/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */

/*

 * Copyright (c) 2007 INRIA, Gustavo Carneiro

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation;

 *

 * 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

 *

 * Authors: Gustavo Carneiro <gjcarneiro@gmail.com>,

 *          Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

 */

#include "object.h"

#include "assert.h"

#include "singleton.h"

#include "trace-resolver.h"

#include "log.h"

#include <vector>

NS_LOG_COMPONENT_DEFINE ("Object");

/*********************************************************************

 *         Helper code

 *********************************************************************/

namespace {

class IidManager

{

public:

  uint16_t AllocateUid (std::string name);

  void SetParent (uint16_t uid, uint16_t parent);

  uint16_t GetUid (std::string name) const;

  std::string GetName (uint16_t uid) const;

  uint16_t GetParent (uint16_t uid) const;

private:

  struct IidInformation {

    std::string name;

    uint16_t parent;

  };

  typedef std::vector<struct IidInformation>::const_iterator Iterator;

  struct IidManager::IidInformation *LookupInformation (uint16_t uid) const;

  std::vector<struct IidInformation> m_information;

};

uint16_t 

IidManager::AllocateUid (std::string name)

{

  uint16_t j = 1;

  for (Iterator i = m_information.begin (); i != m_information.end (); i++)

    {

      if (i->name == name)

        {

          NS_FATAL_ERROR ("Trying to allocate twice the same uid: " << name);

          return 0;

        }

      j++;

    }

  struct IidInformation information;

  information.name = name;

  information.parent = 0;

  m_information.push_back (information);

  uint32_t uid = m_information.size ();

  NS_ASSERT (uid <= 0xffff);

  return uid;

}

struct IidManager::IidInformation *

IidManager::LookupInformation (uint16_t uid) const

{

  NS_ASSERT (uid <= m_information.size ());

  return const_cast<struct IidInformation *> (&m_information[uid-1]);

}

void 

IidManager::SetParent (uint16_t uid, uint16_t parent)

{

  NS_ASSERT (parent <= m_information.size ());

  struct IidInformation *information = LookupInformation (uid);

  information->parent = parent;

}

uint16_t 

IidManager::GetUid (std::string name) const

{

  uint32_t j = 1;

  for (Iterator i = m_information.begin (); i != m_information.end (); i++)

    {

      if (i->name == name)

        {

          NS_ASSERT (j <= 0xffff);

          return j;

        }

      j++;

    }

  return 0;

}

std::string 

IidManager::GetName (uint16_t uid) const

{

  struct IidInformation *information = LookupInformation (uid);

  return information->name;

}

uint16_t 

IidManager::GetParent (uint16_t uid) const

{

  struct IidInformation *information = LookupInformation (uid);

  return information->parent;

}

} // anonymous namespace

/*********************************************************************

 *         The InterfaceId TraceResolver

 *********************************************************************/

namespace ns3 {

class InterfaceIdTraceResolver : public TraceResolver

{

public:

  InterfaceIdTraceResolver (Ptr<const Object> aggregate);

  virtual void Connect (std::string path, CallbackBase const &cb, const TraceContext &context);

  virtual void Disconnect (std::string path, CallbackBase const &cb);

  virtual void CollectSources (std::string path, const TraceContext &context, 

                               SourceCollection *collection);

  virtual void TraceAll (std::ostream &os, const TraceContext &context);

private:

  Ptr<const Object> ParseForInterface (std::string path);

  Ptr<const Object> m_aggregate;

};

InterfaceIdTraceResolver::InterfaceIdTraceResolver (Ptr<const Object> aggregate)

  : m_aggregate (aggregate)

{}

Ptr<const Object>

InterfaceIdTraceResolver::ParseForInterface (std::string path)

{

  std::string element = GetElement (path);

  std::string::size_type dollar_pos = element.find ("$");

  if (dollar_pos != 0)

    {

      return 0;

    }

  std::string interfaceName = element.substr (1, std::string::npos);

  InterfaceId interfaceId = InterfaceId::LookupByName (interfaceName);

  Ptr<Object> interface = m_aggregate->QueryInterface<Object> (interfaceId);

  return interface;

}

void  

InterfaceIdTraceResolver::Connect (std::string path, CallbackBase const &cb, const TraceContext &context)

{

  Ptr<const Object> interface = ParseForInterface (path);

  if (interface != 0)

    {

      interface->GetTraceResolver ()->Connect (GetSubpath (path), cb, context);

    }

}

void 

InterfaceIdTraceResolver::Disconnect (std::string path, CallbackBase const &cb)

{

  Ptr<const Object> interface = ParseForInterface (path);

  if (interface != 0)

    {

      interface->TraceDisconnect (GetSubpath (path), cb);

    }

}

void 

InterfaceIdTraceResolver::CollectSources (std::string path, const TraceContext &context, 

                                          SourceCollection *collection)

{

  m_aggregate->DoCollectSources (path, context, collection);

}

void 

InterfaceIdTraceResolver::TraceAll (std::ostream &os, const TraceContext &context)

{

  m_aggregate->DoTraceAll (os, context);

}

/*********************************************************************

 *         The InterfaceId class

 *********************************************************************/

InterfaceId::InterfaceId (uint16_t iid)

  : m_iid (iid)

{}

InterfaceId::~InterfaceId ()

{}

InterfaceId 

InterfaceId::LookupByName (std::string name)

