| /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ |
| /* ***** BEGIN LICENSE BLOCK ***** |
| * Version: MPL 1.1/GPL 2.0/LGPL 2.1 |
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| * 1.1 (the "License"); you may not use this file except in compliance with |
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| * 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. |
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| * |
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| * ***** END LICENSE BLOCK ***** */ |
| |
| /** |
| * MODULE NOTES: |
| * |
| * The Deque is a very small, very efficient container object |
| * than can hold elements of type void*, offering the following features: |
| * Its interface supports pushing and popping of elements. |
| * It can iterate (via an interator class) its elements. |
| * When full, it can efficiently 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(); |
| * |
| */ |
| |
| class 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 insertion and removal at both ends of |
| * the container. |
| * |
| * The deque stores pointers to items. |
| */ |
| |
| class nsDequeIterator; |
| |
| class NS_COM_GLUE nsDeque { |
| friend class nsDequeIterator; |
| public: |
| nsDeque(nsDequeFunctor* aDeallocator = nsnull); |
| ~nsDeque(); |
| |
| /** |
| * Returns the number of elements currently stored in |
| * this deque. |
| * |
| * @return number of elements currently in the deque |
| */ |
| inline PRInt32 GetSize() const {return mSize;} |
| |
| /** |
| * Appends new member at the end of the deque. |
| * |
| * @param item to store in deque |
| * @return *this |
| */ |
| nsDeque& Push(void* aItem); |
| |
| /** |
| * Inserts new member at the front of the deque. |
| * |
| * @param item to store in deque |
| * @return *this |
| */ |
| nsDeque& PushFront(void* aItem); |
| |
| /** |
| * Remove and return the last item in the container. |
| * |
| * @return the item that was the last item in container |
| */ |
| void* Pop(); |
| |
| /** |
| * Remove and return the first item in the container. |
| * |
| * @return the item that was first item in container |
| */ |
| void* PopFront(); |
| |
| /** |
| * Retrieve the bottom item without removing it. |
| * |
| * @return the first item in container |
| */ |
| |
| void* Peek(); |
| /** |
| * Return topmost item without removing it. |
| * |
| * @return the first item in container |
| */ |
| void* PeekFront(); |
| |
| /** |
| * Retrieve the i'th member from the deque without removing it. |
| * |
| * @param index of desired item |
| * @return i'th element in list |
| */ |
| void* ObjectAt(int aIndex) const; |
| |
| /** |
| * Remove all items from container without destroying them. |
| * |
| * @return *this |
| */ |
| nsDeque& Empty(); |
| |
| /** |
| * Remove and delete all items from container. |
| * Deletes are handled by the deallocator nsDequeFunctor |
| * which is specified at deque construction. |
| * |
| * @return *this |
| */ |
| nsDeque& Erase(); |
| |
| /** |
| * Creates a new iterator, pointing to the first |
| * item in the deque. |
| * |
| * @return new dequeIterator |
| */ |
| nsDequeIterator Begin() const; |
| |
| /** |
| * Creates a new iterator, pointing to the last |
| * item in the deque. |
| * |
| * @return new dequeIterator |
| */ |
| nsDequeIterator End() const; |
| |
| void* Last() const; |
| /** |
| * Call this method when you want to iterate all the |
| * members of the container, passing a functor along |
| * to call your code. |
| * |
| * @param aFunctor object to call for each member |
| * @return *this |
| */ |
| void ForEach(nsDequeFunctor& aFunctor) const; |
| |
| /** |
| * Call this method when you want to iterate all the |
| * members of the container, calling the functor you |
| * passed with each member. This process will interrupt |
| * if your function returns non 0 to this method. |
| * |
| * @param aFunctor object to call for each member |
| * @return first nonzero result of aFunctor or 0. |
| */ |
| const void* FirstThat(nsDequeFunctor& aFunctor) const; |
| |
| void SetDeallocator(nsDequeFunctor* aDeallocator); |
| |
| protected: |
| PRInt32 mSize; |
| PRInt32 mCapacity; |
| PRInt32 mOrigin; |
| nsDequeFunctor* mDeallocator; |
| void* mBuffer[8]; |
| void** mData; |
| |
| private: |
| |
| /** |
| * Copy constructor (PRIVATE) |
| * |
| * @param another deque |
| */ |
| nsDeque(const nsDeque& other); |
| |
| /** |
| * Deque assignment operator (PRIVATE) |
| * |
| * @param another deque |
| * @return *this |
| */ |
| nsDeque& operator=(const nsDeque& anOther); |
| |
| PRInt32 GrowCapacity(); |
| }; |
| |
