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[oweals/gnunet.git] / src / ats / gnunet-service-ats-solver_proportional.c

/*
     This file is part of GNUnet.
     (C) 2011 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 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., 59 Temple Place - Suite 330,
     Boston, MA 02111-1307, USA.
*/

/**
 * @file ats/gnunet-service-ats-solver_proportional.c
 * @brief ATS proportional solver
 * @author Matthias Wachs
 * @author Christian Grothoff
 */
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet-service-ats_addresses.h"
#include "gnunet_statistics_service.h"

#define LOG(kind,...) GNUNET_log_from (kind, "ats-proportional",__VA_ARGS__)

/**
 *
 * NOTE: Do not change this documentation. This documentation is based
 * on gnunet.org:/vcs/fsnsg/ats-paper.git/tech-doku/ats-tech-guide.tex
 * use build_txt.sh to generate plaintext output
 *
 * ATS addresses : simplistic solver
 *
 *    The simplistic solver ("simplistic") distributes the available
 *    bandwidth fair over all the addresses influenced by the
 *    preference values. For each available network type an in- and
 *    outbound quota is configured and the bandwidth available in
 *    these networks is distributed over the addresses.  The solver
 *    first assigns every addresses the minimum amount of bandwidth
 *    GNUNET_CONSTANTS_DEFAULT_BW_IN_OUT and then distributes the
 *    remaining bandwidth available according to the preference
 *    values. For each peer only a single address gets bandwidth
 *    assigned and only one address marked as active.  The most
 *    important functionality for the solver is implemented in: *
 *    find_address_it is an hashmap iterator returning the prefered
 *    address for an peer * update_quota_per_network distributes
 *    available bandwidth for a network over active addresses
 *
 *    Changes to addresses automatically have an impact on the the
 *    bandwidth assigned to other addresses in the same network since
 *    the solver distributes the remaining bandwidth over the
 *    addresses in the network.  When changes to the addresses occur,
 *    the solver first performs the changes, like adding or deleting
 *    addresses, and then updates bandwidth assignment for the
 *    affected network. Bandwidth assignment is only recalculated on
 *    demand when an address is requested by a client for a peer or
 *    when the addresses available have changed or an address changed
 *    the network it is located in. When the bandwidth assignment has
 *    changed the callback is called with the new bandwidth
 *    assignments. The bandwidth distribution for a network is
 *    recalculated due to: * address suggestion requests * address
 *    deletions * address switching networks during address update *
 *    preference changes
 *
 *     3.1 Data structures used
 *
 *    For each ATS network (e.g. WAN, LAN, loopback) a struct Network
 *    is used to specify network related information as total adresses
 *    and active addresses in this network and the configured in- and
 *    outbound quota. Each network also contains a list of addresses
 *    added to the solver located in this network. The simplistic
 *    solver uses the addresses' solver_information field to store the
 *    simplistic network it belongs to for each address.
 *
 *     3.2 Initializing
 *
 *    When the simplistic solver is initialized the solver creates a
 *    new solver handle and initializes the network structures with
 *    the quotas passed from addresses and returns the handle solver.
 *
 *     3.3 Adding an address
 *
 *    When a new address is added to the solver using s_add, a lookup
 *    for the network for this address is done and the address is
 *    enqueued in in the linked list of the network.
 *
 *     3.4 Updating an address
 *
 *    The main purpose of address updates is to update the ATS
 *    information for addresse selection. Important for the simplistic
 *    solver is when an address switches network it is located
 *    in. This is common because addresses added by transport's
 *    validation mechanism are commonly located in
 *    GNUNET_ATS_NET_UNSPECIFIED. Addresses in validation are located
 *    in this network type and only if a connection is successful on
 *    return of payload data transport switches to the real network
 *    the address is located in.  When an address changes networks it
 *    is first of all removed from the old network using the solver
 *    API function GAS_simplistic_address_delete and the network in
 *    the address struct is updated. A lookup for the respective new
 *    simplistic network is done and stored in the addresse's
 *    solver_information field. Next the address is re-added to the
 *    solver using the solver API function
 *    GAS_simplistic_address_add. If the address was marked as in
 *    active, the solver checks if bandwidth is available in the
 *    network and if yes sets the address to active and updates the
 *    bandwidth distribution in this network. If no bandwidth is
 *    available it sets the bandwidth for this address to 0 and tries
 *    to suggest an alternative address. If an alternative address was
 *    found, addresses' callback is called for this address.
 *
 *     3.5 Deleting an address
 *
 *    When an address is removed from the solver, it removes the
 *    respective address from the network and if the address was
 *    marked as active, it updates the bandwidth distribution for this
 *    network.
 *
 *     3.6 Requesting addresses
 *
 *    When an address is requested for a peer the solver performs a
 *    lookup for the peer entry in addresses address hashmap and
 *    selects the best address.  The selection of the most suitable
 *    address is done in the find_address_it hashmap iterator
 *    described in detail in section 3.7. If no address is returned,
 *    no address can be suggested at the moment. If the address
 *    returned is marked as active, the solver can return this
 *    address. If the address is not marked as active, the solver
 *    checks if another address belongign to this peer is marked as
 *    active and marks the address as inactive, updates the bandwidth
 *    for this address to 0, call the bandwidth changed callback for
 *    this address due to the change and updates quota assignment for
 *    the addresse's network. the now in-active address is belonging
 *    to. The solver marks the new address as active and updates the
 *    bandwidth assignment for this network.
 *
 *     3.7 Choosing addresses
 *
 *    Choosing the best possible address for suggestion is done by
 *    iterating over all addresses of a peer stored in addresses'
 *    hashmap and using the hashmap iterator find_address_it to select
 *    the best available address.  Several checks are done when an
 *    address is selected. First if this address is currently blocked
 *    by addresses from being suggested. An address is blocked for the
 *    duration of ATS_BLOCKING_DELTA when it is suggested to
 *    transport. Next it is checked if at least
 *    GNUNET_CONSTANTS_DEFAULT_BW_IN_OUT bytes bandwidth is available
 *    in the addresse's network, because suggesting an address without
 *    bandwidth does not make sense. This also ensures that all active
 *    addresses in this network get at least the minimum amount of
 *    bandwidth assigned. In the next step the solver ensures that for
 *    tcp connections inbound connections are prefered over outbound
 *    connections. In the next stet the solver ensures that
 *    connections are prefered in the following order: * connections
 *    are already established and have bandwidth assigned *
 *    connections with a shorter distance * connectes have a shorter
 *    latency
 *
 *     3.8 Changing preferences
 *
 *     3.9 Shutdown
 *
 *    During shutdown all network entries and aging processes are
 *    destroyed and freed.
 *
 *
 * OLD DOCUMENTATION
 *
 * This solver assigns in and outbound bandwidth equally for all
 * addresses in specific network type (WAN, LAN) based on configured
 * in and outbound quota for this network.
 *
 * The solver is notified by addresses about changes to the addresses
 * and recalculates the bandwith assigned if required. The solver
 * notifies addresses by calling the GAS_bandwidth_changed_cb
 * callback.
 *
 * - Initialization
 *
 *
 *
 *
 * For each peer only a single is selected and marked as "active" in the address
 * struct.
 *
 * E.g.:
 *
 * You have the networks WAN and LAN and quotas
 * WAN_TOTAL_IN, WAN_TOTAL_OUT
 * LAN_TOTAL_IN, LAN_TOTAL_OUT
 *
 * If you have x addresses in the network segment LAN, the quotas are
 * QUOTA_PER_ADDRESS = LAN_TOTAL_OUT / x
 *
 * Quotas are automatically recalculated and reported back when addresses are
 * - requested
 *
 */