{

  uint16_t uid = Singleton<IidManager>::Get ()->GetUid (name);

  NS_ASSERT (uid != 0);

  return InterfaceId (uid);

}

InterfaceId 

InterfaceId::GetParent (void) const

{

  uint16_t parent = Singleton<IidManager>::Get ()->GetParent (m_iid);

  return InterfaceId (parent);

}

std::string 

InterfaceId::GetName (void) const

{

  std::string name = Singleton<IidManager>::Get ()->GetName (m_iid);

  return name;

}

bool operator == (InterfaceId a, InterfaceId b)

{

  return a.m_iid == b.m_iid;

}

bool operator != (InterfaceId a, InterfaceId b)

{

  return a.m_iid != b.m_iid;

}

InterfaceId

MakeInterfaceId (std::string name, InterfaceId parent)

{

  uint16_t uid = Singleton<IidManager>::Get ()->AllocateUid (name);

  NS_ASSERT (uid != 0);

  Singleton<IidManager>::Get ()->SetParent (uid, parent.m_iid);

  return InterfaceId (uid);

}

InterfaceId

MakeObjectInterfaceId (void)

{

  uint16_t uid = Singleton<IidManager>::Get ()->AllocateUid ("Object");

  NS_ASSERT (uid == 1);

  Singleton<IidManager>::Get ()->SetParent (uid, uid);

  return InterfaceId (uid);

}

/*********************************************************************

 *         The Object implementation

 *********************************************************************/

InterfaceId 

Object::iid (void)

{

  static InterfaceId iid = MakeObjectInterfaceId ();

  return iid;

}

Object::Object ()

  : m_count (1),

    m_iid (Object::iid ()),

    m_disposed (false),

    m_collecting (false),

    m_next (this)

{}

Object::~Object () 

{

  m_next = 0;

}

Ptr<Object>

Object::DoQueryInterface (InterfaceId iid) const

{

  NS_ASSERT (CheckLoose ());

  const Object *currentObject = this;

  do {

    NS_ASSERT (currentObject != 0);

    InterfaceId cur = currentObject->m_iid;

    while (cur != iid && cur != Object::iid ())

      {

        cur = cur.GetParent ();

      }

    if (cur == iid)

      {

        return const_cast<Object *> (currentObject);

      }

    currentObject = currentObject->m_next;

  } while (currentObject != this);

  return 0;

}

void 

Object::Dispose (void)

{

  Object *current = this;

  do {

    NS_ASSERT (current != 0);

    NS_ASSERT (!current->m_disposed);

    current->DoDispose ();

    current->m_disposed = true;

    current = current->m_next;

  } while (current != this);

}

void 

Object::AddInterface (Ptr<Object> o)

{

  NS_ASSERT (!m_disposed);

  NS_ASSERT (!o->m_disposed);

  NS_ASSERT (CheckLoose ());

  NS_ASSERT (o->CheckLoose ());

  Object *other = PeekPointer (o);

  Object *next = m_next;

  m_next = other->m_next;

  other->m_next = next;

  NS_ASSERT (CheckLoose ());

  NS_ASSERT (o->CheckLoose ());

}

void 

Object::TraceConnect (std::string path, const CallbackBase &cb) const

{

  NS_ASSERT (CheckLoose ());

  GetTraceResolver ()->Connect (path, cb, TraceContext ());

}

void 

Object::TraceDisconnect (std::string path, const CallbackBase &cb) const

{

  NS_ASSERT (CheckLoose ());

  GetTraceResolver ()->Disconnect (path, cb);

}

void 

Object::SetInterfaceId (InterfaceId iid)

{

  NS_ASSERT (Check ());

  m_iid = iid;

}

void

Object::DoDispose (void)

{

  NS_ASSERT (!m_disposed);

}

Ptr<TraceResolver>

Object::GetTraceResolver (void) const

{

  NS_ASSERT (CheckLoose ());

  Ptr<InterfaceIdTraceResolver> resolver =

    Create<InterfaceIdTraceResolver> (this);

  return resolver;

}

bool 

Object::Check (void) const

{

  return (m_count > 0);

}

/* In some cases, when an event is scheduled against a subclass of

 * Object, and if no one owns a reference directly to this object, the

 * object is alive, has a refcount of zero and the method ran when the

 * event expires runs against the raw pointer which means that we are

 * manipulating an object with a refcount of zero.  So, instead we

 * check the aggregate reference count.

 */

bool 

Object::CheckLoose (void) const

{

  uint32_t refcount = 0;

  const Object *current = this;

  do

    {

      refcount += current->m_count;

      current = current->m_next;

    }

  while (current != this);

  return (refcount > 0);

}

void

Object::MaybeDelete (void) const

{

  // First, check if any of the attached

  // Object has a non-zero count.

  const Object *current = this;

  do {

    NS_ASSERT (current != 0);

    if (current->m_count != 0)

      {

        return;

      }

    current = current->m_next;

  } while (current != this);

  // all attached objects have a zero count so, 

  // we can delete all attached objects.

  current = this;

  const Object *end = this;

  do {

    NS_ASSERT (current != 0);

    Object *next = current->m_next;

    delete current;

    current = next;

  } while (current != end);

}

void 

Object::DoCollectSources (std::string path, const TraceContext &context, 

                          TraceResolver::SourceCollection *collection) const