing went ok, #GNUNET_SYSERROR in case of error
+ * @return #GNUNET_OK if parsing went ok, #GNUNET_SYSERR in case of error
  */
 static int
-version_parse(char *version, uint16_t *major, uint16_t *minor)
+version_parse (char *version, uint16_t * major, uint16_t * minor)
 {
   int majorval = 0;
   int minorval = 0;
 
-  for(; isdigit(*version); version++)
+  for (; isdigit (*version); version++)
   {
     majorval *= 10;
     majorval += *version - '0';
   }
-  if(*version != '.')
+  if (*version != '.')
     return GNUNET_SYSERR;
   version++;
-  for(; isdigit(*version); version++)
+  for (; isdigit (*version); version++)
   {
     minorval *= 10;
     minorval += *version - '0';
   }
-  if(*version != 0)
+  if (*version != 0)
     return GNUNET_SYSERR;
   *major = majorval;
   *minor = minorval;
@@ -80,16 +81,18 @@ version_parse(char *version, uint16_t *major, uint16_t *minor)
   return GNUNET_OK;
 }
 
+
 /**
  * Load sensor definition from configuration
  *
  * @param cfg configuration handle
  * @param sectionname configuration section containing definition
  */
-static struct SensorInfo *
-load_sensor_from_cfg(struct GNUNET_CONFIGURATION_Handle *cfg, const char *sectionname)
+static struct GNUNET_SENSOR_SensorInfo *
+load_sensor_from_cfg (struct GNUNET_CONFIGURATION_Handle *cfg,
+                      const char *sectionname)
 {
-  struct SensorInfo *sensor;
+  struct GNUNET_SENSOR_SensorInfo *sensor;
   char *version_str;
   char *starttime_str;
   char *endtime_str;
@@ -97,256 +100,310 @@ load_sensor_from_cfg(struct GNUNET_CONFIGURATION_Handle *cfg, const char *sectio
   char *dummy;
   struct GNUNET_CRYPTO_EddsaPublicKey public_key;
 
