diff options
Diffstat (limited to 'absl/container/internal')
45 files changed, 3667 insertions, 356 deletions
diff --git a/absl/container/internal/btree.h b/absl/container/internal/btree.h new file mode 100644 index 00000000..fd5c0e7a --- /dev/null +++ b/absl/container/internal/btree.h @@ -0,0 +1,2614 @@ +// Copyright 2018 The Abseil Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// A btree implementation of the STL set and map interfaces. A btree is smaller +// and generally also faster than STL set/map (refer to the benchmarks below). +// The red-black tree implementation of STL set/map has an overhead of 3 +// pointers (left, right and parent) plus the node color information for each +// stored value. So a set<int32_t> consumes 40 bytes for each value stored in +// 64-bit mode. This btree implementation stores multiple values on fixed +// size nodes (usually 256 bytes) and doesn't store child pointers for leaf +// nodes. The result is that a btree_set<int32_t> may use much less memory per +// stored value. For the random insertion benchmark in btree_bench.cc, a +// btree_set<int32_t> with node-size of 256 uses 5.1 bytes per stored value. +// +// The packing of multiple values on to each node of a btree has another effect +// besides better space utilization: better cache locality due to fewer cache +// lines being accessed. Better cache locality translates into faster +// operations. +// +// CAVEATS +// +// Insertions and deletions on a btree can cause splitting, merging or +// rebalancing of btree nodes. And even without these operations, insertions +// and deletions on a btree will move values around within a node. In both +// cases, the result is that insertions and deletions can invalidate iterators +// pointing to values other than the one being inserted/deleted. Therefore, this +// container does not provide pointer stability. This is notably different from +// STL set/map which takes care to not invalidate iterators on insert/erase +// except, of course, for iterators pointing to the value being erased. A +// partial workaround when erasing is available: erase() returns an iterator +// pointing to the item just after the one that was erased (or end() if none +// exists). + +#ifndef ABSL_CONTAINER_INTERNAL_BTREE_H_ +#define ABSL_CONTAINER_INTERNAL_BTREE_H_ + +#include <algorithm> +#include <cassert> +#include <cstddef> +#include <cstdint> +#include <cstring> +#include <functional> +#include <iterator> +#include <limits> +#include <new> +#include <string> +#include <type_traits> +#include <utility> + +#include "absl/base/macros.h" +#include "absl/container/internal/common.h" +#include "absl/container/internal/compressed_tuple.h" +#include "absl/container/internal/container_memory.h" +#include "absl/container/internal/layout.h" +#include "absl/memory/memory.h" +#include "absl/meta/type_traits.h" +#include "absl/strings/string_view.h" +#include "absl/types/compare.h" +#include "absl/utility/utility.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN +namespace container_internal { + +// A helper class that indicates if the Compare parameter is a key-compare-to +// comparator. +template <typename Compare, typename T> +using btree_is_key_compare_to = + std::is_convertible<absl::result_of_t<Compare(const T &, const T &)>, + absl::weak_ordering>; + +struct StringBtreeDefaultLess { + using is_transparent = void; + + StringBtreeDefaultLess() = default; + + // Compatibility constructor. + StringBtreeDefaultLess(std::less<std::string>) {} // NOLINT + StringBtreeDefaultLess(std::less<string_view>) {} // NOLINT + + absl::weak_ordering operator()(absl::string_view lhs, + absl::string_view rhs) const { + return compare_internal::compare_result_as_ordering(lhs.compare(rhs)); + } +}; + +struct StringBtreeDefaultGreater { + using is_transparent = void; + + StringBtreeDefaultGreater() = default; + + StringBtreeDefaultGreater(std::greater<std::string>) {} // NOLINT + StringBtreeDefaultGreater(std::greater<string_view>) {} // NOLINT + + absl::weak_ordering operator()(absl::string_view lhs, + absl::string_view rhs) const { + return compare_internal::compare_result_as_ordering(rhs.compare(lhs)); + } +}; + +// A helper class to convert a boolean comparison into a three-way "compare-to" +// comparison that returns a negative value to indicate less-than, zero to +// indicate equality and a positive value to indicate greater-than. This helper +// class is specialized for less<std::string>, greater<std::string>, +// less<string_view>, and greater<string_view>. +// +// key_compare_to_adapter is provided so that btree users +// automatically get the more efficient compare-to code when using common +// google string types with common comparison functors. +// These string-like specializations also turn on heterogeneous lookup by +// default. +template <typename Compare> +struct key_compare_to_adapter { + using type = Compare; +}; + +template <> +struct key_compare_to_adapter<std::less<std::string>> { + using type = StringBtreeDefaultLess; +}; + +template <> +struct key_compare_to_adapter<std::greater<std::string>> { + using type = StringBtreeDefaultGreater; +}; + +template <> +struct key_compare_to_adapter<std::less<absl::string_view>> { + using type = StringBtreeDefaultLess; +}; + +template <> +struct key_compare_to_adapter<std::greater<absl::string_view>> { + using type = StringBtreeDefaultGreater; +}; + +template <typename Key, typename Compare, typename Alloc, int TargetNodeSize, + bool Multi, typename SlotPolicy> +struct common_params { + // If Compare is a common comparator for a std::string-like type, then we adapt it + // to use heterogeneous lookup and to be a key-compare-to comparator. + using key_compare = typename key_compare_to_adapter<Compare>::type; + // A type which indicates if we have a key-compare-to functor