| /* |
| * Copyright 2011 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef SkTArray_DEFINED |
| #define SkTArray_DEFINED |
| |
| #include "../private/SkTLogic.h" |
| #include "../private/SkTemplates.h" |
| #include "SkTypes.h" |
| |
| #include <new> |
| #include <utility> |
| |
| /** When MEM_COPY is true T will be bit copied when moved. |
| When MEM_COPY is false, T will be copy constructed / destructed. |
| In all cases T will be default-initialized on allocation, |
| and its destructor will be called from this object's destructor. |
| */ |
| template <typename T, bool MEM_COPY = false> class SkTArray { |
| public: |
| /** |
| * Creates an empty array with no initial storage |
| */ |
| SkTArray() { |
| fCount = 0; |
| fReserveCount = gMIN_ALLOC_COUNT; |
| fAllocCount = 0; |
| fMemArray = NULL; |
| fPreAllocMemArray = NULL; |
| } |
| |
| /** |
| * Creates an empty array that will preallocate space for reserveCount |
| * elements. |
| */ |
| explicit SkTArray(int reserveCount) { |
| this->init(0, NULL, reserveCount); |
| } |
| |
| /** |
| * Copies one array to another. The new array will be heap allocated. |
| */ |
| explicit SkTArray(const SkTArray& that) { |
| this->init(that.fCount, NULL, 0); |
| this->copy(that.fItemArray); |
| } |
| explicit SkTArray(SkTArray&& that) { |
| this->init(that.fCount, NULL, 0); |
| that.move(fMemArray); |
| that.fCount = 0; |
| } |
| |
| /** |
| * Creates a SkTArray by copying contents of a standard C array. The new |
| * array will be heap allocated. Be careful not to use this constructor |
| * when you really want the (void*, int) version. |
| */ |
| SkTArray(const T* array, int count) { |
| this->init(count, NULL, 0); |
| this->copy(array); |
| } |
| |
| /** |
| * assign copy of array to this |
| */ |
| SkTArray& operator =(const SkTArray& that) { |
| for (int i = 0; i < fCount; ++i) { |
| fItemArray[i].~T(); |
| } |
| fCount = 0; |
| this->checkRealloc(that.count()); |
| fCount = that.count(); |
| this->copy(that.fItemArray); |
| return *this; |
| } |
| SkTArray& operator =(SkTArray&& that) { |
| for (int i = 0; i < fCount; ++i) { |
| fItemArray[i].~T(); |
| } |
| fCount = 0; |
| this->checkRealloc(that.count()); |
| fCount = that.count(); |
| that.move(fMemArray); |
| that.fCount = 0; |
| return *this; |
| } |
| |
| ~SkTArray() { |
| for (int i = 0; i < fCount; ++i) { |
| fItemArray[i].~T(); |
| } |
| if (fMemArray != fPreAllocMemArray) { |
| sk_free(fMemArray); |
| } |
| } |
| |
| /** |
| * Resets to count() == 0 |
| */ |
| void reset() { this->pop_back_n(fCount); } |
| |
| /** |
| * Resets to count() = n newly constructed T objects. |
| */ |
| void reset(int n) { |
| SkASSERT(n >= 0); |
| for (int i = 0; i < fCount; ++i) { |
| fItemArray[i].~T(); |
| } |
| // Set fCount to 0 before calling checkRealloc so that no elements are moved. |
| fCount = 0; |
| this->checkRealloc(n); |
| fCount = n; |
| for (int i = 0; i < fCount; ++i) { |
| new (fItemArray + i) T; |
| } |
| } |
| |
| /** |
| * Ensures there is enough reserved space for n elements. |
| */ |
| void reserve(int n) { |
| if (fCount < n) { |
| this->checkRealloc(n - fCount); |
| } |
| } |
| |
| /** |
| * Resets to a copy of a C array. |
| */ |
| void reset(const T* array, int count) { |
| for (int i = 0; i < fCount; ++i) { |
| fItemArray[i].~T(); |
| } |
| fCount = 0; |
| this->checkRealloc(count); |
| fCount = count; |
| this->copy(array); |
| } |
| |
| void removeShuffle(int n) { |
| SkASSERT(n < fCount); |
| int newCount = fCount - 1; |
| fCount = newCount; |
| fItemArray[n].~T(); |