-  sensor = GNUNET_new(struct SensorInfo);
+  sensor = GNUNET_new (struct GNUNET_SENSOR_SensorInfo);
+
   //name
-  sensor->name = GNUNET_strdup(sectionname);
+  sensor->name = GNUNET_strdup (sectionname);
   //version
-  if(GNUNET_OK != GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "VERSION", &version_str))
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_string (cfg, sectionname, "VERSION",
+                                             &version_str))
   {
     LOG (GNUNET_ERROR_TYPE_ERROR, _("Error reading sensor version\n"));
-    GNUNET_free(sensor);
+    GNUNET_free (sensor);
     return NULL;
   }
-  if(GNUNET_OK != version_parse(version_str, &(sensor->version_major), &(sensor->version_minor)))
+  if (GNUNET_OK !=
+      version_parse (version_str, &(sensor->version_major),
+                     &(sensor->version_minor)))
   {
-    LOG (GNUNET_ERROR_TYPE_ERROR, _("Invalid sensor version number, format should be major.minor\n"));
-    GNUNET_free(sensor);
-    GNUNET_free(version_str);
+    LOG (GNUNET_ERROR_TYPE_ERROR,
+         _("Invalid sensor version number, format should be major.minor\n"));
+    GNUNET_free (sensor);
+    GNUNET_free (version_str);
     return NULL;
   }
-  GNUNET_free(version_str);
+  GNUNET_free (version_str);
   //description
-  GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "DESCRIPTION", &sensor->description);
+  GNUNET_CONFIGURATION_get_value_string (cfg, sectionname, "DESCRIPTION",
+                                         &sensor->description);
   //category
-  if(GNUNET_OK != GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "CATEGORY", &sensor->category) ||
-        NULL == sensor->category)
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_string (cfg, sectionname, "CATEGORY",
+                                             &sensor->category) ||
+      NULL == sensor->category)
   {
     LOG (GNUNET_ERROR_TYPE_ERROR, _("Error reading sensor category\n"));
-    GNUNET_free(sensor);
+    GNUNET_free (sensor);
     return NULL;
   }
   //enabled
-  if(GNUNET_NO == GNUNET_CONFIGURATION_get_value_yesno(cfg, sectionname, "ENABLED"))
+  if (GNUNET_NO ==
+      GNUNET_CONFIGURATION_get_value_yesno (cfg, sectionname, "ENABLED"))
     sensor->enabled = GNUNET_NO;
   else
     sensor->enabled = GNUNET_YES;
   //start time
   sensor->start_time = NULL;
-  if(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "START_TIME", &starttime_str))
+  if (GNUNET_OK ==
+      GNUNET_CONFIGURATION_get_value_string (cfg, sectionname, "START_TIME",
+                                             &starttime_str))
   {
-    GNUNET_STRINGS_fancy_time_to_absolute(starttime_str, sensor->start_time);
-    LOG (GNUNET_ERROR_TYPE_DEBUG, "Start time loaded: `%s'. Parsed: %d\n", starttime_str, (NULL != sensor->start_time));
-    GNUNET_free(starttime_str);
+    GNUNET_STRINGS_fancy_time_to_absolute (starttime_str, sensor->start_time);
+    GNUNET_free (starttime_str);
   }
   //end time
   sensor->end_time = NULL;
-  if(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "END_TIME", &endtime_str))
+  if (GNUNET_OK ==
+      GNUNET_CONFIGURATION_get_value_string (cfg, sectionname, "END_TIME",
+                                             &endtime_str))
   {
-    GNUNET_STRINGS_fancy_time_to_absolute(endtime_str, sensor->end_time);
-    LOG (GNUNET_ERROR_TYPE_DEBUG, "End time loaded: `%s'. Parsed: %d\n", endtime_str, (NULL != sensor->end_time));
-    GNUNET_free(endtime_str);
+    GNUNET_STRINGS_fancy_time_to_absolute (endtime_str, sensor->end_time);
+    GNUNET_free (endtime_str);
   }
   //interval
-  if(GNUNET_OK != GNUNET_CONFIGURATION_get_value_number(cfg, sectionname, "INTERVAL", &time_sec))
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_number (cfg, sectionname, "INTERVAL",
+                                             &time_sec))
   {
     LOG (GNUNET_ERROR_TYPE_ERROR, _("Error reading sensor run interval\n"));
-    GNUNET_free(sensor);
+    GNUNET_free (sensor);
     return NULL;
   }
-  if(time_sec < MIN_INTERVAL)
+  if (time_sec < MIN_INTERVAL)
   {
-    LOG (GNUNET_ERROR_TYPE_ERROR, _("Sensor run interval too low (%" PRIu64 " < %d)\n"),
-        time_sec, MIN_INTERVAL);
-    GNUNET_free(sensor);
+    LOG (GNUNET_ERROR_TYPE_ERROR,
+         _("Sensor run interval too low (%" PRIu64 " < %d)\n"), time_sec,
+         MIN_INTERVAL);
+    GNUNET_free (sensor);
     return NULL;
   }
-  sensor->interval = GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, time_sec);
+  sensor->interval =
+      GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, time_sec);
   //lifetime
-  if(GNUNET_OK == GNUNET_CONFIGURATION_get_value_number(cfg, sectionname, "LIFETIME", &time_sec))
+  if (GNUNET_OK ==
+      GNUNET_CONFIGURATION_get_value_number (cfg, sectionname, "LIFETIME",
+                                             &time_sec))
   {
-    sensor->lifetime = GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, time_sec);
+    sensor->lifetime =
+        GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, time_sec);
     if (sensor->lifetime.rel_value_us < sensor->interval.rel_value_us)
-      LOG  (GNUNET_ERROR_TYPE_WARNING,
-          "Lifetime of sensor data is preferred to be higher than interval for sensor `%s'.\n",
-          sensor->name);
+      LOG (GNUNET_ERROR_TYPE_WARNING,
+           "Lifetime of sensor data is preferred to be higher than interval for sensor `%s'.\n",
+           sensor->name);
   }
   else
-    sensor->lifetime = sensor->interval;
+    sensor->lifetime = GNUNET_TIME_UNIT_FOREVER_REL;
   //capabilities TODO
   //source
-  if(GNUNET_OK != GNUNET_CONFIGURATION_get_value_choice(cfg, sectionname, "SOURCE", sources, (const char **)&sensor->source))
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_choice (cfg, sectionname, "SOURCE",
+                                             sources,
+                                             (const char **) &sensor->source))
   {
