diff options
Diffstat (limited to 'absl/container/internal/btree.h')
-rw-r--r-- | absl/container/internal/btree.h | 214 |
1 files changed, 107 insertions, 107 deletions
diff --git a/absl/container/internal/btree.h b/absl/container/internal/btree.h index fd5c0e7aba9c..2a5c7314ccae 100644 --- a/absl/container/internal/btree.h +++ b/absl/container/internal/btree.h @@ -252,9 +252,9 @@ struct map_params : common_params<Key, Compare, Alloc, TargetNodeSize, Multi, }; using is_map_container = std::true_type; - static const Key &key(const value_type &x) { return x.first; } - static const Key &key(const init_type &x) { return x.first; } - static const Key &key(const slot_type *x) { return slot_policy::key(x); } + static const Key &key(const value_type &value) { return value.first; } + static const Key &key(const init_type &init) { return init.first; } + static const Key &key(const slot_type *s) { return slot_policy::key(s); } static mapped_type &value(value_type *value) { return value->second; } }; @@ -315,8 +315,8 @@ struct set_params : common_params<Key, Compare, Alloc, TargetNodeSize, Multi, using value_compare = typename set_params::common_params::key_compare; using is_map_container = std::false_type; - static const Key &key(const value_type &x) { return x; } - static const Key &key(const slot_type *x) { return *x; } + static const Key &key(const value_type &value) { return value; } + static const Key &key(const slot_type *slot) { return *slot; } }; // An adapter class that converts a lower-bound compare into an upper-bound @@ -326,8 +326,8 @@ struct set_params : common_params<Key, Compare, Alloc, TargetNodeSize, Multi, template <typename Compare> struct upper_bound_adapter { explicit upper_bound_adapter(const Compare &c) : comp(c) {} - template <typename K, typename LK> - bool operator()(const K &a, const LK &b) const { + template <typename K1, typename K2> + bool operator()(const K1 &a, const K2 &b) const { // Returns true when a is not greater than b. return !compare_internal::compare_result_as_less_than(comp(b, a)); } @@ -736,32 +736,28 @@ class btree_node { // Merges a node with its right sibling, moving all of the values and the // delimiting key in the parent node onto itself. - void merge(btree_node *sibling, allocator_type *alloc); + void merge(btree_node *src, allocator_type *alloc); - // Swap the contents of "this" and "src". - void swap(btree_node *src, allocator_type *alloc); + // Swaps the contents of `this` and `other`. + void swap(btree_node *other, allocator_type *alloc); // Node allocation/deletion routines. - static btree_node *init_leaf(btree_node *n, btree_node *parent, - int max_count) { - n->set_parent(parent); - n->set_position(0); - n->set_start(0); - n->set_finish(0); - n->set_max_count(max_count); + void init_leaf(btree_node *parent, int max_count) { + set_parent(parent); + set_position(0); + set_start(0); + set_finish(0); + set_max_count(max_count); absl::container_internal::SanitizerPoisonMemoryRegion( - n->start_slot(), max_count * sizeof(slot_type)); - return n; + start_slot(), max_count * sizeof(slot_type)); } - static btree_node *init_internal(btree_node *n, btree_node *parent) { - init_leaf(n, parent, kNodeValues); + void init_internal(btree_node *parent) { + init_leaf(parent, kNodeValues); // Set `max_count` to a sentinel value to indicate that this node is // internal. - n->set_max_count(kInternalNodeMaxCount); + set_max_count(kInternalNodeMaxCount); absl::container_internal::SanitizerPoisonMemoryRegion( - &n->mutable_child(n->start()), - (kNodeValues + 1) * sizeof(btree_node *)); - return n; + &mutable_child(start()), (kNodeValues + 1) * sizeof(btree_node *)); } void destroy(allocator_type *alloc) { for (int i = start(); i < finish(); ++i) { @@ -787,13 +783,13 @@ class btree_node { } // Move n values starting at value i in this node into the values starting at - // value j in node x. + // value j in dest_node. void uninitialized_move_n(const size_type n, const size_type i, - const size_type j, btree_node *x, + const size_type j, btree_node *dest_node, allocator_type *alloc) { absl::container_internal::SanitizerUnpoisonMemoryRegion( - x->slot(j), n * sizeof(slot_type)); - for (slot_type *src = slot(i), *end = src + n, *dest = x->slot(j); + dest_node->slot(j), n * sizeof(slot_type)); + for (slot_type *src = slot(i), *end = src + n, *dest = dest_node->slot(j); src != end; ++src, ++dest) { params_type::construct(alloc, dest, src); } @@ -856,8 +852,8 @@ struct btree_iterator { std::is_same<btree_iterator<N, R, P>, iterator>::value && std::is_same<btree_iterator, const_iterator>::value, int> = 0> - btree_iterator(const btree_iterator<N, R, P> &x) // NOLINT - : node(x.node), position(x.position) {} + btree_iterator(const btree_iterator<N, R, P> &other) // NOLINT + : node(other.node), position(other.position) {} private: // This SFINAE allows explicit conversions from const_iterator to @@ -869,8 +865,8 @@ struct btree_iterator { std::is_same<btree_iterator<N, R, P>, const_iterator>::value && std::is_same<btree_iterator, iterator>::value, int> = 0> - explicit btree_iterator(const btree_iterator<N, R, P> &x) - : node(const_cast<node_type *>(x.node)), position(x.position) {} + explicit btree_iterator(const btree_iterator<N, R, P> &other) + : node(const_cast<node_type *>(other.node)), position(other.position) {} // Increment/decrement the iterator. void increment() { @@ -890,11 +886,11 @@ struct btree_iterator { void decrement_slow(); public: - bool operator==(const const_iterator &x) const { - return node == x.node && position == x.position; + bool operator==(const const_iterator &other) const { + return node == other.node && position == other.position; } - bool operator!=(const const_iterator &x) const { - return node != x.node || position != x.position; + bool operator!=(const const_iterator &other) const { + return node != other.node || position != other.position; } // Accessors for the key/value the iterator is pointing at. @@ -942,7 +938,8 @@ struct btree_iterator { // The node in the tree the iterator is pointing at. Node *node; // The position within the node of the tree the iterator is pointing at. - // TODO(ezb): make this a field_type + // NOTE: this is an int rather than a field_type because iterators can point + // to invalid positions (such as -1) in certain circumstances. int position; }; @@ -994,9 +991,9 @@ class btree { node_stats(size_type l, size_type i) : leaf_nodes(l), internal_nodes(i) {} - node_stats &operator+=(const node_stats &x) { - leaf_nodes += x.leaf_nodes; - internal_nodes += x.internal_nodes; + node_stats &operator+=(const node_stats &other) { + leaf_nodes += other.leaf_nodes; + internal_nodes += other.internal_nodes; return *this; } @@ -1028,15 +1025,15 @@ class btree { private: // For use in copy_or_move_values_in_order. - const value_type &maybe_move_from_iterator(const_iterator x) { return *x; } - value_type &&maybe_move_from_iterator(iterator x) { return std::move(*x); } + const value_type &maybe_move_from_iterator(const_iterator it) { return *it; } + value_type &&maybe_move_from_iterator(iterator it) { return std::move(*it); } // Copies or moves (depending on the template parameter) the values in - // x into this btree in their order in x. This btree must be empty before this - // method is called. This method is used in copy construction, copy - // assignment, and move assignment. + // other into this btree in their order in other. This btree must be empty + // before this method is called. This method is used in copy construction, + // copy assignment, and move assignment. template <typename Btree> - void copy_or_move_values_in_order(Btree *x); + void copy_or_move_values_in_order(Btree *other); // Validates that various assumptions/requirements are true at compile time. constexpr static bool static_assert_validation(); @@ -1044,12 +1041,12 @@ class btree { public: btree(const key_compare &comp, const allocator_type &alloc); - btree(const btree &x); - btree(btree &&x) noexcept - : root_(std::move(x.root_)), - rightmost_(absl::exchange(x.rightmost_, EmptyNode())), - size_(absl::exchange(x.size_, 0)) { - x.mutable_root() = EmptyNode(); + btree(const btree &other); + btree(btree &&other) noexcept + : root_(std::move(other.root_)), + rightmost_(absl::exchange(other.rightmost_, EmptyNode())), + size_(absl::exchange(other.size_, 0)) { + other.mutable_root() = EmptyNode(); } ~btree() { @@ -1059,9 +1056,9 @@ class btree { clear(); } - // Assign the contents of x to *this. - btree &operator=(const btree &x); - btree &operator=(btree &&x) noexcept; + // Assign the contents of other to *this. + btree &operator=(const btree &other); + btree &operator=(btree &&other) noexcept; iterator begin() { return iterator(leftmost()); } const_iterator begin() const { return const_iterator(leftmost()); } @@ -1204,15 +1201,15 @@ class btree { // Clear the btree, deleting all of the values it contains. void clear(); - // Swap the contents of *this and x. - void swap(btree &x); + // Swaps the contents of `this` and `other`. + void swap(btree &other); const key_compare &key_comp() const noexcept { return root_.template get<0>(); } - template <typename K, typename LK> - bool compare_keys(const K &x, const LK &y) const { - return compare_internal::compare_result_as_less_than(key_comp()(x, y)); + template <typename K1, typename K2> + bool compare_keys(const K1 &a, const K2 &b) const { + return compare_internal::compare_result_as_less_than(key_comp()(a, b)); } value_compare value_comp() const { return value_compare(key_comp()); } @@ -1322,16 +1319,19 @@ class btree { // Node creation/deletion routines. node_type *new_internal_node(node_type *parent) { - node_type *p = allocate(node_type::InternalSize()); - return node_type::init_internal(p, parent); + node_type *n = allocate(node_type::InternalSize()); + n->init_internal(parent); + return n; } node_type *new_leaf_node(node_type *parent) { - node_type *p = allocate(node_type::LeafSize()); - return node_type::init_leaf(p, parent, kNodeValues); + node_type *n = allocate(node_type::LeafSize()); + n->init_leaf(parent, kNodeValues); + return n; } node_type *new_leaf_root_node(const int max_count) { - node_type *p = allocate(node_type::LeafSize(max_count)); - return node_type::init_leaf(p, p, max_count); + node_type *n = allocate(node_type::LeafSize(max_count)); + n->init_leaf(/*parent=*/n, max_count); + return n; } // Deletion helper routines. @@ -1715,12 +1715,12 @@ void btree_node<P>::merge(btree_node *src, allocator_type *alloc) { } template <typename P> -void btree_node<P>::swap(btree_node *x, allocator_type *alloc) { +void btree_node<P>::swap(btree_node *other, allocator_type *alloc) { using std::swap; - assert(leaf() == x->leaf()); + assert(leaf() == other->leaf()); // Determine which is the smaller/larger node. - btree_node *smaller = this, *larger = x; + btree_node *smaller = this, *larger = other; if (smaller->count() > larger->count()) { swap(smaller, larger); } @@ -1759,7 +1759,7 @@ void btree_node<P>::swap(btree_node *x, allocator_type *alloc) { // Swap the `finish`s. // TODO(ezb): with floating storage, will also need to swap starts. - swap(mutable_finish(), x->mutable_finish()); + swap(mutable_finish(), other->mutable_finish()); } //// @@ -1814,7 +1814,7 @@ void btree_iterator<N, R, P>::decrement_slow() { // btree methods template <typename P> template <typename Btree> -void btree<P>::copy_or_move_values_in_order(Btree *x) { +void btree<P>::copy_or_move_values_in_order(Btree *other) { static_assert(std::is_same<btree, Btree>::value || std::is_same<const btree, Btree>::value, "Btree type must be same or const."); @@ -1822,11 +1822,11 @@ void btree<P>::copy_or_move_values_in_order(Btree *x) { // We can avoid key comparisons because we know the order of the // values is the same order we'll store them in. - auto iter = x->begin(); - if (iter == x->end()) return; + auto iter = other->begin(); + if (iter == other->end()) return; insert_multi(maybe_move_from_iterator(iter)); ++iter; - for (; iter != x->end(); ++iter) { + for (; iter != other->end(); ++iter) { // If the btree is not empty, we can just insert the new value at the end // of the tree. internal_emplace(end(), maybe_move_from_iterator(iter)); @@ -1869,8 +1869,9 @@ btree<P>::btree(const key_compare &comp, const allocator_type &alloc) : root_(comp, alloc, EmptyNode()), rightmost_(EmptyNode()), size_(0) {} template <typename P> -btree<P>::btree(const btree &x) : btree(x.key_comp(), x.allocator()) { - copy_or_move_values_in_order(&x); +btree<P>::btree(const btree &other) + : btree(other.key_comp(), other.allocator()) { + copy_or_move_values_in_order(&other); } template <typename P> @@ -1977,46 +1978,47 @@ void btree<P>::insert_iterator_multi(InputIterator b, InputIterator e) { } template <typename P> -auto btree<P>::operator=(const btree &x) -> btree & { - if (this != &x) { +auto btree<P>::operator=(const btree &other) -> btree & { + if (this != &other) { clear(); - *mutable_key_comp() = x.key_comp(); + *mutable_key_comp() = other.key_comp(); if (absl::allocator_traits< allocator_type>::propagate_on_container_copy_assignment::value) { - *mutable_allocator() = x.allocator(); + *mutable_allocator() = other.allocator(); } - copy_or_move_values_in_order(&x); + copy_or_move_values_in_order(&other); } return *this; } template <typename P> -auto btree<P>::operator=(btree &&x) noexcept -> btree & { - if (this != &x) { +auto btree<P>::operator=(btree &&other) noexcept -> btree & { + if (this != &other) { clear(); using std::swap; if (absl::allocator_traits< allocator_type>::propagate_on_container_copy_assignment::value) { // Note: `root_` also contains the allocator and the key comparator. - swap(root_, x.root_); - swap(rightmost_, x.rightmost_); - swap(size_, x.size_); + swap(root_, other.root_); + swap(rightmost_, other.rightmost_); + swap(size_, other.size_); } else { - if (allocator() == x.allocator()) { - swap(mutable_root(), x.mutable_root()); - swap(*mutable_key_comp(), *x.mutable_key_comp()); - swap(rightmost_, x.rightmost_); - swap(size_, x.size_); + if (allocator() == other.allocator()) { + swap(mutable_root(), other.mutable_root()); + swap(*mutable_key_comp(), *other.mutable_key_comp()); + swap(rightmost_, other.rightmost_); + swap(size_, other.size_); } else { // We aren't allowed to propagate the allocator and the allocator is // different so we can't take over its memory. We must move each element - // individually. We need both `x` and `this` to have `x`s key comparator - // while moving the values so we can't swap the key comparators. - *mutable_key_comp() = x.key_comp(); - copy_or_move_values_in_order(&x); + // individually. We need both `other` and `this` to have `other`s key + // comparator while moving the values so we can't swap the key + // comparators. + *mutable_key_comp() = other.key_comp(); + copy_or_move_values_in_order(&other); } } } @@ -2215,20 +2217,20 @@ void btree<P>::clear() { } template <typename P> -void btree<P>::swap(btree &x) { +void btree<P>::swap(btree &other) { using std::swap; if (absl::allocator_traits< allocator_type>::propagate_on_container_swap::value) { // Note: `root_` also contains the allocator and the key comparator. - swap(root_, x.root_); + swap(root_, other.root_); } else { // It's undefined behavior if the allocators are unequal here. - assert(allocator() == x.allocator()); - swap(mutable_root(), x.mutable_root()); - swap(*mutable_key_comp(), *x.mutable_key_comp()); + assert(allocator() == other.allocator()); + swap(mutable_root(), other.mutable_root()); + swap(*mutable_key_comp(), *other.mutable_key_comp()); } - swap(rightmost_, x.rightmost_); - swap(size_, x.size_); + swap(rightmost_, other.rightmost_); + swap(size_, other.size_); } template <typename P> @@ -2417,8 +2419,7 @@ void btree<P>::try_shrink() { if (root()->leaf()) { assert(size() == 0); delete_leaf_node(root()); - mutable_root() = EmptyNode(); - rightmost_ = EmptyNode(); + mutable_root() = rightmost_ = EmptyNode(); } else { node_type *child = root()->start_child(); child->make_root(); @@ -2463,8 +2464,7 @@ inline auto btree<P>::internal_emplace(iterator iter, Args &&... args) new_leaf_root_node((std::min<int>)(kNodeValues, 2 * max_count)); iter.node->swap(root(), mutable_allocator()); delete_leaf_node(root()); - mutable_root() = iter.node; - rightmost_ = iter.node; + mutable_root() = rightmost_ = iter.node; } else { rebalance_or_split(&iter); } |