#define PREF_AGING_INTERVAL GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 10)
#define PREF_AGING_FACTOR 0.95

#define DEFAULT_PREFERENCE 1.0
#define MIN_UPDATE_INTERVAL GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 10)


/**
 * A handle for the proportional solver
 */
struct GAS_PROPORTIONAL_Handle
{
  /**
   * Statistics handle
   */

  struct GNUNET_STATISTICS_Handle *stats;

  /**
   * Total number of addresses for solver
   */
  unsigned int total_addresses;

  /**
   * Number of active addresses for solver
   */
  unsigned int active_addresses;

  /**
   * Networks array
   */
  struct Network *network_entries;

  /**
   * Number of networks
   */
  unsigned int networks;

  /**
   * Callback
   */
  GAS_bandwidth_changed_cb bw_changed;

  /**
   * Callback cls
   */
  void *bw_changed_cls;

  struct GNUNET_CONTAINER_MultiHashMap *prefs;

  struct PreferenceClient *pc_head;
  struct PreferenceClient *pc_tail;
};


/**
 * Representation of a network
 */
struct Network
{
  /**
   * ATS network type
   */
  unsigned int type;

  /**
   * Network description
   */
  char *desc;

  /**
   * Total inbound quota
   *
   */
  unsigned long long total_quota_in;

  /**
   * Total outbound quota
   *
   */
  unsigned long long total_quota_out;

  /**
   * Number of active addresses for this network
   */
  unsigned int active_addresses;

  /**
   * Number of total addresses for this network
   */
  unsigned int total_addresses;

  /**
   * String for statistics total addresses
   */
  char *stat_total;

  /**
   * String for statistics active addresses
   */
  char *stat_active;

  struct AddressWrapper *head;
  struct AddressWrapper *tail;
};


/**
 * Wrapper for addresses to store them in network's linked list
 */
struct AddressWrapper
{
  /**
   * Next in DLL
   */
  struct AddressWrapper *next;

  /**
   * Previous in DLL
   */
  struct AddressWrapper *prev;

  /**
   * The address
   */
  struct ATS_Address *addr;
};


/**
 * Preference client
 */
struct PreferenceClient
{
  /**
   * Next in DLL
   */
  struct PreferenceClient *prev;

  /**
   * Next in DLL
   */

  struct PreferenceClient *next;

  /**
   * Client handle
   */
  void *client;

  /**
   * Total preference for this peer
   */
  double f_total[GNUNET_ATS_PreferenceCount];

  /**
   * List of peer preferences for this client
   */

  /**
   * Head of peer list
   */
  struct PreferencePeer *p_head;

  /**
   * Tail of peer list
   */
  struct PreferencePeer *p_tail;
};


/**
 * Preference peer
 */
struct PreferencePeer
{
  /**
   * Next in DLL
   */
  struct PreferencePeer *next;

  /**
   * Previous in DLL
   */
  struct PreferencePeer *prev;

  /**
   * Client
   */
  struct PreferenceClient *client;

  /**
   * Solver handle
   */
  struct GAS_PROPORTIONAL_Handle *s;

  /**
   * Peer id
   */
  struct GNUNET_PeerIdentity id;

  /**
   * Preference Values
   */
  double f[GNUNET_ATS_PreferenceCount];

  /**
   * Relative Preference Values
   */
  double f_rel[GNUNET_ATS_PreferenceCount];

  /**
   * Relative Total Preference Value
   */
  double f_rel_total;

  GNUNET_SCHEDULER_TaskIdentifier aging_task;
};


/**
 *  Important solver functions
 *  ---------------------------
 */

/**
 * Test if bandwidth is available in this network to add an additional address
 *
 * @param net the network type to update
 * @return GNUNET_YES or GNUNET_NO
 */
static int
is_bandwidth_available_in_network (struct Network *net)
{
  unsigned int na = net->active_addresses + 1;
  uint32_t min_bw = ntohl (GNUNET_CONSTANTS_DEFAULT_BW_IN_OUT.value__);
  if (((net->total_quota_in / na) > min_bw) &&
      ((net->total_quota_out / na) > min_bw))
  {
    LOG (GNUNET_ERROR_TYPE_DEBUG,
         "Enough bandwidth available for %u active addresses in network `%s'\n",
         na,
         net->desc);

    return GNUNET_YES;
  }
    LOG (GNUNET_ERROR_TYPE_DEBUG,
         "Not enough bandwidth available for %u active addresses in network `%s'\n",
         na,
         net->desc);
  return GNUNET_NO;
}


/**
 * Update bandwidth assigned to peers in this network
 *
 * @param s the solver handle
 * @param net the network type to update
 * @param address_except address excluded from notifcation, since we suggest
 * this address
 */
static void
update_quota_per_network (struct GAS_PROPORTIONAL_Handle *s,
                          struct Network *net,
                          struct ATS_Address *address_except)
{
  unsigned long long remaining_quota_in = 0;
  unsigned long long quota_out_used = 0;

  unsigned long long remaining_quota_out = 0;
  unsigned long long quota_in_used = 0;
  uint32_t min_bw = ntohl (GNUNET_CONSTANTS_DEFAULT_BW_IN_OUT.value__);
  double total_prefs; /* Important: has to be double not float due to precision */
  double cur_pref; /* Important: has to be double not float due to precision */
  double *t = NULL; /* Important: has to be double not float due to precision */

  unsigned long long assigned_quota_in = 0;
  unsigned long long assigned_quota_out = 0;
  struct AddressWrapper *cur;

