queue.h

这是一个从音频信号里提取特征参量的程序

//
template <class TObject>
MemoryManager Queue<TObject>::mgr_d(sizeof(Queue<TObject>), CLASS_NAME);

// below are all the methods for the Queue template class
//      

// ---------------------------------------------------------------------
//
// required static methods
//
//----------------------------------------------------------------------

// method: name
//
// arguments: none
//
// return: a static String& containing the class name
//
// this method returns the class name
//
template<class TObject>
const String& Queue<TObject>::name() {
  
  // create the static name string for this class and return it
  //
  static String cname(CLASS_NAME);
  cname.clear();
  cname.concat(CLASS_NAME);
  cname.concat(L"<");
  cname.concat(TObject::name());
  cname.concat(L">");
  
  // return the name
  //
  return cname;
}

// ---------------------------------------------------------------------
//
// required debug methods
//
//----------------------------------------------------------------------

// method: debug
//
// arguments:
//  unichar* message: (input) information message
//
// return: a boolean value indicating status
//
// this method dumps the contents of an object to the console
// 
template<class TObject>
boolean Queue<TObject>::debug(const unichar* message_a) const {
  
  // declare local variables
  //
  String output;
  String value;

  // print out the memory allocation mode
  //
  output.debugStr(name(), message_a, L"alloc_d",
		  NameMap::ALLOCATION_MAP((long)alloc_d));
  Console::put(output);
  
  // print out the debug level
  //
  value.assign(debug_level_d);
  output.debugStr(name(), message_a, L"debug_level_d", value);
  Console::put(output);
  
  // print out the top of queue message
  //
  value.assign(L"front of queue");
  Console::put(value);
  
  // increment the indention level
  //
  Console::increaseIndention();
  
  // call the list debug method
  //
  queue_d.debug(message_a);
  
  // decrement the indention level
  //
  Console::decreaseIndention();
  
  // exit gracefully
  // 
  return true;
}

//------------------------------------------------------------------------
//
// required destructor/constructor(s)
//
//-----------------------------------------------------------------------

// method: default constructor
//
// arguments:
//  ALLOCATION alloc: (input) the flag to specify whether or not the item
//                     memory is allocated by the node itself
//
// return: none
//
template<class TObject>
Queue<TObject>::Queue(ALLOCATION alloc_a) {

  // set the allocation flag
  //
  alloc_d = alloc_a;

  // the list object must be in USER mode
  //
  queue_d.setAllocationMode(USER);
}

//----------------------------------------------------------------------
//
// required assign methods
//
//----------------------------------------------------------------------

// method: assign
//
// arguments:
//  const Queue<TObject>& copy_queue: (input) queue to be copied
//
// return: a boolean value indicating status
//
// this method copies the elements in queue passed in to the current queue
// 
template<class TObject>
boolean Queue<TObject>::assign(const Queue<TObject>& arg_a) {

  // when the current queue is in USER mode and the queue to be copied
  // is in SYSTEM mode error
  //
  if ((alloc_d == USER) && (arg_a.getAllocationMode() == SYSTEM)) {
    return Error::handle(name(), L"assign", Error::ARG, __FILE__, __LINE__);
  }

  // if this queue is in system mode then temporarily set the list
  // to system mode and assign. this has the side-effect of copying the
  // data to this list
  //
  alloc_d = arg_a.alloc_d;
  queue_d.setAllocationMode(alloc_d);
  queue_d.assign(arg_a.queue_d);
  queue_d.setAllocationMode(USER);
  
  // reposition the Queue
  //
  queue_d.gotoLast();

  // exit gracefully
  //
  return true;
}

//---------------------------------------------------------------------------
//
// class-specific public methods:
//  queue add and remove methods
//
//---------------------------------------------------------------------------

// method: add
//
// arguments:
//  TObject* item: (input) the item added
//  
// return: a boolean value indicating status
//
// this method adds a item to the front of the queue
//
template<class TObject>
boolean Queue<TObject>::add(TObject* item_a) {

  // declare local variables
  //
  TObject* new_obj = (TObject*)NULL;

  // mode: SYSTEM
  //  make a copy of the element
  //
  if (alloc_d == SYSTEM) {
    new_obj = new TObject(*item_a);
  }

  // mode: USER
  //  make a copy of the pointer to the item
  //
  else {
    new_obj = item_a;
  }

  // add the object to the top of the queue
  //
  return queue_d.insertLast(new_obj);
}

// method: add
//
// arguments:
//  Queue<TObject>& item_queue: (input) queue to be added
//  
// return: a boolean value indicating status
//
// this method adds a queue to the front of another queue
//
template<class TObject>
boolean Queue<TObject>::add(Queue<TObject>& item_queue_a) {

  // if the queue is empty exit
  //
  if (item_queue_a.isEmpty()) {
    return false;
  }

  // loop over the queue and add elements
  //
  else {
    for (boolean more = item_queue_a.queue_d.gotoFirst();
	 more; more = item_queue_a.queue_d.gotoNext()) {
    
      // add the element on the queue
      //
      if (!add(item_queue_a.queue_d.getCurr())) {
	return false;
      }
    }
    item_queue_a.queue_d.gotoLast();
  }
  
