pjs/xpcom/ds/nsDeque.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: NPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Netscape Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/NPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the NPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the NPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/**
* MODULE NOTES:
* @update gess 4/15/98 (tax day)
*
* The Deque is a very small, very efficient container object
* than can hold elements of type void*, offering the following features:
* It's interface supports pushing and poping of children.
* It can iterate (via an interator class) it's children.
* When full, it can efficently resize dynamically.
*
*
* NOTE: The only bit of trickery here is that this deque is
* built upon a ring-buffer. Like all ring buffers, the first
* element may not be at index[0]. The mOrigin member determines
* where the first child is. This point is quietly hidden from
* customers of this class.
*
*/
#ifndef _NSDEQUE
#define _NSDEQUE
#include "nscore.h"
/**
* The nsDequefunctor class is used when you want to create
* callbacks between the deque and your generic code.
* Use these objects in a call to ForEach();
*
* @update gess4/20/98
*/
class NS_COM nsDequeFunctor{
public:
virtual void* operator()(void* anObject)=0;
};
/******************************************************
* Here comes the nsDeque class itself...
******************************************************/
/**
* The deque (double-ended queue) class is a common container type,
* whose behavior mimics a line in your favorite checkout stand.
* Classic CS describes the common behavior of a queue as FIFO.
* A Deque allows items to be added and removed from either end of
* the queue.
*
* @update gess4/20/98
*/
class NS_COM nsDeque {
friend class nsDequeIterator;
public:
nsDeque(nsDequeFunctor* aDeallocator);
~nsDeque();
/**
* Returns the number of elements currently stored in
* this deque.
*
* @update gess4/18/98
* @param
* @return int contains element count
*/
inline PRInt32 GetSize() const { return mSize;}
/**
* Pushes new member onto the end of the deque
*
* @update gess4/18/98
* @param ptr to object to store
* @return *this
*/
nsDeque& Push(void* anItem);
/**
* Pushes new member onto the front of the deque
*
* @update gess4/18/98
* @param ptr to object to store
* @return *this
*/
nsDeque& PushFront(void* anItem);
/**
* Remove and return the first item in the container.
*
* @update gess4/18/98
* @param none
* @return ptr to first item in container
*/
void* Pop(void);
/**
* Remove and return the first item in the container.
*
* @update gess4/18/98
* @param none
* @return ptr to first item in container
*/
void* PopFront(void);
/**
* Return bottom item without removing it.
*
* @update sford11/25/99
* @param none
* @return ptr to first item in container
*/
void* Peek(void);
/**
* Return topmost item without removing it.
*
* @update sford 11/25/99
* @param none
* @return ptr to first item in container
*/
void* PeekFront(void);
/**
* method used to retrieve ptr to
* ith member in container. DOesn't remove
* that item.
*
* @update gess4/18/98
* @param index of desired item
* @return ptr to ith element in list
*/
void* ObjectAt(int anIndex) const;
/**
* Remove all items from container without destroying them
*
* @update gess4/18/98
* @param
* @return
*/
nsDeque& Empty();
/**
* Remove and delete all items from container
*
* @update gess4/18/98
* @param
* @return
*/
nsDeque& Erase();
/**
* Creates a new iterator, init'ed to start of container
*
* @update gess4/18/98
* @return new dequeIterator
*/
nsDequeIterator Begin() const;
/**
* Creates a new iterator, init'ed to end of container
*
* @update gess4/18/98
* @return new dequeIterator
*/
nsDequeIterator End() const;
/**
* Call this method when you wanto to iterate all the
* members of the container, passing a functor along
* to call your code.
*
* @update gess4/20/98
* @param aFunctor object to call for each member
* @return *this
*/
void ForEach(nsDequeFunctor& aFunctor) const;
/**
* Call this method when you wanto to iterate all the
* members of the container, passing a functor along
* to call your code. This process will interupt if
* your function returns a null to this iterator.
