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-rw-r--r--absl/container/internal/inlined_vector.h166
1 files changed, 156 insertions, 10 deletions
diff --git a/absl/container/internal/inlined_vector.h b/absl/container/internal/inlined_vector.h
index f117ee0c..a84b5255 100644
--- a/absl/container/internal/inlined_vector.h
+++ b/absl/container/internal/inlined_vector.h
@@ -47,19 +47,23 @@ template <typename AllocatorType, typename ValueType, typename SizeType>
void DestroyElements(AllocatorType* alloc_ptr, ValueType* destroy_first,
SizeType destroy_size) {
using AllocatorTraits = absl::allocator_traits<AllocatorType>;
- for (SizeType i = 0; i < destroy_size; ++i) {
- AllocatorTraits::destroy(*alloc_ptr, destroy_first + i);
- }
+
+ if (destroy_first != nullptr) {
+ for (auto i = destroy_size; i != 0;) {
+ --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);
+ // 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.
+ auto* memory_ptr = static_cast<void*>(destroy_first);
+ auto memory_size = sizeof(ValueType) * destroy_size;
+ std::memset(memory_ptr, 0xab, memory_size);
#endif // NDEBUG
+ }
}
template <typename AllocatorType, typename ValueType, typename ValueAdapter,
@@ -191,6 +195,46 @@ class AllocationTransaction {
size_type capacity_ = 0;
};
+template <typename AllocatorType>
+class ConstructionTransaction {
+ using pointer = typename AllocatorType::pointer;
+ using size_type = typename AllocatorType::size_type;
+
+ public:
+ explicit ConstructionTransaction(AllocatorType* alloc_ptr)
+ : alloc_data_(*alloc_ptr, nullptr) {}
+
+ ConstructionTransaction(const ConstructionTransaction&) = delete;
+ void operator=(const ConstructionTransaction&) = delete;
+
+ template <typename ValueAdapter>
+ void Construct(pointer data, ValueAdapter* values_ptr, size_type size) {
+ inlined_vector_internal::ConstructElements(std::addressof(GetAllocator()),
+ data, values_ptr, size);
+ GetData() = data;
+ GetSize() = size;
+ }
+ void Commit() {
+ GetData() = nullptr;
+ GetSize() = 0;
+ }
+
+ ~ConstructionTransaction() {
+ if (GetData() != nullptr) {
+ inlined_vector_internal::DestroyElements(std::addressof(GetAllocator()),
+ GetData(), GetSize());
+ }
+ }
+
+ private:
+ AllocatorType& GetAllocator() { return alloc_data_.template get<0>(); }
+ pointer& GetData() { return alloc_data_.template get<1>(); }
+ size_type& GetSize() { return size_; }
+
+ container_internal::CompressedTuple<AllocatorType, pointer> alloc_data_;
+ size_type size_ = 0;
+};
+
template <typename T, size_t N, typename A>
class Storage {
public:
@@ -223,6 +267,8 @@ class Storage {
using AllocationTransaction =
inlined_vector_internal::AllocationTransaction<allocator_type>;
+ using ConstructionTransaction =
+ inlined_vector_internal::ConstructionTransaction<allocator_type>;
Storage() : metadata_() {}
@@ -339,6 +385,11 @@ class Storage {
template <typename ValueAdapter>
void Assign(ValueAdapter values, size_type new_size);
+ template <typename ValueAdapter>
+ void Resize(ValueAdapter values, size_type new_size);
+
+ void Reserve(size_type requested_capacity);
+
void ShrinkToFit();
private:
@@ -348,6 +399,16 @@ class Storage {
return metadata_.template get<1>();
}
+ static size_type LegacyNextCapacityFrom(size_type current_capacity,
+ size_type requested_capacity) {
+ // TODO(johnsoncj): Get rid of this old behavior.
