8 files changed, 1849 insertions, 0 deletions

diff --git a/src/statistics/Makefile.am b/src/statistics/Makefile.am
new file mode 100644
index 000000000..2ae254cbf
--- /dev/null
+++ b/src/statistics/Makefile.am
@@ -0,0 +1,59 @@
+INCLUDES = -I$(top_srcdir)/src/include
+
+if MINGW
+ WINFLAGS = -Wl,--no-undefined -Wl,--export-all-symbols 
+endif
+
+if USE_COVERAGE
+  AM_CFLAGS = -fprofile-arcs -ftest-coverage
+endif
+
+
+lib_LTLIBRARIES = libgnunetstatistics.la
+
+libgnunetstatistics_la_SOURCES = \
+  statistics_api.c statistics.h
+libgnunetstatistics_la_LIBADD = \
+  $(top_builddir)/src/util/libgnunetutil.la \
+  $(GN_LIBINTL)
+libgnunetstatistics_la_LDFLAGS = \
+  $(GN_LIB_LDFLAGS)  $(WINFLAGS) \
+  -version-info 0:0:0
+
+
+bin_PROGRAMS = \
+ gnunet-statistics \
+ gnunet-service-statistics
+
+gnunet_statistics_SOURCES = \
+ gnunet-statistics.c         
+gnunet_statistics_LDADD = \
+  $(top_builddir)/src/statistics/libgnunetstatistics.la \
+  $(top_builddir)/src/util/libgnunetutil.la \
+  $(GN_LIBINTL)
+
+gnunet_service_statistics_SOURCES = \
+ gnunet-service-statistics.c         
+gnunet_service_statistics_LDADD = \
+  $(top_builddir)/src/statistics/libgnunetstatistics.la \
+  $(top_builddir)/src/util/libgnunetutil.la \
+  $(GN_LIBINTL)
+
+
+check_PROGRAMS = \
+ test_statistics_api
+
+TESTS = $(check_PROGRAMS) $(check_SCRIPTS)
+
+test_statistics_api_SOURCES = \
+ test_statistics_api.c
+test_statistics_api_LDADD = \
+  $(top_builddir)/src/statistics/libgnunetstatistics.la \
+  $(top_builddir)/src/util/libgnunetutil.la  
+
+EXTRA_DIST = \
+  test_statistics_api_data.conf 
+
+check_SCRIPTS = \
+  test_gnunet_statistics.sh
+
diff --git a/src/statistics/gnunet-service-statistics.c b/src/statistics/gnunet-service-statistics.c
new file mode 100644
index 000000000..0e7b4853d
--- /dev/null
+++ b/src/statistics/gnunet-service-statistics.c
@@ -0,0 +1,470 @@
+/*
+     This file is part of GNUnet.
+     (C) 2009 Christian Grothoff (and other contributing authors)
+
+     GNUnet is free software; you can redistribute it and/or modify
+     it under the terms of the GNU General Public License as published
+     by the Free Software Foundation; either version 2, 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
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+
+/**
+ * @file statistics/gnunet-service-statistics.c
+ * @brief program that tracks statistics
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_disk_lib.h"
+#include "gnunet_getopt_lib.h"
+#include "gnunet_protocols.h"
+#include "gnunet_service_lib.h"
+#include "gnunet_statistics_service.h"
+#include "gnunet_strings_lib.h"
+#include "gnunet_time_lib.h"
+#include "statistics.h"
+
+/**
+ * Entry in the statistics list.
+ */
+struct StatsEntry
+{
+  /**
+   * This is a linked list.
+   */
+  struct StatsEntry *next;
+
+  /**
+   * Name of the service, points into the
+   * middle of msg.
+   */
+  const char *service;
+
+  /**
+   * Name for the value, points into
+   * the middle of msg.
+   */
+  const char *name;
+
+  /**
+   * Message that can be used to set this value,
+   * stored at the end of the memory used by
+   * this struct.
+   */
+  struct GNUNET_STATISTICS_SetMessage *msg;
+
+  /**
+   * Our value.
+   */
+  uint64_t value;
+
+  /**
+   * Unique ID.
+   */
+  uint32_t uid;
+
+  /**
+   * Is this value persistent?
+   */
+  int persistent;
+
+};
+
+/**
+ * Linked list of our active statistics.
+ */
+static struct StatsEntry *start;
+
+/**
+ * Counter used to generate unique values.
+ */
+static uint32_t uidgen;
+
+/**
+ * Load persistent values from disk.  Disk format is
+ * exactly the same format that we also use for
+ * setting the values over the network.
+ */
+static void
+load (struct GNUNET_SERVER_Handle *server,
+      struct GNUNET_CONFIGURATION_Handle *cfg)
+{
+  char *fn;
+  int fd;
+  struct stat sb;
+  char *buf;
+  size_t off;
+  const struct GNUNET_MessageHeader *msg;
+
+  fn = GNUNET_DISK_get_home_filename (cfg,
+                                      "statistics", "statistics.data", NULL);
+  if (fn == NULL)
+    return;
+  if ((0 != stat (fn, &sb)) || (sb.st_size == 0))
+    {
+      GNUNET_free (fn);
+      return;
+    }
+  fd = GNUNET_DISK_file_open (fn, O_RDONLY);
+  if (fd == -1)
+    {
+      GNUNET_free (fn);
+      return;
+    }
+  buf = mmap (NULL, sb.st_size, PROT_READ, MAP_SHARED, fd, 0);
+  if (MAP_FAILED == buf)
+    {
+      GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "mmap", fn);
+      GNUNET_break (0 == CLOSE (fd));
+      GNUNET_free (fn);
+      return;
+    }
+  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+              _("Loading %llu bytes of statistics from `%s'\n"),
+              (unsigned long long) sb.st_size, fn);
+  off = 0;
+  while (off + sizeof (struct GNUNET_MessageHeader) < sb.st_size)
+    {
+      msg = (const struct GNUNET_MessageHeader *) &buf[off];
+      if ((ntohs (msg->size) + off > sb.st_size) ||
+          (GNUNET_OK != GNUNET_SERVER_inject (server, NULL, msg)))
+        {
+          GNUNET_break (0);
+          break;
+        }
+      off += ntohs (msg->size);
+    }
+  GNUNET_break (0 == munmap (buf, sb.st_size));
+  GNUNET_break (0 == CLOSE (fd));
+  GNUNET_free (fn);
+}
+
+
+/**
+ * Write persistent statistics to disk.