     LOG (GNUNET_ERROR_TYPE_ERROR, _("Error reading sensor source\n"));
-    GNUNET_free(sensor);
+    GNUNET_free (sensor);
     return NULL;
   }
-  if(sources[0] == sensor->source) //gnunet-statistics
+  if (sources[0] == sensor->source)     //gnunet-statistics
   {
-    if(GNUNET_OK != GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "GNUNET_STAT_SERVICE", &sensor->gnunet_stat_service) ||
-        GNUNET_OK != GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "GNUNET_STAT_NAME", &sensor->gnunet_stat_name))
+    if (GNUNET_OK !=
+        GNUNET_CONFIGURATION_get_value_string (cfg, sectionname,
+                                               "GNUNET_STAT_SERVICE",
+                                               &sensor->gnunet_stat_service) ||
+        GNUNET_OK != GNUNET_CONFIGURATION_get_value_string (cfg, sectionname,
+                                                            "GNUNET_STAT_NAME",
+                                                            &sensor->gnunet_stat_name))
     {
-      LOG (GNUNET_ERROR_TYPE_ERROR, _("Error reading sensor gnunet-statistics source information\n"));
-      GNUNET_free(sensor);
+      LOG (GNUNET_ERROR_TYPE_ERROR,
+           _("Error reading sensor gnunet-statistics source information\n"));
+      GNUNET_free (sensor);
       return NULL;
     }
     sensor->gnunet_stat_get_handle = NULL;
   }
-  else if(sources[1] == sensor->source) //process
+  else if (sources[1] == sensor->source)        //process
   {
-    if(GNUNET_OK != GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "EXT_PROCESS", &sensor->ext_process))
+    if (GNUNET_OK !=
+        GNUNET_CONFIGURATION_get_value_string (cfg, sectionname, "EXT_PROCESS",
+                                               &sensor->ext_process))
     {
       LOG (GNUNET_ERROR_TYPE_ERROR, _("Error reading sensor process name\n"));
-      GNUNET_free(sensor);
+      GNUNET_free (sensor);
       return NULL;
     }
-    GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "EXT_ARGS", &sensor->ext_args);
+    GNUNET_CONFIGURATION_get_value_string (cfg, sectionname, "EXT_ARGS",
+                                           &sensor->ext_args);
   }
   //expected datatype
-  if(GNUNET_OK != GNUNET_CONFIGURATION_get_value_choice(cfg, sectionname, "EXPECTED_DATATYPE", datatypes, (const char **)&sensor->expected_datatype))
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_choice (cfg, sectionname,
+                                             "EXPECTED_DATATYPE", datatypes,
+                                             (const char **)
+                                             &sensor->expected_datatype))
   {
-    LOG (GNUNET_ERROR_TYPE_ERROR, _("Error reading sensor expected datatype\n"));
-    GNUNET_free(sensor);
+    LOG (GNUNET_ERROR_TYPE_ERROR,
+         _("Error reading sensor expected datatype\n"));
+    GNUNET_free (sensor);
     return NULL;
   }
-  if(sources[0] == sensor->source && datatypes[0] != sensor->expected_datatype)
+  if (sources[0] == sensor->source && datatypes[0] != sensor->expected_datatype)
   {
-    LOG (GNUNET_ERROR_TYPE_ERROR, _("Invalid expected datatype, gnunet-statistics returns uint64 values\n"));
-    GNUNET_free(sensor);
+    LOG (GNUNET_ERROR_TYPE_ERROR,
+         _
+         ("Invalid expected datatype, gnunet-statistics returns uint64 values\n"));
+    GNUNET_free (sensor);
     return NULL;
   }
-  //reporting mechanism
-  if (GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "COLLECTION_POINT", &dummy))
+  //reporting
+  sensor->collection_point = NULL;
+  sensor->report_values = GNUNET_NO;
+  sensor->report_anomalies = GNUNET_NO;
+  if (GNUNET_OK ==
+      GNUNET_CONFIGURATION_get_value_string (cfg, sectionname,
+                                             "COLLECTION_POINT", &dummy))
   {
-    if(GNUNET_OK != GNUNET_CONFIGURATION_get_value_number(cfg, sectionname, "COLLECTION_INTERVAL", &time_sec))
+    if (GNUNET_OK ==
+        GNUNET_CRYPTO_eddsa_public_key_from_string (dummy, strlen (dummy),
+                                                    &public_key))
     {
-      LOG (GNUNET_ERROR_TYPE_ERROR, _("Error reading sensor collection interval\n"));
-    }
-    else
-    {
-      sensor->collection_interval = GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, time_sec);
-      if (GNUNET_OK == GNUNET_CRYPTO_eddsa_public_key_from_string(dummy, strlen(dummy), &public_key))
+      sensor->collection_point = GNUNET_new (struct GNUNET_PeerIdentity);
+
+      sensor->collection_point->public_key = public_key;
+      if (GNUNET_OK ==
+          GNUNET_CONFIGURATION_get_value_number (cfg, sectionname,
+                                                 "VALUE_COLLECTION_INTERVAL",
+                                                 &time_sec))
       {
-        sensor->collection_point = GNUNET_new(struct GNUNET_PeerIdentity);
-        sensor->collection_point->public_key = public_key;
+        sensor->report_values = GNUNET_YES;
+        sensor->value_reporting_interval =
+            GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, time_sec);
       }
+      if (GNUNET_YES ==
+          GNUNET_CONFIGURATION_get_value_yesno (cfg, sectionname,
+                                                "REPORT_ANOMALIES"))
+        sensor->report_anomalies = GNUNET_YES;
     }
-  }
-  sensor->p2p_report = GNUNET_NO;
-  if (GNUNET_YES == GNUNET_CONFIGURATION_get_value_yesno(cfg, sectionname, "P2P_REPORT"))
-  {
-    if(GNUNET_OK != GNUNET_CONFIGURATION_get_value_number(cfg, sectionname, "P2P_INTERVAL", &time_sec))
-    {
-      LOG (GNUNET_ERROR_TYPE_ERROR, _("Error reading sensor p2p reporting interval\n"));
-    }
-    else
-    {
-      sensor->p2p_interval = GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, time_sec);
-      sensor->p2p_report = GNUNET_YES;
-    }
+    GNUNET_free (dummy);
   }
   //execution task
   sensor->execution_task = GNUNET_SCHEDULER_NO_TASK;
   //running
   sensor->running = GNUNET_NO;
-
   return sensor;
 }
 