| if (n != newCount) { |
| this->move(n, newCount); |
| } |
| } |
| |
| /** |
| * Number of elements in the array. |
| */ |
| int count() const { return fCount; } |
| |
| /** |
| * Is the array empty. |
| */ |
| bool empty() const { return !fCount; } |
| |
| /** |
| * Adds 1 new default-initialized T value and returns it by reference. Note |
| * the reference only remains valid until the next call that adds or removes |
| * elements. |
| */ |
| T& push_back() { |
| void* newT = this->push_back_raw(1); |
| return *new (newT) T; |
| } |
| |
| /** |
| * Version of above that uses a copy constructor to initialize the new item |
| */ |
| T& push_back(const T& t) { |
| void* newT = this->push_back_raw(1); |
| return *new (newT) T(t); |
| } |
| |
| /** |
| * Version of above that uses a move constructor to initialize the new item |
| */ |
| T& push_back(T&& t) { |
| void* newT = this->push_back_raw(1); |
| return *new (newT) T(std::move(t)); |
| } |
| |
| /** |
| * Construct a new T at the back of this array. |
| */ |
| template<class... Args> T& emplace_back(Args&&... args) { |
| void* newT = this->push_back_raw(1); |
| return *new (newT) T(std::forward<Args>(args)...); |
| } |
| |
| /** |
| * Allocates n more default-initialized T values, and returns the address of |
| * the start of that new range. Note: this address is only valid until the |
| * next API call made on the array that might add or remove elements. |
| */ |
| T* push_back_n(int n) { |
| SkASSERT(n >= 0); |
| void* newTs = this->push_back_raw(n); |
| for (int i = 0; i < n; ++i) { |
| new (static_cast<char*>(newTs) + i * sizeof(T)) T; |
| } |
| return static_cast<T*>(newTs); |
| } |
| |
| /** |
| * Version of above that uses a copy constructor to initialize all n items |
| * to the same T. |
| */ |
| T* push_back_n(int n, const T& t) { |
| SkASSERT(n >= 0); |
| void* newTs = this->push_back_raw(n); |
| for (int i = 0; i < n; ++i) { |
| new (static_cast<char*>(newTs) + i * sizeof(T)) T(t); |
| } |
| return static_cast<T*>(newTs); |
| } |
| |
| /** |
| * Version of above that uses a copy constructor to initialize the n items |
| * to separate T values. |
| */ |
| T* push_back_n(int n, const T t[]) { |
| SkASSERT(n >= 0); |
| this->checkRealloc(n); |
| for (int i = 0; i < n; ++i) { |
| new (fItemArray + fCount + i) T(t[i]); |
| } |
| fCount += n; |
| return fItemArray + fCount - n; |
| } |
| |
| /** |
| * Removes the last element. Not safe to call when count() == 0. |
| */ |
| void pop_back() { |
| SkASSERT(fCount > 0); |
| --fCount; |
| fItemArray[fCount].~T(); |
| this->checkRealloc(0); |
| } |
| |
| /** |
| * Removes the last n elements. Not safe to call when count() < n. |
| */ |
| void pop_back_n(int n) { |
| SkASSERT(n >= 0); |
| SkASSERT(fCount >= n); |
| fCount -= n; |
| for (int i = 0; i < n; ++i) { |
| fItemArray[fCount + i].~T(); |
| } |
| this->checkRealloc(0); |
| } |
| |
| /** |
| * Pushes or pops from the back to resize. Pushes will be default |
| * initialized. |
| */ |
| void resize_back(int newCount) { |
| SkASSERT(newCount >= 0); |
| |
| if (newCount > fCount) { |
| this->push_back_n(newCount - fCount); |
| } else if (newCount < fCount) { |
| this->pop_back_n(fCount - newCount); |
| } |
| } |
| |
| /** Swaps the contents of this array with that array. Does a pointer swap if possible, |
| otherwise copies the T values. */ |
| void swap(SkTArray* that) { |
| if (this == that) { |
| return; |
| } |
| if (this->fPreAllocMemArray != this->fItemArray && |
| that->fPreAllocMemArray != that->fItemArray) { |
| // If neither is using a preallocated array then just swap. |
