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Diffstat (limited to 'LibOVRKernel/Src/Kernel/OVR_List.h')
| -rw-r--r-- | LibOVRKernel/Src/Kernel/OVR_List.h | 365 |
1 files changed, 365 insertions, 0 deletions
diff --git a/LibOVRKernel/Src/Kernel/OVR_List.h b/LibOVRKernel/Src/Kernel/OVR_List.h new file mode 100644 index 0000000..70027db --- /dev/null +++ b/LibOVRKernel/Src/Kernel/OVR_List.h @@ -0,0 +1,365 @@ +/************************************************************************************ + +PublicHeader: OVR +Filename : OVR_List.h +Content : Template implementation for doubly-connected linked List +Created : September 19, 2012 +Notes : + +Copyright : Copyright 2014 Oculus VR, LLC All Rights reserved. + +Licensed under the Oculus VR Rift SDK License Version 3.2 (the "License"); +you may not use the Oculus VR Rift SDK except in compliance with the License, +which is provided at the time of installation or download, or which +otherwise accompanies this software in either electronic or hard copy form. + +You may obtain a copy of the License at + +http://www.oculusvr.com/licenses/LICENSE-3.2 + +Unless required by applicable law or agreed to in writing, the Oculus VR SDK +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. + +************************************************************************************/ + +#ifndef OVR_List_h +#define OVR_List_h + +#include "OVR_Types.h" + +namespace OVR { + +//----------------------------------------------------------------------------------- +// ***** ListNode +// +// Base class for the elements of the intrusive linked list. +// To store elements in the List do: +// +// class MyData : ListNode<MyData> +// { +// . . . +// }; + +template<class T> +class ListNode +{ +private: + ListNode<T>* pPrev; + ListNode<T>* pNext; + + template<class X, class B> friend class List; + +public: + T* GetPrev() const { return (T*)(pPrev); } + T* GetNext() const { return (T*)(pNext); } + + ListNode() + { + pPrev = nullptr; + pNext = nullptr; + } + + bool IsInList() + { + return (pNext != nullptr); + } + + void RemoveNode() + { + pPrev->pNext = pNext; + pNext->pPrev = pPrev; + pPrev = nullptr; + pNext = nullptr; + } + + // Removes us from the list and inserts pnew there instead. + void ReplaceNodeWith(T* pnew) + { + pPrev->pNext = pnew; + pNext->pPrev = pnew; + pnew->pPrev = pPrev; + pnew->pNext = pNext; + pPrev = nullptr; + pNext = nullptr; + } + + // Inserts the argument linked list node after us in the list. + void InsertNodeAfter(T* p) + { + p->pPrev = pNext->pPrev; // this + p->pNext = pNext; + pNext->pPrev = p; + pNext = p; + } + // Inserts the argument linked list node before us in the list. + void InsertNodeBefore(T* p) + { + p->pNext = pNext->pPrev; // this + p->pPrev = pPrev; + pPrev->pNext = p; + pPrev = p; + } + + void Alloc_MoveTo(ListNode<T>* pdest) + { + pdest->pNext = pNext; + pdest->pPrev = pPrev; + pPrev->pNext = pdest; + pNext->pPrev = pdest; + pPrev = nullptr; + pNext = nullptr; + } +}; + +//------------------------------------------------------------------------ +// ***** List +// +// Doubly linked intrusive list. +// The data type must be derived from ListNode. +// +// Adding: PushFront(), PushBack(). +// Removing: Remove() - the element must be in the list! +// Moving: BringToFront(), SendToBack() - the element must be in the list! +// +// Iterating: +// MyData* data = MyList.GetFirst(); +// while (!MyList.IsNull(data)) +// { +// . . . +// data = MyList.GetNext(data); +// } +// +// Removing: +// MyData* data = MyList.GetFirst(); +// while (!MyList.IsNull(data)) +// { +// MyData* next = MyList.GetNext(data); +// if (ToBeRemoved(data)) +// MyList.Remove(data); +// data = next; +// } +// + +// List<> represents a doubly-linked list of T, where each T must derive +// from ListNode<B>. B specifies the base class that was directly +// derived from ListNode, and is only necessary if there is an intermediate +// inheritance chain. + +template<class T, class B = T> class List +{ +public: + typedef T ValueType; + + List() + { + Root.pNext = Root.pPrev = &Root; + } + + void Clear() + { + Root.pNext = Root.pPrev = &Root; + } + + size_t GetSize() const + { + size_t n = 0; + + for(const ListNode<B>* pNode = Root.pNext; pNode != &Root; pNode = pNode->pNext) + ++n; + + return n; + } + + const ValueType* GetFirst() const { return IsEmpty() ? nullptr : (const ValueType*)Root.pNext; } + const ValueType* GetLast () const { return IsEmpty() ? nullptr : (const ValueType*)Root.pPrev; } + ValueType* GetFirst() { return IsEmpty() ? nullptr : (ValueType*)Root.pNext; } + ValueType* GetLast () { return IsEmpty() ? nullptr : (ValueType*)Root.pPrev; } + + // Determine