/*************************************************************************/ /* cowdata.h */ /*************************************************************************/ /* This file is part of: */ /* GODOT ENGINE */ /* https://godotengine.org */ /*************************************************************************/ /* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */ /* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md). */ /* */ /* Permission is hereby granted, free of charge, to any person obtaining */ /* a copy of this software and associated documentation files (the */ /* "Software"), to deal in the Software without restriction, including */ /* without limitation the rights to use, copy, modify, merge, publish, */ /* distribute, sublicense, and/or sell copies of the Software, and to */ /* permit persons to whom the Software is furnished to do so, subject to */ /* the following conditions: */ /* */ /* The above copyright notice and this permission notice shall be */ /* included in all copies or substantial portions of the Software. */ /* */ /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */ /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */ /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/ /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */ /* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */ /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */ /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ /*************************************************************************/ #ifndef COWDATA_H #define COWDATA_H #include "core/error/error_macros.h" #include "core/os/memory.h" #include "core/templates/safe_refcount.h" #include <string.h> #include <type_traits> template <class T> class Vector; class String; class Char16String; class CharString; template <class T, class V> class VMap; SAFE_NUMERIC_TYPE_PUN_GUARANTEES(uint32_t) // Silence a false positive warning (see GH-52119). #if defined(__GNUC__) && !defined(__clang__) #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wplacement-new" #endif template <class T> class CowData { template <class TV> friend class Vector; friend class String; friend class Char16String; friend class CharString; template <class TV, class VV> friend class VMap; private: mutable T *_ptr = nullptr; // internal helpers _FORCE_INLINE_ SafeNumeric<uint32_t> *_get_refcount() const { if (!_ptr) { return nullptr; } return reinterpret_cast<SafeNumeric<uint32_t> *>(_ptr) - 2; } _FORCE_INLINE_ uint32_t *_get_size() const { if (!_ptr) { return nullptr; } return reinterpret_cast<uint32_t *>(_ptr) - 1; } _FORCE_INLINE_ size_t _get_alloc_size(size_t p_elements) const { return next_power_of_2(p_elements * sizeof(T)); } _FORCE_INLINE_ bool _get_alloc_size_checked(size_t p_elements, size_t *out) const { #if defined(__GNUC__) size_t o; size_t p; if (__builtin_mul_overflow(p_elements, sizeof(T), &o)) { *out = 0; return false; } *out = next_power_of_2(o); if (__builtin_add_overflow(o, static_cast<size_t>(32), &p)) { return false; // No longer allocated here. } return true; #else // Speed is more important than correctness here, do the operations unchecked // and hope for the best. *out = _get_alloc_size(p_elements); return true; #endif } void _unref(void *p_data); void _ref(const CowData *p_from); void _ref(const CowData &p_from); uint32_t _copy_on_write(); public: void operator=(const CowData<T> &p_from) { _ref(p_from); } _FORCE_INLINE_ T *ptrw() { _copy_on_write(); return _ptr; } _FORCE_INLINE_ const T *ptr() const { return _ptr; } _FORCE_INLINE_ int size() const { uint32_t *size = (uint32_t *)_get_size(); if (size) { return *size; } else { return 0; } } _FORCE_INLINE_ void clear() { resize(0); } _FORCE_INLINE_ bool is_empty() const { return _ptr == nullptr; } _FORCE_INLINE_ void set(int p_index, const T &p_elem) { ERR_FAIL_INDEX(p_index, size()); _copy_on_write(); _ptr[p_index] = p_elem; } _FORCE_INLINE_ T &get_m(int p_index) { CRASH_BAD_INDEX(p_index, size()); _copy_on_write(); return _ptr[p_index]; } _FORCE_INLINE_ const T &get(int p_index) const { CRASH_BAD_INDEX(p_index, size()); return _ptr[p_index]; } template <bool p_ensure_zero = false> Error resize(int p_size); _FORCE_INLINE_ void remove_at(int p_index) { ERR_FAIL_INDEX(p_index, size()); T *p = ptrw(); int len = size(); for (int i = p_index; i < len - 1; i++) { p[i] = p[i + 1]; } resize(len - 1); } Error insert(int p_pos, const T &p_val) { ERR_FAIL_INDEX_V(p_pos, size() + 1, ERR_INVALID_PARAMETER); resize(size() + 1); for (int i = (size() - 1); i > p_pos; i--) { set(i, get(i - 1)); } set(p_pos, p_val); return OK; } int find(const T &p_val, int p_from = 0) const; int rfind(const T &p_val, int p_from = -1) const; int count(const T &p_val) const; _FORCE_INLINE_ CowData() {} _FORCE_INLINE_ ~CowData(); _FORCE_INLINE_ CowData(CowData<T> &p_from) { _ref(p_from); }; }; template <class T> void CowData<T>::_unref(void *p_data) { if (!p_data) { return; } SafeNumeric<uint32_t> *refc = _get_refcount(); if (refc->decrement() > 0) { return; // still in use } // clean up if (!std::is_trivially_destructible<T>::value) { uint32_t *count = _get_size(); T *data = (T *)(count + 1); for (uint32_t i = 0; i < *count; ++i) { // call destructors data[i].