+ *
+ * @param cls closure
+ * @param cfg configuration to use
+ */
+static void
+save (void *cls, struct GNUNET_CONFIGURATION_Handle *cfg)
+{
+  struct StatsEntry *pos;
+  char *fn;
+  int fd;
+  uint16_t size;
+  unsigned long long total;
+
+  fd = -1;
+  fn = GNUNET_DISK_get_home_filename (cfg,
+                                      "statistics", "statistics.data", NULL);
+  if (fn != NULL)
+    fd =
+      GNUNET_DISK_file_open (fn, O_WRONLY | O_CREAT | O_TRUNC,
+                             S_IRUSR | S_IWUSR);
+  total = 0;
+  while (NULL != (pos = start))
+    {
+      start = pos->next;
+      if ((pos->persistent) && (fd != -1))
+        {
+          size = htons (pos->msg->header.size);
+          if (size != WRITE (fd, pos->msg, size))
+            {
+              GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
+                                        "write", fn);
+              GNUNET_DISK_file_close (fn, fd);
+              fd = -1;
+            }
+          else
+            total += size;
+        }
+      GNUNET_free (pos);
+    }
+  if (fd != -1)
+    {
+      GNUNET_DISK_file_close (fn, fd);
+      if (total == 0)
+        GNUNET_break (0 == UNLINK (fn));
+      else
+        GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+                    _("Wrote %llu bytes of statistics to `%s'\n"), total, fn);
+    }
+  GNUNET_free_non_null (fn);
+}
+
+
+/**
+ * Transmit the given stats value.
+ */
+static void
+transmit (struct GNUNET_SERVER_TransmitContext *tc,
+          const struct StatsEntry *e)
+{
+  struct GNUNET_STATISTICS_ReplyMessage *m;
+  struct GNUNET_MessageHeader *h;
+  size_t size;
+  uint16_t msize;
+
+  size =
+    sizeof (struct GNUNET_STATISTICS_ReplyMessage) + strlen (e->service) + 1 +
+    strlen (e->name) + 1;
+  GNUNET_assert (size < GNUNET_SERVER_MAX_MESSAGE_SIZE);
+  msize = size - sizeof (struct GNUNET_MessageHeader);
+  m = GNUNET_malloc (size);
+  m->uid = htonl (e->uid);
+  if (e->persistent)
+    m->uid |= htonl (GNUNET_STATISTICS_PERSIST_BIT);
+  m->value = GNUNET_htonll (e->value);
+  size -= sizeof (struct GNUNET_STATISTICS_ReplyMessage);
+  GNUNET_assert (size == GNUNET_STRINGS_buffer_fill ((char *) &m[1],
+                                                     size,
+                                                     2, e->service, e->name));
+#if DEBUG_STATISTICS
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Transmitting value for `%s:%s': %llu\n",
+              e->service, e->name, e->value);
+#endif
+  h = &m->header;
+  GNUNET_SERVER_transmit_context_append (tc,
+                                         &h[1],
+                                         msize,
+                                         GNUNET_MESSAGE_TYPE_STATISTICS_VALUE);
+  GNUNET_free (m);
+}
+
+
+/**
+ * Does this entry match the request?
+ */
+static int
+matches (const struct StatsEntry *e, const char *service, const char *name)
+{
+  return ((0 == strlen (service)) ||
+          (0 == strcmp (service, e->service)))
+    && ((0 == strlen (name)) || (0 == strcmp (name, e->name)));
+}
+
+
+/**
+ * Handle GET-message.
+ *
+ * @param cls closure
+ * @param server the server handling the message
+ * @param client identification of the client
+ * @param message the actual message
+ * @return GNUNET_OK to keep the connection open,
+ *         GNUNET_SYSERR to close it (signal serious error)
+ */
+static void
+handle_get (void *cls,
+            struct GNUNET_SERVER_Handle *server,
+            struct GNUNET_SERVER_Client *client,
+            const struct GNUNET_MessageHeader *message)
+{
+  char *service;
+  char *name;
+  struct StatsEntry *pos;
+  struct GNUNET_SERVER_TransmitContext *tc;
+  size_t size;
+
+  size = ntohs (message->size) - sizeof (struct GNUNET_MessageHeader);
+  if (size != GNUNET_STRINGS_buffer_tokenize ((const char *) &message[1],
+                                              size, 2, &service, &name))
+    {
+      GNUNET_break (0);
+      GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
+      return;
+    }
+#if DEBUG_STATISTICS
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Received request for statistics on `%s:%s'\n",
+              strlen (service) ? service : "*", strlen (name) ? name : "*");
+#endif
+  tc = GNUNET_SERVER_transmit_context_create (client);
+  pos = start;
+  while (pos != NULL)
+    {
+      if (matches (pos, service, name))
+        transmit (tc, pos);
+      pos = pos->next;
+    }
+  GNUNET_SERVER_transmit_context_append (tc, NULL, 0,
+                                         GNUNET_MESSAGE_TYPE_STATISTICS_END);
+  GNUNET_SERVER_transmit_context_run (tc, GNUNET_TIME_UNIT_FOREVER_REL);
+}
+
+
+/**
+ * Handle SET-message.
+ *
+ * @param cls closure
+ * @param server the server handling the message
+ * @param client identification of the client
+ * @param message the actual message
+ */
+static void
+handle_set (void *cls,
+            struct GNUNET_SERVER_Handle *server,
+            struct GNUNET_SERVER_Client *client,
+            const struct GNUNET_MessageHeader *message)
+{
+  char *service;
+  char *name;
+  uint16_t msize;
+  uint16_t size;
+  const struct GNUNET_STATISTICS_SetMessage *msg;
+  struct StatsEntry *pos;
+  struct StatsEntry *prev;
+  uint32_t flags;
+  uint64_t value;
+  int64_t delta;
+
+  msize = ntohs (message->size);
+  if (msize < sizeof (struct GNUNET_STATISTICS_SetMessage))
+    {
+      GNUNET_break (0);
+      GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
+      return;
+    }
+  size = msize - sizeof (struct GNUNET_STATISTICS_SetMessage);
+  msg = (const struct GNUNET_STATISTICS_SetMessage *) message;
+
+  if (size != GNUNET_STRINGS_buffer_tokenize ((const char *) &msg[1],
+                                              size, 2, &service, &name))
+    {
+      GNUNET_break (0);
+      GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
+      return;
+    }
+#if DEBUG_STATISTICS
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Received request to update statistic on `%s:%s'\n",
+              service, name);
+#endif
+  flags = ntohl (msg->flags);
+  value = GNUNET_ntohll (msg->value);
+  pos = start;
+  prev = NULL;
+  while (pos != NULL)
+    {
+      if (matches (pos, service, name))
+        {
+          if ((flags & GNUNET_STATISTICS_SETFLAG_RELATIVE) == 0)
+            {
+              pos->value = value;
+            }
+          else
+            {
+              delta = (int64_t) value;
+              if ((delta < 0) && (pos->value < -delta))
+                {
+                  pos->value = 0;
+                }
+              else
+                {
+                  GNUNET_break ((delta <= 0) ||
+                                (pos->value + delta > pos->value));
+                  pos->value += delta;
+                }
+            }
+          pos->msg->value = GNUNET_htonll (pos->value);
+          pos->msg->flags = msg->flags;
+          pos->persistent =
+            (0 != (flags & GNUNET_STATISTICS_SETFLAG_PERSISTENT));
+          if (prev != NULL)
+            {
+              /* move to front for faster setting next time! */
+              prev->next = pos->next;
+              pos->next = start;
+              start = pos;
+            }
+#if DEBUG_STATISTICS
+          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                      "Statistic `%s:%s' updated to value %llu.\n",
+                      service, name, pos->value);
+#endif
+          GNUNET_SERVER_receive_done (client, GNUNET_OK);
+          return;
+        }
+      prev = pos;
+      pos = pos->next;
+    }
+  pos = GNUNET_malloc (sizeof (struct StatsEntry) + msize);
+  pos->next = start;
+  if (((flags & GNUNET_STATISTICS_SETFLAG_RELATIVE) == 0) ||
+      (0 < (int64_t) GNUNET_ntohll (msg->value)))
+    pos->value = GNUNET_ntohll (msg->value);
+  pos->uid = uidgen++;
+  pos->persistent = (0 != (flags & GNUNET_STATISTICS_SETFLAG_PERSISTENT));
+  pos->msg = (void *) &pos[1];
+  memcpy (pos->msg, message, ntohs (message->size));
+  pos->service = (const char *) &pos->msg[1];
+  pos->name = &pos->service[strlen (pos->service) + 1];
+
+  start = pos;
+#if DEBUG_STATISTICS
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "New statistic on `%s:%s' with value %llu created.\n",
+              service, name, pos->value);
+#endif
+  GNUNET_SERVER_receive_done (client, GNUNET_OK);
+}
+
+
+/**
+ * List of handlers for the messages understood by this
+ * service.
