(no commit message)
[oweals/gnunet.git] / src / datastore / gnunet-service-datastore.c
index c895bb1c845e695ec6a51b7929dccc2b39f6e137..6c064743e89d1019cc2c542106578e94cc5d4b55 100644 (file)
@@ -27,6 +27,7 @@
 #include "platform.h"
 #include "gnunet_util_lib.h"
 #include "gnunet_protocols.h"
+#include "gnunet_statistics_service.h"
 #include "plugin_datastore.h"
 #include "datastore.h"
 
  */
 #define MAX_EXPIRE_DELAY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15)
 
+#define QUOTA_STAT_NAME gettext_noop ("# bytes used in file-sharing datastore")
+
+/**
+ * After how many payload-changing operations
+ * do we sync our statistics?
+ */
+#define MAX_STAT_SYNC_LAG 50
 
 
 /**
@@ -108,6 +116,7 @@ struct ReservationList
 };
 
 
+
 /**
  * Our datastore plugin (NULL if not available).
  */
@@ -123,11 +132,6 @@ static struct ReservationList *reservations;
  */
 static struct GNUNET_CONTAINER_BloomFilter *filter;
 
-/**
- * Static counter to produce reservation identifiers.
- */
-static int reservation_gen;
-
 /**
  * How much space are we allowed to use?
  */
@@ -145,6 +149,24 @@ static unsigned long long cache_size;
  * How much space have we currently reserved?
  */
 static unsigned long long reserved;
+  
+/**
+ * How much data are we currently storing
+ * in the database?
+ */
+static unsigned long long payload;
+
+/**
+ * Number of updates that were made to the
+ * payload value since we last synchronized
+ * it with the statistics service.
+ */
+static unsigned int lastSync;
+
+/**
+ * Did we get an answer from statistics?
+ */
+static int stats_worked;
 
 /**
  * Identity of the task that is used to delete
@@ -162,6 +184,29 @@ const struct GNUNET_CONFIGURATION_Handle *cfg;
  */
 struct GNUNET_SCHEDULER_Handle *sched; 
 
+/**
+ * Handle for reporting statistics.
+ */
+static struct GNUNET_STATISTICS_Handle *stats;
+
+
+/**
+ * Synchronize our utilization statistics with the 
+ * statistics service.
+ */
+static void 
+sync_stats ()
+{
+  GNUNET_STATISTICS_set (stats,
+                        QUOTA_STAT_NAME,
+                        payload,
+                        GNUNET_YES);
+  lastSync = 0;
+}
+
+
+
+
 /**
  * Function called once the transmit operation has
  * either failed or succeeded.
@@ -173,12 +218,31 @@ typedef void (*TransmitContinuation)(void *cls,
                                     int status);
 
 
+/**
+ * Context for transmitting replies to clients.
+ */
 struct TransmitCallbackContext 
 {
+  
+  /**
+   * We keep these in a doubly-linked list (for cleanup).
+   */
+  struct TransmitCallbackContext *next;
+  
+  /**
+   * We keep these in a doubly-linked list (for cleanup).
+   */
+  struct TransmitCallbackContext *prev;
+  
   /**
    * The message that we're asked to transmit.
    */
   struct GNUNET_MessageHeader *msg;
+  
+  /**
+   * Handle for the transmission request.
+   */
+  struct GNUNET_CONNECTION_TransmitHandle *th;
 
   /**
    * Client that we are transmitting to.
@@ -203,6 +267,28 @@ struct TransmitCallbackContext
   int end;
 };
 
+  
+/**
+ * Head of the doubly-linked list (for cleanup).
+ */
+static struct TransmitCallbackContext *tcc_head;
+
+/**
+ * Tail of the doubly-linked list (for cleanup).
+ */
+static struct TransmitCallbackContext *tcc_tail;
+
+/**
+ * Have we already cleaned up the TCCs and are hence no longer
+ * willing (or able) to transmit anything to anyone?
+ */
+static int cleaning_done;
+
+/**
+ * Handle for pending get request.
+ */
+static struct GNUNET_STATISTICS_GetHandle *stat_get;
+
 
 /**
  * Task that is used to remove expired entries from
@@ -245,7 +331,7 @@ expired_processor (void *cls,
                   const GNUNET_HashCode * key,
                   uint32_t size,
                   const void *data,
-                  uint32_t type,
+                  enum GNUNET_BLOCK_Type type,
                   uint32_t priority,
                   uint32_t anonymity,
                   struct GNUNET_TIME_Absolute
@@ -254,21 +340,17 @@ expired_processor (void *cls,
 {
   struct GNUNET_TIME_Absolute now;
 
