// Copyright (C) 2002-2011 Nikolaus Gebhardt // This file is part of the "Irrlicht Engine" and the "irrXML" project. // For conditions of distribution and use, see copyright notice in irrlicht.h and irrXML.h #ifndef __IRR_ARRAY_H_INCLUDED__ #define __IRR_ARRAY_H_INCLUDED__ #include "irrTypes.h" #include "heapsort.h" #include "irrAllocator.h" #include "irrMath.h" namespace irr { namespace core { //! Self reallocating template array (like stl vector) with additional features. /** Some features are: Heap sorting, binary search methods, easier debugging. */ template <class T, typename TAlloc = irrAllocator<T> > class array { public: //! Default constructor for empty array. array() : data(0), allocated(0), used(0), strategy(ALLOC_STRATEGY_DOUBLE), free_when_destroyed(true), is_sorted(true) { } //! Constructs an array and allocates an initial chunk of memory. /** \param start_count Amount of elements to pre-allocate. */ array(u32 start_count) : data(0), allocated(0), used(0), strategy(ALLOC_STRATEGY_DOUBLE), free_when_destroyed(true), is_sorted(true) { reallocate(start_count); } //! Copy constructor array(const array<T, TAlloc>& other) : data(0) { *this = other; } //! Destructor. /** Frees allocated memory, if set_free_when_destroyed was not set to false by the user before. */ ~array() { clear(); } //! Reallocates the array, make it bigger or smaller. /** \param new_size New size of array. */ void reallocate(u32 new_size) { T* old_data = data; data = allocator.allocate(new_size); //new T[new_size]; allocated = new_size; // copy old data s32 end = used < new_size ? used : new_size; for (s32 i=0; i<end; ++i) { // data[i] = old_data[i]; allocator.construct(&data[i], old_data[i]); } // destruct old data for (u32 j=0; j<used; ++j) allocator.destruct(&old_data[j]); if (allocated < used) used = allocated; allocator.deallocate(old_data); //delete [] old_data; } //! set a new allocation strategy /** if the maximum size of the array is unknown, you can define how big the allocation should happen. \param newStrategy New strategy to apply to this array. */ void setAllocStrategy ( eAllocStrategy newStrategy = ALLOC_STRATEGY_DOUBLE ) { strategy = newStrategy; } //! Adds an element at back of array. /** If the array is too small to add this new element it is made bigger. \param element: Element to add at the back of the array. */ void push_back(const T& element) { insert(element, used); } //! Adds an element at the front of the array. /** If the array is to small to add this new element, the array is made bigger. Please note that this is slow, because the whole array needs to be copied for this. \param element Element to add at the back of the array. */ void push_front(const T& element) { insert(element); } //! Insert item into array at specified position. /** Please use this only if you know what you are doing (possible performance loss). The preferred method of adding elements should be push_back(). \param element: Element to be inserted \param index: Where position to insert the new element. */ void insert(const T& element, u32 index=0) { _IRR_DEBUG_BREAK_IF(index>used) // access violation if (used + 1 > allocated) { // this doesn't work if the element is in the same // array. So we'll copy the element first to be sure // we'll get no data corruption const T e(element); // increase data block u32 newAlloc; switch ( strategy ) { case ALLOC_STRATEGY_DOUBLE: newAlloc = used + 1 + (allocated < 500 ? (allocated < 5 ? 5 : used) : used >> 2); break; default: case ALLOC_STRATEGY_SAFE: newAlloc = used + 1; break; } reallocate( newAlloc); // move array content and construct new element // first move end one up for (u32 i=used; i>index; --i) { if (i<used) allocator.destruct(&data[i]); allocator.construct(&data[i], data[i-1]); // data[i] = data[i-1]; } // then add new element if (used > index) allocator.destruct(&data[index]); allocator.construct(&data[index], e); // data[index] = e; } else { // element inserted not at end if ( used > index ) { // create one new element at the end allocator.construct(&data[used], data[used-1]); // move the rest of the array content for (u32 i=used-1; i>index; --i) { data[i] = data[i-1]; } // insert the new element data[index] = element; } else { // insert the new element to the end allocator.construct(&data[index], element); } } // set to false as we don't know if we have the comparison operators is_sorted = false; ++used; } //! Clears the array and deletes all allocated memory. void clear() { if (free_when_destroyed) { for (u32 i=0; i<used; ++i) allocator.destruct(&data[i]); allocator.deallocate(data); // delete [] data; } data = 0; used = 0; allocated = 0; is_sorted = true; } //! Sets pointer to new array, using this as new workspace. /** Make sure that