+ */
+static struct GNUNET_SERVER_MessageHandler handlers[] = {
+  {&handle_set, NULL, GNUNET_MESSAGE_TYPE_STATISTICS_SET, 0},
+  {&handle_get, NULL, GNUNET_MESSAGE_TYPE_STATISTICS_GET, 0},
+  {NULL, NULL, 0, 0}
+};
+
+
+/**
+ * Process statistics requests.
+ *
+ * @param cls closure
+ * @param sched scheduler to use
+ * @param server the initialized server
+ * @param cfg configuration to use
+ */
+static void
+run (void *cls,
+     struct GNUNET_SCHEDULER_Handle *sched,
+     struct GNUNET_SERVER_Handle *server,
+     struct GNUNET_CONFIGURATION_Handle *cfg)
+{
+  GNUNET_SERVER_add_handlers (server, handlers);
+  load (server, cfg);
+}
+
+
+/**
+ * The main function for the statistics service.
+ *
+ * @param argc number of arguments from the command line
+ * @param argv command line arguments
+ * @return 0 ok, 1 on error
+ */
+int
+main (int argc, char *const *argv)
+{
+  return (GNUNET_OK ==
+          GNUNET_SERVICE_run (argc,
+                              argv,
+                              "statistics", &run, NULL, &save, NULL)) ? 0 : 1;
+}
+
+/* end of gnunet-service-statistics.c */
diff --git a/src/statistics/gnunet-statistics.c b/src/statistics/gnunet-statistics.c
new file mode 100644
index 000000000..bafb77c66
--- /dev/null
+++ b/src/statistics/gnunet-statistics.c
@@ -0,0 +1,179 @@
+/*
+     This file is part of GNUnet.
+     (C) 2001, 2002, 2004, 2005, 2006, 2007, 2009 Christian Grothoff (and other contributing authors)
+
+     GNUnet is free software; you can redistribute it and/or modify
+     it under the terms of the GNU General Public License as published
+     by the Free Software Foundation; either version 2, 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
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+
+/**
+ * @file statistics/gnunet-statistics.c
+ * @brief tool to obtain statistics
+ * @author Christian Grothoff
+ * @author Igor Wronsky
+ */
+#include "platform.h"
+#include "gnunet_getopt_lib.h"
+#include "gnunet_program_lib.h"
+#include "gnunet_statistics_service.h"
+#include "statistics.h"
+
+#define GET_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 15)
+
+/**
+ * Final status code.
+ */
+static int ret;
+
+/**
+ * Set to subsystem that we're going to get stats for (or NULL for all).
+ */
+static char *subsystem;
+
+/**
+ * Set to the specific stat value that we are after (or NULL for all).
+ */
+static char *name;
+
+/**
+ * Make the value that is being set persistent.
+ */
+static int persistent;
+
+/**
+ * Callback function to process statistic values.
+ *
+ * @param cls closure
+ * @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
+printer (void *cls,
+         const char *subsystem,
+         const char *sname, unsigned long long value, int is_persistent)
+{
+  FPRINTF (stdout,
+           "%s%-20s %-40s: %16llu\n",
+           is_persistent ? "!" : " ", subsystem, _(sname), value);
+  return GNUNET_OK;
+}
+
+
+/**
+ * Function called last by the statistics code.
+ *
+ * @param cls closure
+ * @param success GNUNET_OK if statistics were
+ *        successfully obtained, GNUNET_SYSERR if not.
+ */
+static void
+cleanup (void *cls, int success)
+{
+  struct GNUNET_STATISTICS_Handle *h = cls;
+
+  if (success != GNUNET_OK)
+    ret = 1;
+  if (h != NULL)
+    GNUNET_STATISTICS_destroy (h);
+}
+
+
+/**
+ * Main function that will be run by the scheduler.
+ *
+ * @param cls closure
+ * @param sched the scheduler to use
+ * @param args remaining command-line arguments
+ * @param cfgfile name of the configuration file used (for saving, can be NULL!)
+ * @param cfg configuration
+ */
+static void
+run (void *cls,
+     struct GNUNET_SCHEDULER_Handle *sched,
+     char *const *args,
+     const char *cfgfile, struct GNUNET_CONFIGURATION_Handle *cfg)
+{
+  struct GNUNET_STATISTICS_Handle *h;
+  unsigned long long val;
+
+  if (args[0] != NULL)
+    {
+      if ((1 != SSCANF (args[0], "%llu", &val)) ||
+          (subsystem == NULL) || (name == NULL))
+        {
+          FPRINTF (stderr, _("Invalid argument `%s'\n"), args[0]);
+          ret = 1;
+          return;
+        }
+      h = GNUNET_STATISTICS_create (sched, subsystem, cfg);
+      if (h == NULL)
+        {
+          ret = 1;
+          return;
+        }
+      GNUNET_STATISTICS_set (h, name, val, persistent);
+      GNUNET_STATISTICS_destroy (h);
+      return;
+    }
+  h = GNUNET_STATISTICS_create (sched, "gnunet-statistics", cfg);
+  if (h == NULL)
+    {
+      ret = 1;
+      return;
+    }
+  GNUNET_STATISTICS_get (h,
+                         subsystem, name, GET_TIMEOUT, &cleanup, &printer, h);
+}
+
+/**
+ * gnunet-statistics command line options
+ */
+static struct GNUNET_GETOPT_CommandLineOption options[] = {
+  {'n', "name", "NAME",
+   gettext_noop ("limit output to statistcs for the given NAME"), 1,
+   &GNUNET_GETOPT_set_string, &name},
+  {'p', "persistent", NULL,
+   gettext_noop ("make the value being set persistent"), 0,
+   &GNUNET_GETOPT_set_one, &persistent},
+  {'s', "subsystem", "SUBSYSTEM",
+   gettext_noop ("limit output to the given SUBSYSTEM"), 1,
+   &GNUNET_GETOPT_set_string, &subsystem},
+  GNUNET_GETOPT_OPTION_END
+};
+
+
+/**
+ * The main function to obtain statistics in GNUnet.