-  expired_kill_task = GNUNET_SCHEDULER_NO_TASK;
   if (key == NULL) 
     {
       expired_kill_task 
        = GNUNET_SCHEDULER_add_delayed (sched,
-                                       GNUNET_NO,
-                                       GNUNET_SCHEDULER_PRIORITY_IDLE,
-                                       GNUNET_SCHEDULER_NO_TASK,
                                        MAX_EXPIRE_DELAY,
                                        &delete_expired,
                                        NULL);
       return GNUNET_SYSERR;
     }
   now = GNUNET_TIME_absolute_get ();
-  if (expiration.value > now.value)
+  if (expiration.abs_value > now.abs_value)
     {
       /* finished processing */
       plugin->api->next_request (next_cls, GNUNET_YES);
@@ -277,9 +359,15 @@ expired_processor (void *cls,
   plugin->api->next_request (next_cls, GNUNET_NO);
 #if DEBUG_DATASTORE
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Deleting content that expired %llu ms ago\n",
-             (unsigned long long) (now.value - expiration.value));
+             "Deleting content `%s' of type %u that expired %llu ms ago\n",
+             GNUNET_h2s (key),
+             type,
+             (unsigned long long) (now.abs_value - expiration.abs_value));
 #endif
+  GNUNET_STATISTICS_update (stats,
+                           gettext_noop ("# bytes expired"),
+                           size,
+                           GNUNET_YES);
   GNUNET_CONTAINER_bloomfilter_remove (filter,
                                       key);
   return GNUNET_NO; /* delete */
@@ -299,6 +387,7 @@ static void
 delete_expired (void *cls,
                const struct GNUNET_SCHEDULER_TaskContext *tc)
 {
+  expired_kill_task = GNUNET_SCHEDULER_NO_TASK;
   plugin->api->iter_ascending_expiration (plugin->api->cls, 
                                          0,
                                          &expired_processor,
@@ -331,7 +420,7 @@ manage (void *cls,
        const GNUNET_HashCode * key,
        uint32_t size,
        const void *data,
-       uint32_t type,
+       enum GNUNET_BLOCK_Type type,
        uint32_t priority,
        uint32_t anonymity,
        struct GNUNET_TIME_Absolute
@@ -353,10 +442,16 @@ manage (void *cls,
                             (0 == *need) ? GNUNET_YES : GNUNET_NO);
 #if DEBUG_DATASTORE
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Deleting %llu bytes of low-priority content (still trying to free another %llu bytes)\n",
-             size + GNUNET_DATASTORE_ENTRY_OVERHEAD,
+             "Deleting %llu bytes of low-priority content `%s' of type %u (still trying to free another %llu bytes)\n",
+             (unsigned long long) (size + GNUNET_DATASTORE_ENTRY_OVERHEAD),
+             GNUNET_h2s (key),
+             type,
              *need);
 #endif
+  GNUNET_STATISTICS_update (stats,
+                           gettext_noop ("# bytes purged (low-priority)"),
+                           size,
+                           GNUNET_YES);
   GNUNET_CONTAINER_bloomfilter_remove (filter,
                                       key);
   return GNUNET_NO;
@@ -412,19 +507,24 @@ transmit_callback (void *cls,
   struct TransmitCallbackContext *tcc = cls;
   size_t msize;
   
+  tcc->th = NULL;
+  GNUNET_CONTAINER_DLL_remove (tcc_head,
+                              tcc_tail,
+                              tcc);
   msize = ntohs(tcc->msg->size);
   if (size == 0)
     {
-#if DEBUG_DATASTORE
       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-                 "Transmission failed.\n");
-#endif
+                 _("Transmission to client failed!\n"));
       if (tcc->tc != NULL)
        tcc->tc (tcc->tc_cls, GNUNET_SYSERR);
       if (GNUNET_YES == tcc->end)
        {
-         GNUNET_SERVER_receive_done (tcc->client, GNUNET_SYSERR);
+         GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                     _("Disconnecting client due to transmission failure!\n"));
+         GNUNET_SERVER_receive_done (tcc->client, GNUNET_SYSERR);       
        }
+      GNUNET_SERVER_client_drop (tcc->client);
       GNUNET_free (tcc->msg);
       GNUNET_free (tcc);
       return 0;
@@ -444,6 +544,7 @@ transmit_callback (void *cls,
                  "Response transmitted, more pending!\n");
 #endif
     }
+  GNUNET_SERVER_client_drop (tcc->client);
   GNUNET_free (tcc->msg);
   GNUNET_free (tcc);
   return msize;
@@ -470,34 +571,47 @@ transmit (struct GNUNET_SERVER_Client *client,
 {
   struct TransmitCallbackContext *tcc;
 
+  if (GNUNET_YES == cleaning_done)
+    {
+#if DEBUG_DATASTORE
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                 "Shutdown in progress, aborting transmission.\n");
+#endif
+      GNUNET_free (msg);
+      if (NULL != tc)
+       tc (tc_cls, GNUNET_SYSERR);
+      return;
+    }
   tcc = GNUNET_malloc (sizeof(struct TransmitCallbackContext));
   tcc->msg = msg;
   tcc->client = client;
   tcc->tc = tc;
   tcc->tc_cls = tc_cls;
   tcc->end = end;
-
   if (NULL ==
-      GNUNET_SERVER_notify_transmit_ready (client,
-                                          ntohs(msg->size),
-                                          GNUNET_TIME_UNIT_FOREVER_REL,
-                                          &transmit_callback,
-                                          tcc))
+      (tcc->th = GNUNET_SERVER_notify_transmit_ready (client,
+                                                     ntohs(msg->size),
+                                                     GNUNET_TIME_UNIT_FOREVER_REL,
+                                                     &transmit_callback,
+                                                     tcc)))
     {
       GNUNET_break (0);
       if (GNUNET_YES == end)
        {
-#if DEBUG_DATASTORE
          GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-                     "Disconnecting client.\n");
-#endif   
+                     _("Forcefully disconnecting client.\n"));
          GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
        }
       if (NULL != tc)
        tc (tc_cls, GNUNET_SYSERR);
       GNUNET_free (msg);
       GNUNET_free (tcc);
+      return;
     }
+  GNUNET_SERVER_client_keep (client);
+  GNUNET_CONTAINER_DLL_insert (tcc_head,
+                              tcc_tail,
+                              tcc);
 }
 