  LOG (GNUNET_ERROR_TYPE_DEBUG,
              "Recalculate quota for network type `%s' for %u addresses (in/out): %llu/%llu \n",
              net->desc, net->active_addresses, net->total_quota_in, net->total_quota_in);

  if (net->active_addresses == 0)
    return; /* no addresses to update */

  /* Idea
   * Assign every peer in network minimum Bandwidth
   * Distribute bandwidth left according to preference
   */

  if ((net->active_addresses * min_bw) > net->total_quota_in)
  {
    GNUNET_break (0);
    return;
  }
  if ((net->active_addresses * min_bw) > net->total_quota_out)
  {
    GNUNET_break (0);
    return;
  }

  remaining_quota_in = net->total_quota_in - (net->active_addresses * min_bw);
  remaining_quota_out = net->total_quota_out - (net->active_addresses * min_bw);
  LOG (GNUNET_ERROR_TYPE_DEBUG, "Remaining bandwidth : (in/out): %llu/%llu \n",
              remaining_quota_in, remaining_quota_out);
  total_prefs = 0.0;
  for (cur = net->head; NULL != cur; cur = cur->next)
  {
      if (GNUNET_YES == cur->addr->active)
      {
        t = GNUNET_CONTAINER_multihashmap_get (s->prefs, &cur->addr->peer.hashPubKey);
        if (NULL == t)
                total_prefs += DEFAULT_PREFERENCE;
        else
         {
                        total_prefs += (*t);
         }
      }
  }
  for (cur = net->head; NULL != cur; cur = cur->next)
  {
     if (GNUNET_YES == cur->addr->active)
     {
       cur_pref = 0.0;
       t = GNUNET_CONTAINER_multihashmap_get (s->prefs, &cur->addr->peer.hashPubKey);
       if (NULL == t)
         cur_pref = DEFAULT_PREFERENCE;
       else
         cur_pref = (*t);
       assigned_quota_in = min_bw + ((cur_pref / total_prefs) * remaining_quota_in);
       assigned_quota_out = min_bw + ((cur_pref / total_prefs) * remaining_quota_out);

       LOG (GNUNET_ERROR_TYPE_DEBUG,
                   "New quota for peer `%s' with preference (cur/total) %.3f/%.3f (in/out): %llu / %llu\n",
                   GNUNET_i2s (&cur->addr->peer),
                   cur_pref, total_prefs,
                   assigned_quota_in, assigned_quota_out);
     }
     else
     {
       assigned_quota_in = 0;
       assigned_quota_out = 0;
     }

     quota_in_used += assigned_quota_in;
     quota_out_used += assigned_quota_out;
     /* Prevent overflow due to rounding errors */
     if (assigned_quota_in > UINT32_MAX)
       assigned_quota_in = UINT32_MAX;
     if (assigned_quota_out > UINT32_MAX)
       assigned_quota_out = UINT32_MAX;

     /* Compare to current bandwidth assigned */
     if ((assigned_quota_in != ntohl(cur->addr->assigned_bw_in.value__)) ||
         (assigned_quota_out != ntohl(cur->addr->assigned_bw_out.value__)))
     {
       cur->addr->assigned_bw_in.value__ = htonl (assigned_quota_in);
       cur->addr->assigned_bw_out.value__ = htonl (assigned_quota_out);
       /* Notify on change */
       if ((GNUNET_YES == cur->addr->active) && (cur->addr != address_except))
         s->bw_changed (s->bw_changed_cls, cur->addr);
     }

  }
  LOG (GNUNET_ERROR_TYPE_DEBUG,
                          "Total bandwidth assigned is (in/out): %llu /%llu\n",
                          quota_in_used,
                          quota_out_used);
  if (quota_out_used > net->total_quota_out + 1) /* +1 is required due to rounding errors */
  {
      LOG (GNUNET_ERROR_TYPE_ERROR,
                            "Total outbound bandwidth assigned is larger than allowed (used/allowed) for %u active addresses: %llu / %llu\n",
                            net->active_addresses,
                            quota_out_used,
                            net->total_quota_out);
  }
  if (quota_in_used > net->total_quota_in + 1) /* +1 is required due to rounding errors */
  {
      LOG (GNUNET_ERROR_TYPE_ERROR,
                            "Total inbound bandwidth assigned is larger than allowed (used/allowed) for %u active addresses: %llu / %llu\n",
                            net->active_addresses,
                            quota_in_used,
                            net->total_quota_in);
  }
}


/**
 * Extract an ATS performance info from an address
 *
 * @param address the address
 * @param type the type to extract in HBO
 * @return the value in HBO or GNUNET_ATS_VALUE_UNDEFINED in HBO if value does not exist
 */
static int
get_performance_info (struct ATS_Address *address, uint32_t type);

/**
 * Find a "good" address to use for a peer by iterating over the addresses for this peer.
 * If we already have an existing address, we stick to it.
 * Otherwise, we pick by lowest distance and then by lowest latency.
 *
 * @param cls the 'struct ATS_Address**' where we store the result
 * @param key unused
 * @param value another 'struct ATS_Address*' to consider using
 * @return GNUNET_OK (continue to iterate)
 */
static int
find_address_it (void *cls, const struct GNUNET_HashCode * key, void *value)
{
  struct ATS_Address **previous_p = cls;
  struct ATS_Address *current = (struct ATS_Address *) value;
  struct ATS_Address *previous = *previous_p;
  struct GNUNET_TIME_Absolute now;
  struct Network *net = (struct Network *) current->solver_information;
  uint32_t p_distance_cur;
  uint32_t p_distance_prev;
  uint32_t p_delay_cur;
  uint32_t p_delay_prev;

  now = GNUNET_TIME_absolute_get();

  if (current->blocked_until.abs_value == GNUNET_TIME_absolute_max (now, current->blocked_until).abs_value)
  {
    /* This address is blocked for suggestion */
    LOG (GNUNET_ERROR_TYPE_DEBUG,
                "Address %p blocked for suggestion for %llu ms \n",
                current,
                GNUNET_TIME_absolute_get_difference(now, current->blocked_until).rel_value);
    return GNUNET_OK;
  }

  if (GNUNET_NO == is_bandwidth_available_in_network (net))
    return GNUNET_OK; /* There's no bandwidth available in this network */

  if (NULL != previous)
  {
        GNUNET_assert (NULL != previous->plugin);
        GNUNET_assert (NULL != current->plugin);
    if (0 == strcmp (previous->plugin, current->plugin))
    {
      if ((0 != previous->addr_len) &&
          (0 == current->addr_len))
      {
        /* saved address was an outbound address, but we have an inbound address */
        *previous_p = current;
        return GNUNET_OK;
      }
      if (0 == previous->addr_len)
      {
        /* saved address was an inbound address, so do not overwrite */
        return GNUNET_OK;
      }
    }
  }

  if (NULL == previous)
  {
    *previous_p = current;
    return GNUNET_OK;
  }
  if ((ntohl (previous->assigned_bw_in.value__) == 0) &&
      (ntohl (current->assigned_bw_in.value__) > 0))
  {
    /* stick to existing connection */
    *previous_p = current;
    return GNUNET_OK;
  }

  p_distance_prev = get_performance_info (previous, GNUNET_ATS_QUALITY_NET_DISTANCE);
  p_distance_cur = get_performance_info (current, GNUNET_ATS_QUALITY_NET_DISTANCE);
  if ((p_distance_prev != GNUNET_ATS_VALUE_UNDEFINED) && (p_distance_cur != GNUNET_ATS_VALUE_UNDEFINED) &&
                (p_distance_prev > p_distance_cur))
  {
    /* user shorter distance */
    *previous_p = current;
    return GNUNET_OK;
  }

  p_delay_prev = get_performance_info (previous, GNUNET_ATS_QUALITY_NET_DELAY);
  p_delay_cur = get_performance_info (current, GNUNET_ATS_QUALITY_NET_DELAY);
  if ((p_delay_prev != GNUNET_ATS_VALUE_UNDEFINED) && (p_delay_cur != GNUNET_ATS_VALUE_UNDEFINED) &&
                (p_delay_prev > p_delay_cur))
  {
    /* user lower latency */
    *previous_p = current;
    return GNUNET_OK;
  }