+ *
+ * @param argc number of arguments from the command line
+ * @param argv command line arguments
+ * @return 0 ok, 1 on error
+ */
+int
+main (int argc, char *const *argv)
+{
+  return (GNUNET_OK ==
+          GNUNET_PROGRAM_run (argc,
+                              argv,
+                              "gnunet-statistics",
+                              gettext_noop
+                              ("Print statistics about GNUnet operations."),
+                              options, &run, NULL)) ? ret : 1;
+}
+
+/* end of gnunet-statistics.c */
diff --git a/src/statistics/statistics.h b/src/statistics/statistics.h
new file mode 100644
index 000000000..6eedd4d34
--- /dev/null
+++ b/src/statistics/statistics.h
@@ -0,0 +1,94 @@
+/*
+     This file is part of GNUnet.
+     (C) 2001, 2002, 2003, 2004, 2009 Christian Grothoff (and other contributing authors)
+
+     GNUnet is free software; you can redistribute it and/or modify
+     it under the terms of the GNU General Public License as published
+     by the Free Software Foundation; either version 2, 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
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+
+/**
+ * @author Christian Grothoff
+ * @file statistics/statistics.h
+ */
+#ifndef STATISTICS_H
+#define STATISTICS_H
+
+#include "gnunet_common.h"
+
+#define DEBUG_STATISTICS 0
+
+/**
+ * Statistics message. Contains how long the system is up
+ * and one value.
+ *
+ * The struct is be followed by the service name and
+ * name of the statistic, both 0-terminated.
+ */
+struct GNUNET_STATISTICS_ReplyMessage
+{
+  /**
+   * Type:  GNUNET_MESSAGE_TYPE_STATISTICS_VALUE
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * Unique numerical identifier for the value (will
+   * not change during the same client-session).  Highest
+   * bit will be set for persistent values.
+   */
+  uint32_t uid GNUNET_PACKED;
+
+  /**
+   * The value.
+   */
+  uint64_t value GNUNET_PACKED;
+
+};
+
+#define GNUNET_STATISTICS_PERSIST_BIT (1<<31)
+
+#define GNUNET_STATISTICS_SETFLAG_ABSOLUTE 0
+
+#define GNUNET_STATISTICS_SETFLAG_RELATIVE 1
+
+#define GNUNET_STATISTICS_SETFLAG_PERSISTENT 2
+
+/**
+ * Message to set a statistic.  Followed
+ * by the subsystem name and the name of
+ * the statistic (each 0-terminated).
+ */
+struct GNUNET_STATISTICS_SetMessage
+{
+  /**
+   * Type: GNUNET_MESSAGE_TYPE_STATISTICS_SET
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * 0 for absolute value, 1 for relative value; 2 to make persistent
+   * (see GNUNET_STATISTICS_SETFLAG_*).
+   */
+  uint32_t flags GNUNET_PACKED;
+
+  /**
+   * Value. Note that if this is a relative value, it will
+   * be signed even though the type given here is unsigned.
+   */
+  uint64_t value GNUNET_PACKED;
+
+};
+
+#endif
diff --git a/src/statistics/statistics_api.c b/src/statistics/statistics_api.c
new file mode 100644
index 000000000..f68cf9396
--- /dev/null
+++ b/src/statistics/statistics_api.c
@@ -0,0 +1,688 @@
+/*
+     This file is part of GNUnet.
+     (C) 2009 Christian Grothoff (and other contributing authors)
+
+     GNUnet is free software; you can redistribute it and/or modify
+     it under the terms of the GNU General Public License as published
+     by the Free Software Foundation; either version 2, 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
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+
+/**
+ * @file statistics/statistics_api.c
+ * @brief API of the statistics service
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_client_lib.h"
+#include "gnunet_protocols.h"
+#include "gnunet_server_lib.h"
+#include "gnunet_statistics_service.h"
+#include "gnunet_strings_lib.h"
+#include "statistics.h"
+
+#define SET_TRANSMIT_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 30)
+
+
+/**
+ * Types of actions.
+ */
+enum ActionType
+{
+  ACTION_GET,
+  ACTION_SET,
+  ACTION_UPDATE
+};
+
+
+/**
+ * Linked list of things we still need to do.
+ */
+struct ActionItem
+{
+  /**
+   * This is a linked list.
+   */
+  struct ActionItem *next;
+
+  /**
+   * What subsystem is this action about? (can be NULL)
+   */
+  char *subsystem;
+
+  /**
+   * What value is this action about? (can be NULL)
+   */
+  char *name;
+
+  /**
+   * Continuation to call once action is complete.
+   */
+  GNUNET_STATISTICS_Callback cont;
+
+  /**
+   * Function to call (for GET actions only).
+   */
+  GNUNET_STATISTICS_Iterator proc;
+
+  /**
+   * Closure for proc and cont.
+   */
+  void *cls;
+
+  /**
+   * Timeout for this action.
+   */
+  struct GNUNET_TIME_Absolute timeout;
+
+  /**
+   * Associated value.
+   */
+  unsigned long long value;
+
+  /**
+   * Flag for SET/UPDATE actions.
+   */
+  int make_persistent;
+
+  /**
+   * Has the current iteration been aborted; for GET actions.
+   */
+  int aborted;
+
+  /**
+   * Is this a GET, SET or UPDATE?
+   */
+  enum ActionType type;
+
+  /**
+   * Size of the message that we will be transmitting.
+   */
+  uint16_t msize;
+
+};
+
+
+/**
+ * Handle for the service.
+ */
+struct GNUNET_STATISTICS_Handle
+{
+  /**
+   * Our scheduler.
+   */
+  struct GNUNET_SCHEDULER_Handle *sched;
+
+  /**
+   * Name of our subsystem.
+   */
+  char *subsystem;
+
+  /**
+   * Configuration to use.
+   */
+  struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Socket (if available).
+   */
+  struct GNUNET_CLIENT_Connection *client;
+
+  /**
+   * Head of the linked list of pending actions (first action
+   * to be performed).
+   */
+  struct ActionItem *action_head;
+
+  /**
+   * Tail of the linked list of actions (for fast append).
+   */
+  struct ActionItem *action_tail;
+
+  /**
+   * Action we are currently busy with (action request has been
+   * transmitted, we're now receiving the response from the
+   * service).
+   */
+  struct ActionItem *current;
+
+  /**
+   * Should this handle be destroyed once we've processed
+   * all actions?
+   */
+  int do_destroy;
+
+};
+
+
+/**
+ * Try to (re)connect to the statistics service.
+ *
+ * @return GNUNET_YES on success, GNUNET_NO on failure.
