/**************************************************************************\
 *
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 *  Copyright (C) 1998-2006 by Systems in Motion.  All rights reserved.
 *
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 *  See the file LICENSE.GPL at the root directory of this source
 *  distribution for additional information about the GNU GPL.
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 *  support services, please contact Systems in Motion about acquiring
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 *
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\**************************************************************************/

/*!
  \class SoAuditorList SoAuditorList.h Inventor/lists/SoAuditorList.h
  \brief The SoAuditorList class is used to keep track of auditors for certain object classes.
  \ingroup general

  This class is mainly for internal use (from SoBase) and it should
  not be necessary to be familiar with it for "ordinary" Coin use.
*/


#include <Inventor/fields/SoField.h>
#include <Inventor/fields/SoFieldContainer.h>
#include <Inventor/sensors/SoDataSensor.h>
#if COIN_DEBUG
#include <Inventor/errors/SoDebugError.h>
#endif // COIN_DEBUG

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif // HAVE_CONFIG_H

#ifdef COIN_THREADSAFE
#include <Inventor/C/threads/recmutexp.h>
// we need this lock to avoid that auditors are added/removed by one
// thread while another thread is notifying
#define NOTIFY_LOCK (void) cc_recmutex_internal_notify_lock()
#define NOTIFY_UNLOCK (void) cc_recmutex_internal_notify_unlock()
#else // COIN_THREADSAFE
#define NOTIFY_LOCK
#define NOTIFY_UNLOCK
#endif // !COIN_THREADSAFE

/*!
  Default constructor.
*/
SoAuditorList::SoAuditorList(void)
  : SbPList(8)
{
}

/*!
  Destructor.
*/
SoAuditorList::~SoAuditorList()
{
}

/*!
  Append an \a auditor of \a type to the list.
*/
void
SoAuditorList::append(void * const auditor, const SoNotRec::Type type)
{
  NOTIFY_LOCK;
  SbPList::append(auditor);
  SbPList::append((void *)type);
  NOTIFY_UNLOCK;
}

/*!
  Set \a auditor pointer and auditor \a type in list at \a index.
*/
void
SoAuditorList::set(const int index,
                   void * const auditor, const SoNotRec::Type type)
{
  NOTIFY_LOCK;
  assert(index >= 0 && index < this->getLength());

  SbPList::set(index * 2, auditor);
  SbPList::set(index * 2 + 1, (void *)type);
  NOTIFY_UNLOCK;
}

/*!
  Returns number of elements in list.
*/
int
SoAuditorList::getLength(void) const
{
  return SbPList::getLength() / 2;
}

/*!
  Find \a auditor of \a type in list and return index. Returns -1 if
  \a auditor is not in the list.
*/
int
SoAuditorList::find(void * const auditor, const SoNotRec::Type type) const
{
  const int num = this->getLength();
  for (int i = 0; i < num; i++) {
    if (this->getObject(i) == auditor && this->getType(i) == type)
      return i;
  }
  return -1;
}

/*!
  Returns auditor pointer at \a index.
*/
void *
SoAuditorList::getObject(const int index) const
{
  return SbPList::operator[](index * 2);
}

/*!
  Returns auditor type at \a index.
*/
SoNotRec::Type
SoAuditorList::getType(const int index) const
{
  const uintptr_t tmp = (uintptr_t)(SbPList::operator[](index*2+1));
  return (SoNotRec::Type)tmp;
}

/*!
  Remove auditor at \a index.
*/
void
SoAuditorList::remove(const int index)
{
  NOTIFY_LOCK;
  assert(index >= 0 && index < this->getLength());
  SbPList::remove(index * 2); // ptr
  SbPList::remove(index * 2); // type
  NOTIFY_UNLOCK;
}

/*!
  Remove \a auditor of \a type from list.
*/
void
SoAuditorList::remove(void * const auditor, const SoNotRec::Type type)
{
  this->remove(this->find(auditor, type));
}

/*!
  Send notification to all our auditors.
*/
void
SoAuditorList::notify(SoNotList * l)
{
  const int num = this->getLength();
  if (num == 1) { // fast path for common case
    this->doNotify(l, this->getObject(0), this->getType(0));
  }
  // handle multiple auditors by copying the list, in case any one of
  // the notifications we're sending out changes the list
  // mid-traversal (that's also why we take special care of the
  // 1-auditor case above -- so we don't have to copy the list for the
  // common case)
  else if (num > 1) {
    // FIXME: should perhaps use a more general mechanism to detect when
    // to ignore notification? (In SoFieldContainer::notify() -- based
    // on SoNotList::getTimeStamp()?) 20000304 mortene.
    SbPList notified(num);
    
    for (int i = 0; i < num; i++) {
      void * auditor = this->getObject(i);
      if (notified.find(auditor) == -1) {
        // use a copy of 'l', since the notification list might change
        // when auditors are notified
        SoNotList listcopy(l);
        this->doNotify(&listcopy, auditor, this->getType(i));
        notified.append(auditor);
      }
    }
    
    // FIXME: it should be possible for the application programmer to
    // do this (it is for instance useful and tempting to do it upon
    // changes in engines). pederb, 2001-11-06
    assert(num == this->getLength() &&
           "auditors can not be removed during the notification loop");
  }
}

//
// Private method used to propagate 'l' to the 'auditor' of type 'type'
//
void 
SoAuditorList::doNotify(SoNotList * l, const void * auditor, const SoNotRec::Type type)
{
  l->setLastType(type);

  switch (type) {
  case SoNotRec::CONTAINER:
  case SoNotRec::PARENT:
    {
      SoFieldContainer * obj = (SoFieldContainer *)auditor;
      obj->notify(l);
    }
    break;
    
  case SoNotRec::SENSOR:
    {
      SoDataSensor * obj = (SoDataSensor *)auditor;
#if COIN_DEBUG && 0 // debug
      SoDebugError::postInfo("SoAuditorList::notify",
                             "notify and schedule sensor: %p", obj);
#endif // debug
      // don't schedule the sensor here. The sensor instance will do
      // that in notify() (it might also choose _not_ to schedule),
      obj->notify(l);
    }
    break;
    
  case SoNotRec::FIELD:
  case SoNotRec::ENGINE:
    {
      // We used to check whether or not the fields was already
      // dirty before we transmitted the notification
      // message. This is _not_ correct (the dirty flag is
      // conceptually only relevant for whether or not to do
      // re-evaluation), so don't try to "optimize" the
      // notification mechanism by re-introducing that "feature".
      // :^/
      ((SoField *)auditor)->notify(l);
    }
    break;
    
  default:
    assert(0 && "Unknown auditor type");
  }
}

#undef NOTIFY_LOCK
#undef NOTIFY_UNLOCK
