/* -*- mode: C; c-file-style: "gnu" -*- */

/* dbus-resources.c Resource tracking/limits

 *

 * Copyright (C) 2003  Red Hat Inc.

 * Portion Copyright © 2008 Nokia Corporation and/or its subsidiary(-ies). All rights reserved.

 * Licensed under the Academic Free License version 2.1

 * 

 * This program 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 of the License, or

 * (at your option) any later version.

 *

 * This program 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 this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 */

#ifdef __SYMBIAN32__

//these are not system headers in build time

#include "dbus-resources.h"

#include "dbus-internals.h"

#else

#include <dbus/dbus-resources.h>

#include <dbus/dbus-internals.h>

#endif

/**

 * @defgroup DBusResources Resource limits related code

 * @ingroup  DBusInternals

 * @brief DBusCounter and other stuff related to resource limits

 *

 * Types and functions related to tracking resource limits,

 * such as the maximum amount of memory a connection can use

 * for messages, etc.

 */

/**

 * @defgroup DBusResourcesInternals Resource limits implementation details

 * @ingroup  DBusInternals

 * @brief Resource limits implementation details

 *

 * Implementation details of resource limits code.

 *

 * @{

 */

/**

 * @brief Internals of DBusCounter.

 * 

 * DBusCounter internals. DBusCounter is an opaque object, it must be

 * used via accessor functions.

 */

struct DBusCounter

{

  int refcount;  /**< reference count */

  long value;    /**< current counter value */

  long notify_guard_value; /**< call notify function when crossing this value */

  DBusCounterNotifyFunction notify_function; /**< notify function */

  void *notify_data; /**< data for notify function */

};

/** @} */  /* end of resource limits internals docs */

/**

 * @addtogroup DBusResources

 * @{

 */

/**

 * Creates a new DBusCounter. DBusCounter is used

 * to count usage of some resource such as memory.

 *

 * @returns new counter or #NULL on failure

 */

DBusCounter*

_dbus_counter_new (void)

{

  DBusCounter *counter;

  counter = dbus_new (DBusCounter, 1);

  if (counter == NULL)

    return NULL;

  counter->refcount = 1;

  counter->value = 0;

  counter->notify_guard_value = 0;

  counter->notify_function = NULL;

  counter->notify_data = NULL;

  return counter;

}

/**

 * Increments refcount of the counter

 *

 * @param counter the counter

 * @returns the counter

 */

DBusCounter *

_dbus_counter_ref (DBusCounter *counter)

{

  _dbus_assert (counter->refcount > 0);

  counter->refcount += 1;

  return counter;

}

/**

 * Decrements refcount of the counter and possibly

 * finalizes the counter.

 *

 * @param counter the counter

 */

void

_dbus_counter_unref (DBusCounter *counter)

{

  _dbus_assert (counter->refcount > 0);

  counter->refcount -= 1;

  if (counter->refcount == 0)

    {

      dbus_free (counter);

    }

}

/**

 * Adjusts the value of the counter by the given

 * delta which may be positive or negative.

 * Calls the notify function from _dbus_counter_set_notify()

 * if that function has been specified.

 *

 * @param counter the counter

 * @param delta value to add to the counter's current value

 */

void

_dbus_counter_adjust (DBusCounter *counter,

                      long         delta)

{

  long old = counter->value;

  counter->value += delta;

#if 0

  _dbus_verbose ("Adjusting counter %ld by %ld = %ld\n",

                 old, delta, counter->value);

#endif

  if (counter->notify_function != NULL &&

      ((old < counter->notify_guard_value &&

        counter->value >= counter->notify_guard_value) ||

       (old >= counter->notify_guard_value &&

        counter->value < counter->notify_guard_value)))

    (* counter->notify_function) (counter, counter->notify_data);

}

/**

 * Gets the current value of the counter.

 *

 * @param counter the counter

 * @returns its current value

 */

long

_dbus_counter_get_value (DBusCounter *counter)

{

  return counter->value;

}

/**

 * Sets the notify function for this counter; the notify function is

 * called whenever the counter's value crosses the guard value in

 * either direction (moving up, or moving down).

 *

 * @param counter the counter

 * @param guard_value the value we're notified if the counter crosses

 * @param function function to call in order to notify

 * @param user_data data to pass to the function

 */

void

_dbus_counter_set_notify (DBusCounter               *counter,

                          long                       guard_value,

                          DBusCounterNotifyFunction  function,

                          void                      *user_data)

{

  counter->notify_guard_value = guard_value;

  counter->notify_function = function;

  counter->notify_data = user_data;

}

/** @} */  /* end of resource limits exported API */