or a plain old + // key-compare functor. + using is_key_compare_to = btree_is_key_compare_to<key_compare, Key>; + + using allocator_type = Alloc; + using key_type = Key; + using size_type = std::make_signed<size_t>::type; + using difference_type = ptrdiff_t; + + // True if this is a multiset or multimap. + using is_multi_container = std::integral_constant<bool, Multi>; + + using slot_policy = SlotPolicy; + using slot_type = typename slot_policy::slot_type; + using value_type = typename slot_policy::value_type; + using init_type = typename slot_policy::mutable_value_type; + using pointer = value_type *; + using const_pointer = const value_type *; + using reference = value_type &; + using const_reference = const value_type &; + + enum { + kTargetNodeSize = TargetNodeSize, + + // Upper bound for the available space for values. This is largest for leaf + // nodes, which have overhead of at least a pointer + 4 bytes (for storing + // 3 field_types and an enum). + kNodeValueSpace = + TargetNodeSize - /*minimum overhead=*/(sizeof(void *) + 4), + }; + + // This is an integral type large enough to hold as many + // ValueSize-values as will fit a node of TargetNodeSize bytes. + using node_count_type = + absl::conditional_t<(kNodeValueSpace / sizeof(value_type) > + (std::numeric_limits<uint8_t>::max)()), + uint16_t, uint8_t>; // NOLINT + + // The following methods are necessary for passing this struct as PolicyTraits + // for node_handle and/or are used within btree. + static value_type &element(slot_type *slot) { + return slot_policy::element(slot); + } + static const value_type &element(const slot_type *slot) { + return slot_policy::element(slot); + } + template <class... Args> + static void construct(Alloc *alloc, slot_type *slot, Args &&... args) { + slot_policy::construct(alloc, slot, std::forward<Args>(args)...); + } + static void construct(Alloc *alloc, slot_type *slot, slot_type *other) { + slot_policy::construct(alloc, slot, other); + } + static void destroy(Alloc *alloc, slot_type *slot) { + slot_policy::destroy(alloc, slot); + } + static void transfer(Alloc *alloc, slot_type *new_slot, slot_type *old_slot) { + construct(alloc, new_slot, old_slot); + destroy(alloc, old_slot); + } + static void swap(Alloc *alloc, slot_type *a, slot_type *b) { + slot_policy::swap(alloc, a, b); + } + static void move(Alloc *alloc, slot_type *src, slot_type *dest) { + slot_policy::move(alloc, src, dest); + } + static void move(Alloc *alloc, slot_type *first, slot_type *last, + slot_type *result) { + slot_policy::move(alloc, first, last, result); + } +}; + +// A parameters structure for holding the type parameters for a btree_map. +// Compare and Alloc should be nothrow copy-constructible. +template <typename Key, typename Data, typename Compare, typename Alloc, + int TargetNodeSize, bool Multi> +struct map_params : common_params<Key, Compare, Alloc, TargetNodeSize, Multi, + map_slot_policy<Key, Data>> { + using super_type = typename map_params::common_params; + using mapped_type = Data; + // This type allows us to move keys when it is safe to do so. It is safe + // for maps in which value_type and mutable_value_type are layout compatible. + using slot_policy = typename super_type::slot_policy; + using slot_type = typename super_type::slot_type; + using value_type = typename super_type::value_type; + using init_type = typename super_type::init_type; + + using key_compare = typename super_type::key_compare; + // Inherit from key_compare for empty base class optimization. + struct value_compare : private key_compare { + value_compare() = default; + explicit value_compare(const key_compare &cmp) : key_compare(cmp) {} + + template <typename T, typename U> + auto operator()(const T &left, const U &right) const + -> decltype(std::declval<key_compare>()(left.first, right.first)) { + return key_compare::operator()(left.first, right.first); + } + }; + 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 mapped_type &value(value_type *value) { return value->second; } +}; + +// This type implements the necessary functions from the +// absl::container_internal::slot_type interface. +template <typename Key> +struct set_slot_policy { + using slot_type = Key; + using value_type = Key; + using mutable_value_type = Key; + + static value_type &element(slot_type *slot) { return *slot; } + static const value_type &element(const slot_type *slot) { return *slot; } + + template <typename Alloc, class... Args> + static void construct(Alloc *alloc, slot_type *slot, Args &&... args) { + absl::allocator_traits<Alloc>::construct(*alloc, slot, + std::forward<Args>(args)...); + } + + template <typename Alloc> + static void construct(Alloc *alloc, slot_type *slot, slot_type *other) { + absl::allocator_traits<Alloc>::construct(*alloc, slot, std::move(*other)); + } + + template <typename Alloc> + static void destroy(Alloc *alloc, slot_type *slot) { + absl::allocator_traits<Alloc>::destroy(*alloc, slot); + } + + template <typename Alloc> + static void swap(Alloc * /*alloc*/, slot_type *a, slot_type *b) { + using std::swap; + swap(*a, *b); + } + + template <typename Alloc> + static void move(Alloc * /*alloc*/, slot_type *src, slot_type *dest) { + *dest = std::move(*src); + } + + template <typename Alloc> + static void move(Alloc *alloc, slot_type *first, slot_type *last, + slot_type *result) { + for (slot_type *src = first, *dest = result; src != last; ++src, ++dest) + move(alloc, src, dest); + } +}; + +// A parameters structure for holding the type parameters for a btree_set. +// Compare and Alloc should be nothrow copy-constructible. +template <typename Key, typename Compare, typename Alloc, int TargetNodeSize, + bool Multi> +struct set_params : common_params<Key, Compare, Alloc, TargetNodeSize, Multi, + set_slot_policy<Key>> { + using value_type = Key; + using