set_free_when_destroyed is used properly. \param newPointer: Pointer to new array of elements. \param size: Size of the new array. \param _is_sorted Flag which tells whether the new array is already sorted. \param _free_when_destroyed Sets whether the new memory area shall be freed by the array upon destruction, or if this will be up to the user application. */ void set_pointer(T* newPointer, u32 size, bool _is_sorted=false, bool _free_when_destroyed=true) { clear(); data = newPointer; allocated = size; used = size; is_sorted = _is_sorted; free_when_destroyed=_free_when_destroyed; } //! Sets if the array should delete the memory it uses upon destruction. /** Also clear and set_pointer will only delete the (original) memory area if this flag is set to true, which is also the default. The methods reallocate, set_used, push_back, push_front, insert, and erase will still try to deallocate the original memory, which might cause troubles depending on the intended use of the memory area. \param f If true, the array frees the allocated memory in its destructor, otherwise not. The default is true. */ void set_free_when_destroyed(bool f) { free_when_destroyed = f; } //! Sets the size of the array and allocates new elements if necessary. /** Please note: This is only secure when using it with simple types, because no default constructor will be called for the added elements. \param usedNow Amount of elements now used. */ void set_used(u32 usedNow) { if (allocated < usedNow) reallocate(usedNow); used = usedNow; } //! Assignment operator const array<T, TAlloc>& operator=(const array<T, TAlloc>& other) { if (this == &other) return *this; strategy = other.strategy; if (data) clear(); //if (allocated < other.allocated) if (other.allocated == 0) data = 0; else data = allocator.allocate(other.allocated); // new T[other.allocated]; used = other.used; free_when_destroyed = true; is_sorted = other.is_sorted; allocated = other.allocated; for (u32 i=0; i<other.used; ++i) allocator.construct(&data[i], other.data[i]); // data[i] = other.data[i]; return *this; } //! Equality operator bool operator == (const array<T, TAlloc>& other) const { if (used != other.used) return false; for (u32 i=0; i<other.used; ++i) if (data[i] != other[i]) return false; return true; } //! Inequality operator bool operator != (const array<T, TAlloc>& other) const { return !(*this==other); } //! Direct access operator T& operator [](u32 index) { _IRR_DEBUG_BREAK_IF(index>=used) // access violation return data[index]; } //! Direct const access operator const T& operator [](u32 index) const { _IRR_DEBUG_BREAK_IF(index>=used) // access violation return data[index]; } //! Gets last element. T& getLast() { _IRR_DEBUG_BREAK_IF(!used) // access violation return data[used-1]; } //! Gets last element const T& getLast() const { _IRR_DEBUG_BREAK_IF(!used) // access violation return data[used-1]; } //! Gets a pointer to the array. /** \return Pointer to the array. */ T* pointer() { return data; } //! Gets a const pointer to the array. /** \return Pointer to the array. */ const T* const_pointer() const { return data; } //! Get number of occupied elements of the array. /** \return Size of elements in the array which are actually occupied. */ u32 size() const { return used; } //! Get amount of memory allocated. /** \return Amount of memory allocated. The amount of bytes allocated would be allocated_size() * sizeof(ElementTypeUsed); */ u32 allocated_size() const { return allocated; } //! Check if array is empty. /** \return True if the array is empty false if not. */ bool empty() const { return used == 0; } //! Sorts the array using heapsort. /** There is no additional memory waste and the algorithm performs O(n*log n) in worst case. */ void sort() { if (!is_sorted && used>1) heapsort(data, used); is_sorted = true; } //! Performs a binary search for an element, returns -1 if not found. /** The array will be sorted before the binary search if it is not already sorted. Caution is advised! Be careful not to call this on unsorted const arrays, or the slower method will be used. \param element Element to search for. \return Position of the searched element if it was found, otherwise -1 is returned. */ s32 binary_search(const T& element) { sort(); return binary_search(element, 0, used-1); } //! Performs a binary search for an element if possible, returns -1 if not found. /** This method is for const arrays and so cannot call sort(), if the array is not sorted then linear_search will be used instead. Potentially very slow! \param element Element to search for. \return Position of the searched element if it was found, otherwise -1 is returned. */ s32 binary_search(const T& element) const { if (is_sorted) return binary_search(element, 