| /* |
| * Copyright 2012 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef SkTLList_DEFINED |
| #define SkTLList_DEFINED |
| |
| #include "SkTInternalLList.h" |
| #include "SkTemplates.h" |
| |
| template <typename T> class SkTLList; |
| template <typename T> |
| inline void* operator new(size_t, SkTLList<T>* list, |
| typename SkTLList<T>::Placement placement, |
| const typename SkTLList<T>::Iter& location); |
| |
| /** Doubly-linked list of objects. The objects' lifetimes are controlled by the list. I.e. the |
| the list creates the objects and they are deleted upon removal. This class block-allocates |
| space for entries based on a param passed to the constructor. |
| |
| Elements of the list can be constructed in place using the following macros: |
| SkNEW_INSERT_IN_LLIST_BEFORE(list, location, type_name, args) |
| SkNEW_INSERT_IN_LLIST_AFTER(list, location, type_name, args) |
| where list is a SkTLList<type_name>*, location is an iterator, and args is the paren-surrounded |
| constructor arguments for type_name. These macros behave like addBefore() and addAfter(). |
| */ |
| template <typename T> |
| class SkTLList : public SkNoncopyable { |
| private: |
| struct Block; |
| struct Node { |
| char fObj[sizeof(T)]; |
| SK_DECLARE_INTERNAL_LLIST_INTERFACE(Node); |
| Block* fBlock; // owning block. |
| }; |
| typedef SkTInternalLList<Node> NodeList; |
| |
| public: |
| |
| class Iter; |
| |
| /** allocCnt is the number of objects to allocate as a group. In the worst case fragmentation |
| each object is using the space required for allocCnt unfragmented objects. */ |
| SkTLList(int allocCnt = 1) : fCount(0), fAllocCnt(allocCnt) { |
| SkASSERT(allocCnt > 0); |
| this->validate(); |
| } |
| |
| ~SkTLList() { |
| this->validate(); |
| typename NodeList::Iter iter; |
| Node* node = iter.init(fList, Iter::kHead_IterStart); |
| while (NULL != node) { |
| SkTCast<T*>(node->fObj)->~T(); |
| Block* block = node->fBlock; |
| node = iter.next(); |
| if (0 == --block->fNodesInUse) { |
| for (int i = 0; i < fAllocCnt; ++i) { |
| block->fNodes[i].~Node(); |
| } |
| sk_free(block); |
| } |
| } |
| } |
| |
| T* addToHead(const T& t) { |
| this->validate(); |
| Node* node = this->createNode(); |
| fList.addToHead(node); |
| SkNEW_PLACEMENT_ARGS(node->fObj, T, (t)); |
| this->validate(); |
| return reinterpret_cast<T*>(node->fObj); |
| } |
| |
| T* addToTail(const T& t) { |
| this->validate(); |
| Node* node = this->createNode(); |
| fList.addToTail(node); |
| SkNEW_PLACEMENT_ARGS(node->fObj, T, (t)); |
| this->validate(); |
| return reinterpret_cast<T*>(node->fObj); |
| } |
| |
| /** Adds a new element to the list before the location indicated by the iterator. If the |
| iterator refers to a NULL location then the new element is added at the tail */ |
| T* addBefore(const T& t, const Iter& location) { |
| return SkNEW_PLACEMENT_ARGS(this->internalAddBefore(location), T, (t)); |
| } |
| |
| /** Adds a new element to the list after the location indicated by the iterator. If the |
| iterator refers to a NULL location then the new element is added at the head */ |
| T* addAfter(const T& t, const Iter& location) { |
| return SkNEW_PLACEMENT_ARGS(this->internalAddAfter(location), T, (t)); |
| } |
| |
| /** Convenience methods for getting an iterator initialized to the head/tail of the list. */ |
| Iter headIter() const { return Iter(*this, Iter::kHead_IterStart); } |
| Iter tailIter() const { return Iter(*this, Iter::kTail_IterStart); } |
| |
| T* head() { return Iter(*this, Iter::kHead_IterStart).get(); } |
| T* tail() { return Iter(*this, Iter::kTail_IterStart).get(); } |
| const T* head() const { return Iter(*this, Iter::kHead_IterStart).get(); } |
| const T* tail() const { return Iter(*this, Iter::kTail_IterStart).get(); } |
| |
| void popHead() { |
| this->validate(); |
| Node* node = fList.head(); |
| if (NULL != node) { |