  /* don't care */
  return GNUNET_OK;
}

/**
 *  Helper functions
 *  ---------------------------
 */

/**
 * Update bandwidth assignment for all networks
 *
 * @param s the solver handle
 */
static void
update_all_networks (struct GAS_PROPORTIONAL_Handle *s)
{
        int i;
        for (i = 0; i < s->networks; i++)
                update_quota_per_network (s, &s->network_entries[i], NULL);

}


/**
 * Lookup network struct by type
 *
 * @param s the solver handle
 * @param type the network type
 * @return the network struct
 */
static struct Network *
get_network (struct GAS_PROPORTIONAL_Handle *s, uint32_t type)
{
  int c;
  for (c = 0 ; c < s->networks; c++)
  {
      if (s->network_entries[c].type == type)
        return &s->network_entries[c];
  }
  return NULL;
}


/**
 * Hashmap Iterator to find current active address for peer
 *
 * @param cls last active address
 * @param key peer's key
 * @param value address to check
 * @return GNUNET_NO on double active address else GNUNET_YES
 */
static int
get_active_address_it (void *cls, const struct GNUNET_HashCode * key, void *value)
{
  struct ATS_Address * dest = (struct ATS_Address *) (*(struct ATS_Address **)cls);
  struct ATS_Address * aa = (struct ATS_Address *) value;

  if (GNUNET_YES == aa->active)
  {
      if (dest != NULL)
      {
          /* should never happen */
          LOG (GNUNET_ERROR_TYPE_ERROR, "Multiple active addresses for peer `%s'\n", GNUNET_i2s (&aa->peer));
          GNUNET_break (0);
          return GNUNET_NO;
      }
      dest = aa;
  }
  return GNUNET_OK;
}


/**
 * Find current active address for peer
 *
 * @param solver the solver handle
 * @param addresses the address set
 * @param peer the peer
 * @return active address or NULL
 */
static struct ATS_Address *
get_active_address (void *solver,
                     struct GNUNET_CONTAINER_MultiHashMap * addresses,
                     const struct GNUNET_PeerIdentity *peer)
{
  struct ATS_Address * dest = NULL;

  GNUNET_CONTAINER_multihashmap_get_multiple(addresses,
       &peer->hashPubKey,
       &get_active_address_it, &dest);
  return dest;
}


static int
free_pref (void *cls,
           const struct GNUNET_HashCode * key,
           void *value)
{
  float *v = value;
  GNUNET_free (v);
  return GNUNET_OK;
}


static void
addresse_increment (struct GAS_PROPORTIONAL_Handle *s,
                                struct Network *net,
                                int total,
                                int active)
{
  if (GNUNET_YES == total)
  {
      s->total_addresses ++;
      net->total_addresses ++;
      GNUNET_STATISTICS_update (s->stats, "# ATS addresses total", 1, GNUNET_NO);
      GNUNET_STATISTICS_update (s->stats, net->stat_total, 1, GNUNET_NO);
  }
  if (GNUNET_YES == active)
  {
    net->active_addresses ++;
    s->active_addresses ++;
    GNUNET_STATISTICS_update (s->stats, "# ATS active addresses total", 1, GNUNET_NO);
    GNUNET_STATISTICS_update (s->stats, net->stat_active, 1, GNUNET_NO);
  }

}


static int
addresse_decrement (struct GAS_PROPORTIONAL_Handle *s,
                    struct Network *net,
                    int total,
                    int active)
{
  int res = GNUNET_OK;
  if (GNUNET_YES == total)
  {
    if (s->total_addresses < 1)
    {
      GNUNET_break (0);
      res = GNUNET_SYSERR;
    }
    else
    {
      s->total_addresses --;
      GNUNET_STATISTICS_update (s->stats, "# ATS addresses total", -1, GNUNET_NO);
    }
    if (net->total_addresses < 1)
    {
      GNUNET_break (0);
      res = GNUNET_SYSERR;
    }
    else
    {
      net->total_addresses --;
      GNUNET_STATISTICS_update (s->stats, net->stat_total, -1, GNUNET_NO);
    }
  }

  if (GNUNET_YES == active)
  {
    if (net->active_addresses < 1)
    {
      GNUNET_break (0);
      res = GNUNET_SYSERR;
    }
    else
    {
      net->active_addresses --;
      GNUNET_STATISTICS_update (s->stats, net->stat_active, -1, GNUNET_NO);
    }
    if (s->active_addresses < 1)
    {
      GNUNET_break (0);
      res = GNUNET_SYSERR;
    }
    else
    {
      s->active_addresses --;
      GNUNET_STATISTICS_update (s->stats, "# ATS addresses total", -1, GNUNET_NO);
    }
  }
  return res;
}


/**
 * Extract an ATS performance info from an address
 *
 * @param address the address
 * @param type the type to extract in HBO
 * @return the value in HBO or GNUNET_ATS_VALUE_UNDEFINED in HBO if value does not exist
 */
static int
get_performance_info (struct ATS_Address *address, uint32_t type)
{
        int c1;
        GNUNET_assert (NULL != address);

        if ((NULL == address->atsi) || (0 == address->atsi_count))
                        return GNUNET_ATS_VALUE_UNDEFINED;

        for (c1 = 0; c1 < address->atsi_count; c1++)
        {
                        if (ntohl(address->atsi[c1].type) == type)
                                return ntohl(address->atsi[c1].value);
        }
        return GNUNET_ATS_VALUE_UNDEFINED;
}



/**
 *  Preference calculation
 *  ---------------------------
 */

static void
recalculate_preferences (struct PreferencePeer *p)
{
        struct GAS_PROPORTIONAL_Handle *s = p->s;
        struct PreferencePeer *p_cur;
        struct PreferenceClient *c_cur = p->client;
        double p_rel_global;
  double *dest;
  int kind;
  int rkind;
  int clients;