if list is empty (i.e.) points to itself. + // Go through void* access to avoid issues with strict-aliasing optimizing out the + // access after RemoveNode(), etc. + bool IsEmpty() const { return Root.pNext == &Root; } + bool IsFirst(const ValueType* p) const { return p == Root.pNext; } + bool IsLast (const ValueType* p) const { return p == Root.pPrev; } + bool IsNull (const ListNode<B>* p) const { return p == nullptr || p == &Root; } + + inline const ValueType* GetPrev(const ValueType* p) const { return IsNull(p->pPrev) ? nullptr : (const ValueType*)p->pPrev; } + inline const ValueType* GetNext(const ValueType* p) const { return IsNull(p->pNext) ? nullptr : (const ValueType*)p->pNext; } + inline ValueType* GetPrev( ValueType* p) { return IsNull(p->pPrev) ? nullptr : (ValueType*)p->pPrev; } + inline ValueType* GetNext( ValueType* p) { return IsNull(p->pNext) ? nullptr : (ValueType*)p->pNext; } + + void PushFront(ValueType* p) + { + p->pNext = Root.pNext; + p->pPrev = &Root; + Root.pNext->pPrev = p; + Root.pNext = p; + } + + void PushBack(ValueType* p) + { + p->pPrev = Root.pPrev; + p->pNext = &Root; + Root.pPrev->pNext = p; + Root.pPrev = p; + } + + static void Remove(ValueType* p) + { + p->pPrev->pNext = p->pNext; + p->pNext->pPrev = p->pPrev; + p->pPrev = nullptr; + p->pNext = nullptr; + } + + void BringToFront(ValueType* p) + { + Remove(p); + PushFront(p); + } + + void SendToBack(ValueType* p) + { + Remove(p); + PushBack(p); + } + + // Appends the contents of the argument list to the front of this list; + // items are removed from the argument list. + void PushListToFront(List<T>& src) + { + if (!src.IsEmpty()) + { + ValueType* pfirst = src.GetFirst(); + ValueType* plast = src.GetLast(); + src.Clear(); + plast->pNext = Root.pNext; + pfirst->pPrev = &Root; + Root.pNext->pPrev = plast; + Root.pNext = pfirst; + } + } + + void PushListToBack(List<T>& src) + { + if (!src.IsEmpty()) + { + ValueType* pfirst = src.GetFirst(); + ValueType* plast = src.GetLast(); + src.Clear(); + plast->pNext = &Root; + pfirst->pPrev = Root.pPrev; + Root.pPrev->pNext = pfirst; + Root.pPrev = plast; + } + } + + // Removes all source list items after (and including) the 'pfirst' node from the + // source list and adds them to out list. + void PushFollowingListItemsToFront(List<T>& src, ValueType *pfirst) + { + if (pfirst != &src.Root) + { + ValueType *plast = src.Root.pPrev; + + // Remove list remainder from source. + pfirst->pPrev->pNext = &src.Root; + src.Root.pPrev = pfirst->pPrev; + // Add the rest of the items to list. + plast->pNext = Root.pNext; + pfirst->pPrev = &Root; + Root.pNext->pPrev = plast; + Root.pNext = pfirst; + } + } + + // Removes all source list items up to but NOT including the 'pend' node from the + // source list and adds them to out list. + void PushPrecedingListItemsToFront(List<T>& src, ValueType *ptail) + { + if (src.GetFirst() != ptail) + { + ValueType *pfirst = src.Root.pNext; + ValueType *plast = ptail->pPrev; + + // Remove list remainder from source. + ptail->pPrev = &src.Root; + src.Root.pNext = ptail; + + // Add the rest of the items to list. + plast->pNext = Root.pNext; + pfirst->pPrev = &Root; + Root.pNext->pPrev = plast; + Root.pNext = pfirst; + } + } + + + // Removes a range of source list items starting at 'pfirst' and up to, but not including 'pend', + // and adds them to out list. Note that source items MUST already be in the list. + void PushListItemsToFront(ValueType *pfirst, ValueType *pend) + { + if (pfirst != pend) + { + ValueType *plast = pend->pPrev; + + // Remove list remainder from source. + pfirst->pPrev->pNext = pend; + pend->pPrev = pfirst->pPrev; + // Add the rest of the items to list. + plast->pNext = Root.pNext; + pfirst->pPrev = &Root; + Root.pNext->pPrev = plast; + Root.pNext = pfirst; + } + } + + + void Alloc_MoveTo(List<T>* pdest) + { + if (IsEmpty()) + pdest->Clear(); + else + { + pdest->Root.pNext = Root.pNext; + pdest->Root.pPrev = Root.pPrev; + + Root.pNext->pPrev = &pdest->Root; + Root.pPrev->pNext = &pdest->Root; + } + } + + +private: + // Copying is prohibited + List(const List<T>&); + const List<T>& operator = (const List<T>&); + + ListNode<B> Root; +}; + + +//------------------------------------------------------------------------ +// ***** FreeListElements +// +// Remove all elements in the list and free them in the allocator + +template<class List, class Allocator> +void FreeListElements(List& list, Allocator& allocator) +{ + typename List::ValueType* self = list.GetFirst(); + while(!list.IsNull(self)) + { + typename List::ValueType* next = list.GetNext(self); + allocator.Free(self); + self = next; + } + list.Clear(); +} + +} // OVR + +#endif |