 
@@ -548,8 +662,9 @@ get_next(void *next_cls,
   if (status != GNUNET_OK)
     {
       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-                 _("Failed to transmit an item to the client; aborting iteration.\n"));    
-      plugin->api->next_request (next_cls, GNUNET_YES);
+                 _("Failed to transmit an item to the client; aborting iteration.\n"));
+      if (plugin != NULL)
+       plugin->api->next_request (next_cls, GNUNET_YES);
       return;
     }
   plugin->api->next_request (next_cls, GNUNET_NO);
@@ -581,7 +696,7 @@ transmit_item (void *cls,
               const GNUNET_HashCode * key,
               uint32_t size,
               const void *data,
-              uint32_t type,
+              enum GNUNET_BLOCK_Type type,
               uint32_t priority,
               uint32_t anonymity,
               struct GNUNET_TIME_Absolute
@@ -620,9 +735,15 @@ transmit_item (void *cls,
   memcpy (&dm[1], data, size);
 #if DEBUG_DATASTORE
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Transmitting `%s' message\n",
-             "DATA");
+             "Transmitting `%s' message for `%s' of type %u\n",
+             "DATA",
+             GNUNET_h2s (key),
+             type);
 #endif
+  GNUNET_STATISTICS_update (stats,
+                           gettext_noop ("# results found"),
+                           1,
+                           GNUNET_NO);
   transmit (client, &dm->header, &get_next, next_cls, GNUNET_NO);
   return GNUNET_OK;
 }
@@ -640,6 +761,11 @@ handle_reserve (void *cls,
                struct GNUNET_SERVER_Client *client,
                const struct GNUNET_MessageHeader *message)
 {
+  /**
+   * Static counter to produce reservation identifiers.
+   */
+  static int reservation_gen;
+
   const struct ReserveMessage *msg = (const struct ReserveMessage*) message;
   struct ReservationList *e;
   unsigned long long used;
@@ -654,7 +780,7 @@ handle_reserve (void *cls,
 #endif
   amount = GNUNET_ntohll(msg->amount);
   entries = ntohl(msg->entries);
-  used = plugin->api->get_size (plugin->api->cls) + reserved;
+  used = payload + reserved;
   req = amount + ((unsigned long long) GNUNET_DATASTORE_ENTRY_OVERHEAD) * entries;
   if (used + req > quota)
     {
@@ -688,6 +814,10 @@ handle_reserve (void *cls,
       return;      
     }
   reserved += req;
+  GNUNET_STATISTICS_set (stats,
+                        gettext_noop ("# reserved"),
+                        reserved,
+                        GNUNET_NO);
   e = GNUNET_malloc (sizeof(struct ReservationList));
   e->next = reservations;
   reservations = e;
@@ -739,6 +869,10 @@ handle_release_reserve (void *cls,
          rem = pos->amount + ((unsigned long long) GNUNET_DATASTORE_ENTRY_OVERHEAD) * pos->entries;
          GNUNET_assert (reserved >= rem);
          reserved -= rem;
+         GNUNET_STATISTICS_set (stats,
+                        gettext_noop ("# reserved"),
+                                reserved,
+                                GNUNET_NO);
 #if DEBUG_DATASTORE
          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                      "Returning %llu remaining reserved bytes to storage pool\n",
@@ -784,6 +918,144 @@ check_data (const struct GNUNET_MessageHeader *message)
 }
 