+
 /**
  * Load sensor definition from file
  *
  * @param filename full path to file containing sensor definition
  */
-static struct SensorInfo *
-load_sensor_from_file(const char *filename)
+static struct GNUNET_SENSOR_SensorInfo *
+load_sensor_from_file (const char *filename)
 {
   struct GNUNET_CONFIGURATION_Handle *sensorcfg;
   const char *filebasename;
-  struct SensorInfo *sensor;
+  struct GNUNET_SENSOR_SensorInfo *sensor;
 
   //test file
-  if(GNUNET_YES != GNUNET_DISK_file_test(filename))
+  if (GNUNET_YES != GNUNET_DISK_file_test (filename))
   {
-    LOG (GNUNET_ERROR_TYPE_ERROR, _("Failed to access sensor file: %s\n"), filename);
+    LOG (GNUNET_ERROR_TYPE_ERROR, _("Failed to access sensor file: %s\n"),
+         filename);
     return NULL;
   }
   //load file as configuration
-  sensorcfg = GNUNET_CONFIGURATION_create();
-  if(GNUNET_SYSERR == GNUNET_CONFIGURATION_parse(sensorcfg, filename))
+  sensorcfg = GNUNET_CONFIGURATION_create ();
+  if (GNUNET_SYSERR == GNUNET_CONFIGURATION_parse (sensorcfg, filename))
   {
-    GNUNET_CONFIGURATION_destroy(sensorcfg);
-    LOG (GNUNET_ERROR_TYPE_ERROR, _("Failed to load sensor definition: %s\n"), filename);
+    GNUNET_CONFIGURATION_destroy (sensorcfg);
+    LOG (GNUNET_ERROR_TYPE_ERROR, _("Failed to load sensor definition: %s\n"),
+         filename);
     return NULL;
   }
   //configuration section should be the same as filename
-  filebasename = GNUNET_STRINGS_get_short_name(filename);
-  sensor = load_sensor_from_cfg(sensorcfg, filebasename);
-  if(NULL == sensor)
+  filebasename = GNUNET_STRINGS_get_short_name (filename);
+  sensor = load_sensor_from_cfg (sensorcfg, filebasename);
+  if (NULL == sensor)
   {
-    GNUNET_CONFIGURATION_destroy(sensorcfg);
+    GNUNET_CONFIGURATION_destroy (sensorcfg);
     return NULL;
   }
-  sensor->def_file = GNUNET_strdup(filename);
+  sensor->def_file = GNUNET_strdup (filename);
   sensor->cfg = sensorcfg;
-
   return sensor;
 }
 