slot_type = typename set_params::common_params::slot_type; + 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; } +}; + +// An adapter class that converts a lower-bound compare into an upper-bound +// compare. Note: there is no need to make a version of this adapter specialized +// for key-compare-to functors because the upper-bound (the first value greater +// than the input) is never an exact match. +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 { + // Returns true when a is not greater than b. + return !compare_internal::compare_result_as_less_than(comp(b, a)); + } + + private: + Compare comp; +}; + +enum class MatchKind : uint8_t { kEq, kNe }; + +template <typename V, bool IsCompareTo> +struct SearchResult { + V value; + MatchKind match; + + static constexpr bool HasMatch() { return true; } + bool IsEq() const { return match == MatchKind::kEq; } +}; + +// When we don't use CompareTo, `match` is not present. +// This ensures that callers can't use it accidentally when it provides no +// useful information. +template <typename V> +struct SearchResult<V, false> { + V value; + + static constexpr bool HasMatch() { return false; } + static constexpr bool IsEq() { return false; } +}; + +// A node in the btree holding. The same node type is used for both internal +// and leaf nodes in the btree, though the nodes are allocated in such a way +// that the children array is only valid in internal nodes. +template <typename Params> +class btree_node { + using is_key_compare_to = typename Params::is_key_compare_to; + using is_multi_container = typename Params::is_multi_container; + using field_type = typename Params::node_count_type; + using allocator_type = typename Params::allocator_type; + using slot_type = typename Params::slot_type; + + public: + using params_type = Params; + using key_type = typename Params::key_type; + using value_type = typename Params::value_type; + using pointer = typename Params::pointer; + using const_pointer = typename Params::const_pointer; + using reference = typename Params::reference; + using const_reference = typename Params::const_reference; + using key_compare = typename Params::key_compare; + using size_type = typename Params::size_type; + using difference_type = typename Params::difference_type; + + // Btree decides whether to use linear node search as follows: + // - If the key is arithmetic and the comparator is std::less or + // std::greater, choose linear. + // - Otherwise, choose binary. + // TODO(ezb): Might make sense to add condition(s) based on node-size. + using use_linear_search = std::integral_constant< + bool, + std::is_arithmetic<key_type>::value && + (std::is_same<std::less<key_type>, key_compare>::value || + std::is_same<std::greater<key_type>, key_compare>::value)>; + + // This class is organized by gtl::Layout as if it had the following + // structure: + // // A pointer to the node's parent. + // btree_node *parent; + // + // // The position of the node in the node's parent. + // field_type position; + // // The index of the first populated value in `values`. + // // TODO(ezb): right now, `start` is always 0. Update insertion/merge + // // logic to allow for floating storage within nodes. + // field_type start; + // // The index after the last populated value in `values`. Currently, this + // // is the same as the count of values. + // field_type finish; + // // The maximum number of values the node can hold. This is an integer in + // // [1, kNodeValues] for root leaf nodes, kNodeValues for non-root leaf + // // nodes, and kInternalNodeMaxCount (as a sentinel value) for internal + // // nodes (even though there are still kNodeValues values in the node). + // // TODO(ezb): make max_count use only 4 bits and record log2(capacity) + // // to free extra bits for is_root, etc. + // field_type max_count; + // + // // The array of values. The capacity is `max_count` for leaf nodes and + // // kNodeValues for internal nodes. Only the values in + // // [start, finish) have been initialized and are valid. + // slot_type values[max_count]; + // + // // The array of child pointers. The keys in children[i] are all less + // // than key(i). The keys in children[i + 1] are all greater than key(i). + // // There are 0 children for leaf nodes and kNodeValues + 1 children for + // // internal nodes. + // btree_node *children[kNodeValues + 1]; + // + // This class is only constructed by EmptyNodeType. Normally, pointers to the + // layout above are allocated, cast to btree_node*, and de-allocated within + // the btree implementation. + ~btree_node() = default; + btree_node(btree_node const &) = delete; + btree_node &operator=(btree_node const &) = delete; + + // Public for EmptyNodeType. + constexpr static size_type Alignment() { + static_assert(LeafLayout(1).Alignment() == InternalLayout().Alignment(), + "Alignment of all nodes must be equal."); + return InternalLayout().Alignment(); + } + + protected: + btree_node() = default; + + private: + using layout_type = absl::container_internal::Layout<btree_node *, field_type, + slot_type, btree_node *>; + constexpr static size_type SizeWithNValues(size_type n) { + return layout_type(/*parent*/ 1, + /*position, start, finish, max_count*/ 4, + /*values*/ n, + /*children*/ 0) + .AllocSize(); + } + // A lower bound for the overhead of fields other than values in a leaf node. + constexpr static size_type MinimumOverhead() { + return SizeWithNValues(1) - sizeof(value_type); + } + + // Compute how many values we can fit onto a leaf node taking into account + // padding. + constexpr static size_type NodeTargetValues(const int begin, const int end) { + return begin == end ? begin + : SizeWithNValues((begin + end) / 2 + 1) > + params_type::kTargetNodeSize + ? NodeTargetValues(begin, (begin + end) / 2) + : NodeTargetValues((begin + end) / 