~T(); } } // free mem Memory::free_static((uint8_t *)p_data, true); } template <class T> uint32_t CowData<T>::_copy_on_write() { if (!_ptr) { return 0; } SafeNumeric<uint32_t> *refc = _get_refcount(); uint32_t rc = refc->get(); if (unlikely(rc > 1)) { /* in use by more than me */ uint32_t current_size = *_get_size(); uint32_t *mem_new = (uint32_t *)Memory::alloc_static(_get_alloc_size(current_size), true); new (mem_new - 2) SafeNumeric<uint32_t>(1); //refcount *(mem_new - 1) = current_size; //size T *_data = (T *)(mem_new); // initialize new elements if (std::is_trivially_copyable<T>::value) { memcpy(mem_new, _ptr, current_size * sizeof(T)); } else { for (uint32_t i = 0; i < current_size; i++) { memnew_placement(&_data[i], T(_ptr[i])); } } _unref(_ptr); _ptr = _data; rc = 1; } return rc; } template <class T> template <bool p_ensure_zero> Error CowData<T>::resize(int p_size) { ERR_FAIL_COND_V(p_size < 0, ERR_INVALID_PARAMETER); int current_size = size(); if (p_size == current_size) { return OK; } if (p_size == 0) { // wants to clean up _unref(_ptr); _ptr = nullptr; return OK; } // possibly changing size, copy on write uint32_t rc = _copy_on_write(); size_t current_alloc_size = _get_alloc_size(current_size); size_t alloc_size; ERR_FAIL_COND_V(!_get_alloc_size_checked(p_size, &alloc_size), ERR_OUT_OF_MEMORY); if (p_size > current_size) { if (alloc_size != current_alloc_size) { if (current_size == 0) { // alloc from scratch uint32_t *ptr = (uint32_t *)Memory::alloc_static(alloc_size, true); ERR_FAIL_COND_V(!ptr, ERR_OUT_OF_MEMORY); *(ptr - 1) = 0; //size, currently none new (ptr - 2) SafeNumeric<uint32_t>(1); //refcount _ptr = (T *)ptr; } else { uint32_t *_ptrnew = (uint32_t *)Memory::realloc_static(_ptr, alloc_size, true); ERR_FAIL_COND_V(!_ptrnew, ERR_OUT_OF_MEMORY); new (_ptrnew - 2) SafeNumeric<uint32_t>(rc); //refcount _ptr = (T *)(_ptrnew); } } // construct the newly created elements if (!std::is_trivially_constructible<T>::value) { for (int i = *_get_size(); i < p_size; i++) { memnew_placement(&_ptr[i], T); } } else if (p_ensure_zero) { memset((void *)(_ptr + current_size), 0, (p_size - current_size) * sizeof(T)); } *_get_size() = p_size; } else if (p_size < current_size) { if (!std::is_trivially_destructible<T>::value) { // deinitialize no longer needed elements for (uint32_t i = p_size; i < *_get_size(); i++) { T *t = &_ptr[i]; t->~T(); } } if (alloc_size != current_alloc_size) { uint32_t *_ptrnew = (uint32_t *)Memory::realloc_static(_ptr, alloc_size, true); ERR_FAIL_COND_V(!_ptrnew, ERR_OUT_OF_MEMORY); new (_ptrnew - 2) SafeNumeric<uint32_t>(rc); //refcount _ptr = (T *)(_ptrnew); } *_get_size() = p_size; } return OK; } template <class T> int CowData<T>::find(const T &p_val, int p_from) const { int ret = -1; if (p_from < 0 || size() == 0) { return ret; } for (int i = p_from; i < size(); i++) { if (get(i) == p_val) { ret = i; break; } } return ret; } template <class T> int CowData<T>::rfind(const T &p_val, int p_from) const { const int s = size(); if (p_from < 0) { p_from = s + p_from; } if (p_from < 0 || p_from >= s) { p_from = s - 1; } for (int i = p_from; i >= 0; i--) { if (get(i) == p_val) { return i; } } return -1; } template <class T> int CowData<T>::count(const T &p_val) const { int amount = 0; for (int i = 0; i < size(); i++) { if (get(i) == p_val) { amount++; } } return amount; } template <class T> void CowData<T>::_ref(const CowData *p_from) { _ref(*p_from); } template <class T> void CowData<T>::_ref(const CowData &p_from) { if (_ptr == p_from._ptr) { return; // self assign, do nothing. } _unref(_ptr); _ptr = nullptr; if (!p_from._ptr) { return; //nothing to do } if (p_from._get_refcount()->conditional_increment() > 0) { // could reference _ptr = p_from._ptr; } } template <class T> CowData<T>::~CowData() { _unref(_ptr); } #if defined(__GNUC__) && !defined(__clang__) #pragma GCC diagnostic pop #endif #endif // COWDATA_H