+ */
+static int
+try_connect (struct GNUNET_STATISTICS_Handle *ret)
+{
+  if (ret->client != NULL)
+    return GNUNET_OK;
+  ret->client = GNUNET_CLIENT_connect (ret->sched, "statistics", ret->cfg);
+  if (ret->client != NULL)
+    return GNUNET_YES;
+  GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+              _("Failed to connect to statistics service!\n"));
+  return GNUNET_NO;
+}
+
+
+/**
+ * Free memory associated with the given action item.
+ */
+static void
+free_action_item (struct ActionItem *ai)
+{
+  GNUNET_free_non_null (ai->subsystem);
+  GNUNET_free_non_null (ai->name);
+  GNUNET_free (ai);
+}
+
+
+/**
+ * Get handle for the statistics service.
+ *
+ * @param subsystem name of subsystem using the service
+ * @param cfg services configuration in use
+ * @return handle to use
+ */
+struct GNUNET_STATISTICS_Handle *
+GNUNET_STATISTICS_create (struct GNUNET_SCHEDULER_Handle *sched,
+                          const char *subsystem,
+                          struct GNUNET_CONFIGURATION_Handle *cfg)
+{
+  struct GNUNET_STATISTICS_Handle *ret;
+
+  GNUNET_assert (subsystem != NULL);
+  GNUNET_assert (sched != NULL);
+  GNUNET_assert (cfg != NULL);
+  ret = GNUNET_malloc (sizeof (struct GNUNET_STATISTICS_Handle));
+  ret->sched = sched;
+  ret->cfg = cfg;
+  ret->subsystem = GNUNET_strdup (subsystem);
+  try_connect (ret);
+  return ret;
+}
+
+
+/**
+ * Actually free the handle.
+ */
+static void
+do_destroy (struct GNUNET_STATISTICS_Handle *h)
+{
+  GNUNET_assert (h->action_head == NULL);
+  GNUNET_assert (h->current == NULL);
+  if (h->client != NULL)
+    {
+      GNUNET_CLIENT_disconnect (h->client);
+      h->client = NULL;
+    }
+  GNUNET_free (h->subsystem);
+  GNUNET_free (h);
+}
+
+
+/**
+ * Destroy a handle (free all state associated with
+ * it).
+ */
+void
+GNUNET_STATISTICS_destroy (struct GNUNET_STATISTICS_Handle *handle)
+{
+  GNUNET_assert (handle->do_destroy == GNUNET_NO);
+  if ((handle->action_head != NULL) || (handle->current != NULL))
+    {
+      handle->do_destroy = GNUNET_YES;
+      return;
+    }
+  do_destroy (handle);
+}
+
+
+/**
+ * Process the message.
+ *
+ * @return GNUNET_OK if the message was well-formed
+ */
+static int
+process_message (struct GNUNET_STATISTICS_Handle *h,
+                 const struct GNUNET_MessageHeader *msg)
+{
+  char *service;
+  char *name;
+  const struct GNUNET_STATISTICS_ReplyMessage *smsg;
+  uint16_t size;
+
+  if (h->current->aborted)
+    return GNUNET_OK;           /* don't bother */
+  size = ntohs (msg->size);
+  if (size < sizeof (struct GNUNET_STATISTICS_ReplyMessage))
+    {
+      GNUNET_break (0);
+      return GNUNET_SYSERR;
+    }
+  smsg = (const struct GNUNET_STATISTICS_ReplyMessage *) msg;
+  size -= sizeof (struct GNUNET_STATISTICS_ReplyMessage);
+  if (size != GNUNET_STRINGS_buffer_tokenize ((const char *) &smsg[1],
+                                              size, 2, &service, &name))
+    {
+      GNUNET_break (0);
+      return GNUNET_SYSERR;
+    }
+#if DEBUG_STATISTICS
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Received valid statistic on `%s:%s': %llu\n",
+              service, name, GNUNET_ntohll (smsg->value));
+#endif
+  if (GNUNET_OK !=
+      h->current->proc (h->current->cls,
+                        service,
+                        name,
+                        GNUNET_ntohll (smsg->value),
+                        0 !=
+                        (ntohl (smsg->uid) & GNUNET_STATISTICS_PERSIST_BIT)))
+    {
+#if DEBUG_STATISTICS
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "Processing of remaining statistics aborted by client.\n");
+#endif
+      h->current->aborted = GNUNET_YES;
+    }
+  return GNUNET_OK;
+}
+
+
+
+/**
+ * Schedule the next action to be performed.
+ */
+static void schedule_action (struct GNUNET_STATISTICS_Handle *h);
+
+
+/**
+ * GET processing is complete, tell client about it.
+ */
+static void
+finish (struct GNUNET_STATISTICS_Handle *h, int code)
+{
+  struct ActionItem *pos = h->current;
+  h->current = NULL;
+  schedule_action (h);
+  if (pos->cont != NULL)
+    pos->cont (pos->cls, code);
+  free_action_item (pos);
+}
+
+
+/**
+ * Function called with messages from stats service.
+ *
+ * @param cls closure
+ * @param msg message received, NULL on timeout or fatal error
+ */
+static void
+receive_stats (void *cls, const struct GNUNET_MessageHeader *msg)
+{
+  struct GNUNET_STATISTICS_Handle *h = cls;
+
+  if (msg == NULL)
+    {
+      GNUNET_CLIENT_disconnect (h->client);
+      h->client = NULL;
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK,
+                  _
+                  ("Error receiving statistics from service, is the service running?\n"));
+      finish (h, GNUNET_SYSERR);
+      return;
+    }
+  switch (ntohs (msg->type))
+    {
+    case GNUNET_MESSAGE_TYPE_STATISTICS_END:
+#if DEBUG_STATISTICS
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "Received end of statistics marker\n");
+#endif
+      finish (h, GNUNET_OK);
+      return;
+    case GNUNET_MESSAGE_TYPE_STATISTICS_VALUE:
+      if (GNUNET_OK == process_message (h, msg))
+        {
+          /* finally, look for more! */
+          GNUNET_CLIENT_receive (h->client,
+                                 &receive_stats,
+                                 h,
+                                 GNUNET_TIME_absolute_get_remaining (h->
+                                                                     current->
+                                                                     timeout));
+          return;
+        }
+      GNUNET_break (0);
+      break;
+    default:
+      GNUNET_break (0);
+      break;
+    }
+  GNUNET_CLIENT_disconnect (h->client);
+  h->client = NULL;
+  finish (h, GNUNET_SYSERR);
+}
+
+
+/**
+ * Transmit a GET request (and if successful, start to receive
+ * the response).