+
 /**
- * Compares version numbers of two sensors
+ * Given two version numbers as major and minor, compare them.
  *
- * @param s1 first sensor
- * @param s2 second sensor
- * @return 1: s1 > s2, 0: s1 == s2, -1: s1 < s2
+ * @param v1_major First part of first version number
+ * @param v1_minor Second part of first version number
+ * @param v2_major First part of second version number
+ * @param v2_minor Second part of second version number
  */
-static int
-sensor_version_compare(struct SensorInfo *s1, struct SensorInfo *s2)
+int
+GNUNET_SENSOR_version_compare (uint16_t v1_major, uint16_t v1_minor,
+                               uint16_t v2_major, uint16_t v2_minor)
 {
-  if(s1->version_major == s2->version_major)
-    return (s1->version_minor < s2->version_minor) ? -1 : (s1->version_minor > s2->version_minor);
+  if (v1_major == v2_major)
+    return (v1_minor < v2_minor) ? -1 : (v1_minor > v2_minor);
   else
-    return (s1->version_major < s2->version_major) ? -1 : (s1->version_major > s2->version_major);
+    return (v1_major < v2_major) ? -1 : (v1_major > v2_major);
 }
 
+
 /**
  * Adds a new sensor to given hashmap.
  * If the same name exist, compares versions and update if old.
  *
  * @param sensor Sensor structure to add
  * @param map Hashmap to add to
- * @return #GNUNET_YES if added, #GNUNET_NO if not added which is not necessarily an error
+ * @return #GNUNET_YES if added
+ *         #GNUNET_NO if not added which is not necessarily an error
  */
 static int
-add_sensor_to_hashmap(struct SensorInfo *sensor, struct GNUNET_CONTAINER_MultiHashMap *map)
+add_sensor_to_hashmap (struct GNUNET_SENSOR_SensorInfo *sensor,
+                       struct GNUNET_CONTAINER_MultiHashMap *map)
 {
   struct GNUNET_HashCode key;
-  struct SensorInfo *existing;
+  struct GNUNET_SENSOR_SensorInfo *existing;
 
-  GNUNET_CRYPTO_hash(sensor->name, strlen(sensor->name), &key);
-  existing = GNUNET_CONTAINER_multihashmap_get(map, &key);
-  if(NULL != existing) //sensor with same name already exists
+  GNUNET_CRYPTO_hash (sensor->name, strlen (sensor->name) + 1, &key);
+  existing = GNUNET_CONTAINER_multihashmap_get (map, &key);
+  if (NULL != existing)         //sensor with same name already exists
   {
-    if(sensor_version_compare(existing, sensor) >= 0) //same or newer version already exist
+    if (GNUNET_SENSOR_version_compare
+        (existing->version_major, existing->version_minor,
+         sensor->version_major, sensor->version_minor) >= 0)
     {
-      LOG (GNUNET_ERROR_TYPE_INFO, _("Sensor `%s' already exists with same or newer version\n"), sensor->name);
+      LOG (GNUNET_ERROR_TYPE_INFO,
+           _("Sensor `%s' already exists with same or newer version\n"),
+           sensor->name);
       return GNUNET_NO;
     }
     else
     {
-      GNUNET_CONTAINER_multihashmap_remove(map, &key, existing); //remove the old version
-      GNUNET_free(existing);
-      LOG (GNUNET_ERROR_TYPE_INFO, "Upgrading sensor `%s' to a newer version\n", sensor->name);
+      GNUNET_CONTAINER_multihashmap_remove (map, &key, existing);       //remove the old version
+      GNUNET_free (existing);
+      LOG (GNUNET_ERROR_TYPE_INFO, "Upgrading sensor `%s' to a newer version\n",
+           sensor->name);
     }
   }
-  if(GNUNET_SYSERR == GNUNET_CONTAINER_multihashmap_put(map, &key, sensor, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
+  if (GNUNET_SYSERR ==
+      GNUNET_CONTAINER_multihashmap_put (map, &key, sensor,
+                                         GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
   {
-    LOG (GNUNET_ERROR_TYPE_ERROR, _("Error adding new sensor `%s' to global hashmap, this should not happen\n"), sensor->name);
+    LOG (GNUNET_ERROR_TYPE_ERROR,
+         _("Error adding new sensor `%s' to global hashmap.\n"), sensor->name);
     return GNUNET_NO;
   }
-
   return GNUNET_YES;
 }
 