| SkTSwap(fItemArray, that->fItemArray); |
| SkTSwap(fCount, that->fCount); |
| SkTSwap(fAllocCount, that->fAllocCount); |
| } else { |
| // This could be more optimal... |
| SkTArray copy(std::move(*that)); |
| *that = std::move(*this); |
| *this = std::move(copy); |
| } |
| } |
| |
| T* begin() { |
| return fItemArray; |
| } |
| const T* begin() const { |
| return fItemArray; |
| } |
| T* end() { |
| return fItemArray ? fItemArray + fCount : NULL; |
| } |
| const T* end() const { |
| return fItemArray ? fItemArray + fCount : NULL; |
| } |
| |
| /** |
| * Get the i^th element. |
| */ |
| T& operator[] (int i) { |
| SkASSERT(i < fCount); |
| SkASSERT(i >= 0); |
| return fItemArray[i]; |
| } |
| |
| const T& operator[] (int i) const { |
| SkASSERT(i < fCount); |
| SkASSERT(i >= 0); |
| return fItemArray[i]; |
| } |
| |
| /** |
| * equivalent to operator[](0) |
| */ |
| T& front() { SkASSERT(fCount > 0); return fItemArray[0];} |
| |
| const T& front() const { SkASSERT(fCount > 0); return fItemArray[0];} |
| |
| /** |
| * equivalent to operator[](count() - 1) |
| */ |
| T& back() { SkASSERT(fCount); return fItemArray[fCount - 1];} |
| |
| const T& back() const { SkASSERT(fCount > 0); return fItemArray[fCount - 1];} |
| |
| /** |
| * equivalent to operator[](count()-1-i) |
| */ |
| T& fromBack(int i) { |
| SkASSERT(i >= 0); |
| SkASSERT(i < fCount); |
| return fItemArray[fCount - i - 1]; |
| } |
| |
| const T& fromBack(int i) const { |
| SkASSERT(i >= 0); |
| SkASSERT(i < fCount); |
| return fItemArray[fCount - i - 1]; |
| } |
| |
| bool operator==(const SkTArray<T, MEM_COPY>& right) const { |
| int leftCount = this->count(); |
| if (leftCount != right.count()) { |
| return false; |
| } |
| for (int index = 0; index < leftCount; ++index) { |
| if (fItemArray[index] != right.fItemArray[index]) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| bool operator!=(const SkTArray<T, MEM_COPY>& right) const { |
| return !(*this == right); |
| } |
| |
| protected: |
| /** |
| * Creates an empty array that will use the passed storage block until it |
| * is insufficiently large to hold the entire array. |
| */ |
| template <int N> |
| SkTArray(SkAlignedSTStorage<N,T>* storage) { |
| this->init(0, storage->get(), N); |
| } |
| |
| /** |
| * Copy another array, using preallocated storage if preAllocCount >= |
| * array.count(). Otherwise storage will only be used when array shrinks |
| * to fit. |
| */ |
| template <int N> |
| SkTArray(const SkTArray& array, SkAlignedSTStorage<N,T>* storage) { |
| this->init(array.fCount, storage->get(), N); |
| this->copy(array.fItemArray); |
| } |
| |
| /** |
| * Copy a C array, using preallocated storage if preAllocCount >= |
| * count. Otherwise storage will only be used when array shrinks |
| * to fit. |
| */ |
| template <int N> |
| SkTArray(const T* array, int count, SkAlignedSTStorage<N,T>* storage) { |
| this->init(count, storage->get(), N); |
| this->copy(array); |
| } |
| |
| void init(int count, void* preAllocStorage, int preAllocOrReserveCount) { |
| SkASSERT(count >= 0); |
| SkASSERT(preAllocOrReserveCount >= 0); |
| fCount = count; |
| fReserveCount = (preAllocOrReserveCount > 0) ? |
| preAllocOrReserveCount : |
| gMIN_ALLOC_COUNT; |
| fPreAllocMemArray = preAllocStorage; |
| if (fReserveCount >= fCount && |
| preAllocStorage) { |
| fAllocCount = fReserveCount; |
| fMemArray = preAllocStorage; |
| } else { |
| fAllocCount = SkMax32(fCount, fReserveCount); |
| fMemArray = sk_malloc_throw(fAllocCount * sizeof(T)); |
| } |
| } |
| |
