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| -rw-r--r-- | src/libs/xpcom18a4/xpcom/ds/nsDeque.h | 405 |
1 files changed, 405 insertions, 0 deletions
diff --git a/src/libs/xpcom18a4/xpcom/ds/nsDeque.h b/src/libs/xpcom18a4/xpcom/ds/nsDeque.h new file mode 100644 index 00000000..7fdf7465 --- /dev/null +++ b/src/libs/xpcom18a4/xpcom/ds/nsDeque.h @@ -0,0 +1,405 @@ +/* -*- 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 + * + * The contents of this file are subject to the Mozilla 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/MPL/ + * + * 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 of 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 MPL, 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 MPL, the GPL or the LGPL. + * + * ***** 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 nsDeque { + friend class nsDequeIterator; + public: + nsDeque(nsDequeFunctor* aDeallocator); + ~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: + + /** + * Simple default constructor (PRIVATE) + */ + nsDeque(); + + /** + * 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 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 |