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author | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
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committer | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
commit | 5f8de423f190bbb79a62f804151bc24824fa32d8 (patch) | |
tree | 10027f336435511475e392454359edea8e25895d /xpcom/glue/nsDeque.h | |
parent | 49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff) | |
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Add m-esr52 at 52.6.0
Diffstat (limited to 'xpcom/glue/nsDeque.h')
-rw-r--r-- | xpcom/glue/nsDeque.h | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/xpcom/glue/nsDeque.h b/xpcom/glue/nsDeque.h new file mode 100644 index 000000000..ace7607d3 --- /dev/null +++ b/xpcom/glue/nsDeque.h @@ -0,0 +1,195 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* 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" +#include "nsDebug.h" +#include "mozilla/Attributes.h" +#include "mozilla/fallible.h" +#include "mozilla/MemoryReporting.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* aObject) = 0; + virtual ~nsDequeFunctor() {} +}; + +/****************************************************** + * 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 nsDeque +{ + typedef mozilla::fallible_t fallible_t; +public: + explicit nsDeque(nsDequeFunctor* aDeallocator = nullptr); + ~nsDeque(); + + /** + * Returns the number of elements currently stored in + * this deque. + * + * @return number of elements currently in the deque + */ + inline size_t GetSize() const { return mSize; } + + /** + * Appends new member at the end of the deque. + * + * @param item to store in deque + */ + void Push(void* aItem) + { + if (!Push(aItem, mozilla::fallible)) { + NS_ABORT_OOM(mSize * sizeof(void*)); + } + } + + MOZ_MUST_USE bool Push(void* aItem, const fallible_t&); + + /** + * Inserts new member at the front of the deque. + * + * @param item to store in deque + */ + void PushFront(void* aItem) + { + if (!PushFront(aItem, mozilla::fallible)) { + NS_ABORT_OOM(mSize * sizeof(void*)); + } + } + + MOZ_MUST_USE bool PushFront(void* aItem, const fallible_t&); + + /** + * 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() const; + /** + * Return topmost item without removing it. + * + * @return the first item in container + */ + void* PeekFront() const; + + /** + * Retrieve a member from the deque without removing it. + * + * @param index of desired item + * @return element in list + */ + void* ObjectAt(size_t aIndex) const; + + /** + * Remove and delete all items from container. + * Deletes are handled by the deallocator nsDequeFunctor + * which is specified at deque construction. + */ + void Erase(); + + /** + * 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 + */ + void ForEach(nsDequeFunctor& aFunctor) const; + + size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const; + size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const; + +protected: + size_t mSize; + size_t mCapacity; + size_t mOrigin; + nsDequeFunctor* mDeallocator; + void* mBuffer[8]; + void** mData; + +private: + + /** + * Copy constructor (PRIVATE) + * + * @param aOther another deque + */ + nsDeque(const nsDeque& aOther); + + /** + * Deque assignment operator (PRIVATE) + * + * @param aOther another deque + * @return *this + */ + nsDeque& operator=(const nsDeque& aOther); + + bool GrowCapacity(); + void SetDeallocator(nsDequeFunctor* aDeallocator); + + /** + * Remove all items from container without destroying them. + */ + void Empty(); +}; +#endif |