| this->removeNode(node); |
| } |
| this->validate(); |
| } |
| |
| void popTail() { |
| this->validate(); |
| Node* node = fList.head(); |
| if (NULL != node) { |
| this->removeNode(node); |
| } |
| this->validate(); |
| } |
| |
| void remove(T* t) { |
| this->validate(); |
| Node* node = reinterpret_cast<Node*>(t); |
| SkASSERT(reinterpret_cast<T*>(node->fObj) == t); |
| this->removeNode(node); |
| this->validate(); |
| } |
| |
| void reset() { |
| this->validate(); |
| Iter iter(*this, Iter::kHead_IterStart); |
| while (iter.get()) { |
| Iter next = iter; |
| next.next(); |
| this->remove(iter.get()); |
| iter = next; |
| } |
| SkASSERT(0 == fCount); |
| this->validate(); |
| } |
| |
| int count() const { return fCount; } |
| bool isEmpty() const { this->validate(); return 0 == fCount; } |
| |
| bool operator== (const SkTLList& list) const { |
| if (this == &list) { |
| return true; |
| } |
| if (fCount != list.fCount) { |
| return false; |
| } |
| for (Iter a(*this, Iter::kHead_IterStart), b(list, Iter::kHead_IterStart); |
| a.get(); |
| a.next(), b.next()) { |
| SkASSERT(NULL != b.get()); // already checked that counts match. |
| if (!(*a.get() == *b.get())) { |
| return false; |
| } |
| } |
| return true; |
| } |
| bool operator!= (const SkTLList& list) const { return !(*this == list); } |
| |
| /** The iterator becomes invalid if the element it refers to is removed from the list. */ |
| class Iter : private NodeList::Iter { |
| private: |
| typedef typename NodeList::Iter INHERITED; |
| |
| public: |
| typedef typename INHERITED::IterStart IterStart; |
| //!< Start the iterator at the head of the list. |
| static const IterStart kHead_IterStart = INHERITED::kHead_IterStart; |
| //!< Start the iterator at the tail of the list. |
| static const IterStart kTail_IterStart = INHERITED::kTail_IterStart; |
| |
| Iter() {} |
| |
| Iter(const SkTLList& list, IterStart start) { |
| INHERITED::init(list.fList, start); |
| } |
| |
| T* init(const SkTLList& list, IterStart start) { |
| return this->nodeToObj(INHERITED::init(list.fList, start)); |
| } |
| |
| T* get() { return this->nodeToObj(INHERITED::get()); } |
| |
| T* next() { return this->nodeToObj(INHERITED::next()); } |
| |
| T* prev() { return this->nodeToObj(INHERITED::prev()); } |
| |
| Iter& operator= (const Iter& iter) { INHERITED::operator=(iter); return *this; } |
| |
| private: |
| friend class SkTLList; |
| Node* getNode() { return INHERITED::get(); } |
| |
| T* nodeToObj(Node* node) { |
| if (NULL != node) { |
| return reinterpret_cast<T*>(node->fObj); |
| } else { |
| return NULL; |
| } |
| } |
| }; |
| |
| // For use with operator new |
| enum Placement { |
| kBefore_Placement, |
| kAfter_Placement, |
| }; |
| |
| private: |
| struct Block { |
| int fNodesInUse; |
| Node fNodes[1]; |
| }; |
| |
| size_t blockSize() const { return sizeof(Block) + sizeof(Node) * (fAllocCnt-1); } |
| |
| Node* createNode() { |
| Node* node = fFreeList.head(); |
| if (NULL != node) { |
| fFreeList.remove(node); |
| ++node->fBlock->fNodesInUse; |
| } else { |
| Block* block = reinterpret_cast<Block*>(sk_malloc_flags(this->blockSize(), 0)); |
| node = &block->fNodes[0]; |
| SkNEW_PLACEMENT(node, Node); |
| node->fBlock = block; |
| block->fNodesInUse = 1; |
| for (int i = 1; i < fAllocCnt; ++i) { |
| SkNEW_PLACEMENT(block->fNodes + i, Node); |
| fFreeList.addToHead(block->fNodes + i); |
| block->fNodes[i].fBlock = block; |
| } |
| } |
| ++fCount; |
| return node; |
| } |
| |
| void removeNode(Node* node) { |
| SkASSERT(NULL != node); |
| fList.remove(node); |
| SkTCast<T*>(node->fObj)->~T(); |
| if (0 == --node->fBlock->fNodesInUse) { |
| Block* block = node->fBlock; |
| for (int i = 0; i < fAllocCnt; ++i) { |
| if (block->fNodes + i != node) { |
| fFreeList.remove(block->fNodes + i); |
| } |
| block->fNodes[i].~Node(); |
| } |
| sk_free(block); |
| } else { |
