diff options
author | Vincent Ambo <mail@tazj.in> | 2020-11-21T13·43+0100 |
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committer | Vincent Ambo <mail@tazj.in> | 2020-11-21T14·48+0100 |
commit | 082c006c04343a78d87b6c6ab3608c25d6213c3f (patch) | |
tree | 16e6f04f8d1d1d2d67e8e917d5e7bb48c1b60375 /third_party/abseil_cpp/absl/container/internal/inlined_vector.h | |
parent | cc27324d0226953943f408ce3c69ad7d648e005e (diff) |
merge(3p/absl): subtree merge of Abseil up to e19260f r/1889
... notably, this includes Abseil's own StatusOr type, which conflicted with our implementation (that was taken from TensorFlow). Change-Id: Ie7d6764b64055caaeb8dc7b6b9d066291e6b538f
Diffstat (limited to 'third_party/abseil_cpp/absl/container/internal/inlined_vector.h')
-rw-r--r-- | third_party/abseil_cpp/absl/container/internal/inlined_vector.h | 125 |
1 files changed, 64 insertions, 61 deletions
diff --git a/third_party/abseil_cpp/absl/container/internal/inlined_vector.h b/third_party/abseil_cpp/absl/container/internal/inlined_vector.h index 4d80b727bf4c..c98c25c44221 100644 --- a/third_party/abseil_cpp/absl/container/internal/inlined_vector.h +++ b/third_party/abseil_cpp/absl/container/internal/inlined_vector.h @@ -462,6 +462,9 @@ class Storage { Inlined inlined; }; + template <typename... Args> + ABSL_ATTRIBUTE_NOINLINE reference EmplaceBackSlow(Args&&... args); + Metadata metadata_; Data data_; }; @@ -542,48 +545,42 @@ template <typename T, size_t N, typename A> template <typename ValueAdapter> auto Storage<T, N, A>::Resize(ValueAdapter values, size_type new_size) -> void { StorageView storage_view = MakeStorageView(); - - IteratorValueAdapter<MoveIterator> move_values( - MoveIterator(storage_view.data)); - - AllocationTransaction allocation_tx(GetAllocPtr()); - ConstructionTransaction construction_tx(GetAllocPtr()); - - absl::Span<value_type> construct_loop; - absl::Span<value_type> move_construct_loop; - absl::Span<value_type> destroy_loop; - - if (new_size > storage_view.capacity) { + auto* const base = storage_view.data; + const size_type size = storage_view.size; + auto* alloc = GetAllocPtr(); + if (new_size <= size) { + // Destroy extra old elements. + inlined_vector_internal::DestroyElements(alloc, base + new_size, + size - new_size); + } else if (new_size <= storage_view.capacity) { + // Construct new elements in place. + inlined_vector_internal::ConstructElements(alloc, base + size, &values, + new_size - size); + } else { + // Steps: + // a. Allocate new backing store. + // b. Construct new elements in new backing store. + // c. Move existing elements from old backing store to now. + // d. Destroy all elements in old backing store. + // Use transactional wrappers for the first two steps so we can roll + // back if necessary due to exceptions. + AllocationTransaction allocation_tx(alloc); size_type new_capacity = ComputeCapacity(storage_view.capacity, new_size); pointer new_data = allocation_tx.Allocate(new_capacity); - construct_loop = {new_data + storage_view.size, - new_size - storage_view.size}; - move_construct_loop = {new_data, storage_view.size}; - destroy_loop = {storage_view.data, storage_view.size}; - } else if (new_size > storage_view.size) { - construct_loop = {storage_view.data + storage_view.size, - new_size - storage_view.size}; - } else { - destroy_loop = {storage_view.data + new_size, storage_view.size - new_size}; - } - - construction_tx.Construct(construct_loop.data(), &values, - construct_loop.size()); - inlined_vector_internal::ConstructElements( - GetAllocPtr(), move_construct_loop.data(), &move_values, - move_construct_loop.size()); + ConstructionTransaction construction_tx(alloc); + construction_tx.Construct(new_data + size, &values, new_size - size); - inlined_vector_internal::DestroyElements(GetAllocPtr(), destroy_loop.data(), - destroy_loop.size()); + IteratorValueAdapter<MoveIterator> move_values((MoveIterator(base))); + inlined_vector_internal::ConstructElements(alloc, new_data, &move_values, + size); - construction_tx.Commit(); - if (allocation_tx.DidAllocate()) { + inlined_vector_internal::DestroyElements(alloc, base, size); + construction_tx.Commit(); DeallocateIfAllocated(); AcquireAllocatedData(&allocation_tx); SetIsAllocated(); } - SetSize(new_size); } @@ -684,44 +681,50 @@ template <typename T, size_t N, typename A> template <typename... Args> auto Storage<T, N, A>::EmplaceBack(Args&&... args) -> reference { StorageView storage_view = MakeStorageView(); + const auto n = storage_view.size; + if (ABSL_PREDICT_TRUE(n != storage_view.capacity)) { + // Fast path; new element fits. + pointer last_ptr = storage_view.data + n; + AllocatorTraits::construct(*GetAllocPtr(), last_ptr, + std::forward<Args>(args)...); + AddSize(1); + return *last_ptr; + } + // TODO(b/173712035): Annotate with musttail attribute to prevent regression. + return EmplaceBackSlow(std::forward<Args>(args)...); +} +template <typename T, size_t N, typename A> +template <typename... Args> +auto Storage<T, N, A>::EmplaceBackSlow(Args&&... args) -> reference { + StorageView storage_view = MakeStorageView(); AllocationTransaction allocation_tx(GetAllocPtr()); - IteratorValueAdapter<MoveIterator> move_values( MoveIterator(storage_view.data)); - - pointer construct_data; - if (storage_view.size == storage_view.capacity) { - size_type new_capacity = NextCapacity(storage_view.capacity); - construct_data = allocation_tx.Allocate(new_capacity); - } else { - construct_data = storage_view.data; - } - + size_type new_capacity = NextCapacity(storage_view.capacity); + pointer construct_data = allocation_tx.Allocate(new_capacity); pointer last_ptr = construct_data + storage_view.size; + // Construct new element. AllocatorTraits::construct(*GetAllocPtr(), last_ptr, std::forward<Args>(args)...); - - if (allocation_tx.DidAllocate()) { - ABSL_INTERNAL_TRY { - inlined_vector_internal::ConstructElements( - GetAllocPtr(), allocation_tx.GetData(), &move_values, - storage_view.size); - } - ABSL_INTERNAL_CATCH_ANY { - AllocatorTraits::destroy(*GetAllocPtr(), last_ptr); - ABSL_INTERNAL_RETHROW; - } - - inlined_vector_internal::DestroyElements(GetAllocPtr(), storage_view.data, - storage_view.size); - - DeallocateIfAllocated(); - AcquireAllocatedData(&allocation_tx); - SetIsAllocated(); + // Move elements from old backing store to new backing store. + ABSL_INTERNAL_TRY { + inlined_vector_internal::ConstructElements( + GetAllocPtr(), allocation_tx.GetData(), &move_values, + storage_view.size); } + ABSL_INTERNAL_CATCH_ANY { + AllocatorTraits::destroy(*GetAllocPtr(), last_ptr); + ABSL_INTERNAL_RETHROW; + } + // Destroy elements in old backing store. + inlined_vector_internal::DestroyElements(GetAllocPtr(), storage_view.data, + storage_view.size); + DeallocateIfAllocated(); + AcquireAllocatedData(&allocation_tx); + SetIsAllocated(); AddSize(1); return *last_ptr; } |