diff options
Diffstat (limited to 'absl/container/inlined_vector.h')
| -rw-r--r-- | absl/container/inlined_vector.h | 168 |
1 files changed, 19 insertions, 149 deletions
diff --git a/absl/container/inlined_vector.h b/absl/container/inlined_vector.h index 7552723d6a37..84ac67eb5eb5 100644 --- a/absl/container/inlined_vector.h +++ b/absl/container/inlined_vector.h @@ -549,15 +549,15 @@ class InlinedVector { // of `v` starting at `pos`. Returns an `iterator` pointing to the first of // the newly inserted elements. iterator insert(const_iterator pos, size_type n, const_reference v) { - assert(pos >= begin() && pos <= end()); - if (ABSL_PREDICT_FALSE(n == 0)) { + assert(pos >= begin()); + assert(pos <= end()); + + if (ABSL_PREDICT_TRUE(n != 0)) { + value_type dealias = v; + return storage_.Insert(pos, CopyValueAdapter(dealias), n); + } else { return const_cast<iterator>(pos); } - value_type copy = v; - std::pair<iterator, iterator> it_pair = ShiftRight(pos, n); - std::fill(it_pair.first, it_pair.second, copy); - UninitializedFill(it_pair.second, it_pair.first + n, copy); - return it_pair.first; } // Overload of `InlinedVector::insert()` for copying the contents of the @@ -577,17 +577,15 @@ class InlinedVector { EnableIfAtLeastForwardIterator<ForwardIterator>* = nullptr> iterator insert(const_iterator pos, ForwardIterator first, ForwardIterator last) { - assert(pos >= begin() && pos <= end()); - if (ABSL_PREDICT_FALSE(first == last)) { + assert(pos >= begin()); + assert(pos <= end()); + + if (ABSL_PREDICT_TRUE(first != last)) { + return storage_.Insert(pos, IteratorValueAdapter<ForwardIterator>(first), + std::distance(first, last)); + } else { return const_cast<iterator>(pos); } - auto n = std::distance(first, last); - std::pair<iterator, iterator> it_pair = ShiftRight(pos, n); - size_type used_spots = it_pair.second - it_pair.first; - auto open_spot = std::next(first, used_spots); - std::copy(first, open_spot, it_pair.first); - UninitializedCopy(open_spot, last, it_pair.second); - return it_pair.first; } // Overload of `InlinedVector::insert()` for inserting elements constructed @@ -615,23 +613,12 @@ class InlinedVector { iterator emplace(const_iterator pos, Args&&... args) { assert(pos >= begin()); assert(pos <= end()); - if (ABSL_PREDICT_FALSE(pos == end())) { - emplace_back(std::forward<Args>(args)...); - return end() - 1; - } - T new_t = T(std::forward<Args>(args)...); - - auto range = ShiftRight(pos, 1); - if (range.first == range.second) { - // constructing into uninitialized memory - Construct(range.first, std::move(new_t)); - } else { - // assigning into moved-from object - *range.first = T(std::move(new_t)); - } - - return range.first; + value_type dealias(std::forward<Args>(args)...); + return storage_.Insert(pos, + IteratorValueAdapter<MoveIterator>( + MoveIterator(std::addressof(dealias))), + 1); } // `InlinedVector::emplace_back()` @@ -746,123 +733,6 @@ class InlinedVector { template <typename H, typename TheT, size_t TheN, typename TheA> friend H AbslHashValue(H h, const absl::InlinedVector<TheT, TheN, TheA>& a); - void ResetAllocation(pointer new_data, size_type new_capacity, - size_type new_size) { - if (storage_.GetIsAllocated()) { - Destroy(storage_.GetAllocatedData(), - storage_.GetAllocatedData() + size()); - assert(begin() == storage_.GetAllocatedData()); - AllocatorTraits::deallocate(*storage_.GetAllocPtr(), - storage_.GetAllocatedData(), - storage_.GetAllocatedCapacity()); - } else { - Destroy(storage_.GetInlinedData(), storage_.GetInlinedData() + size()); - } - - storage_.SetAllocatedData(new_data, new_capacity); - storage_.SetAllocatedSize(new_size); - } - - template <typename... Args> - reference Construct(pointer p, Args&&... args) { - absl::allocator_traits<allocator_type>::construct( - *storage_.GetAllocPtr(), p, std::forward<Args>(args)...); - return *p; - } - - template <typename Iterator> - void UninitializedCopy(Iterator src, Iterator src_last, pointer dst) { - for (; src != src_last; ++dst, ++src) Construct(dst, *src); - } - - template <typename... Args> - void UninitializedFill(pointer dst, pointer dst_last, const Args&... args) { - for (; dst != dst_last; ++dst) Construct(dst, args...); - } - - // Destroy [`from`, `to`) in place. - void Destroy(pointer from, pointer to) { - for (pointer cur = from; cur != to; ++cur) { - absl::allocator_traits<allocator_type>::destroy(*storage_.GetAllocPtr(), - cur); - } -#if !defined(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. - if (from != to) { - auto len = sizeof(value_type) * std::distance(from, to); - std::memset(reinterpret_cast<void*>(from), 0xab, len); - } -#endif // !defined(NDEBUG) - } - - // Shift all elements from `position` to `end()` by `n` places to the right. - // If the vector needs to be enlarged, memory will be allocated. - // Returns `iterator`s pointing to the start of the previously-initialized - // portion and the start of the uninitialized portion of the created gap. - // The number of initialized spots is `pair.second - pair.first`. The number - // of raw spots is `n - (pair.second - pair.first)`. - // - // Updates the size of the InlinedVector internally. - std::pair<iterator, iterator> ShiftRight(const_iterator position, - size_type n) { - iterator start_used = const_cast<iterator>(position); - iterator start_raw = const_cast<iterator>(position); - size_type s = size(); - size_type required_size = s + n; - - if (required_size > capacity()) { - // Compute new capacity by repeatedly doubling current capacity - size_type new_capacity = capacity(); - while (new_capacity < required_size) { - new_capacity <<= 1; - } - // Move everyone into the new allocation, leaving a gap of `n` for the - // requested shift. - pointer new_data = - AllocatorTraits::allocate(*storage_.GetAllocPtr(), new_capacity); - size_type index = position - begin(); - UninitializedCopy(std::make_move_iterator(data()), - std::make_move_iterator(data() + index), new_data); - UninitializedCopy(std::make_move_iterator(data() + index), - std::make_move_iterator(data() + s), - new_data + index + n); - ResetAllocation(new_data, new_capacity, s); - - // New allocation means our iterator is invalid, so we'll recalculate. - // Since the entire gap is in new space, there's no used space to reuse. - start_raw = begin() + index; - start_used = start_raw; - } else { - // If we had enough space, it's a two-part move. Elements going into - // previously-unoccupied space need an `UninitializedCopy()`. Elements - // going into a previously-occupied space are just a `std::move()`. - iterator pos = const_cast<iterator>(position); - iterator raw_space = end(); - size_type slots_in_used_space = raw_space - pos; - size_type new_elements_in_used_space = (std::min)(n, slots_in_used_space); - size_type new_elements_in_raw_space = n - new_elements_in_used_space; - size_type old_elements_in_used_space = - slots_in_used_space - new_elements_in_used_space; - - UninitializedCopy( - std::make_move_iterator(pos + old_elements_in_used_space), - std::make_move_iterator(raw_space), - raw_space + new_elements_in_raw_space); - std::move_backward(pos, pos + old_elements_in_used_space, raw_space); - - // If the gap is entirely in raw space, the used space starts where the - // raw space starts, leaving no elements in used space. If the gap is - // entirely in used space, the raw space starts at the end of the gap, - // leaving all elements accounted for within the used space. - start_used = pos; - start_raw = pos + new_elements_in_used_space; - } - storage_.AddSize(n); - return std::make_pair(start_used, start_raw); - } - Storage storage_; }; |