mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-14 15:37:55 +00:00
377 lines
9.5 KiB
C++
377 lines
9.5 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
/**
|
|
* 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 = nullptr);
|
|
~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;
|
|
|
|
/**
|
|
* Removes and returns the i'th member from the deque.
|
|
*
|
|
* @param index of desired item
|
|
* @return the element which was removed
|
|
*/
|
|
void* RemoveObjectAt(int aIndex);
|
|
|
|
/**
|
|
* 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);
|
|
|
|
bool 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.
|
|
*/
|
|
bool 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.
|
|
*/
|
|
bool operator<(nsDequeIterator& aIter);
|
|
|
|
/**
|
|
* Compare two iterators for equivalence.
|
|
*
|
|
* @param aIter is the other iterator to be compared to
|
|
* @return TRUE if EQUAL
|
|
*/
|
|
bool 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.
|
|
*/
|
|
bool 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
|