 
+/**
+ * Context for a put request used to see if the content is
+ * already present.
+ */
+struct PutContext
+{
+  /**
+   * Client to notify on completion.
+   */
+  struct GNUNET_SERVER_Client *client;
+
+  /**
+   * Did we find the data already in the database?
+   */
+  int is_present;
+  
+  /* followed by the 'struct DataMessage' */
+};
+
+
+/**
+ * Actually put the data message.
+ */
+static void
+execute_put (struct GNUNET_SERVER_Client *client,
+            const struct DataMessage *dm)
+{
+  uint32_t size;
+  char *msg;
+  int ret;
+
+  size = ntohl(dm->size);
+  msg = NULL;
+  ret = plugin->api->put (plugin->api->cls,
+                         &dm->key,
+                         size,
+                         &dm[1],
+                         ntohl(dm->type),
+                         ntohl(dm->priority),
+                         ntohl(dm->anonymity),
+                         GNUNET_TIME_absolute_ntoh(dm->expiration),
+                         &msg);
+  if (GNUNET_OK == ret)
+    {
+      GNUNET_STATISTICS_update (stats,
+                               gettext_noop ("# bytes stored"),
+                               size,
+                               GNUNET_YES);
+      GNUNET_CONTAINER_bloomfilter_add (filter,
+                                       &dm->key);
+#if DEBUG_DATASTORE
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                 "Successfully stored %u bytes of type %u under key `%s'\n",
+                 size,
+                 ntohl(dm->type),
+                 GNUNET_h2s (&dm->key));
+#endif
+    }
+  transmit_status (client, 
+                  (GNUNET_SYSERR == ret) ? GNUNET_SYSERR : GNUNET_OK, 
+                  msg);
+  GNUNET_free_non_null (msg);
+  if (quota - reserved - cache_size < payload)
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+                 _("Need %llu bytes more space (%llu allowed, using %llu)\n"),
+                 (unsigned long long) size + GNUNET_DATASTORE_ENTRY_OVERHEAD,
+                 (unsigned long long) (quota - reserved - cache_size),
+                 (unsigned long long) payload);
+      manage_space (size + GNUNET_DATASTORE_ENTRY_OVERHEAD);
+    }
+}
+
+
+
+/**
+ * Function that will check if the given datastore entry
+ * matches the put and if none match executes the put.
+ *
+ * @param cls closure, pointer to the client (of type 'struct PutContext').
+ * @param next_cls closure to use to ask for the next item
+ * @param key key for the content
+ * @param size number of bytes in data
+ * @param data content stored
+ * @param type type of the content
+ * @param priority priority of the content
+ * @param anonymity anonymity-level for the content
+ * @param expiration expiration time for the content
+ * @param uid unique identifier for the datum;
+ *        maybe 0 if no unique identifier is available
+ *
+ * @return GNUNET_SYSERR to abort the iteration, GNUNET_OK to continue,
+ *         GNUNET_NO to delete the item and continue (if supported)
+ */
+static int
+check_present (void *cls,
+              void *next_cls,
+              const GNUNET_HashCode * key,
+              uint32_t size,
+              const void *data,
+              enum GNUNET_BLOCK_Type type,
+              uint32_t priority,
+              uint32_t anonymity,
+              struct GNUNET_TIME_Absolute
+              expiration, uint64_t uid)
+{
+  struct PutContext *pc = cls;
+  const struct DataMessage *dm;
+
+  dm = (const struct DataMessage*) &pc[1];
+  if (key == NULL)
+    {
+      if (pc->is_present == GNUNET_YES)        
+       transmit_status (pc->client, GNUNET_OK, NULL);
+      else
+       execute_put (pc->client, dm);
+      GNUNET_SERVER_client_drop (pc->client);
+      GNUNET_free (pc);
+      return GNUNET_SYSERR;
+    }
+  if ( (GNUNET_BLOCK_TYPE_FS_DBLOCK == type) ||
+       (GNUNET_BLOCK_TYPE_FS_IBLOCK == type) ||
+       ( (size == ntohl(dm->size)) &&
+        (0 == memcmp (&dm[1],
+                      data,
+                      size)) ) )
+    {
+      pc->is_present = GNUNET_YES;
+      plugin->api->next_request (next_cls, GNUNET_YES);
+    }
+  else
+    {
+      plugin->api->next_request (next_cls, GNUNET_NO);
+    }
+  return GNUNET_OK;
+}
+
+
 /**
  * Handle PUT-message.
  *
@@ -797,28 +1069,25 @@ handle_put (void *cls,
            const struct GNUNET_MessageHeader *message)
 {
   const struct DataMessage *dm = check_data (message);
-  char *msg;
-  int ret;
   int rid;
   struct ReservationList *pos;
+  struct PutContext *pc;
   uint32_t size;
 
-#if DEBUG_DATASTORE
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Processing `%s' request\n",
-             "PUT");
-#endif
-  if (ntohl(dm->type) == 0) 
-    {
-      GNUNET_break (0);
-      dm = NULL;
-    }
-  if (dm == NULL)
+  if ( (dm == NULL) ||
+       (ntohl(dm->type) == 0) ) 
     {
       GNUNET_break (0);
       GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
       return;
     }
+#if DEBUG_DATASTORE
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Processing `%s' request for `%s' of type %u\n",
+             "PUT",
+             GNUNET_h2s (&dm->key),
+             ntohl (dm->type));
+#endif
   rid = ntohl(dm->rid);
   size = ntohl(dm->size);
   if (rid > 0)
@@ -831,39 +1100,32 @@ handle_put (void *cls,
       if (NULL != pos)
        {
          GNUNET_break (pos->entries > 0);
-         GNUNET_break (pos->amount > size);
+         GNUNET_break (pos->amount >= size);
          pos->entries--;
          pos->amount -= size;
          reserved -= (size + GNUNET_DATASTORE_ENTRY_OVERHEAD);
+         GNUNET_STATISTICS_set (stats,
+                                gettext_noop ("# reserved"),
+                                reserved,
+                                GNUNET_NO);
        }
     }
-  msg = NULL;
-  ret = plugin->api->put (plugin->api->cls,
-                         &dm->key,
-                         size,
-                         &dm[1],
-                         ntohl(dm->type),
-                         ntohl(dm->priority),
-                         ntohl(dm->anonymity),
-                         GNUNET_TIME_absolute_ntoh(dm->expiration),
-                         &msg);
-  if (GNUNET_OK == ret)
+  if (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (filter,
+                                                      &dm->key))
     {
-      GNUNET_CONTAINER_bloomfilter_add (filter,
-                                       &dm->key);
-#if DEBUG_DATASTORE
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                 "Successfully stored %u bytes under key `%s'\n",
-                 size,
-                 GNUNET_h2s (&dm->key));
-#endif
+      pc = GNUNET_malloc (sizeof (struct PutContext) + size + sizeof (struct DataMessage));
+      pc->client = client;
+      GNUNET_SERVER_client_keep (client);
+      memcpy (&pc[1], dm, size + sizeof (struct DataMessage));
+      plugin->api->get (plugin->api->cls,
+                       &dm->key,
+                       NULL,
+                       ntohl (dm->type),
+                       &check_present,
+                       pc);      
+      return;
     }
-  transmit_status (client, 
-                  (GNUNET_SYSERR == ret) ? GNUNET_SYSERR : GNUNET_OK, 
-                  msg);
-  GNUNET_free_non_null (msg);
-  if (quota - reserved - cache_size < plugin->api->get_size (plugin->api->cls))
-    manage_space (size + GNUNET_DATASTORE_ENTRY_OVERHEAD);
+  execute_put (client, dm);
 }
 