| private: |
| /** In the following move and copy methods, 'dst' is assumed to be uninitialized raw storage. |
| * In the following move methods, 'src' is destroyed leaving behind uninitialized raw storage. |
| */ |
| template <bool E = MEM_COPY> SK_WHEN(E, void) copy(const T* src) { |
| sk_careful_memcpy(fMemArray, src, fCount * sizeof(T)); |
| } |
| template <bool E = MEM_COPY> SK_WHEN(E, void) move(int dst, int src) { |
| memcpy(&fItemArray[dst], &fItemArray[src], sizeof(T)); |
| } |
| template <bool E = MEM_COPY> SK_WHEN(E, void) move(void* dst) { |
| sk_careful_memcpy(dst, fMemArray, fCount * sizeof(T)); |
| } |
| |
| template <bool E = MEM_COPY> SK_WHEN(!E, void) copy(const T* src) { |
| for (int i = 0; i < fCount; ++i) { |
| new (fItemArray + i) T(src[i]); |
| } |
| } |
| template <bool E = MEM_COPY> SK_WHEN(!E, void) move(int dst, int src) { |
| new (&fItemArray[dst]) T(std::move(fItemArray[src])); |
| fItemArray[src].~T(); |
| } |
| template <bool E = MEM_COPY> SK_WHEN(!E, void) move(void* dst) { |
| for (int i = 0; i < fCount; ++i) { |
| new (static_cast<char*>(dst) + sizeof(T) * i) T(std::move(fItemArray[i])); |
| fItemArray[i].~T(); |
| } |
| } |
| |
| static const int gMIN_ALLOC_COUNT = 8; |
| |
| // Helper function that makes space for n objects, adjusts the count, but does not initialize |
| // the new objects. |
| void* push_back_raw(int n) { |
| this->checkRealloc(n); |
| void* ptr = fItemArray + fCount; |
| fCount += n; |
| return ptr; |
| } |
| |
| inline void checkRealloc(int delta) { |
| SkASSERT(fCount >= 0); |
| SkASSERT(fAllocCount >= 0); |
| |
| SkASSERT(-delta <= fCount); |
| |
| int newCount = fCount + delta; |
| int newAllocCount = fAllocCount; |
| |
| if (newCount > fAllocCount || newCount < (fAllocCount / 3)) { |
| // whether we're growing or shrinking, we leave at least 50% extra space for future |
| // growth (clamped to the reserve count). |
| newAllocCount = SkMax32(newCount + ((newCount + 1) >> 1), fReserveCount); |
| } |
| if (newAllocCount != fAllocCount) { |
| |
| fAllocCount = newAllocCount; |
| void* newMemArray; |
| |
| if (fAllocCount == fReserveCount && fPreAllocMemArray) { |
| newMemArray = fPreAllocMemArray; |
| } else { |
| newMemArray = sk_malloc_throw(fAllocCount*sizeof(T)); |
| } |
| |
| this->move(newMemArray); |
| |
| if (fMemArray != fPreAllocMemArray) { |
| sk_free(fMemArray); |
| } |
| fMemArray = newMemArray; |
| } |
| } |
| |
| int fReserveCount; |
| int fCount; |
| int fAllocCount; |
| void* fPreAllocMemArray; |
| union { |
| T* fItemArray; |
| void* fMemArray; |
| }; |
| }; |
| |
| /** |
| * Subclass of SkTArray that contains a preallocated memory block for the array. |
| */ |
| template <int N, typename T, bool MEM_COPY = false> |
| class SkSTArray : public SkTArray<T, MEM_COPY> { |
| private: |
| typedef SkTArray<T, MEM_COPY> INHERITED; |
| |
| public: |
| SkSTArray() : INHERITED(&fStorage) { |
| } |
| |
| SkSTArray(const SkSTArray& array) |
| : INHERITED(array, &fStorage) { |
| } |
| |
| explicit SkSTArray(const INHERITED& array) |
| : INHERITED(array, &fStorage) { |
| } |
| |
| explicit SkSTArray(int reserveCount) |
| : INHERITED(reserveCount) { |
| } |
| |
| SkSTArray(const T* array, int count) |
| : INHERITED(array, count, &fStorage) { |
| } |
| |
| SkSTArray& operator= (const SkSTArray& array) { |
| return *this = *(const INHERITED*)&array; |
| } |
| |
| SkSTArray& operator= (const INHERITED& array) { |
| INHERITED::operator=(array); |
| return *this; |
| } |
| |
| private: |
| SkAlignedSTStorage<N,T> fStorage; |
| }; |
| |
| #endif |