path: root/src/statistics/gnunet-service-statistics.c

/*
     This file is part of GNUnet.
     Copyright (C) 2009, 2010, 2012, 2014, 2016 GNUnet e.V.

     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 3, 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., 51 Franklin Street, Fifth Floor,
     Boston, MA 02110-1301, USA.
*/

/**
 * @file statistics/gnunet-service-statistics.c
 * @brief program that tracks statistics
 * @author Christian Grothoff
 */
#include "platform.h"
#include "gnunet_bio_lib.h"
#include "gnunet_container_lib.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"

/**
 * Watch entry.
 */
struct WatchEntry
{

  /**
   * Watch entries are kept in a linked list.
   */
  struct WatchEntry *next;

  /**
   * Watch entries are kept in a linked list.
   */
  struct WatchEntry *prev;

  /**
   * For which client is this watch entry?
   */
  struct ClientEntry *ce;

  /**
   * Last value we communicated to the client for this watch entry.
   */
  uint64_t last_value;

  /**
   * Unique watch number for this client and this watched value.
   */
  uint32_t wid;

  /**
   * Is last_value valid
   * #GNUNET_NO : last_value is n/a, #GNUNET_YES: last_value is valid
   */
  int last_value_set;

};


/**
 * We keep the statistics organized by subsystem for faster
 * lookup during SET operations.
 */
struct SubsystemEntry;


/**
 * Entry in the statistics list.
 */
struct StatsEntry
{
  /**
   * This is a linked list.
   */
  struct StatsEntry *next;

  /**
   * This is a linked list.
   */
  struct StatsEntry *prev;

  /**
   * Subsystem this entry belongs to.
   */
  struct SubsystemEntry *subsystem;

  /**
   * Name for the value stored by this entry, allocated at the end of
   * this struct.
   */
  const char *name;

  /**
   * Watch context for changes to this value, or NULL for none.
   */
  struct WatchEntry *we_head;

  /**
   * Watch context for changes to this value, or NULL for none.
   */
  struct WatchEntry *we_tail;

  /**
   * Our value.
   */
  uint64_t value;

  /**
   * Unique ID.
   */
  uint32_t uid;

  /**
   * Is this value persistent?
   */
  int persistent;

  /**
   * Is this value set?
   * #GNUNET_NO: value is n/a, #GNUNET_YES: value is valid
   */
  int set;

};


/**
 * We keep the statistics organized by subsystem for faster
 * lookup during SET operations.
 */
struct SubsystemEntry
{
  /**
   * Subsystems are kept in a DLL.
   */
  struct SubsystemEntry *next;

  /**
   * Subsystems are kept in a DLL.
   */
  struct SubsystemEntry *prev;

  /**
   * Head of list of values kept for this subsystem.
   */
  struct StatsEntry *stat_head;

  /**
   * Tail of list of values kept for this subsystem.
   */
  struct StatsEntry *stat_tail;

  /**
   * Name of the subsystem this entry is for, allocated at
   * the end of this struct, do not free().
   */
  const char *service;

};


/**
 * Client entry.
 */
struct ClientEntry
{
  /**
   * Corresponding server handle.
   */
  struct GNUNET_SERVICE_Client *client;

  /**
   * Corresponding message queue.
   */
  struct GNUNET_MQ_Handle *mq;

  /**
   * Which subsystem is this client writing to (SET/UPDATE)?
   */
  struct SubsystemEntry *subsystem;

  /**
   * Maximum watch ID used by this client so far.
   */
  uint32_t max_wid;

};


/**
 * Our configuration.
 */
static const struct GNUNET_CONFIGURATION_Handle *cfg;

/**
 * Head of linked list of subsystems with active statistics.
 */
static struct SubsystemEntry *sub_head;

/**
 * Tail of linked list of subsystems with active statistics.
 */
static struct SubsystemEntry *sub_tail;

/**
 * Number of connected clients.
 */
static unsigned int client_count;

/**
 * Our notification context.
 */
static struct GNUNET_NotificationContext *nc;

/**
 * Counter used to generate unique values.
 */
static uint32_t uidgen;

/**
 * Set to #GNUNET_YES if we are shutting down as soon as possible.
 */
static int in_shutdown;


/**
 * Write persistent statistics to disk.
 */
static void
save ()
{
  struct SubsystemEntry *se;
  struct StatsEntry *pos;
  char *fn;
  struct GNUNET_BIO_WriteHandle *wh;
  uint16_t size;
  unsigned long long total;
  size_t</