| /****************************************************** |
| * Here comes the nsDequeIterator class... |
| ******************************************************/ |
| |
| class NS_COM_GLUE nsDequeIterator { |
| public: |
| /** |
| * DequeIterator is an object that knows how to iterate |
| * (forward and backward) through a Deque. Normally, |
| * you don't need to do this, but there are some special |
| * cases where it is pretty handy. |
| * |
| * One warning: the iterator is not bound to an item, |
| * it is bound to an index, so if you insert or remove |
| * from the beginning while using an iterator |
| * (which is not recommended) then the iterator will |
| * point to a different item. @see GetCurrent() |
| * |
| * Here you go. |
| * |
| * @param aQueue is the deque object to be iterated |
| * @param aIndex is the starting position for your iteration |
| */ |
| nsDequeIterator(const nsDeque& aQueue, int aIndex=0); |
| |
| /** |
| * Create a copy of a DequeIterator |
| * |
| * @param aCopy is another iterator to copy from |
| */ |
| nsDequeIterator(const nsDequeIterator& aCopy); |
| |
| /** |
| * Moves iterator to first element in the deque |
| * @return *this |
| */ |
| nsDequeIterator& First(); |
| |
| /** |
| * Standard assignment operator for dequeiterator |
| * @param aCopy is another iterator to copy from |
| * @return *this |
| */ |
| nsDequeIterator& operator=(const nsDequeIterator& aCopy); |
| |
| /** |
| * preform ! operation against two iterators to test for equivalence |
| * (or lack thereof)! |
| * |
| * @param aIter is the object to be compared to |
| * @return TRUE if NOT equal. |
| */ |
| PRBool operator!=(nsDequeIterator& aIter); |
| |
| /** |
| * Compare two iterators for increasing order. |
| * |
| * @param aIter is the other iterator to be compared to |
| * @return TRUE if this object points to an element before |
| * the element pointed to by aIter. |
| * FALSE if this and aIter are not iterating over |
| * the same deque. |
| */ |
| PRBool operator<(nsDequeIterator& aIter); |
| |
| /** |
| * Compare two iterators for equivalence. |
| * |
| * @param aIter is the other iterator to be compared to |
| * @return TRUE if EQUAL |
| */ |
| PRBool operator==(nsDequeIterator& aIter); |
| |
| /** |
| * Compare two iterators for non strict decreasing order. |
| * |
| * @param aIter is the other iterator to be compared to |
| * @return TRUE if this object points to the same element, or |
| * an element after the element pointed to by aIter. |
| * FALSE if this and aIter are not iterating over |
| * the same deque. |
| */ |
| PRBool operator>=(nsDequeIterator& aIter); |
| |
| /** |
| * Pre-increment operator |
| * Iterator will advance one index towards the end. |
| * |
| * @return object_at(++index) |
| */ |
| void* operator++(); |
| |
| /** |
| * Post-increment operator |
| * Iterator will advance one index towards the end. |
| * |
| * @param param is ignored |
| * @return object_at(mIndex++) |
| */ |
| void* operator++(int); |
| |
| /** |
| * Pre-decrement operator |
| * Iterator will advance one index towards the beginning. |
| * |
| * @return object_at(--index) |
| */ |
| void* operator--(); |
| |
| /** |
| * Post-decrement operator |
| * Iterator will advance one index towards the beginning. |
| * |
| * @param param is ignored |
| * @return object_at(index--) |
| */ |
| void* operator--(int); |
| |
| /** |
| * Retrieve the the iterator's notion of current node. |
| * |
| * Note that the iterator floats, so you don't need to do: |
| * <code>++iter; aDeque.PopFront();</code> |
| * Unless you actually want your iterator to jump 2 positions |
| * relative to its origin. |
| * |
| * Picture: [1 2i 3 4] |
| * PopFront() |
| * Picture: [2 3i 4] |
| * Note that I still happily points to object at the second index. |
| * |
| * @return object at i'th index |
| */ |
| void* GetCurrent(); |
| |
| /** |
| * Call this method when you want to iterate all the |
| * members of the container, passing a functor along |
| * to call your code. |
| * |
| * @param aFunctor object to call for each member |
| * @return *this |
| */ |
| void ForEach(nsDequeFunctor& aFunctor) const; |
| |
| /** |
| * Call this method when you want to iterate all the |
| * members of the container, calling the functor you |
| * passed with each member. This process will interrupt |
| * if your function returns non 0 to this method. |
| * |
| * @param aFunctor object to call for each member |
| * @return first nonzero result of aFunctor or 0. |
| */ |
| const void* FirstThat(nsDequeFunctor& aFunctor) const; |
| |
| protected: |
| |
| PRInt32 mIndex; |
| const nsDeque& mDeque; |
| }; |
| #endif |