diff options
Diffstat (limited to 'absl/container/internal/raw_hash_set.h')
| -rw-r--r-- | absl/container/internal/raw_hash_set.h | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/absl/container/internal/raw_hash_set.h b/absl/container/internal/raw_hash_set.h index b23e0078..669785e6 100644 --- a/absl/container/internal/raw_hash_set.h +++ b/absl/container/internal/raw_hash_set.h @@ -628,7 +628,9 @@ class raw_hash_set { static Layout MakeLayout(size_t capacity) { assert(IsValidCapacity(capacity)); - return Layout(capacity + Group::kWidth + 1, capacity); + // The extra control bytes are for 1 sentinel byte followed by + // `Group::kWidth - 1` bytes that are cloned from the beginning. + return Layout(capacity + Group::kWidth, capacity); } using AllocTraits = absl::allocator_traits<allocator_type>; @@ -1782,8 +1784,8 @@ class raw_hash_set { growth_left() = CapacityToGrowth(capacity()) - size_; } - // Sets the control byte, and if `i < Group::kWidth`, set the cloned byte at - // the end too. + // Sets the control byte, and if `i < Group::kWidth - 1`, set the cloned byte + // at the end too. void set_ctrl(size_t i, ctrl_t h) { assert(i < capacity_); @@ -1794,8 +1796,8 @@ class raw_hash_set { } ctrl_[i] = h; - ctrl_[((i - Group::kWidth) & capacity_) + 1 + - ((Group::kWidth - 1) & capacity_)] = h; + constexpr size_t kClonedBytes = Group::kWidth - 1; + ctrl_[((i - kClonedBytes) & capacity_) + (kClonedBytes & capacity_)] = h; } size_t& growth_left() { return settings_.template get<0>(); } @@ -1814,7 +1816,7 @@ class raw_hash_set { // TODO(alkis): Investigate removing some of these fields: // - ctrl/slots can be derived from each other // - size can be moved into the slot array - ctrl_t* ctrl_ = EmptyGroup(); // [(capacity + 1) * ctrl_t] + ctrl_t* ctrl_ = EmptyGroup(); // [(capacity + Group::kWidth) * ctrl_t] slot_type* slots_ = nullptr; // [capacity * slot_type] size_t size_ = 0; // number of full slots size_t capacity_ = 0; // total number of slots |