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Diffstat (limited to 'source/blender/blenlib/BLI_chunk_list.hh')
| -rw-r--r-- | source/blender/blenlib/BLI_chunk_list.hh | 527 |
1 files changed, 527 insertions, 0 deletions
diff --git a/source/blender/blenlib/BLI_chunk_list.hh b/source/blender/blenlib/BLI_chunk_list.hh new file mode 100644 index 00000000000..963e7af90e8 --- /dev/null +++ b/source/blender/blenlib/BLI_chunk_list.hh @@ -0,0 +1,527 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ + +#pragma once + +/** \file + * \ingroup bli + * + * A `blender::ChunkList` is a dynamically growing ordered container for values of type T. + * It is *not* guaranteed that all values will be stored in one contiguous array. Instead, multiple + * arrays may be used. + * + * Comparison to `blender::Vector`: + * - `ChunkList` has better performance when appending many elements, because it does not have to + * move existing values. + * - This also means that `ChunkList` can be used with types that cannot be moved. + * - A `ChunkList` can not be indexed efficiently. So while the container is ordered, one can not + * efficiently get the value at a specific index. + * - Iterating over a `ChunkList` is a little bit slower, because it may have to iterate over + * multiple arrays. That is likely negligible in most cases. + * + * `ChunkList` should be used instead of `Vector` when the following two statements are true: + * - The elements do not have to be in a contiguous array. + * - The elements do not have to be accessed with an index. + */ + +#include "BLI_allocator.hh" +#include "BLI_math_base.hh" +#include "BLI_memory_utils.hh" +#include "BLI_vector.hh" + +namespace blender { + +namespace chunk_list_detail { + +template<typename T> struct RawChunk { + T *begin; + T *end_if_inactive; + T *capacity_end; + /** + * Pointer to the beginning of the allocation of this chunk. Might not be the same as `begin`, + * because the might be allocated together with #AllocInfo. Can be null when this chunk is + * inlined into the #ChunkList. + */ + void *allocation; + + RawChunk() = default; + RawChunk(T *begin, T *end_if_inactive, T *capacity_end, void *allocation) + : begin(begin), + end_if_inactive(end_if_inactive), + capacity_end(capacity_end), + allocation(allocation) + { + } +}; + +template<typename T> struct AllocInfo { + int64_t active; + Vector<RawChunk<T>> raw_chunks; +}; + +} // namespace chunk_list_detail + +template<typename T, + int64_t InlineBufferCapacity = default_inline_buffer_capacity(sizeof(T)), + typename Allocator = GuardedAllocator> +class ChunkList { + private: + using RawChunk = chunk_list_detail::RawChunk<T>; + using AllocInfo = chunk_list_detail::AllocInfo<T>; + + T *active_begin_; + T *active_end_; + T *active_capacity_end_; + AllocInfo *alloc_info_ = nullptr; + BLI_NO_UNIQUE_ADDRESS TypedBuffer<T, InlineBufferCapacity> inline_buffer_; + BLI_NO_UNIQUE_ADDRESS Allocator allocator_; + + template<typename OtherT, int64_t OtherInlineBufferCapacity, typename OtherAllocator> + friend class ChunkList; + + public: + ChunkList(Allocator allocator = {}) noexcept : allocator_(allocator) + { + active_begin_ = inline_buffer_; + active_end_ = active_begin_; + active_capacity_end_ = active_end_ + InlineBufferCapacity; + } + + ChunkList(NoExceptConstructor, Allocator allocator = {}) noexcept : ChunkList(allocator) + { + } + + ChunkList(const ChunkList &other) : ChunkList(other.allocator()) + { + this->extend(other); + } + + template<int64_t OtherInlineBufferCapacity> + ChunkList(const ChunkList<T, OtherInlineBufferCapacity, Allocator> &other) + : ChunkList(other.allocator()) + { + this->extend(other); + } + + ChunkList(ChunkList &&other) : ChunkList(other.allocator()) + { + this->extend(std::move(other)); + } + + ~ChunkList() + { + if (alloc_info_ == nullptr) { + destruct_n<T>(inline_buffer_, active_end_ - inline_buffer_); + } + else { + for (const int64_t i : alloc_info_->raw_chunks.index_range()) { + RawChunk &raw_chunk = alloc_info_->raw_chunks[i]; + T *begin = raw_chunk.begin; + T *end = i == alloc_info_->active ? active_end_ : raw_chunk.end_if_inactive; + destruct_n(begin, end - begin); + if (i >= 1) { + allocator_.deallocate(begin); + } + } + alloc_info_->~AllocInfo(); + allocator_.deallocate(alloc_info_); + } + } + + ChunkList &operator=(const ChunkList &other) + { + return copy_assign_container(*this, other); + } + + ChunkList &operator=(ChunkList &&other) + { + return move_assign_container(*this, std::move(other)); + } + + void clear() + { + this->~ChunkList(); + new (this) ChunkList(); + } + + const Allocator &allocator() const + { + return allocator_; + } + + template<typename Fn> void foreach_chunk(Fn &&fn) const + { + for (const int64_t i : IndexRange(this->get_chunk_num())) { + const Span<T> chunk = this->get_chunk(i); + fn(chunk); + } + } + + template<typename Fn> void foreach_chunk(Fn &&fn) + { + const_cast<const ChunkList *>(this)->foreach_chunk([&](const Span<T> chunk) { + fn(MutableSpan(const_cast<T *>(chunk.data()), chunk.size())); + }); + } + + template<typename Fn> void foreach_elem(Fn &&fn) const + { + for (const int64_t i : IndexRange(this->get_chunk_num())) { + const Span<T> chunk = this->get_chunk(i); + for (const T &value : chunk) { + fn(value); + } + } + } + + bool is_empty() const + { + return active_end_ == inline_buffer_; + } + + int64_t size() const + { + int64_t chunk_size_sum = 0; + this->foreach_chunk([&](const Span<T> chunk) { chunk_size_sum += chunk.size(); }); + return chunk_size_sum; + } + + int64_t get_chunk_num() const + { + if (alloc_info_ == nullptr) { + return 1; + } + return alloc_info_->active + 1; + } + + BLI_NOINLINE Span<T> get_chunk(const int64_t index) const + { + BLI_assert(index >= 0); + if (alloc_info_ == nullptr) { + BLI_assert(index == 0); + return {inline_buffer_, active_end_ - inline_buffer_}; + } + BLI_assert(index <= alloc_info_->active); + const RawChunk &chunk = alloc_info_->raw_chunks[index]; + const T *begin = chunk.begin; + const T *end = index == alloc_info_->active ? active_end_ : chunk.end_if_inactive; + return {begin, end - begin}; + } + + MutableSpan<T> get_chunk(const int64_t index) + { + const Span<T> chunk = const_cast<const ChunkList *>(this)->get_chunk(index); + return {const_cast<T *>(chunk.data()), chunk.size()}; + } + + T &last() + { + BLI_assert(!this->is_empty()); + return *(active_end_ - 1); + } + const T &last() const + { + BLI_assert(!this->is_empty()); + return *(active_end_ - 1); + } + + void append(const T &value) + { + this->append_as(value); + } + void append(T &&value) + { + this->append_as(std::move(value)); + } + template<typename... Args> void append_as(Args &&...args) + { + this->ensure_space_for_one(); + BLI_assert(active_end_ < active_capacity_end_); + try { + new (active_end_) T(std::forward<Args>(args)...); + } + catch (...) { + this->move_end_back_to_prev_element(); + throw; + } + active_end_++; + } + + template<int64_t OtherInlineBufferCapacity> + void extend(const ChunkList<T, OtherInlineBufferCapacity, Allocator> &other) + { + other.foreach_chunk([&](const Span<T> chunk) { this->extend(chunk); }); + } + + template<int64_t OtherInlineBufferCapacity> + void extend(ChunkList<T, OtherInlineBufferCapacity, Allocator> &&other) + { + AllocInfo *other_alloc_info = other.alloc_info_; + + if (other_alloc_info == nullptr) { + /* Handle case when the other list is fully inline. */ + this->extend_move({other.active_begin_, other.active_end_ - other.active_begin_}); + } + else { + /* Make sure all chunks are up to date. */ + RawChunk &other_active_chunk = other_alloc_info->raw_chunks[other_alloc_info->active]; + other_active_chunk.end_if_inactive = other.active_end_; + for (const int64_t other_chunk_index : other_alloc_info->raw_chunks.index_range()) { + const RawChunk &other_chunk = other_alloc_info->raw_chunks[other_chunk_index]; + if (other_chunk.allocation == nullptr) { + /* This chunk is inline. */ + this->extend_move({other_chunk.begin, other_chunk.end_if_inactive - other_chunk.begin}); + } + else if (alloc_info_ == nullptr) { + alloc_info_ = other_alloc_info; + other.alloc_info_ = nullptr; + RawChunk &first_chunk = alloc_info_->raw_chunks[0]; + BLI_assert(first_chunk.allocation == nullptr); + first_chunk.begin = active_begin_; + first_chunk.capacity_end = active_capacity_end_; + first_chunk.end_if_inactive = active_end_; + break; + } + else { + alloc_info_->raw_chunks.append(other_chunk); + if (other_chunk.begin < other_chunk.end_if_inactive) { + alloc_info_->active = alloc_info_->raw_chunks.size() - 1; + } + } + } + + if (alloc_info_ != nullptr) { + const RawChunk &active_chunk = alloc_info_->raw_chunks[alloc_info_->active]; + active_begin_ = active_chunk.begin; + active_end_ = active_chunk.end_if_inactive; + active_capacity_end_ = active_chunk.capacity_end; + } + if (other.alloc_info_ != nullptr) { + other.alloc_info_->raw_chunks.resize(1); + } + } + + /* Reset the other list. */ + other.active_begin_ = other.inline_buffer_; + other.active_end_ = other.active_begin_; + other.active_capacity_end_ = other.active_begin_ + OtherInlineBufferCapacity; + } + + void extend_move(const MutableSpan<T> values) + { + this->extend_impl<true>(values); + } + + void extend(const Span<T> values) + { + this->extend_impl<false>(values); + } + + template<bool UseMove> void extend_impl(const Span<T> values) + { + const T *src_begin = values.data(); + const T *src_end = src_begin + values.size(); + const T *src = src_begin; + while (src < src_end) { + const int64_t remaining_copies = src_end - src; + const int64_t remaining_capacity = active_capacity_end_ - active_end_; + const int64_t copy_num = std::min(remaining_copies, remaining_capacity); + try { + if constexpr (UseMove) { + uninitialized_move_n(const_cast<T *>(src), copy_num, active_end_); + } + else { + uninitialized_copy_n(src, copy_num, active_end_); + } + } + catch (...) { + if (alloc_info_ != nullptr) { + int64_t remaining_destructs = src - src_begin; + while (remaining_destructs > 0) { + this->move_end_back_to_prev_element(); + const int64_t chunk_size = active_end_ - active_begin_; + const int64_t destruct_num = std::min(chunk_size, remaining_destructs); + destruct_n(active_end_ - destruct_num, destruct_num); + active_end_ -= destruct_num; + remaining_destructs -= destruct_num; + } + } + throw; + } + active_end_ += copy_num; + + if (copy_num == remaining_copies) { + break; + } + src += copy_num; + this->activate_next_chunk(); + } + } + + T pop_last() + { + BLI_assert(!this->is_empty()); + T value = std::move(*(active_end_ - 1)); + active_end_--; + std::destroy_at(active_end_); + this->move_end_back_to_prev_element(); + return value; + } + + void move_end_back_to_prev_element() + { + if (active_end_ > active_begin_) { + return; + } + if (alloc_info_ == nullptr) { + return; + } + if (alloc_info_->active == 0) { + return; + } + RawChunk &old_chunk = alloc_info_->raw_chunks[alloc_info_->active]; + old_chunk.end_if_inactive = active_end_; + int new_active = alloc_info_->active - 1; + while (new_active >= 0) { + RawChunk &chunk = alloc_info_->raw_chunks[new_active]; + if (chunk.begin < chunk.end_if_inactive) { + break; + } + new_active--; + } + RawChunk &new_chunk = alloc_info_->raw_chunks[new_active]; + alloc_info_->active = new_active; + active_begin_ = new_chunk.begin; + active_end_ = new_chunk.end_if_inactive; + active_capacity_end_ = new_chunk.capacity_end; + } + + class Iterator { + private: + using iterator_category = std::forward_iterator_tag; + using value_type = T; + using pointer = const T *; + using reference = const T &; + + const T *begin_; + const T *current_; + const T *end_; + int64_t chunk_index_; + int64_t chunk_num_; + const ChunkList *chunk_list_; + + friend ChunkList; + + public: + constexpr Iterator &operator++() + { + BLI_assert(chunk_index_ < chunk_num_); + current_++; + if (current_ == end_) { + chunk_index_++; + if (chunk_index_ < chunk_num_) { + const Span<T> next_chunk = chunk_list_->get_chunk(chunk_index_); + begin_ = next_chunk.data(); + current_ = begin_; + end_ = begin_ + next_chunk.size(); + } + } + return *this; + } + + constexpr friend bool operator!=(const Iterator &a, const Iterator &b) + { + BLI_assert(a.chunk_list_ == b.chunk_list_); + return a.current_ != b.current_; + } + + constexpr const T &operator*() const + { + return *current_; + } + }; + + Iterator begin() const + { + const int64_t span_num = this->get_chunk_num(); + BLI_assert(span_num >= 1); + const Span<T> span = this->get_chunk(0); + Iterator it; + it.chunk_list_ = this; + it.chunk_index_ = 0; + it.chunk_num_ = span_num; + it.begin_ = span.data(); + it.end_ = it.begin_ + span.size(); + it.current_ = it.begin_; + return it; + } + + Iterator end() const + { + const int64_t span_num = this->get_chunk_num(); + BLI_assert(span_num >= 1); + const Span<T> last_span = this->get_chunk(span_num - 1); + + Iterator it; + it.chunk_list_ = this; + it.chunk_index_ = span_num; + it.chunk_num_ = span_num; + it.begin_ = last_span.data(); + it.end_ = it.begin_ + last_span.size(); + it.current_ = it.end_; + return it; + } + + private: + void ensure_space_for_one() + { + if (active_end_ >= active_capacity_end_) { + this->activate_next_chunk(); + } + } + + void activate_next_chunk() + { + if (alloc_info_ == nullptr) { + this->prepare_alloc_info(); + } + + RawChunk &old_active_chunk = alloc_info_->raw_chunks[alloc_info_->active]; + old_active_chunk.end_if_inactive = active_end_; + BLI_assert(old_active_chunk.capacity_end == active_capacity_end_); + + alloc_info_->active++; + if (alloc_info_->active == alloc_info_->raw_chunks.size()) { + this->add_chunk(1); + } + + RawChunk &new_active_chunk = alloc_info_->raw_chunks[alloc_info_->active]; + active_begin_ = new_active_chunk.begin; + active_end_ = new_active_chunk.end_if_inactive; + active_capacity_end_ = new_active_chunk.capacity_end; + } + + BLI_NOINLINE void prepare_alloc_info() + { + BLI_assert(alloc_info_ == nullptr); + void *buffer = allocator_.allocate(sizeof(AllocInfo), alignof(AllocInfo), __func__); + alloc_info_ = new (buffer) AllocInfo(); + alloc_info_->raw_chunks.append_as(inline_buffer_, active_end_, active_capacity_end_, nullptr); + alloc_info_->active = 0; + } + + BLI_NOINLINE void add_chunk(const int64_t min_chunk_size) + { + const RawChunk &last_chunk = alloc_info_->raw_chunks.last(); + const int64_t last_chunk_size = last_chunk.capacity_end - last_chunk.begin; + const int64_t new_chunk_size = std::max<int64_t>(min_chunk_size, + std::min<int64_t>(last_chunk_size * 2, 4096)); + void *buffer = allocator_.allocate( + sizeof(T) * static_cast<size_t>(new_chunk_size), alignof(T), __func__); + T *new_chunk_begin = static_cast<T *>(buffer); + T *new_chunk_capacity_end = new_chunk_begin + new_chunk_size; + alloc_info_->raw_chunks.append_as( + new_chunk_begin, new_chunk_begin, new_chunk_capacity_end, buffer); + } +}; + +} // namespace blender |