+ */
+static size_t
+transmit_get (struct GNUNET_STATISTICS_Handle *handle, size_t size, void *buf)
+{
+  struct GNUNET_MessageHeader *hdr;
+  size_t slen1;
+  size_t slen2;
+  uint16_t msize;
+
+  if (buf == NULL)
+    {
+      /* timeout / error */
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                  _("Transmission of request for statistics failed!\n"));
+      finish (handle, GNUNET_SYSERR);
+      return 0;
+    }
+  slen1 = strlen (handle->current->subsystem) + 1;
+  slen2 = strlen (handle->current->name) + 1;
+  msize = slen1 + slen2 + sizeof (struct GNUNET_MessageHeader);
+  GNUNET_assert (msize <= size);
+  hdr = (struct GNUNET_MessageHeader *) buf;
+  hdr->size = htons (msize);
+  hdr->type = htons (GNUNET_MESSAGE_TYPE_STATISTICS_GET);
+  GNUNET_assert (slen1 + slen2 ==
+                 GNUNET_STRINGS_buffer_fill ((char *) &hdr[1],
+                                             slen1 + slen2,
+                                             2,
+                                             handle->current->subsystem,
+                                             handle->current->name));
+  GNUNET_CLIENT_receive (handle->client,
+                         &receive_stats,
+                         handle,
+                         GNUNET_TIME_absolute_get_remaining (handle->current->
+                                                             timeout));
+  return msize;
+}
+
+
+
+/**
+ * Transmit a SET/UPDATE request.
+ */
+static size_t
+transmit_set (struct GNUNET_STATISTICS_Handle *handle, size_t size, void *buf)
+{
+  struct GNUNET_STATISTICS_SetMessage *r;
+  size_t slen;
+  size_t nlen;
+  size_t nsize;
+
+  if (NULL == buf)
+    {
+      finish (handle, GNUNET_SYSERR);
+      return 0;
+    }
+
+  slen = strlen (handle->current->subsystem) + 1;
+  nlen = strlen (handle->current->name) + 1;
+  nsize = sizeof (struct GNUNET_STATISTICS_SetMessage) + slen + nlen;
+  if (size < nsize)
+    {
+      GNUNET_break (0);
+      finish (handle, GNUNET_SYSERR);
+      return 0;
+    }
+  r = buf;
+  r->header.size = htons (nsize);
+  r->header.type = htons (GNUNET_MESSAGE_TYPE_STATISTICS_SET);
+  r->flags = 0;
+  r->value = GNUNET_htonll (handle->current->value);
+  if (handle->current->make_persistent)
+    r->flags |= htonl (GNUNET_STATISTICS_SETFLAG_PERSISTENT);
+  if (handle->current->type == ACTION_UPDATE)
+    r->flags |= htonl (GNUNET_STATISTICS_SETFLAG_RELATIVE);
+  GNUNET_assert (slen + nlen ==
+                 GNUNET_STRINGS_buffer_fill ((char *) &r[1],
+                                             slen + nlen,
+                                             2,
+                                             handle->current->subsystem,
+                                             handle->current->name));
+  finish (handle, GNUNET_OK);
+  return nsize;
+}
+
+
+static size_t
+transmit_action (void *cls, size_t size, void *buf)
+{
+  struct GNUNET_STATISTICS_Handle *handle = cls;
+  size_t ret;
+
+  switch (handle->current->type)
+    {
+    case ACTION_GET:
+      ret = transmit_get (handle, size, buf);
+      break;
+    case ACTION_SET:
+    case ACTION_UPDATE:
+      ret = transmit_set (handle, size, buf);
+      break;
+    }
+  return ret;
+}
+
+
+/**
+ * Schedule the next action to be performed.
+ */
+static void
+schedule_action (struct GNUNET_STATISTICS_Handle *h)
+{
+  struct GNUNET_TIME_Relative timeout;
+
+  if (h->current != NULL)
+    return;                     /* action already pending */
+  if (GNUNET_YES != try_connect (h))
+    {
+      finish (h, GNUNET_SYSERR);
+      return;
+    }
+
+  /* schedule next action */
+  h->current = h->action_head;
+  if (NULL == h->current)
+    {
+      /* no pending network action, check destroy! */
+      if (h->do_destroy != GNUNET_YES)
+        return;
+      do_destroy (h);
+      return;
+    }
+  h->action_head = h->action_head->next;
+  if (NULL == h->action_head)
+    h->action_tail = NULL;
+  h->current->next = NULL;
+
+  timeout = GNUNET_TIME_absolute_get_remaining (h->current->timeout);
+  if (NULL ==
+      GNUNET_CLIENT_notify_transmit_ready (h->client,
+                                           h->current->msize,
+                                           timeout, &transmit_action, h))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                  "Failed to transmit request to statistics service.\n");
+      finish (h, GNUNET_SYSERR);
+    }
+}
+
+
+static void
+insert_ai (struct GNUNET_STATISTICS_Handle *h, struct ActionItem *ai)
+{
+  if (h->action_tail == NULL)
+    {
+      h->action_head = ai;
+      h->action_tail = ai;
+      schedule_action (h);
+    }
+  else
+    {
+      h->action_tail->next = ai;
+      h->action_tail = ai;
+    }
+}
+
+
+/**
+ * Get statistic from the peer.
+ *
+ * @param handle identification of the statistics service
+ * @param subsystem limit to the specified subsystem, NULL for our subsystem
+ * @param name name of the statistic value, NULL for all values
+ * @param timeout after how long should we give up (and call
+ *        cont with an error code)?
+ * @param cont continuation to call when done (can be NULL)
+ * @param proc function to call on each value
+ * @param cls closure for cont and proc
+ */
+void
+GNUNET_STATISTICS_get (struct GNUNET_STATISTICS_Handle *handle,
+                       const char *subsystem,
+                       const char *name,
+                       struct GNUNET_TIME_Relative timeout,
+                       GNUNET_STATISTICS_Callback cont,
+                       GNUNET_STATISTICS_Iterator proc, void *cls)
+{
+  size_t slen1;
+  size_t slen2;
+  struct ActionItem *ai;
+
+  GNUNET_assert (handle != NULL);
+  GNUNET_assert (proc != NULL);
+  if (GNUNET_YES != try_connect (handle))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                  "Failed to connect to statistics service, can not get value `%s:%s'.\n",
+                  strlen (subsystem) ? subsystem : "*",
+                  strlen (name) ? name : "*");
+      cont (cls, GNUNET_SYSERR);
+      return;
+    }
+  if (subsystem == NULL)
+    subsystem = "";
+  if (name == NULL)
+    name = "";
+  slen1 = strlen (subsystem);
+  slen2 = strlen (name);
+  GNUNET_assert (slen1 + slen2 + sizeof (struct GNUNET_MessageHeader) <
+                 GNUNET_SERVER_MAX_MESSAGE_SIZE);
+  ai = GNUNET_malloc (sizeof (struct ActionItem));
+  ai->subsystem = GNUNET_strdup (subsystem);
+  ai->name = GNUNET_strdup (name);
+  ai->cont = cont;
+  ai->proc = proc;
+  ai->cls = cls;
+  ai->timeout = GNUNET_TIME_relative_to_absolute (timeout);
+  ai->type = ACTION_GET;
+  ai->msize = slen1 + slen2 + sizeof (struct GNUNET_MessageHeader);
+  insert_ai (handle, ai);
+}
+
+
+static void
+add_setter_action (struct GNUNET_STATISTICS_Handle *h,
+                   const char *name,
+                   int make_persistent,
+                   unsigned long long value, enum ActionType type)
+{
+  struct ActionItem *ai;
+  size_t slen;
+  size_t nlen;
+  size_t nsize;
+
+  GNUNET_assert (h != NULL);
+  GNUNET_assert (name != NULL);
+  if (GNUNET_YES != try_connect (h))
+    return;
+  slen = strlen (h->subsystem) + 1;
+  nlen = strlen (name) + 1;
+  nsize = sizeof (struct GNUNET_STATISTICS_SetMessage) + slen + nlen;
+  if (nsize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
+    {
+      GNUNET_break (0);
+      return;
+    }
+  ai = GNUNET_malloc (sizeof (struct ActionItem));
+  ai->subsystem = GNUNET_strdup (h->subsystem);
+  ai->name = GNUNET_strdup (name);
+  ai->timeout = GNUNET_TIME_relative_to_absolute (SET_TRANSMIT_TIMEOUT);
+  ai->make_persistent = make_persistent;
+  ai->msize = nsize;
+  ai->value = value;
+  ai->type = type;
+  insert_ai (h, ai);
+  schedule_action (h);
+}
+
+
+/**
+ * Set statistic value for the peer.  Will always use our
+ * subsystem (the argument used when "handle" was created).