2 + 1, end); + } + + enum { + kTargetNodeSize = params_type::kTargetNodeSize, + kNodeTargetValues = NodeTargetValues(0, params_type::kTargetNodeSize), + + // We need a minimum of 3 values per internal node in order to perform + // splitting (1 value for the two nodes involved in the split and 1 value + // propagated to the parent as the delimiter for the split). + kNodeValues = kNodeTargetValues >= 3 ? kNodeTargetValues : 3, + + // The node is internal (i.e. is not a leaf node) if and only if `max_count` + // has this value. + kInternalNodeMaxCount = 0, + }; + + // Leaves can have less than kNodeValues values. + constexpr static layout_type LeafLayout(const int max_values = kNodeValues) { + return layout_type(/*parent*/ 1, + /*position, start, finish, max_count*/ 4, + /*values*/ max_values, + /*children*/ 0); + } + constexpr static layout_type InternalLayout() { + return layout_type(/*parent*/ 1, + /*position, start, finish, max_count*/ 4, + /*values*/ kNodeValues, + /*children*/ kNodeValues + 1); + } + constexpr static size_type LeafSize(const int max_values = kNodeValues) { + return LeafLayout(max_values).AllocSize(); + } + constexpr static size_type InternalSize() { + return InternalLayout().AllocSize(); + } + + // N is the index of the type in the Layout definition. + // ElementType<N> is the Nth type in the Layout definition. + template <size_type N> + inline typename layout_type::template ElementType<N> *GetField() { + // We assert that we don't read from values that aren't there. + assert(N < 3 || !leaf()); + return InternalLayout().template Pointer<N>(reinterpret_cast<char *>(this)); + } + template <size_type N> + inline const typename layout_type::template ElementType<N> *GetField() const { + assert(N < 3 || !leaf()); + return InternalLayout().template Pointer<N>( + reinterpret_cast<const char *>(this)); + } + void set_parent(btree_node *p) { *GetField<0>() = p; } + field_type &mutable_finish() { return GetField<1>()[2]; } + slot_type *slot(int i) { return &GetField<2>()[i]; } + slot_type *start_slot() { return slot(start()); } + slot_type *finish_slot() { return slot(finish()); } + const slot_type *slot(int i) const { return &GetField<2>()[i]; } + void set_position(field_type v) { GetField<1>()[0] = v; } + void set_start(field_type v) { GetField<1>()[1] = v; } + void set_finish(field_type v) { GetField<1>()[2] = v; } + // This method is only called by the node init methods. + void set_max_count(field_type v) { GetField<1>()[3] = v; } + + public: + // Whether this is a leaf node or not. This value doesn't change after the + // node is created. + bool leaf() const { return GetField<1>()[3] != kInternalNodeMaxCount; } + + // Getter for the position of this node in its parent. + field_type position() const { return GetField<1>()[0]; } + + // Getter for the offset of the first value in the `values` array. + field_type start() const { + // TODO(ezb): when floating storage is implemented, return GetField<1>()[1]; + assert(GetField<1>()[1] == 0); + return 0; + } + + // Getter for the offset after the last value in the `values` array. + field_type finish() const { return GetField<1>()[2]; } + + // Getters for the number of values stored in this node. + field_type count() const { + assert(finish() >= start()); + return finish() - start(); + } + field_type max_count() const { + // Internal nodes have max_count==kInternalNodeMaxCount. + // Leaf nodes have max_count in [1, kNodeValues]. + const field_type max_count = GetField<1>()[3]; + return max_count == field_type{kInternalNodeMaxCount} + ? field_type{kNodeValues} + : max_count; + } + + // Getter for the parent of this node. + btree_node *parent() const { return *GetField<0>(); } + // Getter for whether the node is the root of the tree. The parent of the + // root of the tree is the leftmost node in the tree which is guaranteed to + // be a leaf. + bool is_root() const { return parent()->leaf(); } + void make_root() { + assert(parent()->is_root()); + set_parent(parent()->parent()); + } + + // Getters for the key/value at position i in the node. + const key_type &key(int i) const { return params_type::key(slot(i)); } + reference value(int i) { return params_type::element(slot(i)); } + const_reference value(int i) const { return params_type::element(slot(i)); } + + // Getters/setter for the child at position i in the node. + btree_node *child(int i) const { return GetField<3>()[i]; } + btree_node *start_child() const { return child(start()); } + btree_node *&mutable_child(int i) { return GetField<3>()[i]; } + void clear_child(int i) { + absl::container_internal::SanitizerPoisonObject(&mutable_child(i)); + } + void set_child(int i, btree_node *c) { + absl::container_internal::SanitizerUnpoisonObject(&mutable_child(i)); + mutable_child(i) = c; + c->set_position(i); + } + void init_child(int i, btree_node *c) { + set_child(i, c); + c->set_parent(this); + } + + // Returns the position of the first value whose key is not less than k. + template <typename K> + SearchResult<int, is_key_compare_to::value> lower_bound( + const K &k, const key_compare &comp) const { + return use_linear_search::value ? linear_search(k, comp) + : binary_search(k, comp); + } + // Returns the position of the first value whose key is greater than k. + template <typename K> + int upper_bound(const K &k, const key_compare &comp) const { + auto upper_compare = upper_bound_adapter<key_compare>(comp); + return use_linear_search::value ? linear_search(k, upper_compare).value + : binary_search(k, upper_compare).value; + } + + template <typename K, typename Compare> + SearchResult<int, btree_is_key_compare_to<Compare, key_type>::value> + linear_search(const K &k, const Compare &comp) const { + return linear_search_impl(k, start(), finish(), comp, + btree_is_key_compare_to<Compare, key_type>()); + } + + template <typename K, typename Compare> + SearchResult<int, btree_is_key_compare_to<Compare, key_type>::value> + binary_search(const K &k, const Compare &comp) const { + return binary_search_impl(k, start(), finish(), comp, + btree_is_key_compare_to<Compare, key_type>()); + } + + // Returns the position of the first value whose key is not less than k using + // linear search performed using plain compare. + template <typename K, typename Compare> + SearchResult<int, false> linear_search_impl( + const K &k, int s, const int e, const Compare &comp, + std::false_type /* IsCompareTo */) const { + while (s < e) { + if (!comp(key(s), k)) { + break; + } + ++s; + } + return {s}; + } + + // Returns the position of the first value whose key is not less than k using + // linear search performed using compare-to. + template <typename K, typename Compare> + SearchResult<int, true> linear_search_impl( + const K &k, int s, const int e, const Compare &comp, + std::true_type /* IsCompareTo */) const { + while (s < e) { + const absl::weak_ordering c = comp(key(s), k); + if (c == 0) { + return {s, MatchKind::kEq}; + } else if (c > 0) { + break; + } + ++s; + } + return {s, MatchKind::kNe}; + } + + // Returns the position of the first value whose key is not less than k using + // binary search performed using plain compare. + template <typename K, typename Compare> + SearchResult<int, false> binary_search_impl( + const K &k, int s, int e, const Compare &comp, + std::false_type /* IsCompareTo */) const { + while (s != e) { + const int mid = (s + e) >> 1; + if (comp(key(mid), k)) { + s = mid + 1; + } else { + e = mid; + } + } + return {s}; + } + + // Returns the position of the first value whose key is not less than k using + // binary search performed using compare-to. + template <typename K, typename CompareTo> + SearchResult<int, true> binary_search_impl( + const K &k, int s, int e, const CompareTo &comp, + std::true_type /* IsCompareTo */) const { + if (is_multi_container::value) { + MatchKind exact_match = MatchKind::kNe; + while (s != e) { + const int mid = (s + e) >> 1; + const absl::weak_ordering c = comp(key(mid), k); + if (c < 0) { + s = mid + 1; + } else { + e = mid; + if (c == 0) { + // Need to return the first value whose key is not less than k, + // which requires continuing the binary search if this is a + // multi-container. + exact_match = MatchKind::kEq; + } + } + } + return {s, exact_match}; + } else { // Not a multi-container. + while (s != e) { + const int mid = (s + e) >> 1; + const absl::weak_ordering c = comp(key(mid), k); + if (c < 0) { + s = mid + 1; + } else if (c > 0) { + e = mid; + } else { + return {mid, MatchKind::kEq}; + } + } + return {s, MatchKind::kNe}; + } + } + + // Emplaces a value at position i, shifting all existing values and + // children at positions >= i to the right by 1. + template <typename... Args> + void emplace_value(size_type i, allocator_type *alloc, Args &&... args); + + // Removes the value at position i, shifting all existing values and children + // at positions > i to the left by 1. + void remove_value(int i, allocator_type *alloc); + + // Removes the values at positions [i, i + to_erase), shifting all values + // after that range to the left by to_erase. Does not change children at all. + void remove_values_ignore_children(int i, int to_erase, + allocator_type *alloc); + + // Rebalances a node with its right sibling. + void rebalance_right_to_left(int to_move, btree_node *right, + allocator_type *alloc); + void rebalance_left_to_right(int to_move, btree_node *right, + allocator_type *alloc); + + // Splits a node, moving a portion of the node's values to its right sibling. + void split(int insert_position, btree_node *dest, allocator_type *alloc); + + // 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); + + // Swap the contents of "this" and "src". + void swap(btree_node *src, 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); + absl::container_internal::SanitizerPoisonMemoryRegion( + n->start_slot(), max_count * sizeof(slot_type)); + return n; + } + static btree_node *init_internal(btree_node *n, btree_node *parent) { + init_leaf(n, parent, kNodeValues); + // Set `max_count` to a sentinel value to indicate that this node is + // internal. + n->set_max_count(kInternalNodeMaxCount); + absl::container_internal::SanitizerPoisonMemoryRegion( + &n->mutable_child(n->start()), + (kNodeValues + 1) * sizeof(btree_node *)); + return n; + } + void destroy(allocator_type *alloc) { + for (int i = start(); i < finish(); ++i) { + value_destroy(i, alloc); + } + } + + public: + // Exposed only for tests. + static bool testonly_uses_linear_node_search() { + return use_linear_search::value; + } + + private: + template <typename... Args> + void value_init(const size_type i, allocator_type *alloc, Args &&... args) { + absl::container_internal::SanitizerUnpoisonObject(slot(i)); + params_type::construct(alloc, slot(i), std::forward<Args>(args)...); + } + void value_destroy(const size_type i, allocator_type *alloc) { + params_type::destroy(alloc, slot(i)); + absl::container_internal::SanitizerPoisonObject(slot(i)); + } + + // Move n values starting at value i in this node into the values starting at + // value j in node x. + void uninitialized_move_n(const size_type n, const size_type i, + const size_type j, btree_node *x, + 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); + src != end; ++src, ++dest) { + params_type::construct(alloc, dest, src); + } + } + + // Destroys a range of n values, starting at index i. + void value_destroy_n(const size_type i, const size_type n, + allocator_type *alloc) { + for (int j = 0; j < n; ++j) { + value_destroy(i + j, alloc); + } + } + + template <typename P> + friend class btree; + template <typename N, typename R, typename P> + friend struct