  /**
   * Idea:
   *
   * We have:
   * Set of clients c
   * Set of peers p_i in P
   * Set of preference kinds k
   * A preference value f_k_p_i with an unknown range
   *
   * We get:
   * A client specific relative preference f_p_i_rel [1..2] for all peers
   *
   * For every client c
   * {
   *   For every preference kind k:
   *   {
   *     We remember for the preference f_p_i for each peer p_i.
   *     We have a default preference value f_p_i = 0
   *     We have a sum of all preferences f_t = sum (f_p_i)
   *     So we can calculate a relative preference value fr_p_i:
   *
   *     f_k_p_i_ *  / f_t
   *     f_k_p_i_rel = [1..2], default 1.0
   *    }
   *    f_p_i_rel = sum (f_k_p_i_rel) / count(k)
   * }
   *
   **/

  /* For this client: for all preferences, except TERMINATOR */
  for (kind = GNUNET_ATS_PREFERENCE_END + 1 ; kind < GNUNET_ATS_PreferenceCount; kind ++)
  {
          /* Recalcalculate total preference for this quality kind over all peers*/
          c_cur->f_total[kind] = 0;
          for (p_cur = c_cur->p_head; NULL != p_cur; p_cur = p_cur->next)
                c_cur->f_total[kind] += p_cur->f[kind];

          LOG (GNUNET_ERROR_TYPE_DEBUG, "Client %p has total preference for %s of %.3f\n",
                        c_cur->client,
              GNUNET_ATS_print_preference_type (kind),
              c_cur->f_total[kind]);

          /* Recalcalculate relative preference for all peers */
          for (p_cur = c_cur->p_head; NULL != p_cur; p_cur = p_cur->next)
          {
            /* Calculate relative preference for specific kind */
                if (0.0 == c_cur->f_total[kind])
                {
                                /* No one has preference, so set default preference */
                                p_cur->f_rel[kind] = DEFAULT_PREFERENCE;
                }
                else
                {
                                p_cur->f_rel[kind] = (c_cur->f_total[kind] + p_cur->f[kind]) / c_cur->f_total[kind];
                }
            LOG (GNUNET_ERROR_TYPE_DEBUG, "Client %p: peer `%s' has relative preference for %s of %.3f\n",
                        c_cur->client,
                GNUNET_i2s (&p_cur->id),
                GNUNET_ATS_print_preference_type (kind),
                p_cur->f_rel[kind]);

            /* Calculate peer relative preference */
            /* Start with kind = 1 to exclude terminator */
            p_cur->f_rel_total = 0;
            for (rkind = GNUNET_ATS_PREFERENCE_END + 1; rkind < GNUNET_ATS_PreferenceCount; rkind ++)
            {
                p_cur->f_rel_total += p_cur->f_rel[rkind];
            }
            p_cur->f_rel_total /=  (GNUNET_ATS_PreferenceCount - 1.0); /* -1 due to terminator */
            LOG (GNUNET_ERROR_TYPE_DEBUG, "Client %p: peer `%s' has total relative preference of %.3f\n",
                        c_cur->client,
                GNUNET_i2s (&p_cur->id),
                p_cur->f_rel_total);
          }
  }

  /* Calculcate global total relative peer preference over all clients */
  p_rel_global = 0.0;
  clients = 0;
  for (c_cur = s->pc_head; NULL != c_cur; c_cur = c_cur->next)
  {
      for (p_cur = c_cur->p_head; NULL != p_cur; p_cur = p_cur->next)
          if (0 == memcmp (&p_cur->id, &p->id, sizeof (p_cur->id)))
              break;
      if (NULL != p_cur)
      {
          clients++;
          p_rel_global += p_cur->f_rel_total;
      }
  }
  p_rel_global /= clients;
  LOG (GNUNET_ERROR_TYPE_DEBUG, "Global preference value for peer `%s': %.3f\n",
      GNUNET_i2s (&p->id), p_rel_global);

  /* Update global map */
  if (NULL != (dest = GNUNET_CONTAINER_multihashmap_get(s->prefs, &p->id.hashPubKey)))
      (*dest) = p_rel_global;
  else
  {
      dest = GNUNET_malloc (sizeof (double));
      (*dest) = p_rel_global;
      GNUNET_CONTAINER_multihashmap_put(s->prefs,
          &p->id.hashPubKey,
          dest,
          GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
  }
}


static void
update_preference (struct PreferencePeer *p,
                                                                         enum GNUNET_ATS_PreferenceKind kind,
                                                         float score_f)
{
        double score = score_f;

  /* Update preference value according to type */
  switch (kind) {
    case GNUNET_ATS_PREFERENCE_BANDWIDTH:
    case GNUNET_ATS_PREFERENCE_LATENCY:
      p->f[kind] = (p->f[kind] + score) / 2;
      break;
    case GNUNET_ATS_PREFERENCE_END:
      break;
    default:
      break;
  }
  recalculate_preferences(p);
  update_all_networks (p->s);
}


static void
preference_aging (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
        int i;
        double *t = NULL;
        double backup;
        struct PreferencePeer *p = cls;
        GNUNET_assert (NULL != p);


        p->aging_task = GNUNET_SCHEDULER_NO_TASK;

  LOG (GNUNET_ERROR_TYPE_DEBUG, "Aging preferences for peer `%s'\n",
                GNUNET_i2s (&p->id));

  /* Issue for aging :
   *
   * Not for every peer preference values are set by default, so reducing the
   * absolute preference value does not help for aging because it does not have
   * influence on the relative values.
   *
   * So we have to reduce the relative value to have an immediate impact on
   * quota calculation. In addition we cannot call recalculate_preferences here
   * but instead reduce the absolute value to have an aging impact on future
   * calls to change_preference where recalculate_preferences is called
   *
   */
  /* Aging absolute values: */
  for (i = 0; i < GNUNET_ATS_PreferenceCount; i++)
  {
                if (p->f[i] > 1.0)
                {
                        backup = p->f[i];
                        p->f[i] *= PREF_AGING_FACTOR;
                        LOG (GNUNET_ERROR_TYPE_DEBUG, "Aged preference for peer `%s' from %.3f to %.3f\n",
                        GNUNET_i2s (&p->id), backup, p->f[i]);
                }
  }
  /* Updating relative value */
  t = GNUNET_CONTAINER_multihashmap_get (p->s->prefs, &p->id.hashPubKey);
  if (NULL == t)
  {
        GNUNET_break (0);
  }
  else
  {
                if ((*t) > 1.0)
                        (*t) = (*t) * PREF_AGING_FACTOR;
                else
                        (*t) = 1.0;
                update_all_networks (p->s);
  }
  p->aging_task = GNUNET_SCHEDULER_add_delayed (PREF_AGING_INTERVAL,
                &preference_aging, p);
}