0, used-1); else return linear_search(element); } //! Performs a binary search for an element, returns -1 if not found. /** \param element: Element to search for. \param left First left index \param right Last right index. \return Position of the searched element if it was found, otherwise -1 is returned. */ s32 binary_search(const T& element, s32 left, s32 right) const { if (!used) return -1; s32 m; do { m = (left+right)>>1; if (element < data[m]) right = m - 1; else left = m + 1; } while((element < data[m] || data[m] < element) && left<=right); // this last line equals to: // " while((element != array[m]) && left<=right);" // but we only want to use the '<' operator. // the same in next line, it is "(element == array[m])" if (!(element < data[m]) && !(data[m] < element)) return m; return -1; } //! Performs a binary search for an element, returns -1 if not found. //! it is used for searching a multiset /** The array will be sorted before the binary search if it is not already sorted. \param element Element to search for. \param &last return lastIndex of equal elements \return Position of the first searched element if it was found, otherwise -1 is returned. */ s32 binary_search_multi(const T& element, s32 &last) { sort(); s32 index = binary_search(element, 0, used-1); if ( index < 0 ) return index; // The search can be somewhere in the middle of the set // look linear previous and past the index last = index; while ( index > 0 && !(element < data[index - 1]) && !(data[index - 1] < element) ) { index -= 1; } // look linear up while ( last < (s32) used - 1 && !(element < data[last + 1]) && !(data[last + 1] < element) ) { last += 1; } return index; } //! Finds an element in linear time, which is very slow. /** Use binary_search for faster finding. Only works if ==operator is implemented. \param element Element to search for. \return Position of the searched element if it was found, otherwise -1 is returned. */ s32 linear_search(const T& element) const { for (u32 i=0; i<used; ++i) if (element == data[i]) return (s32)i; return -1; } //! Finds an element in linear time, which is very slow. /** Use binary_search for faster finding. Only works if ==operator is implemented. \param element: Element to search for. \return Position of the searched element if it was found, otherwise -1 is returned. */ s32 linear_reverse_search(const T& element) const { for (s32 i=used-1; i>=0; --i) if (data[i] == element) return i; return -1; } //! Erases an element from the array. /** May be slow, because all elements following after the erased element have to be copied. \param index: Index of element to be erased. */ void erase(u32 index) { _IRR_DEBUG_BREAK_IF(index>=used) // access violation for (u32 i=index+1; i<used; ++i) { allocator.destruct(&data[i-1]); allocator.construct(&data[i-1], data[i]); // data[i-1] = data[i]; } allocator.destruct(&data[used-1]); --used; } //! Erases some elements from the array. /** May be slow, because all elements following after the erased element have to be copied. \param index: Index of the first element to be erased. \param count: Amount of elements to be erased. */ void erase(u32 index, s32 count) { if (index>=used || count<1) return; if (index+count>used) count = used-index; u32 i; for (i=index; i<index+count; ++i) allocator.destruct(&data[i]); for (i=index+count; i<used; ++i) { if (i > index+count) allocator.destruct(&data[i-count]); allocator.construct(&data[i-count], data[i]); // data[i-count] = data[i]; if (i >= used-count) allocator.destruct(&data[i]); } used-= count; } //! Sets if the array is sorted void set_sorted(bool _is_sorted) { is_sorted = _is_sorted; } //! Swap the content of this array container with the content of another array /** Afterwards this object will contain the content of the other object and the other object will contain the content of this object. \param other Swap content with this object */ void swap(array<T, TAlloc>& other) { core::swap(data, other.data); core::swap(allocated, other.allocated); core::swap(used, other.used); core::swap(allocator, other.allocator); // memory is still released by the same allocator used for allocation eAllocStrategy helper_strategy(strategy); // can't use core::swap with bitfields strategy = other.strategy; other.strategy = helper_strategy; bool helper_free_when_destroyed(free_when_destroyed); free_when_destroyed = other.free_when_destroyed; other.free_when_destroyed = helper_free_when_destroyed; bool helper_is_sorted(is_sorted); is_sorted = other.is_sorted; other.is_sorted = helper_is_sorted; } private: T* data; u32 allocated; u32 used; TAlloc allocator; eAllocStrategy strategy:4; bool free_when_destroyed:1; bool is_sorted:1; }; } // end namespace core } // end namespace irr #endif