btree_iterator; + friend class BtreeNodePeer; +}; + +template <typename Node, typename Reference, typename Pointer> +struct btree_iterator { + private: + using key_type = typename Node::key_type; + using size_type = typename Node::size_type; + using params_type = typename Node::params_type; + + using node_type = Node; + using normal_node = typename std::remove_const<Node>::type; + using const_node = const Node; + using normal_pointer = typename params_type::pointer; + using normal_reference = typename params_type::reference; + using const_pointer = typename params_type::const_pointer; + using const_reference = typename params_type::const_reference; + using slot_type = typename params_type::slot_type; + + using iterator = + btree_iterator<normal_node, normal_reference, normal_pointer>; + using const_iterator = + btree_iterator<const_node, const_reference, const_pointer>; + + public: + // These aliases are public for std::iterator_traits. + using difference_type = typename Node::difference_type; + using value_type = typename params_type::value_type; + using pointer = Pointer; + using reference = Reference; + using iterator_category = std::bidirectional_iterator_tag; + + btree_iterator() : node(nullptr), position(-1) {} + explicit btree_iterator(Node *n) : node(n), position(n->start()) {} + btree_iterator(Node *n, int p) : node(n), position(p) {} + + // NOTE: this SFINAE allows for implicit conversions from iterator to + // const_iterator, but it specifically avoids defining copy constructors so + // that btree_iterator can be trivially copyable. This is for performance and + // binary size reasons. + template <typename N, typename R, typename P, + absl::enable_if_t< + 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) {} + + private: + // This SFINAE allows explicit conversions from const_iterator to + // iterator, but also avoids defining a copy constructor. + // NOTE: the const_cast is safe because this constructor is only called by + // non-const methods and the container owns the nodes. + template <typename N, typename R, typename P, + absl::enable_if_t< + 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) {} + + // Increment/decrement the iterator. + void increment() { + if (node->leaf() && ++position < node->finish()) { + return; + } + increment_slow(); + } + void increment_slow(); + + void decrement() { + if (node->leaf() && --position >= node->start()) { + return; + } + decrement_slow(); + } + void decrement_slow(); + + public: + bool operator==(const const_iterator &x) const { + return node == x.node && position == x.position; + } + bool operator!=(const const_iterator &x) const { + return node != x.node || position != x.position; + } + + // Accessors for the key/value the iterator is pointing at. + reference operator*() const { return node->value(position); } + pointer operator->() const { return &node->value(position); } + + btree_iterator &operator++() { + increment(); + return *this; + } + btree_iterator &operator--() { + decrement(); + return *this; + } + btree_iterator operator++(int) { + btree_iterator tmp = *this; + ++*this; + return tmp; + } + btree_iterator operator--(int) { + btree_iterator tmp = *this; + --*this; + return tmp; + } + + private: + template <typename Params> + friend class btree; + template <typename Tree> + friend class btree_container; + template <typename Tree> + friend class btree_set_container; + template <typename Tree> + friend class btree_map_container; + template <typename Tree> + friend class btree_multiset_container; + template <typename N, typename R, typename P> + friend struct btree_iterator; + template <typename TreeType, typename CheckerType> + friend class base_checker; + + const key_type &key() const { return node->key(position); } + slot_type *slot() { return node->slot(position); } + + // 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 + int position; +}; + +template <typename Params> +class btree { + using node_type = btree_node<Params>; + using is_key_compare_to = typename Params::is_key_compare_to; + + // We use a static empty node for the root/leftmost/rightmost of empty btrees + // in order to avoid branching in begin()/end(). + struct alignas(node_type::Alignment()) EmptyNodeType : node_type { + using field_type = typename node_type::field_type; + node_type *parent; + field_type position = 0; + field_type start = 0; + field_type finish = 0; + // max_count must be != kInternalNodeMaxCount (so that this node is regarded + // as a leaf node). max_count() is never called when the tree is empty. + field_type max_count = node_type::kInternalNodeMaxCount + 1; + +#ifdef _MSC_VER + // MSVC has constexpr code generations bugs here. + EmptyNodeType() : parent(this) {} +#else + constexpr EmptyNodeType(node_type *p) : parent(p) {} +#endif + }; + + static node_type *EmptyNode() { +#ifdef _MSC_VER + static EmptyNodeType *empty_node = new EmptyNodeType; + // This assert fails on some other construction methods. + assert(empty_node->parent == empty_node); + return empty_node; +#else + static constexpr EmptyNodeType empty_node( + const_cast<EmptyNodeType *>(&empty_node)); + return const_cast<EmptyNodeType *>(&empty_node); +#endif + } + + enum { + kNodeValues = node_type::kNodeValues, + kMinNodeValues = kNodeValues / 2, + }; + + struct node_stats { + using size_type = typename Params::size_type; + + 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; + return *this; + } + + size_type leaf_nodes; + size_type internal_nodes; + }; + + public: + using key_type = typename Params::key_type; + using value_type = typename Params::value_type; + using size_type = typename Params::size_type; + using difference_type = typename Params::difference_type; + using key_compare = typename Params::key_compare; + using value_compare = typename Params::value_compare; + using