| // Copyright 2019 The Abseil Authors. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // https://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // 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 ABSL_CONTAINER_INTERNAL_INLINED_VECTOR_INTERNAL_H_ |
| #define ABSL_CONTAINER_INTERNAL_INLINED_VECTOR_INTERNAL_H_ |
| |
| #include <cstddef> |
| #include <cstring> |
| #include <iterator> |
| #include <memory> |
| #include <utility> |
| |
| #include "absl/container/internal/compressed_tuple.h" |
| #include "absl/meta/type_traits.h" |
| |
| namespace absl { |
| namespace inlined_vector_internal { |
| |
| template <typename Iterator> |
| using IsAtLeastForwardIterator = std::is_convertible< |
| typename std::iterator_traits<Iterator>::iterator_category, |
| std::forward_iterator_tag>; |
| |
| template <typename AllocatorType, typename ValueType, typename SizeType> |
| void DestroyElements(AllocatorType* alloc_ptr, ValueType* destroy_first, |
| SizeType destroy_size) { |
| using AllocatorTraits = std::allocator_traits<AllocatorType>; |
| |
| // Destroys `destroy_size` elements from `destroy_first`. |
| // |
| // Destroys the range |
| // [`destroy_first`, `destroy_first + destroy_size`). |
| // |
| // NOTE: We assume destructors do not throw and thus make no attempt to roll |
| // back. |
| for (SizeType i = 0; i < destroy_size; ++i) { |
| AllocatorTraits::destroy(*alloc_ptr, destroy_first + i); |
| } |
| |
| #ifndef NDEBUG |
| // Overwrite unused memory with `0xab` so we can catch uninitialized usage. |
| // |
| // Cast to `void*` to tell the compiler that we don't care that we might be |
| // scribbling on a vtable pointer. |
| void* memory = reinterpret_cast<void*>(destroy_first); |
| size_t memory_size = sizeof(ValueType) * destroy_size; |
| std::memset(memory, 0xab, memory_size); |
| #endif // NDEBUG |
| } |
| |
| template <typename T, size_t N, typename A> |
| class Storage { |
| public: |
| using allocator_type = A; |
| using value_type = typename allocator_type::value_type; |
| using pointer = typename allocator_type::pointer; |
| using const_pointer = typename allocator_type::const_pointer; |
| using reference = typename allocator_type::reference; |
| using const_reference = typename allocator_type::const_reference; |
| using rvalue_reference = typename allocator_type::value_type&&; |
| using size_type = typename allocator_type::size_type; |
| using difference_type = typename allocator_type::difference_type; |
| using iterator = pointer; |
| using const_iterator = const_pointer; |
| using reverse_iterator = std::reverse_iterator<iterator>; |
| using const_reverse_iterator = std::reverse_iterator<const_iterator>; |
| using AllocatorTraits = std::allocator_traits<allocator_type>; |
| |
| explicit Storage(const allocator_type& alloc) |
| : metadata_(alloc, /* empty and inlined */ 0) {} |
| |
| size_type GetSize() const { return GetSizeAndIsAllocated() >> 1; } |
| |
| bool GetIsAllocated() const { return GetSizeAndIsAllocated() & 1; } |
| |
| pointer GetInlinedData() { |
| return reinterpret_cast<pointer>( |
| std::addressof(data_.inlined.inlined_data[0])); |
| } |
| |
| const_pointer GetInlinedData() const { |
| return reinterpret_cast<const_pointer>( |
| std::addressof(data_.inlined.inlined_data[0])); |
| } |
| |
| pointer GetAllocatedData() { return data_.allocated.allocated_data; } |
| |
| const_pointer GetAllocatedData() const { |
| return data_.allocated.allocated_data; |
| } |
| |
| size_type GetAllocatedCapacity() const { |
| return data_.allocated.allocated_capacity; |
| } |
| |
| allocator_type* GetAllocPtr() { |
| return std::addressof(metadata_.template get<0>()); |
| } |
| |
| const allocator_type* GetAllocPtr() const { |
| return std::addressof(metadata_.template get<0>()); |
| } |
| |
| void SetAllocatedSize(size_type size) { |
| GetSizeAndIsAllocated() = (size << 1) | static_cast<size_type>(1); |
| } |
| |
| void SetInlinedSize(size_type size) { GetSizeAndIsAllocated() = size << 1; } |
| |
| void AddSize(size_type count) { GetSizeAndIsAllocated() += count << 1; } |
| |
| void SetAllocatedData(pointer data) { data_.allocated.allocated_data = data; } |
| |
| void SetAllocatedCapacity(size_type capacity) { |
| data_.allocated.allocated_capacity = capacity; |
| } |
| |
| void SwapSizeAndIsAllocated(Storage* other) { |
| using std::swap; |
| swap(GetSizeAndIsAllocated(), other->GetSizeAndIsAllocated()); |
| } |
| |
| void SwapAllocatedSizeAndCapacity(Storage* other) { |
| using std::swap; |
| swap(data_.allocated, other->data_.allocated); |
| } |
| |
| private: |
| size_type& GetSizeAndIsAllocated() { return metadata_.template get<1>(); } |
| |
| const size_type& GetSizeAndIsAllocated() const { |
| return metadata_.template get<1>(); |
| } |
| |
| using Metadata = |
| container_internal::CompressedTuple<allocator_type, size_type>; |
| |
| struct Allocated { |
| pointer allocated_data; |
| size_type allocated_capacity; |
| }; |
| |
| struct Inlined { |
| using InlinedDataElement = |
| absl::aligned_storage_t<sizeof(value_type), alignof(value_type)>; |
| InlinedDataElement inlined_data[N]; |
| }; |
| |
| union Data { |
| Allocated allocated; |
| Inlined inlined; |
| }; |
| |
| Metadata metadata_; |
| Data data_; |
| }; |
| |
| } // namespace inlined_vector_internal |
| } // namespace absl |
| |
| #endif // ABSL_CONTAINER_INTERNAL_INLINED_VECTOR_INTERNAL_H_ |