+
 /**
  * Iterating over files in sensors directory
  *
@@ -355,70 +412,137 @@ add_sensor_to_hashmap(struct SensorInfo *sensor, struct GNUNET_CONTAINER_MultiHa
  * @return #GNUNET_OK to continue to iterate
  */
 static int
-reload_sensors_dir_cb(void *cls, const char *filename)
+reload_sensors_dir_cb (void *cls, const char *filename)
 {
   struct GNUNET_CONTAINER_MultiHashMap *sensors = cls;
-  struct SensorInfo *sensor;
+  struct GNUNET_SENSOR_SensorInfo *sensor;
 
-  if(GNUNET_YES != GNUNET_DISK_file_test(filename))
+  if (GNUNET_YES != GNUNET_DISK_file_test (filename))
     return GNUNET_OK;
-  sensor = load_sensor_from_file(filename);
-  if(NULL == sensor)
+  sensor = load_sensor_from_file (filename);
+  if (NULL == sensor)
   {
-    LOG (GNUNET_ERROR_TYPE_ERROR,
-        _("Error loading sensor from file: %s\n"), filename);
+    LOG (GNUNET_ERROR_TYPE_ERROR, _("Error loading sensor from file: %s\n"),
+         filename);
     return GNUNET_OK;
   }
-  if(GNUNET_YES == add_sensor_to_hashmap(sensor, sensors))
-    LOG (GNUNET_ERROR_TYPE_DEBUG,
-        "Sensor `%s' added to global hashmap\n", sensor->name);
-  else
+  if (GNUNET_YES != add_sensor_to_hashmap (sensor, sensors))
     LOG (GNUNET_ERROR_TYPE_WARNING,
-        "Could not add sensor `%s' to global hashmap\n", sensor->name);
-
+         "Could not add sensor `%s' to global hashmap\n", sensor->name);
   return GNUNET_OK;
 }
 
-/*
- * Get path to the directory containing the sensor definition files
+
+/**
+ * Get path to the default directory containing the sensor definition files with
+ * a trailing directory separator.
  *
- * @return sensor files directory
+ * @return Default sensor files directory full path
  */
 char *
-GNUNET_SENSOR_get_sensor_dir ()
+GNUNET_SENSOR_get_default_sensor_dir ()
 {
-  char* datadir;
-  char* sensordir;
-
-  datadir = GNUNET_OS_installation_get_path(GNUNET_OS_IPK_DATADIR);
-  GNUNET_asprintf(&sensordir, "%ssensors%s",
-      datadir, DIR_SEPARATOR_STR);
-  GNUNET_free(datadir);
+  char *datadir;
+  char *sensordir;
 
+  datadir = GNUNET_OS_installation_get_path (GNUNET_OS_IPK_DATADIR);
+  GNUNET_asprintf (&sensordir, "%ssensors%s", datadir, DIR_SEPARATOR_STR);
+  GNUNET_free (datadir);
   return sensordir;
 }
 
+
 /**
- * Reads sensor definitions from local data files
+ * Reads sensor definitions from given sensor directory.
  *
+ * @param sensordir Path to sensor directory.
  * @return a multihashmap of loaded sensors
  */
 struct GNUNET_CONTAINER_MultiHashMap *
-GNUNET_SENSOR_load_all_sensors ()
+GNUNET_SENSOR_load_all_sensors (char *sensor_dir)
 {
-  char* sensordir;
   struct GNUNET_CONTAINER_MultiHashMap *sensors;
 