  // exit gracefully
  //
  return true;
}

// method: add
//
// arguments:
//  TObject** items: (input) list of items to be added
//  long num_items: (input) number of items in the list
//  
// return: a boolean value indicating status
//
// this method adds num_items from the items list to the front of the queue
//
template<class TObject>
boolean Queue<TObject>::add(TObject** items_a, long num_items_a) {

  // loop over all elements in the queue and add each one
  //
  for (long i = 0; i < num_items_a; i++) {
    if (!add(items_a[i])) {
      return false;
    }
  }
  
  // exit gracefully
  //
  return true;
}

// method: peek
//
// arguments: none
//  
// return: TObject* of the item on top of the queue
//
// this method lets the user manipulate the item on top of the queue without
// removing the item from the queue
//
template<class TObject>
const TObject* Queue<TObject>::peek() const {
  
  // if the queue is empty then return an error
  //
  if (isEmpty()) {
    Error::handle(name(), L"peek", Queue::ERR_EMPTY, __FILE__, __LINE__);
    return (TObject*)NULL;
  }

  // return the pointer
  //
  return queue_d.getFirst();
}

// method: peek
//
// arguments: none
//  
// return: TObject* of the item on top of the queue
//
// this method lets the user manipulate the item on top of the queue without
// removing the item from the queue
//
template<class TObject>
TObject* Queue<TObject>::peek() {
  
  // if the queue is empty then return an error
  //
  if (isEmpty()) {
    Error::handle(name(), L"peek", Queue::ERR_EMPTY, __FILE__, __LINE__);
    return (TObject*)NULL;
  }

  // return the pointer
  //
  return queue_d.getFirst();
}

// method: remove
//
// arguments:
//  TObject* item: (input) memory space for the object
//  
// return: a TObject* pointer to the object removed
//
// this method removes the front item in the queue and returns it to the user
//
template<class TObject>
TObject* Queue<TObject>::remove(TObject* item_a) {

  // declare local variables
  //
  boolean result = false;
  TObject* ptr = (TObject*)NULL;

  // when in SYSTEM mode the item passed in should not be
  // null, if we are in reference mode the item should be null
  //
  if (((alloc_d == SYSTEM) && (item_a == (TObject*)NULL)) ||
      ((alloc_d == USER) && (item_a != (TObject*)NULL))) {
    Error::handle(name(), L"remove", ERR, __FILE__, __LINE__);
    return (TObject*)NULL;
  }

  // when in USER mode the item should be null
  //
  if ((alloc_d == USER) && (item_a != (TObject*)NULL)) {
    Error::handle(name(), L"remove", ERR, __FILE__, __LINE__);
    return (TObject*)NULL;
  }
  
  // if the queue is empty exit
  //
  if (!isEmpty()) {

    // the returned item is valid so remove the item and make sure we are
    // positioned at the front of the queue
    //
    result = queue_d.removeFirst(ptr);
    queue_d.gotoLast();
    
    // mode: SYSTEM
    //
    if (alloc_d == SYSTEM) {

      // make a copy of the object
      //
      item_a->assign(*ptr);

      // delete the reference to the object      
      //
      delete ptr;

      // return a pointer to the object (so that the return value can
      // be compared)
      //
      return item_a;
    }

    // mode: USER
    //
    else {
      return ptr;
    }
  }

  // nothing in queue, return null
  //
  return (TObject*)NULL;
}

// method: remove
//
// arguments:
//  Queue& item_a: (output) the items to be removed
//  long num_items_a: (input) the number of items
//  
// return: a boolean value indicating status
//
// this method removes the first num_items off of the queue and places them
// in the input queue passed as an argument.
//
template<class TObject>
long Queue<TObject>::remove(Queue<TObject>& items_a, long num_items_a) {

  // check that the modes are compatible
  //
  if (items_a.getAllocationMode() != alloc_d) {
    return Error::handle(name(), L"remove", Queue::ERR,
			 __FILE__, __LINE__);
  }

  // declare local variables
  //
  long count = 0;
  long queue_len = 0;  
  TObject* ptr = NULL;

  // get the initial queue length
  //
  queue_len = queue_d.length();
  
  // the remove method was called with REMOVE_ALL
  //
  if (num_items_a == REMOVE_ALL) {
    while ((count < queue_len) && queue_d.removeFirst(ptr)) {
      items_a.queue_d.insertLast(ptr);
      count++;    
    }
  }
  
  // the remove method was called with REMOVE_TO_MARK
  //  
  else if (num_items_a == REMOVE_TO_MARK) {

    // position the queue
    //
    queue_d.gotoFirst();

    // remove element by element
    //
    while (!queue_d.isMarkedElement() && queue_d.removeFirst(ptr)) {
      items_a.queue_d.insertLast(ptr);
      count++;
    }
  }

  // the remove method was called with num_items_a
  //
  else if (num_items_a >= 0) {
    while ((count < num_items_a) && queue_d.removeFirst(ptr)) {
      items_a.queue_d.insertLast(ptr);
      count++;    
    }
  }

  // none of the valid options to remove were found
  //
  else {
    return Error::handle(name(), L"remove", Queue::ERR,
			 __FILE__, __LINE__);
  }
  
  // return the current pointer to the end of the list
  //
  queue_d.gotoLast();

  // return the number of items removed
  //
  return count;
}

// end of include file
//
#endif