+ size_type new_capacity = current_capacity;
+ while (new_capacity < requested_capacity) {
+ new_capacity *= 2;
+ }
+ return new_capacity;
+ }
+
using Metadata =
container_internal::CompressedTuple<allocator_type, size_type>;
@@ -434,11 +495,70 @@ auto Storage<T, N, A>::Assign(ValueAdapter values, size_type new_size) -> void {
inlined_vector_internal::AssignElements(assign_loop.data(), &values,
assign_loop.size());
+
inlined_vector_internal::ConstructElements(
GetAllocPtr(), construct_loop.data(), &values, construct_loop.size());
+
+ inlined_vector_internal::DestroyElements(GetAllocPtr(), destroy_loop.data(),
+ destroy_loop.size());
+
+ if (allocation_tx.DidAllocate()) {
+ DeallocateIfAllocated();
+ AcquireAllocation(&allocation_tx);
+ SetIsAllocated();
+ }
+
+ SetSize(new_size);
+}
+
+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();
+
+ AllocationTransaction allocation_tx(GetAllocPtr());
+ ConstructionTransaction construction_tx(GetAllocPtr());
+
+ IteratorValueAdapter<MoveIterator> move_values(
+ MoveIterator(storage_view.data));
+
+ 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) {
+ pointer new_data = allocation_tx.Allocate(
+ LegacyNextCapacityFrom(storage_view.capacity, new_size));
+
+ // Construct new objects in `new_data`
+ construct_loop = {new_data + storage_view.size,
+ new_size - storage_view.size};
+
+ // Move all existing objects into `new_data`
+ move_construct_loop = {new_data, storage_view.size};
+
+ // Destroy all existing objects in `storage_view.data`
+ destroy_loop = {storage_view.data, storage_view.size};
+ } else if (new_size > storage_view.size) {
+ // Construct new objects in `storage_view.data`
+ construct_loop = {storage_view.data + storage_view.size,
+ new_size - storage_view.size};
+ } else {
+ // Destroy end `storage_view.size - new_size` objects in `storage_view.data`
+ 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());
+
inlined_vector_internal::DestroyElements(GetAllocPtr(), destroy_loop.data(),
destroy_loop.size());
+ construction_tx.Commit();
if (allocation_tx.DidAllocate()) {
DeallocateIfAllocated();
AcquireAllocation(&allocation_tx);
@@ -449,6 +569,31 @@ auto Storage<T, N, A>::Assign(ValueAdapter values, size_type new_size) -> void {
}
template <typename T, size_t N, typename A>
+auto Storage<T, N, A>::Reserve(size_type requested_capacity) -> void {
+ StorageView storage_view = MakeStorageView();
+
+ if (ABSL_PREDICT_FALSE(requested_capacity <= storage_view.capacity)) return;
+
+ AllocationTransaction allocation_tx(GetAllocPtr());
+
+ IteratorValueAdapter<MoveIterator> move_values(
+ MoveIterator(storage_view.data));
+
+ pointer new_data = allocation_tx.Allocate(
+ LegacyNextCapacityFrom(storage_view.capacity, requested_capacity));
+
+ inlined_vector_internal::ConstructElements(GetAllocPtr(), new_data,
+ &move_values, storage_view.size);
+
+ inlined_vector_internal::DestroyElements(GetAllocPtr(), storage_view.data,
+ storage_view.size);
+
+ DeallocateIfAllocated();
+ AcquireAllocation(&allocation_tx);
+ SetIsAllocated();
+}
+
+template <typename T, size_t N, typename A>
auto Storage<T, N, A>::ShrinkToFit() -> void {
// May only be called on allocated instances!
assert(GetIsAllocated());
@@ -484,6 +629,7 @@ auto Storage<T, N, A>::ShrinkToFit() -> void {
inlined_vector_internal::DestroyElements(GetAllocPtr(), storage_view.data,
storage_view.size);
+
AllocatorTraits::deallocate(*GetAllocPtr(), storage_view.data,
storage_view.capacity);