-  sensors = GNUNET_CONTAINER_multihashmap_create(10, GNUNET_NO);
-  sensordir = GNUNET_SENSOR_get_sensor_dir ();
+  GNUNET_assert (NULL != sensor_dir);
+  sensors = GNUNET_CONTAINER_multihashmap_create (10, GNUNET_NO);
   LOG (GNUNET_ERROR_TYPE_INFO,
-      "Loading sensor definitions from directory `%s'\n", sensordir);
-  GNUNET_assert(GNUNET_YES == GNUNET_DISK_directory_test(sensordir, GNUNET_YES));
-
-  //read all files in sensors directory
-  GNUNET_DISK_directory_scan(sensordir, &reload_sensors_dir_cb, sensors);
+       "Loading sensor definitions from directory `%s'\n", sensor_dir);
+  GNUNET_assert (GNUNET_YES ==
+                 GNUNET_DISK_directory_test (sensor_dir, GNUNET_YES));
+  /* read all files in sensors directory */
+  GNUNET_DISK_directory_scan (sensor_dir, &reload_sensors_dir_cb, sensors);
   LOG (GNUNET_ERROR_TYPE_INFO, "Loaded %d sensors from directory `%s'\n",
-      GNUNET_CONTAINER_multihashmap_size(sensors), sensordir);
-  GNUNET_free(sensordir);
+       GNUNET_CONTAINER_multihashmap_size (sensors), sensor_dir);
   return sensors;
 }
+
+
+/**
+ * Remove sensor execution from scheduler
+ *
+ * @param cls unused
+ * @param key hash of sensor name, key to hashmap
+ * @param value a `struct GNUNET_SENSOR_SensorInfo *`
+ * @return #GNUNET_YES if we should continue to
+ *         iterate,
+ *         #GNUNET_NO if not.
+ */
+static int
+destroy_sensor (void *cls, const struct GNUNET_HashCode *key, void *value)
+{
+  struct GNUNET_SENSOR_SensorInfo *sensor = value;
+
+  if (GNUNET_SCHEDULER_NO_TASK != sensor->execution_task)
+  {
+    GNUNET_SCHEDULER_cancel (sensor->execution_task);
+    sensor->execution_task = GNUNET_SCHEDULER_NO_TASK;
+  }
+  if (NULL != sensor->gnunet_stat_get_handle)
+  {
+    GNUNET_STATISTICS_get_cancel (sensor->gnunet_stat_get_handle);
+    sensor->gnunet_stat_get_handle = NULL;
+  }
+  if (NULL != sensor->ext_cmd)
+  {
+    GNUNET_OS_command_stop (sensor->ext_cmd);
+    sensor->ext_cmd = NULL;
+  }
+  if (NULL != sensor->cfg)
+    GNUNET_CONFIGURATION_destroy (sensor->cfg);
+  if (NULL != sensor->name)
+    GNUNET_free (sensor->name);
+  if (NULL != sensor->def_file)
+    GNUNET_free (sensor->def_file);
+  if (NULL != sensor->description)
+    GNUNET_free (sensor->description);
+  if (NULL != sensor->category)
+    GNUNET_free (sensor->category);
+  if (NULL != sensor->capabilities)
+    GNUNET_free (sensor->capabilities);
+  if (NULL != sensor->gnunet_stat_service)
+    GNUNET_free (sensor->gnunet_stat_service);
+  if (NULL != sensor->gnunet_stat_name)
+    GNUNET_free (sensor->gnunet_stat_name);
+  if (NULL != sensor->ext_process)
+    GNUNET_free (sensor->ext_process);
+  if (NULL != sensor->ext_args)
+    GNUNET_free (sensor->ext_args);
+  if (NULL != sensor->collection_point)
+    GNUNET_free (sensor->collection_point);
+  GNUNET_free (sensor);
+  return GNUNET_YES;
+}
+
+
+/**
+ * Destroys a group of sensors in a hashmap and the hashmap itself
+ *
+ * @param sensors hashmap containing the sensors
+ */
+void
+GNUNET_SENSOR_destroy_sensors (struct GNUNET_CONTAINER_MultiHashMap *sensors)
+{
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying sensor list.\n");
+  GNUNET_CONTAINER_multihashmap_iterate (sensors, &destroy_sensor, NULL);
+  GNUNET_CONTAINER_multihashmap_destroy (sensors);
+}