+ *
+ * @param handle identification of the statistics service
+ * @param name name of the statistic value
+ * @param value new value to set
+ * @param make_persistent should the value be kept across restarts?
+ */
+void
+GNUNET_STATISTICS_set (struct GNUNET_STATISTICS_Handle *handle,
+                       const char *name,
+                       unsigned long long value, int make_persistent)
+{
+  add_setter_action (handle, name, make_persistent, value, ACTION_SET);
+}
+
+
+/**
+ * Set statistic value for the peer.  Will always use our
+ * subsystem (the argument used when "handle" was created).
+ *
+ * @param handle identification of the statistics service
+ * @param name name of the statistic value
+ * @param delta change in value (added to existing value)
+ * @param make_persistent should the value be kept across restarts?
+ */
+void
+GNUNET_STATISTICS_update (struct GNUNET_STATISTICS_Handle *handle,
+                          const char *name,
+                          long long delta, int make_persistent)
+{
+  add_setter_action (handle, name, make_persistent,
+                     (unsigned long long) delta, ACTION_UPDATE);
+}
+
+
+/* end of statistics_api.c */
diff --git a/src/statistics/test_gnunet_statistics.sh b/src/statistics/test_gnunet_statistics.sh
new file mode 100755
index 000000000..43f629f36
--- /dev/null
+++ b/src/statistics/test_gnunet_statistics.sh
@@ -0,0 +1,177 @@
+#!/bin/bash
+
+rm -rf /tmp/test-gnunetd-statistics/
+exe="./gnunet-statistics -c test_statistics_api_data.conf"
+base=/tmp/gnunet-test-statistics
+#DEBUG="-L DEBUG"
+# -----------------------------------
+echo -n "Preparing: Starting service..."
+./gnunet-service-statistics $DEBUG -c test_statistics_api_data.conf  &
+sleep 1
+echo "DONE"
+
+# ----------------------------------------------------------------------------------
+echo -n "TEST: Bad argument checking..."
+
+if $exe -x 2> /dev/null; then
+  echo "FAIL: error running $exe"
+  kill %%
+  exit 1
+fi
+echo "PASS"
+
+# ----------------------------------------------------------------------------------
+echo -n "TEST: Set value..."
+
+if ! $exe $DEBUG -n test -s subsystem 42 ; then
+  echo "FAIL: error running $exe"
+  kill %%
+  exit 1
+fi
+echo "PASS"
+
+# ----------------------------------------------------------------------------------
+echo -n "TEST: Set another value..."
+
+if ! $exe $DEBUG -n other -s osystem 43 ; then
+  echo "FAIL: error running $exe"
+  kill %%
+  exit 1
+fi
+echo "PASS"
+
+# ----------------------------------------------------------------------------------
+echo -n "TEST: viewing all stats..."
+
+if ! $exe $DEBUG > $base.out; then
+    echo "FAIL: error running $exe"
+    kill %%
+    exit 1
+fi
+LINES=`cat $base.out | wc -l`
+if test $LINES -ne 2; then
+    echo "FAIL: unexpected output"
+    kill %%
+    exit 1
+fi
+echo "PASS"
+
+# ----------------------------------------------------------------------------------
+echo -n "TEST: viewing stats by name..."
+
+if ! $exe $DEBUG -n other > $base.out; then
+    echo "FAIL: error running $exe"
+    kill %%
+    exit 1
+fi
+LINES=`cat $base.out | grep 43 | wc -l`
+if test $LINES -ne 1; then
+    echo "FAIL: unexpected output"
+    kill %%
+    exit 1
+fi
+echo "PASS"
+
+# ----------------------------------------------------------------------------------
+echo -n "TEST: viewing stats by subsystem..."
+
+if ! $exe $DEBUG -s subsystem > $base.out; then
+    echo "FAIL: error running $exe"
+    kill %%
+    exit 1
+fi
+LINES=`cat $base.out | grep 42 | wc -l`
+if test $LINES -ne 1; then
+    echo "FAIL: unexpected output"
+    kill %%
+    exit 1
+fi
+echo "PASS"
+
+
+# ----------------------------------------------------------------------------------
+echo -n "TEST: Set persistent value..."
+
+if ! $exe $DEBUG -n lasting -s subsystem 40 -p; then
+  echo "FAIL: error running $exe"
+  kill %%
+  exit 1
+fi
+echo "PASS"
+
+# -----------------------------------
+echo -n "Restarting service..."
+sleep 1
+if ! kill %%;
+then
+  echo "FAIL: could not kill service"
+  kill %%
+  exit 1
+fi
+sleep 1
+./gnunet-service-statistics $DEBUG  -c test_statistics_api_data.conf  &
+sleep 1
+
+
+# ----------------------------------------------------------------------------------
+echo -n "TEST: checking persistence..."
+
+if ! $exe $DEBUG > $base.out; then
+    echo "FAIL: error running $exe"
+    kill %%
+    exit 1
+fi
+LINES=`cat $base.out | grep 40 | wc -l`
+if test $LINES -ne 1; then
+    echo "FAIL: unexpected output"
+    kill %%
+    exit 1
+fi
+echo "PASS"
+
+
+
+# ----------------------------------------------------------------------------------
+echo -n "TEST: Removing persistence..."
+
+if ! $exe  $DEBUG -n lasting -s subsystem 40; then
+  echo "FAIL: error running $exe"
+  kill %%
+  exit 1
+fi
+echo "PASS"
+
+
+# -----------------------------------
+echo -n "Restarting service..."
+sleep 1
+if ! kill %%;
+then
+  echo "FAIL: could not kill service"
+  kill %%
+  exit 1
+fi
+sleep 1
+./gnunet-service-statistics $DEBUG -c test_statistics_api_data.conf  &
+sleep 1
+
+
+# ----------------------------------------------------------------------------------
+echo -n "TEST: checking removed persistence..."