/**
 * Changes the preferences for a peer in the problem
 *
 * @param solver the solver handle
 * @param client the client with this preference
 * @param peer the peer to change the preference for
 * @param kind the kind to change the preference
 * @param score the score
 */
void
GAS_simplistic_address_change_preference (void *solver,
                                   void *client,
                                   const struct GNUNET_PeerIdentity *peer,
                                   enum GNUNET_ATS_PreferenceKind kind,
                                   float score)
{
  static struct GNUNET_TIME_Absolute next_update;
  struct GAS_PROPORTIONAL_Handle *s = solver;
  struct PreferenceClient *c_cur;
  struct PreferencePeer *p_cur;
  int i;

  GNUNET_assert (NULL != solver);
  GNUNET_assert (NULL != client);
  GNUNET_assert (NULL != peer);

  LOG (GNUNET_ERROR_TYPE_DEBUG, "Client %p changes preference for peer `%s' %s %f\n",
                                client,
                                GNUNET_i2s (peer),
                                GNUNET_ATS_print_preference_type (kind),
                                score);

  if (kind >= GNUNET_ATS_PreferenceCount)
  {
      GNUNET_break (0);
      return;
  }

  /* Find preference client */
  for (c_cur = s->pc_head; NULL != c_cur; c_cur = c_cur->next)
  {
      if (client == c_cur->client)
        break;
  }
  /* Not found: create new preference client */
  if (NULL == c_cur)
  {
    c_cur = GNUNET_malloc (sizeof (struct PreferenceClient));
    c_cur->client = client;
    GNUNET_CONTAINER_DLL_insert (s->pc_head, s->pc_tail, c_cur);
  }

  /* Find entry for peer */
  for (p_cur = c_cur->p_head; NULL != p_cur; p_cur = p_cur->next)
    if (0 == memcmp (&p_cur->id, peer, sizeof (p_cur->id)))
        break;

  /* Not found: create new peer entry */
  if (NULL == p_cur)
  {
      p_cur = GNUNET_malloc (sizeof (struct PreferencePeer));
      p_cur->s = s;
      p_cur->client = c_cur;
      p_cur->id = (*peer);
      for (i = 0; i < GNUNET_ATS_PreferenceCount; i++)
      {
        /* Default value per peer absolut preference for a quality:
         * No value set, so absolute preference 0 */
        p_cur->f[i] = 0.0;
        /* Default value per peer relative preference for a quality: 1.0 */
        p_cur->f_rel[i] = DEFAULT_PREFERENCE;
      }
      p_cur->aging_task = GNUNET_SCHEDULER_add_delayed (PREF_AGING_INTERVAL, &preference_aging, p_cur);
      GNUNET_CONTAINER_DLL_insert (c_cur->p_head, c_cur->p_tail, p_cur);
  }

  update_preference (p_cur, kind, score);

  /* FIXME: We should update quotas if UPDATE_INTERVAL is reached */
  if (GNUNET_TIME_absolute_get().abs_value > next_update.abs_value)
  {
      /* update quotas*/
      next_update = GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(),
                                              MIN_UPDATE_INTERVAL);
  }
}


/**
 *  Solver API functions
 *  ---------------------------
 */

/**
 * Get the preferred address for a specific peer
 *
 * @param solver the solver handle
 * @param addresses the address hashmap containing all addresses
 * @param peer the identity of the peer
 */
const struct ATS_Address *
GAS_proportional_get_preferred_address (void *solver,
                               struct GNUNET_CONTAINER_MultiHashMap * addresses,
                               const struct GNUNET_PeerIdentity *peer)
{
  struct GAS_PROPORTIONAL_Handle *s = solver;
  struct Network *net_prev;
  struct Network *net_cur;
  struct ATS_Address *cur;
  struct ATS_Address *prev;

  GNUNET_assert (s != NULL);
  cur = NULL;
  /* Get address with: stick to current address, lower distance, lower latency */
  GNUNET_CONTAINER_multihashmap_get_multiple (addresses, &peer->hashPubKey,
                                              &find_address_it, &cur);
  if (NULL == cur)
  {
    LOG (GNUNET_ERROR_TYPE_DEBUG, "Cannot suggest address for peer `%s'\n", GNUNET_i2s (peer));
    return NULL;
  }

  LOG (GNUNET_ERROR_TYPE_DEBUG, "Suggesting %s address %p for peer `%s'\n",
      (GNUNET_NO == cur->active) ? "inactive" : "active",
      cur, GNUNET_i2s (peer));
  net_cur = (struct Network *) cur->solver_information;
  if (GNUNET_YES == cur->active)
  {
      /* This address was selected previously, so no need to update quotas */
      return cur;
  }

  /* This address was not active, so we have to:
   *
   * - mark previous active address as not active
   * - update quota for previous address network
   * - update quota for this address network
   */

  prev = get_active_address (s, addresses, peer);
  if (NULL != prev)
  {
      net_prev = (struct Network *) prev->solver_information;
      prev->active = GNUNET_NO; /* No active any longer */
      prev->assigned_bw_in = GNUNET_BANDWIDTH_value_init (0); /* no bw assigned */
      prev->assigned_bw_out = GNUNET_BANDWIDTH_value_init (0); /* no bw assigned */
      s->bw_changed (s->bw_changed_cls, prev); /* notify about bw change, REQUIRED? */
      if (GNUNET_SYSERR == addresse_decrement (s, net_prev, GNUNET_NO, GNUNET_YES))
        GNUNET_break (0);
      update_quota_per_network (s, net_prev, NULL);
  }

  if (GNUNET_NO == (is_bandwidth_available_in_network (cur->solver_information)))
  {
    GNUNET_break (0); /* This should never happen*/
    return NULL;
  }

  cur->active = GNUNET_YES;
  addresse_increment(s, net_cur, GNUNET_NO, GNUNET_YES);
  update_quota_per_network (s, net_cur, cur);

  return cur;
}


/**
 * Stop notifying about address and bandwidth changes for this peer
 *
 * @param solver the solver handle
 * @param addresses address hashmap
 * @param peer the peer
 */
void
GAS_proportional_stop_get_preferred_address (void *solver,
                                     struct GNUNET_CONTAINER_MultiHashMap *addresses,
                                     const struct GNUNET_PeerIdentity *peer)
{
        return;
}


/**
 * Remove an address from the solver
 *
 * @param solver the solver handle
 * @param addresses the address hashmap containing all addresses
 * @param address the address to remove
 * @param session_only delete only session not whole address
 */
void
GAS_proportional_address_delete (void *solver,
    struct GNUNET_CONTAINER_MultiHashMap * addresses,
    struct ATS_Address *address, int session_only)
{
  struct GAS_PROPORTIONAL_Handle *s = solver;
  struct Network *net;
  struct AddressWrapper *aw;