allocator_type = typename Params::allocator_type; + using reference = typename Params::reference; + using const_reference = typename Params::const_reference; + using pointer = typename Params::pointer; + using const_pointer = typename Params::const_pointer; + using iterator = btree_iterator<node_type, reference, pointer>; + using const_iterator = typename iterator::const_iterator; + using reverse_iterator = std::reverse_iterator<iterator>; + using const_reverse_iterator = std::reverse_iterator<const_iterator>; + using node_handle_type = node_handle<Params, Params, allocator_type>; + + // Internal types made public for use by btree_container types. + using params_type = Params; + using slot_type = typename Params::slot_type; + + 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); } + + // 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. + template <typename Btree> + void copy_or_move_values_in_order(Btree *x); + + // Validates that various assumptions/requirements are true at compile time. + constexpr static bool static_assert_validation(); + + 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() { + // Put static_asserts in destructor to avoid triggering them before the type + // is complete. + static_assert(static_assert_validation(), "This call must be elided."); + clear(); + } + + // Assign the contents of x to *this. + btree &operator=(const btree &x); + btree &operator=(btree &&x) noexcept; + + iterator begin() { return iterator(leftmost()); } + const_iterator begin() const { return const_iterator(leftmost()); } + iterator end() { return iterator(rightmost_, rightmost_->finish()); } + const_iterator end() const { + return const_iterator(rightmost_, rightmost_->finish()); + } + reverse_iterator rbegin() { return reverse_iterator(end()); } + const_reverse_iterator rbegin() const { + return const_reverse_iterator(end()); + } + reverse_iterator rend() { return reverse_iterator(begin()); } + const_reverse_iterator rend() const { + return const_reverse_iterator(begin()); + } + + // Finds the first element whose key is not less than key. + template <typename K> + iterator lower_bound(const K &key) { + return internal_end(internal_lower_bound(key)); + } + template <typename K> + const_iterator lower_bound(const K &key) const { + return internal_end(internal_lower_bound(key)); + } + + // Finds the first element whose key is greater than key. + template <typename K> + iterator upper_bound(const K &key) { + return internal_end(internal_upper_bound(key)); + } + template <typename K> + const_iterator upper_bound(const K &key) const { + return internal_end(internal_upper_bound(key)); + } + + // Finds the range of values which compare equal to key. The first member of + // the returned pair is equal to lower_bound(key). The second member pair of + // the pair is equal to upper_bound(key). + template <typename K> + std::pair<iterator, iterator> equal_range(const K &key) { + return {lower_bound(key), upper_bound(key)}; + } + template <typename K> + std::pair<const_iterator, const_iterator> equal_range(const K &key) const { + return {lower_bound(key), upper_bound(key)}; + } + + // Inserts a value into the btree only if it does not already exist. The + // boolean return value indicates whether insertion succeeded or failed. + // Requirement: if `key` already exists in the btree, does not consume `args`. + // Requirement: `key` is never referenced after consuming `args`. + template <typename... Args> + std::pair<iterator, bool> insert_unique(const key_type &key, Args &&... args); + + // Inserts with hint. Checks to see if the value should be placed immediately + // before `position` in the tree. If so, then the insertion will take + // amortized constant time. If not, the insertion will take amortized + // logarithmic time as if a call to insert_unique() were made. + // Requirement: if `key` already exists in the btree, does not consume `args`. + // Requirement: `key` is never referenced after consuming `args`. + template <typename... Args> + std::pair<iterator, bool> insert_hint_unique(iterator position, + const key_type &key, + Args &&... args); + + // Insert a range of values into the btree. + template <typename InputIterator> + void insert_iterator_unique(InputIterator b, InputIterator e); + + // Inserts a value into the btree. + template <typename ValueType> + iterator insert_multi(const key_type &key, ValueType &&v); + + // Inserts a value into the btree. + template <typename ValueType> + iterator insert_multi(ValueType &&v) { + return insert_multi(params_type::key(v), std::forward<ValueType>(v)); + } + + // Insert with hint. Check to see if the value should be placed immediately + // before position in the tree. If it does, then the insertion will take + // amortized constant time. If not, the insertion will take amortized + // logarithmic time as if a call to insert_multi(v) were made. + template <typename ValueType> + iterator insert_hint_multi(iterator position, ValueType &&v); + + // Insert a range of values into the btree. + template <typename InputIterator> + void insert_iterator_multi(InputIterator b, InputIterator e); + + // Erase the specified iterator from the btree. The iterator must be valid + // (i.e. not equal to end()). Return an iterator pointing to the node after + // the one that was erased (or end() if none exists). + // Requirement: does not read the value at `*iter`. + iterator erase(iterator iter); + + // Erases range. Returns the number of keys erased and an iterator pointing + // to the element after the last erased element. + std::pair<size_type, iterator> erase_range(iterator begin, iterator end); + + // Erases the specified key from the btree. Returns 1 if an element was + // erased and 0 otherwise. + template <typename K> + size_type erase_unique(const K &key); + + // Erases all