 
@@ -876,17 +1138,12 @@ handle_put (void *cls,
  */
 static void
 handle_get (void *cls,
-            struct GNUNET_SERVER_Client *client,
-            const struct GNUNET_MessageHeader *message)
+           struct GNUNET_SERVER_Client *client,
+           const struct GNUNET_MessageHeader *message)
 {
   const struct GetMessage *msg;
   uint16_t size;
 
-#if DEBUG_DATASTORE
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Processing `%s' request\n",
-             "GET");
-#endif
   size = ntohs(message->size);
   if ( (size != sizeof(struct GetMessage)) &&
        (size != sizeof(struct GetMessage) - sizeof(GNUNET_HashCode)) )
@@ -896,6 +1153,18 @@ handle_get (void *cls,
       return;
     }
   msg = (const struct GetMessage*) message;
+#if DEBUG_DATASTORE
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Processing `%s' request for `%s' of type %u\n",
+             "GET",
+             GNUNET_h2s (&msg->key),
+             ntohl (msg->type));
+#endif
+  GNUNET_STATISTICS_update (stats,
+                           gettext_noop ("# GET requests received"),
+                           1,
+                           GNUNET_NO);
+  GNUNET_SERVER_client_keep (client);
   if ( (size == sizeof(struct GetMessage)) &&
        (GNUNET_YES != GNUNET_CONTAINER_bloomfilter_test (filter,
                                                         &msg->key)) )
@@ -903,17 +1172,19 @@ handle_get (void *cls,
       /* don't bother database... */
 #if DEBUG_DATASTORE
       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                 "Empty result set for `%s' request for `%s'.\n",
+                 "Empty result set for `%s' request for `%s' (bloomfilter).\n",
                  "GET",
                  GNUNET_h2s (&msg->key));
 #endif 
-      GNUNET_SERVER_client_keep (client);
+      GNUNET_STATISTICS_update (stats,
+                               gettext_noop ("# requests filtered by bloomfilter"),
+                               1,
+                               GNUNET_NO);
       transmit_item (client,
                     NULL, NULL, 0, NULL, 0, 0, 0, 
                     GNUNET_TIME_UNIT_ZERO_ABS, 0);
       return;
     }
-  GNUNET_SERVER_client_keep (client);
   plugin->api->get (plugin->api->cls,
                    ((size == sizeof(struct GetMessage)) ? &msg->key : NULL),
                    NULL,
@@ -939,13 +1210,18 @@ handle_update (void *cls,
   int ret;
   char *emsg;
 
+  GNUNET_STATISTICS_update (stats,
+                           gettext_noop ("# UPDATE requests received"),
+                           1,
+                           GNUNET_NO);
+  msg = (const struct UpdateMessage*) message;
+  emsg = NULL;
 #if DEBUG_DATASTORE
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Processing `%s' request\n",
-             "UPDATE");
+             "Processing `%s' request for %llu\n",
+             "UPDATE",
+             (unsigned long long) GNUNET_ntohll (msg->uid));
 #endif
-  msg = (const struct UpdateMessage*) message;
-  emsg = NULL;
   ret = plugin->api->update (plugin->api->cls,
                             GNUNET_ntohll(msg->uid),
                             (int32_t) ntohl(msg->priority),
@@ -973,13 +1249,49 @@ handle_get_random (void *cls,
              "Processing `%s' request\n",
              "GET_RANDOM");
 #endif
+  GNUNET_STATISTICS_update (stats,
+                           gettext_noop ("# GET RANDOM requests received"),
+                           1,
+                           GNUNET_NO);
   GNUNET_SERVER_client_keep (client);
   plugin->api->iter_migration_order (plugin->api->cls,
-                                    0,
+                                    GNUNET_BLOCK_TYPE_ANY,
                                     &transmit_item,
                                     client);  
 }
 