  /* Remove an adress completely, we have to:
   * - Remove from specific network
   * - Decrease number of total addresses
   * - If active:
   *   - decrease number of active addreses
   *   - update quotas
   */

  net = (struct Network *) address->solver_information;

  if (GNUNET_NO == session_only)
  {
    LOG (GNUNET_ERROR_TYPE_DEBUG, "Deleting %s address %p for peer `%s' from network `%s' (total: %u/ active: %u)\n",
        (GNUNET_NO == address->active) ? "inactive" : "active",
        address, GNUNET_i2s (&address->peer),
        net->desc, net->total_addresses, net->active_addresses);

    /* Remove address */
    addresse_decrement (s, net, GNUNET_YES, GNUNET_NO);
    for (aw = net->head; NULL != aw; aw = aw->next)
    {
        if (aw->addr == address)
          break;
    }
    if (NULL == aw )
    {
        GNUNET_break (0);
        return;
    }
    GNUNET_CONTAINER_DLL_remove (net->head, net->tail, aw);
    GNUNET_free (aw);
  }
  else
  {
      /* Remove session only: remove if active and update */
      LOG (GNUNET_ERROR_TYPE_DEBUG, "Deleting %s session %p for peer `%s' from network `%s' (total: %u/ active: %u)\n",
          (GNUNET_NO == address->active) ? "inactive" : "active",
          address, GNUNET_i2s (&address->peer),
          net->desc, net->total_addresses, net->active_addresses);
  }

  if (GNUNET_YES == address->active)
  {
      /* Address was active, remove from network and update quotas*/
      address->active = GNUNET_NO;
      if (GNUNET_SYSERR == addresse_decrement (s, net, GNUNET_NO, GNUNET_YES))
        GNUNET_break (0);
      update_quota_per_network (s, net, NULL);
  }
  LOG (GNUNET_ERROR_TYPE_DEBUG, "After deleting address now total %u and active %u addresses in network `%s'\n",
      net->total_addresses,
      net->active_addresses,
      net->desc);

}


/**
 * Add a new single address to a network
 *
 * @param solver the solver Handle
 * @param addresses the address hashmap containing all addresses
 * @param address the address to add
 * @param network network type of this address
 */
void
GAS_proportional_address_add (void *solver,
                                                        struct GNUNET_CONTAINER_MultiHashMap *addresses,
                                                        struct ATS_Address *address,
                                                        uint32_t network);

/**
 * Updates a single address in the solver and checks previous values
 *
 * @param solver the solver Handle
 * @param addresses the address hashmap containing all addresses
 * @param address the update address
 * @param session the previous session
 * @param in_use the previous address in use state
 * @param prev_ats previous ATS information
 * @param prev_atsi_count the previous atsi count
 */
void
GAS_proportional_address_update (void *solver,
                              struct GNUNET_CONTAINER_MultiHashMap *addresses,
                              struct ATS_Address *address,
                              uint32_t session,
                              int in_use,
                              const struct GNUNET_ATS_Information *prev_ats,
                              uint32_t prev_atsi_count)
{
  struct ATS_Address *new;
  struct GAS_PROPORTIONAL_Handle *s = (struct GAS_PROPORTIONAL_Handle *) solver;
  int i;
  uint32_t prev_value;
  uint32_t prev_type;
  uint32_t addr_net;
  int save_active = GNUNET_NO;
  struct Network *new_net = NULL;

  /* Check updates to performance information */
  for (i = 0; i < prev_atsi_count; i++)
  {
    prev_type = ntohl (prev_ats[i].type);
    prev_value = ntohl (prev_ats[i].value);
    switch (prev_type)
    {
    case GNUNET_ATS_UTILIZATION_UP:
    case GNUNET_ATS_UTILIZATION_DOWN:
    case GNUNET_ATS_QUALITY_NET_DELAY:
    case GNUNET_ATS_QUALITY_NET_DISTANCE:
    case GNUNET_ATS_COST_WAN:
    case GNUNET_ATS_COST_LAN:
    case GNUNET_ATS_COST_WLAN:
        /* No actions required here*/
        break;
    case GNUNET_ATS_NETWORK_TYPE:

      addr_net = get_performance_info (address, GNUNET_ATS_NETWORK_TYPE);
      if (GNUNET_ATS_VALUE_UNDEFINED == addr_net)
      {
        GNUNET_break (0);
        addr_net = GNUNET_ATS_NET_UNSPECIFIED;
      }
      if (addr_net != prev_value)
      {
        /* Network changed */
        LOG (GNUNET_ERROR_TYPE_DEBUG, "Network type changed, moving %s address from `%s' to `%s'\n",
            (GNUNET_YES == address->active) ? "active" : "inactive",
             GNUNET_ATS_print_network_type(prev_value),
             GNUNET_ATS_print_network_type(addr_net));

        save_active = address->active;
        /* remove from old network */
        GAS_proportional_address_delete (solver, addresses, address, GNUNET_NO);

        /* set new network type */
        new_net = get_network (solver, addr_net);
        address->solver_information = new_net;

        /* Add to new network and update*/
        GAS_proportional_address_add (solver, addresses, address, addr_net);
        if (GNUNET_YES == save_active)
        {
          /* check if bandwidth available in new network */
          if (GNUNET_YES == (is_bandwidth_available_in_network (new_net)))
          {
              /* Suggest updated address */
              address->active = GNUNET_YES;
              addresse_increment (s, new_net, GNUNET_NO, GNUNET_YES);
              update_quota_per_network (solver, new_net, NULL);
          }
          else
          {
            LOG (GNUNET_ERROR_TYPE_DEBUG, "Not enough bandwidth in new network, suggesting alternative address ..\n");

            /* Set old address to zero bw */
            address->assigned_bw_in = GNUNET_BANDWIDTH_value_init (0);
            address->assigned_bw_out = GNUNET_BANDWIDTH_value_init (0);
            s->bw_changed  (s->bw_changed_cls, address);

            /* Find new address to suggest since no bandwidth in network*/
            new = (struct ATS_Address *) GAS_proportional_get_preferred_address (s, addresses, &address->peer);
            if (NULL != new)
            {
                /* Have an alternative address to suggest */
                s->bw_changed  (s->bw_changed_cls, new);
            }

          }
        }
      }

      break;
    case GNUNET_ATS_ARRAY_TERMINATOR:
      break;
    default:
      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                  "Received unsupported ATS type %u\n", prev_type);
      GNUNET_break (0);
      break;

    }

  }
  if (address->session_id != session)
  {
      LOG (GNUNET_ERROR_TYPE_DEBUG,
                  "Session changed from %u to %u\n", session, address->session_id);
  }
  if (address->used != in_use)
  {
      LOG (GNUNET_ERROR_TYPE_DEBUG,
                  "Usage changed from %u to %u\n", in_use, address->used);
  }