*
* @update gess4/20/98
* @param aFunctor object to call for each member
* @return *this
*/
const void* FirstThat(nsDequeFunctor& aFunctor) const;
void SetDeallocator(nsDequeFunctor* aDeallocator);
/**
* Perform automated selftest on the deque
*
* @update gess4/18/98
* @param
* @return
*/
static void SelfTest();
protected:
PRInt32 mSize;
PRInt32 mCapacity;
PRInt32 mOrigin;
nsDequeFunctor* mDeallocator;
void* mBuffer[8];
void** mData;
private:
/**
* Simple default constructor (PRIVATE)
*
* @update gess4/18/98
* @param
* @return
*/
nsDeque();
/**
* Copy constructor (PRIVATE)
*
* @update gess4/18/98
* @param
* @return
*/
nsDeque(const nsDeque& other);
/**
* Deque assignment operator (PRIVATE)
*
* @update gess4/18/98
* @param another deque
* @return *this
*/
nsDeque& operator=(const nsDeque& anOther);
nsDeque& GrowCapacity(void);
};
/******************************************************
* Here comes the nsDequeIterator class...
******************************************************/
class NS_COM nsDequeIterator {
public:
/**
* DequeIterator is an object that knows how to iterate (forward and backward)
* a Deque. Normally, you don't need to do this, but there are some special
* cases where it is pretty handy, so here you go.
*
* @update gess4/18/98
* @param aQueue is the deque object to be iterated
* @param anIndex is the starting position for your iteration
*/
nsDequeIterator(const nsDeque& aQueue,int anIndex=0);
/**
* DequeIterator is an object that knows how to iterate (forward and backward)
* a Deque. Normally, you don't need to do this, but there are some special
* cases where it is pretty handy, so here you go.
*
* @update gess4/18/98
* @param aQueue is the deque object to be iterated
* @param anIndex is the starting position for your iteration
*/
nsDequeIterator(const nsDequeIterator& aCopy);
/**
* Moves iterator to first element in deque
* @update gess4/18/98
* @return this
*/
nsDequeIterator& First(void);
/**
* Standard assignment operator for deque
* @update gess4/18/98
* @param
* @return
*/
nsDequeIterator& operator=(const nsDequeIterator& aCopy);
/**
* preform ! operation against to iterators to test for equivalence
* (or lack thereof)!
*
* @update gess4/18/98
* @param anIter is the object to be compared to
* @return TRUE if NOT equal.
*/
PRBool operator!=(nsDequeIterator& anIter);
/**
* Compare 2 iterators for equivalence.
*
* @update gess4/18/98
* @param anIter is the other iterator to be compared to
* @return TRUE if EQUAL
*/
PRBool operator<(nsDequeIterator& anIter);
/**
* Compare 2 iterators for equivalence.
*
* @update gess4/18/98
* @param anIter is the other iterator to be compared to
* @return TRUE if EQUAL
*/
PRBool operator==(nsDequeIterator& anIter);
/**
* Compare 2 iterators for equivalence.
*
* @update gess4/18/98
* @param anIter is the other iterator to be compared to
* @return TRUE if EQUAL
*/
PRBool operator>=(nsDequeIterator& anIter);
/**
* Pre-increment operator
*
* @update gess4/18/98
* @return object at preincremented index
*/
void* operator++();
/**
* Post-increment operator
*
* @update gess4/18/98
* @param param is ignored
* @return object at post-incremented index
*/
void* operator++(int);
/**
* Pre-decrement operator
*
* @update gess4/18/98
* @return object at pre-decremented index
*/
void* operator--();
/**
* Post-decrement operator
*
* @update gess4/18/98
* @param param is ignored
* @return object at post-decremented index
*/
void* operator--(int);
/**
* Retrieve the ptr to the iterators notion of current node
*
* @update gess4/18/98
* @return object at ith index
*/
void* GetCurrent(void);
/**
* Call this method when you wanto to iterate all the
* members of the container, passing a functor along
* to call your code.
*
* @update gess4/20/98
* @param aFunctor object to call for each member
* @return *this
*/
void ForEach(nsDequeFunctor& aFunctor) const;
/**
* Call this method when you wanto to iterate all the
* members of the container, passing a functor along
* to call your code.
*
* @update gess4/20/98
* @param aFunctor object to call for each member
* @return *this
*/
const void* FirstThat(nsDequeFunctor& aFunctor) const;
protected:
PRInt32 mIndex;
const nsDeque& mDeque;
};
#endif