| fFreeList.addToHead(node); |
| } |
| --fCount; |
| this->validate(); |
| } |
| |
| void validate() const { |
| #ifdef SK_DEBUG |
| SkASSERT((0 == fCount) == fList.isEmpty()); |
| SkASSERT((0 != fCount) || fFreeList.isEmpty()); |
| |
| fList.validate(); |
| fFreeList.validate(); |
| typename NodeList::Iter iter; |
| Node* freeNode = iter.init(fFreeList, Iter::kHead_IterStart); |
| while (freeNode) { |
| SkASSERT(fFreeList.isInList(freeNode)); |
| Block* block = freeNode->fBlock; |
| SkASSERT(block->fNodesInUse > 0 && block->fNodesInUse < fAllocCnt); |
| |
| int activeCnt = 0; |
| int freeCnt = 0; |
| for (int i = 0; i < fAllocCnt; ++i) { |
| bool free = fFreeList.isInList(block->fNodes + i); |
| bool active = fList.isInList(block->fNodes + i); |
| SkASSERT(free != active); |
| activeCnt += active; |
| freeCnt += free; |
| } |
| SkASSERT(activeCnt == block->fNodesInUse); |
| freeNode = iter.next(); |
| } |
| |
| int count = 0; |
| Node* activeNode = iter.init(fList, Iter::kHead_IterStart); |
| while (activeNode) { |
| ++count; |
| SkASSERT(fList.isInList(activeNode)); |
| Block* block = activeNode->fBlock; |
| SkASSERT(block->fNodesInUse > 0 && block->fNodesInUse <= fAllocCnt); |
| |
| int activeCnt = 0; |
| int freeCnt = 0; |
| for (int i = 0; i < fAllocCnt; ++i) { |
| bool free = fFreeList.isInList(block->fNodes + i); |
| bool active = fList.isInList(block->fNodes + i); |
| SkASSERT(free != active); |
| activeCnt += active; |
| freeCnt += free; |
| } |
| SkASSERT(activeCnt == block->fNodesInUse); |
| activeNode = iter.next(); |
| } |
| SkASSERT(count == fCount); |
| #endif |
| } |
| |
| // Support in-place initializing of objects inserted into the list via operator new. |
| friend void* operator new<T>(size_t, |
| SkTLList* list, |
| Placement placement, |
| const Iter& location); |
| |
| |
| // Helpers that insert the node and returns a pointer to where the new object should be init'ed. |
| void* internalAddBefore(Iter location) { |
| this->validate(); |
| Node* node = this->createNode(); |
| fList.addBefore(node, location.getNode()); |
| this->validate(); |
| return node->fObj; |
| } |
| |
| void* internalAddAfter(Iter location) { |
| this->validate(); |
| Node* node = this->createNode(); |
| fList.addAfter(node, location.getNode()); |
| this->validate(); |
| return node->fObj; |
| } |
| |
| NodeList fList; |
| NodeList fFreeList; |
| int fCount; |
| int fAllocCnt; |
| |
| }; |
| |
| // Use the below macros rather than calling this directly |
| template <typename T> |
| void *operator new(size_t, SkTLList<T>* list, |
| typename SkTLList<T>::Placement placement, |
| const typename SkTLList<T>::Iter& location) { |
| SkASSERT(NULL != list); |
| if (SkTLList<T>::kBefore_Placement == placement) { |
| return list->internalAddBefore(location); |
| } else { |
| return list->internalAddAfter(location); |
| } |
| } |
| |
| // Skia doesn't use C++ exceptions but it may be compiled with them enabled. Having an op delete |
| // to match the op new silences warnings about missing op delete when a constructor throws an |
| // exception. |
| template <typename T> |
| void operator delete(void*, |
| SkTLList<T>*, |
| typename SkTLList<T>::Placement, |
| const typename SkTLList<T>::Iter&) { |
| SK_CRASH(); |
| } |
| |
| #define SkNEW_INSERT_IN_LLIST_BEFORE(list, location, type_name, args) \ |
| (new ((list), SkTLList< type_name >::kBefore_Placement, (location)) type_name args) |
| |
| #define SkNEW_INSERT_IN_LLIST_AFTER(list, location, type_name, args) \ |
| (new ((list), SkTLList< type_name >::kAfter_Placement, (location)) type_name args) |
| |
| #define SkNEW_INSERT_AT_LLIST_HEAD(list, type_name, args) \ |
| SkNEW_INSERT_IN_LLIST_BEFORE((list), (list)->headIter(), type_name, args) |
| |
| #define SkNEW_INSERT_AT_LLIST_TAIL(list, type_name, args) \ |
| SkNEW_INSERT_IN_LLIST_AFTER((list), (list)->tailIter(), type_name, args) |
| |
| #endif |