+/**
+ * Handle GET_ZERO_ANONYMITY-message.
+ *
+ * @param cls closure
+ * @param client identification of the client
+ * @param message the actual message
+ */
+static void
+handle_get_zero_anonymity (void *cls,
+                          struct GNUNET_SERVER_Client *client,
+                          const struct GNUNET_MessageHeader *message)
+{
+  const struct GetZeroAnonymityMessage * msg = (const struct GetZeroAnonymityMessage*) message;
+  enum GNUNET_BLOCK_Type type;
+
+  type = (enum GNUNET_BLOCK_Type) ntohl (msg->type);
+#if DEBUG_DATASTORE
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Processing `%s' request\n",
+             "GET_ZERO_ANONYMITY");
+#endif
+  GNUNET_STATISTICS_update (stats,
+                           gettext_noop ("# GET ZERO ANONYMITY requests received"),
+                           1,
+                           GNUNET_NO);
+  GNUNET_SERVER_client_keep (client);
+  plugin->api->iter_zero_anonymity (plugin->api->cls,
+                                   type,
+                                   &transmit_item,
+                                   client);  
+}
+
 
 /**
  * Context for the 'remove_callback'.
@@ -1008,7 +1320,7 @@ remove_callback (void *cls,
                 const GNUNET_HashCode * key,
                 uint32_t size,
                 const void *data,
-                uint32_t type,
+                enum GNUNET_BLOCK_Type type,
                 uint32_t priority,
                 uint32_t anonymity,
                 struct GNUNET_TIME_Absolute
@@ -1034,10 +1346,16 @@ remove_callback (void *cls,
   rc->found = GNUNET_YES;
 #if DEBUG_DATASTORE
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Item %llu matches `%s' request.\n",
+             "Item %llu matches `%s' request for key `%s' and type %u.\n",
              (unsigned long long) uid,
-             "REMOVE");
+             "REMOVE",
+             GNUNET_h2s (key),
+             type);
 #endif 
+  GNUNET_STATISTICS_update (stats,
+                           gettext_noop ("# bytes removed (explicit request)"),
+                           size,
+                           GNUNET_YES);
   GNUNET_CONTAINER_bloomfilter_remove (filter,
                                       key);
   plugin->api->next_request (next_cls, GNUNET_YES);
@@ -1061,17 +1379,23 @@ handle_remove (void *cls,
   GNUNET_HashCode vhash;
   struct RemoveContext *rc;
 
-#if DEBUG_DATASTORE
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Processing `%s' request\n",
-             "REMOVE");
-#endif
   if (dm == NULL)
     {
       GNUNET_break (0);
       GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
       return;
     }
+#if DEBUG_DATASTORE
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Processing `%s' request for `%s' of type %u\n",
+             "REMOVE",
+             GNUNET_h2s (&dm->key),
+             ntohl (dm->type));
+#endif
+  GNUNET_STATISTICS_update (stats,
+                           gettext_noop ("# REMOVE requests received"),
+                           1,
+                           GNUNET_NO);
   rc = GNUNET_malloc (sizeof(struct RemoveContext));
   GNUNET_SERVER_client_keep (client);
   rc->client = client;
@@ -1081,7 +1405,7 @@ handle_remove (void *cls,
   plugin->api->get (plugin->api->cls,
                    &dm->key,
                    &vhash,
-                   ntohl(dm->type),
+                   (enum GNUNET_BLOCK_Type) ntohl(dm->type),
                    &remove_callback,
                    rc);
 }
@@ -1110,27 +1434,76 @@ handle_drop (void *cls,
 
 
 /**
- * List of handlers for the messages understood by this
- * service.
+ * Function called by plugins to notify us about a
+ * change in their disk utilization.
+ *
+ * @param cls closure (NULL)
+ * @param delta change in disk utilization, 
+ *        0 for "reset to empty"
  */
-static struct GNUNET_SERVER_MessageHandler handlers[] = {
-  {&handle_reserve, NULL, GNUNET_MESSAGE_TYPE_DATASTORE_RESERVE, 
-   sizeof(struct ReserveMessage) }, 
-  {&handle_release_reserve, NULL, GNUNET_MESSAGE_TYPE_DATASTORE_RELEASE_RESERVE, 
-   sizeof(struct ReleaseReserveMessage) }, 
-  {&handle_put, NULL, GNUNET_MESSAGE_TYPE_DATASTORE_PUT, 0 }, 
-  {&handle_update, NULL, GNUNET_MESSAGE_TYPE_DATASTORE_UPDATE, 
-   sizeof (struct UpdateMessage) }, 
-  {&handle_get, NULL, GNUNET_MESSAGE_TYPE_DATASTORE_GET, 0 }, 
-  {&handle_get_random, NULL, GNUNET_MESSAGE_TYPE_DATASTORE_GET_RANDOM, 
-   sizeof(struct GNUNET_MessageHeader) }, 
-  {&handle_remove, NULL, GNUNET_MESSAGE_TYPE_DATASTORE_REMOVE, 0 }, 
-  {&handle_drop, NULL, GNUNET_MESSAGE_TYPE_DATASTORE_DROP, 
-   sizeof(struct GNUNET_MessageHeader) }, 
-  {NULL, NULL, 0, 0}
-};
+static void
+disk_utilization_change_cb (void *cls,
+                           int delta)
+{
+  if ( (delta < 0) &&
+       (payload < -delta) )
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                 _("Datastore payload inaccurate (%lld < %lld).  Trying to fix.\n"),
+                 (long long) payload,
+                 (long long) -delta);
+      payload = plugin->api->get_size (plugin->api->cls);
+      sync_stats ();
+      return;
+    }
+  payload += delta;
+  lastSync++;
+  if (lastSync >= MAX_STAT_SYNC_LAG)
+    sync_stats ();
+}
 