}


/**
 * Add a new single address to a network
 *
 * @param solver the solver Handle
 * @param addresses the address hashmap containing all addresses
 * @param address the address to add
 * @param network network type of this address
 */
void
GAS_proportional_address_add (void *solver,
                                                        struct GNUNET_CONTAINER_MultiHashMap *addresses,
                                                        struct ATS_Address *address,
                                                        uint32_t network)
{
  struct GAS_PROPORTIONAL_Handle *s = solver;
  struct Network *net = NULL;
  struct AddressWrapper *aw = NULL;
  GNUNET_assert (NULL != s);

  net = get_network (s, network);
  if (NULL == net)
  {
    GNUNET_break (0);
    return;
  }

  aw = GNUNET_malloc (sizeof (struct AddressWrapper));
  aw->addr = address;
  GNUNET_CONTAINER_DLL_insert (net->head, net->tail, aw);
  addresse_increment (s, net, GNUNET_YES, GNUNET_NO);
  aw->addr->solver_information = net;

  LOG (GNUNET_ERROR_TYPE_DEBUG, "After adding address now total %u and active %u addresses in network `%s'\n",
      net->total_addresses,
      net->active_addresses,
      net->desc);
}


/**
 * Init the proportional problem solver
 *
 * Quotas:
 * network[i] contains the network type as type GNUNET_ATS_NetworkType[i]
 * out_quota[i] contains outbound quota for network type i
 * in_quota[i] contains inbound quota for network type i
 *
 * Example
 * network = {GNUNET_ATS_NET_UNSPECIFIED, GNUNET_ATS_NET_LOOPBACK, GNUNET_ATS_NET_LAN, GNUNET_ATS_NET_WAN, GNUNET_ATS_NET_WLAN}
 * network[2]   == GNUNET_ATS_NET_LAN
 * out_quota[2] == 65353
 * in_quota[2]  == 65353
 *
 * @param cfg configuration handle
 * @param stats the GNUNET_STATISTICS handle
 * @param network array of GNUNET_ATS_NetworkType with length dest_length
 * @param out_quota array of outbound quotas
 * @param in_quota array of outbound quota
 * @param dest_length array length for quota arrays
 * @param bw_changed_cb callback for changed bandwidth amounts
 * @param bw_changed_cb_cls cls for callback
 * @return handle for the solver on success, NULL on fail
 */
void *
GAS_proportional_init (const struct GNUNET_CONFIGURATION_Handle *cfg,
                       const struct GNUNET_STATISTICS_Handle *stats,
                       int *network,
                       unsigned long long *out_quota,
                       unsigned long long *in_quota,
                       int dest_length,
                       GAS_bandwidth_changed_cb bw_changed_cb,
                       void *bw_changed_cb_cls)
{
  int c;
  struct GAS_PROPORTIONAL_Handle *s = GNUNET_malloc (sizeof (struct GAS_PROPORTIONAL_Handle));
  struct Network * cur;
  char * net_str[GNUNET_ATS_NetworkTypeCount] = GNUNET_ATS_NetworkTypeString;


  s->stats = (struct GNUNET_STATISTICS_Handle *) stats;
  s->bw_changed = bw_changed_cb;
  s->bw_changed_cls = bw_changed_cb_cls;
  s->networks = dest_length;
  s->network_entries = GNUNET_malloc (dest_length * sizeof (struct Network));
  s->active_addresses = 0;
  s->total_addresses = 0;
  s->prefs = GNUNET_CONTAINER_multihashmap_create (10, GNUNET_NO);

  for (c = 0; c < dest_length; c++)
  {
      cur = &s->network_entries[c];
      cur->total_addresses = 0;
      cur->active_addresses = 0;
      cur->type = network[c];
      cur->total_quota_in = in_quota[c];
      cur->total_quota_out = out_quota[c];
      cur->desc = net_str[c];
      GNUNET_asprintf (&cur->stat_total, "# ATS addresses %s total", cur->desc);
      GNUNET_asprintf (&cur->stat_active, "# ATS active addresses %s total", cur->desc);
  }
  return s;
}


/**
 * Shutdown the proportional problem solver
 *
 * @param solver the respective handle to shutdown
 */
void
GAS_proportional_done (void *solver)
{
  struct GAS_PROPORTIONAL_Handle *s = solver;
  struct PreferenceClient *pc;
  struct PreferenceClient *next_pc;
  struct PreferencePeer *p;
  struct PreferencePeer *next_p;
  struct AddressWrapper *cur;
  struct AddressWrapper *next;
  int c;
  GNUNET_assert (s != NULL);

  for (c = 0; c < s->networks; c++)
  {
      if (s->network_entries[c].total_addresses > 0)
      {
        LOG (GNUNET_ERROR_TYPE_ERROR,
                    "Had %u addresses for network `%s' not deleted during shutdown\n",
                    s->network_entries[c].total_addresses,
                    s->network_entries[c].desc);
        GNUNET_break (0);
      }

      if (s->network_entries[c].active_addresses > 0)
      {
        LOG (GNUNET_ERROR_TYPE_ERROR,
                    "Had %u active addresses for network `%s' not deleted during shutdown\n",
                    s->network_entries[c].active_addresses,
                    s->network_entries[c].desc);
        GNUNET_break (0);
      }

      next = s->network_entries[c].head;
      while (NULL != (cur = next))
      {
          next = cur->next;
          GNUNET_CONTAINER_DLL_remove (s->network_entries[c].head,
                                       s->network_entries[c].tail,
                                       cur);
          GNUNET_free (cur);
      }
      GNUNET_free (s->network_entries[c].stat_total);
      GNUNET_free (s->network_entries[c].stat_active);
  }
  if (s->total_addresses > 0)
  {
    LOG (GNUNET_ERROR_TYPE_ERROR,
                "Had %u addresses not deleted during shutdown\n",
                s->total_addresses);
    GNUNET_break (0);
  }
  if (s->active_addresses > 0)
  {
    LOG (GNUNET_ERROR_TYPE_ERROR,
                "Had %u active addresses not deleted during shutdown\n",
                s->active_addresses);
    GNUNET_break (0);
  }
  GNUNET_free (s->network_entries);

  next_pc = s->pc_head;
  while (NULL != (pc = next_pc))
  {
      next_pc = pc->next;
      GNUNET_CONTAINER_DLL_remove (s->pc_head, s->pc_tail, pc);
      next_p = pc->p_head;
      while (NULL != (p = next_p))
      {
          next_p = p->next;
          if (GNUNET_SCHEDULER_NO_TASK != p->aging_task)
          {
                GNUNET_SCHEDULER_cancel(p->aging_task);
                p->aging_task = GNUNET_SCHEDULER_NO_TASK;
          }
          GNUNET_CONTAINER_DLL_remove (pc->p_head, pc->p_tail, p);
          GNUNET_free (p);
      }
      GNUNET_free (pc);
  }

  GNUNET_CONTAINER_multihashmap_iterate (s->prefs, &free_pref, NULL);
  GNUNET_CONTAINER_multihashmap_destroy (s->prefs);
  GNUNET_free (s);
}


/* end of gnunet-service-ats-solver_proportional.c */