+
+if ! $exe $DEBUG > $base.out; then
+    echo "FAIL: error running $exe"
+    kill %%
+    exit 1
+fi
+LINES=`cat $base.out | grep 40 | wc -l`
+if test $LINES -ne 0; then
+    echo "FAIL: unexpected output"
+    kill %%
+    exit 1
+fi
+echo "PASS"
+
+kill %%
+rm -f $base.out
+rm -rf /tmp/test-gnunetd-statistics/
diff --git a/src/statistics/test_statistics_api.c b/src/statistics/test_statistics_api.c
new file mode 100644
index 000000000..7a39f54b6
--- /dev/null
+++ b/src/statistics/test_statistics_api.c
@@ -0,0 +1,177 @@
+/*
+     This file is part of GNUnet.
+     (C) 2009 Christian Grothoff (and other contributing authors)
+
+     GNUnet is free software; you can redistribute it and/or modify
+     it under the terms of the GNU General Public License as published
+     by the Free Software Foundation; either version 2, 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
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+/**
+ * @file statistics/test_statistics_api.c
+ * @brief testcase for statistics_api.c
+ */
+#include "platform.h"
+#include "gnunet_common.h"
+#include "gnunet_getopt_lib.h"
+#include "gnunet_os_lib.h"
+#include "gnunet_program_lib.h"
+#include "gnunet_scheduler_lib.h"
+#include "gnunet_statistics_service.h"
+
+#define VERBOSE GNUNET_NO
+
+static int
+check_1 (void *cls,
+         const char *subsystem,
+         const char *name, unsigned long long value, int is_persistent)
+{
+  GNUNET_assert (0 == strcmp (name, "test-1"));
+  GNUNET_assert (0 == strcmp (subsystem, "test-statistics-api"));
+  GNUNET_assert (value == 1);
+  GNUNET_assert (is_persistent == GNUNET_NO);
+  return GNUNET_OK;
+}
+
+static int
+check_2 (void *cls,
+         const char *subsystem,
+         const char *name, unsigned long long value, int is_persistent)
+{
+  GNUNET_assert (0 == strcmp (name, "test-2"));
+  GNUNET_assert (0 == strcmp (subsystem, "test-statistics-api"));
+  GNUNET_assert (value == 2);
+  GNUNET_assert (is_persistent == GNUNET_NO);
+  return GNUNET_OK;
+}
+
+static int
+check_3 (void *cls,
+         const char *subsystem,
+         const char *name, unsigned long long value, int is_persistent)
+{
+  GNUNET_assert (0 == strcmp (name, "test-3"));
+  GNUNET_assert (0 == strcmp (subsystem, "test-statistics-api"));
+  GNUNET_assert (value == 3);
+  GNUNET_assert (is_persistent == GNUNET_YES);
+  return GNUNET_OK;
+}
+
+static struct GNUNET_STATISTICS_Handle *h;
+
+static void
+next_fin (void *cls, int success)
+{
+  int *ok = cls;
+
+  GNUNET_STATISTICS_destroy (h);
+  GNUNET_assert (success == GNUNET_OK);
+  *ok = 0;
+}
+
+static void
+next (void *cls, int success)
+{
+  GNUNET_assert (success == GNUNET_OK);
+  GNUNET_STATISTICS_get (h, NULL, "test-2",
+                         GNUNET_TIME_UNIT_SECONDS, &next_fin, &check_2, cls);
+}
+
+static void
+run (void *cls,
+     struct GNUNET_SCHEDULER_Handle *sched,
+     char *const *args,
+     const char *cfgfile, struct GNUNET_CONFIGURATION_Handle *cfg)
+{
+
+  h = GNUNET_STATISTICS_create (sched, "test-statistics-api", cfg);
+  GNUNET_STATISTICS_set (h, "test-1", 1, GNUNET_NO);
+  GNUNET_STATISTICS_set (h, "test-2", 2, GNUNET_NO);
+  GNUNET_STATISTICS_set (h, "test-3", 2, GNUNET_NO);
+  GNUNET_STATISTICS_update (h, "test-3", 1, GNUNET_YES);
+  GNUNET_STATISTICS_get (h, NULL, "test-1",
+                         GNUNET_TIME_UNIT_SECONDS, &next, &check_1, cls);
+}
+
+static void
+run_more (void *cls,
+          struct GNUNET_SCHEDULER_Handle *sched,
+          char *const *args,
+          const char *cfgfile, struct GNUNET_CONFIGURATION_Handle *cfg)
+{
+  h = GNUNET_STATISTICS_create (sched, "test-statistics-api", cfg);
+  GNUNET_STATISTICS_get (h, NULL, "test-3",
+                         GNUNET_TIME_UNIT_SECONDS, &next_fin, &check_3, cls);
+}
+
+static int
+check ()
+{
+  int ok = 1;
+  pid_t pid;
+  char *const argv[] = { "test-statistics-api",
+    "-c",
+    "test_statistics_api_data.conf",
+    NULL
+  };
+  struct GNUNET_GETOPT_CommandLineOption options[] = {
+    GNUNET_GETOPT_OPTION_END
+  };
+  pid = GNUNET_OS_start_process ("gnunet-service-statistics",
+                                 "gnunet-service-statistics",
+#if DEBUG_STATISTICS
+                                 "-L", "DEBUG",
+#endif
+                                 "-c", "test_statistics_api_data.conf", NULL);
+  sleep (1);
+  GNUNET_PROGRAM_run (3, argv, "test-statistics-api", "nohelp",
+                      options, &run, &ok);
+  if (0 != PLIBC_KILL (pid, SIGTERM))
+    {
+      GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "kill");
+      ok = 1;
+    }
+  waitpid (pid, NULL, 0);
+  if (ok != 0)
+    return ok;
+  ok = 1;
+  /* restart to check persistence! */
+  pid = GNUNET_OS_start_process ("gnunet-service-statistics",
+                                 "gnunet-service-statistics",
+#if DEBUG_STATISTICS
+                                 "-L", "DEBUG",
+#endif
+                                 "-c", "test_statistics_api_data.conf", NULL);
+  sleep (1);
+  GNUNET_PROGRAM_run (3, argv, "test-statistics-api", "nohelp",
+                      options, &run_more, &ok);
+  if (0 != PLIBC_KILL (pid, SIGTERM))
+    {
+      GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "kill");
+      ok = 1;
+    }
+  waitpid (pid, NULL, 0);
+  return ok;
+}
+
+int
+main (int argc, char *argv[])
+{
+  int ret;
+
+  ret = check ();
+
+  return ret;
+}
+
+/* end of test_statistics_api.c */
diff --git a/src/statistics/test_statistics_api_data.conf b/src/statistics/test_statistics_api_data.conf
new file mode 100644
index 000000000..571a9b3e4
--- /dev/null
+++ b/src/statistics/test_statistics_api_data.conf
@@ -0,0 +1,5 @@
+[PATHS]
+SERVICEHOME = /tmp/test-gnunetd-statistics/
+
+[statistics]
+PORT = 22353