 
+/**
+ * Callback function to process statistic values.
+ *
+ * @param cls closure (struct Plugin*)
+ * @param subsystem name of subsystem that created the statistic
+ * @param name the name of the datum
+ * @param value the current value
+ * @param is_persistent GNUNET_YES if the value is persistent, GNUNET_NO if not
+ * @return GNUNET_OK to continue, GNUNET_SYSERR to abort iteration
+ */
+static int
+process_stat_in (void *cls,
+                const char *subsystem,
+                const char *name,
+                uint64_t value,
+                int is_persistent)
+{
+  GNUNET_assert (stats_worked == GNUNET_NO);
+  stats_worked = GNUNET_YES;
+  payload += value;
+#if DEBUG_SQLITE
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Notification from statistics about existing payload (%llu), new payload is %llu\n",
+             abs_value,
+             payload);
+#endif
+  return GNUNET_OK;
+}
+
+
+static void
+process_stat_done (void *cls,
+                  int success)
+{
+  struct DatastorePlugin *plugin = cls;
+
+  stat_get = NULL;
+  if (stats_worked == GNUNET_NO) 
+    payload = plugin->api->get_size (plugin->api->cls);
+}
+
 
 /**
  * Load the datastore plugin.
@@ -1155,6 +1528,8 @@ load_plugin ()
   ret = GNUNET_malloc (sizeof(struct DatastorePlugin));
   ret->env.cfg = cfg;
   ret->env.sched = sched;  
+  ret->env.duc = &disk_utilization_change_cb;
+  ret->env.cls = NULL;
   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
               _("Loading `%s' datastore plugin\n"), name);
   GNUNET_asprintf (&libname, "libgnunet_plugin_datastore_%s", name);
@@ -1195,11 +1570,11 @@ unload_plugin (struct DatastorePlugin *plug)
 
 
 /**
- * Last task run during shutdown.  Disconnects us from
- * the transport and core.
+ * Final task run after shutdown.  Unloads plugins and disconnects us from
+ * statistics.
  */
 static void
-cleaning_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+unload_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 {
   unload_plugin (plugin);
   plugin = NULL;
@@ -1208,6 +1583,56 @@ cleaning_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
       GNUNET_CONTAINER_bloomfilter_free (filter);
       filter = NULL;
     }
+  if (lastSync > 0)
+    sync_stats ();
+  if (stat_get != NULL)
+    {
+      GNUNET_STATISTICS_get_cancel (stat_get);
+      stat_get = NULL;
+    }
+  if (stats != NULL)
+    {
+      GNUNET_STATISTICS_destroy (stats, GNUNET_YES);
+      stats = NULL;
+    }
+}
+
+
+/**
+ * Last task run during shutdown.  Disconnects us from
+ * the transport and core.
+ */
+static void
+cleaning_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+  struct TransmitCallbackContext *tcc;
+
+  cleaning_done = GNUNET_YES;
+  while (NULL != (tcc = tcc_head))
+    {
+      GNUNET_CONTAINER_DLL_remove (tcc_head,
+                                  tcc_tail,
+                                  tcc);
+      if (tcc->th != NULL)
+       {
+         GNUNET_CONNECTION_notify_transmit_ready_cancel (tcc->th);
+         GNUNET_SERVER_client_drop (tcc->client);
+       }
+      if (NULL != tcc->tc)
+       tcc->tc (tcc->tc_cls, GNUNET_SYSERR);
+      GNUNET_free (tcc->msg);
+      GNUNET_free (tcc);
+    }
+  if (expired_kill_task != GNUNET_SCHEDULER_NO_TASK)
+    {
+      GNUNET_SCHEDULER_cancel (sched,
+                              expired_kill_task);
+      expired_kill_task = GNUNET_SCHEDULER_NO_TASK;
+    }
+  GNUNET_SCHEDULER_add_continuation (sched,
+                                    &unload_task,
+                                    NULL,
+                                    GNUNET_SCHEDULER_REASON_PREREQ_DONE);
 }
 
 
@@ -1228,6 +1653,8 @@ cleanup_reservations (void *cls,
   struct ReservationList *prev;
   struct ReservationList *next;
 
+  if (client == NULL)
+    return;
   prev = NULL;
   pos = reservations;
   while (NULL != pos)
@@ -1248,6 +1675,10 @@ cleanup_reservations (void *cls,
        }
       pos = next;
     }
+  GNUNET_STATISTICS_set (stats,
+                        gettext_noop ("# reserved"),
+                        reserved,
+                        GNUNET_NO);
 }
 
 
@@ -1265,6 +1696,24 @@ run (void *cls,
      struct GNUNET_SERVER_Handle *server,
      const struct GNUNET_CONFIGURATION_Handle *c)
 {
+  static const struct GNUNET_SERVER_MessageHandler handlers[] = {
+    {&handle_reserve, NULL, GNUNET_MESSAGE_TYPE_DATASTORE_RESERVE, 
+     sizeof(struct ReserveMessage) }, 
+    {&handle_release_reserve, NULL, GNUNET_MESSAGE_TYPE_DATASTORE_RELEASE_RESERVE, 
+     sizeof(struct ReleaseReserveMessage) }, 
+    {&handle_put, NULL, GNUNET_MESSAGE_TYPE_DATASTORE_PUT, 0 }, 
+    {&handle_update, NULL, GNUNET_MESSAGE_TYPE_DATASTORE_UPDATE, 
+     sizeof (struct UpdateMessage) }, 
+    {&handle_get, NULL, GNUNET_MESSAGE_TYPE_DATASTORE_GET, 0 }, 
+    {&handle_get_random, NULL, GNUNET_MESSAGE_TYPE_DATASTORE_GET_RANDOM, 
+     sizeof(struct GNUNET_MessageHeader) }, 
+    {&handle_get_zero_anonymity, NULL, GNUNET_MESSAGE_TYPE_DATASTORE_GET_ZERO_ANONYMITY, 
+     sizeof(struct GetZeroAnonymityMessage) }, 
+    {&handle_remove, NULL, GNUNET_MESSAGE_TYPE_DATASTORE_REMOVE, 0 }, 
+    {&handle_drop, NULL, GNUNET_MESSAGE_TYPE_DATASTORE_DROP, 
+     sizeof(struct GNUNET_MessageHeader) }, 
+    {NULL, NULL, 0, 0}
+  };
   char *fn;
   unsigned int bf_size;
 
@@ -1280,7 +1729,16 @@ run (void *cls,
                  "DATASTORE");
       return;
     }
+  stats = GNUNET_STATISTICS_create (sched, "datastore", cfg);
+  GNUNET_STATISTICS_set (stats,
+                        gettext_noop ("# quota"),
+                        quota,
+                        GNUNET_NO);
   cache_size = quota / 8; /* Or should we make this an option? */
+  GNUNET_STATISTICS_set (stats,
+                        gettext_noop ("# cache size"),
+                        cache_size,
+                        GNUNET_NO);
   bf_size = quota / 32; /* 8 bit per entry, 1 bit per 32 kb in DB */
   fn = NULL;
   if ( (GNUNET_OK !=
@@ -1303,6 +1761,11 @@ run (void *cls,
     {
       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                  _("Failed to initialize bloomfilter.\n"));
+      if (stats != NULL)
+       {
+         GNUNET_STATISTICS_destroy (stats, GNUNET_YES);
+         stats = NULL;
+       }
       return;
     }
   plugin = load_plugin ();
@@ -1310,24 +1773,29 @@ run (void *cls,
     {
       GNUNET_CONTAINER_bloomfilter_free (filter);
       filter = NULL;
+      if (stats != NULL)
+       {
+         GNUNET_STATISTICS_destroy (stats, GNUNET_YES);
+         stats = NULL;
+       }
       return;
     }
+  stat_get = GNUNET_STATISTICS_get (stats,
+                                   "datastore",
+                                   QUOTA_STAT_NAME,
+                                   GNUNET_TIME_UNIT_SECONDS,
+                                   &process_stat_done,
+                                   &process_stat_in,
+                                   plugin);
   GNUNET_SERVER_disconnect_notify (server, &cleanup_reservations, NULL);
   GNUNET_SERVER_add_handlers (server, handlers);
   expired_kill_task
-    = GNUNET_SCHEDULER_add_delayed (sched,
-                                   GNUNET_NO,
-                                   GNUNET_SCHEDULER_PRIORITY_IDLE,
-                                   GNUNET_SCHEDULER_NO_TASK,
-                                   GNUNET_TIME_UNIT_ZERO,
-                                   &delete_expired, NULL);
+    = GNUNET_SCHEDULER_add_with_priority (sched,
+                                         GNUNET_SCHEDULER_PRIORITY_IDLE,
+                                         &delete_expired, NULL);
   GNUNET_SCHEDULER_add_delayed (sched,
-                                GNUNET_YES,
-                                GNUNET_SCHEDULER_PRIORITY_IDLE,
-                                GNUNET_SCHEDULER_NO_TASK,
                                 GNUNET_TIME_UNIT_FOREVER_REL,
                                 &cleaning_task, NULL);
-  
 }
 
 
@@ -1346,7 +1814,9 @@ main (int argc, char *const *argv)
   ret = (GNUNET_OK ==
          GNUNET_SERVICE_run (argc,
                              argv,
-                             "datastore", &run, NULL, NULL, NULL)) ? 0 : 1;
+                             "datastore",
+                            GNUNET_SERVICE_OPTION_NONE,
+                            &run, NULL)) ? 0 : 1;
   return ret;
 }