of the entries matching the specified key from the + // btree. Returns the number of elements erased. + template <typename K> + size_type erase_multi(const K &key); + + // Finds the iterator corresponding to a key or returns end() if the key is + // not present. + template <typename K> + iterator find(const K &key) { + return internal_end(internal_find(key)); + } + template <typename K> + const_iterator find(const K &key) const { + return internal_end(internal_find(key)); + } + + // Returns a count of the number of times the key appears in the btree. + template <typename K> + size_type count_unique(const K &key) const { + const iterator begin = internal_find(key); + if (begin.node == nullptr) { + // The key doesn't exist in the tree. + return 0; + } + return 1; + } + // Returns a count of the number of times the key appears in the btree. + template <typename K> + size_type count_multi(const K &key) const { + const auto range = equal_range(key); + return std::distance(range.first, range.second); + } + + // Clear the btree, deleting all of the values it contains. + void clear(); + + // Swap the contents of *this and x. + void swap(btree &x); + + 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)); + } + + value_compare value_comp() const { return value_compare(key_comp()); } + + // Verifies the structure of the btree. + void verify() const; + + // Size routines. + size_type size() const { return size_; } + size_type max_size() const { return (std::numeric_limits<size_type>::max)(); } + bool empty() const { return size_ == 0; } + + // The height of the btree. An empty tree will have height 0. + size_type height() const { + size_type h = 0; + if (!empty()) { + // Count the length of the chain from the leftmost node up to the + // root. We actually count from the root back around to the level below + // the root, but the calculation is the same because of the circularity + // of that traversal. + const node_type *n = root(); + do { + ++h; + n = n->parent(); + } while (n != root()); + } + return h; + } + + // The number of internal, leaf and total nodes used by the btree. + size_type leaf_nodes() const { return internal_stats(root()).leaf_nodes; } + size_type internal_nodes() const { + return internal_stats(root()).internal_nodes; + } + size_type nodes() const { + node_stats stats = internal_stats(root()); + return stats.leaf_nodes + stats.internal_nodes; + } + + // The total number of bytes used by the btree. + size_type bytes_used() const { + node_stats stats = internal_stats(root()); + if (stats.leaf_nodes == 1 && stats.internal_nodes == 0) { + return sizeof(*this) + node_type::LeafSize(root()->max_count()); + } else { + return sizeof(*this) + stats.leaf_nodes * node_type::LeafSize() + + stats.internal_nodes * node_type::InternalSize(); + } + } + + // The average number of bytes used per value stored in the btree. + static double average_bytes_per_value() { + // Returns the number of bytes per value on a leaf node that is 75% + // full. Experimentally, this matches up nicely with the computed number of + // bytes per value in trees that had their values inserted in random order. + return node_type::LeafSize() / (kNodeValues * 0.75); + } + + // The fullness of the btree. Computed as the number of elements in the btree + // divided by the maximum number of elements a tree with the current number + // of nodes could hold. A value of 1 indicates perfect space + // utilization. Smaller values indicate space wastage. + // Returns 0 for empty trees. + double fullness() const { + if (empty()) return 0.0; + return static_cast<double>(size()) / (nodes() * kNodeValues); + } + // The overhead of the btree structure in bytes per node. Computed as the + // total number of bytes used by the btree minus the number of bytes used for + // storing elements divided by the number of elements. + // Returns 0 for empty trees. + double overhead() const { + if (empty()) return 0.0; + return (bytes_used() - size() * sizeof(value_type)) / + static_cast<double>(size()); + } + + // The allocator used by the btree. + allocator_type get_allocator() const { return allocator(); } + + private: + // Internal accessor routines. + node_type *root() { return root_.template get<2>(); } + const node_type *root() const { return root_.template get<2>(); } + node_type *&mutable_root() noexcept { return root_.template get<2>(); } + key_compare *mutable_key_comp() noexcept { return &root_.template get<0>(); } + + // The leftmost node is stored as the parent of the root node. + node_type *leftmost() { return root()->parent(); } + const node_type *leftmost() const { return root()->parent(); } + + // Allocator routines. + allocator_type *mutable_allocator() noexcept { + return &root_.template get<1>(); + } + const allocator_type &allocator() const noexcept { + return root_.template get<1>(); + } + + // Allocates a correctly aligned node of at least size bytes using the + // allocator. + node_type *allocate(const size_type size) { + return reinterpret_cast<node_type *>( + absl::container_internal::Allocate<node_type::Alignment()>( + mutable_allocator(), size)); + } + + // 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 *new_leaf_node(node_type *parent) { + node_type *p = allocate(node_type::LeafSize()); + return node_type::init_leaf(p, parent, kNodeValues); + } + 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); + } + + // Deletion helper routines. + void erase_same_node(iterator begin, iterator end); + iterator erase_from_leaf_node(iterator begin, size_type to_erase); + iterator rebalance_after_delete(iterator iter); + + // Deallocates a node of a certain size in bytes using the allocator. + void deallocate(const size_type size, node_type *node) { + absl::container_internal::Deallocate<node_type::Alignment()>( + mutable_allocator(), node, size); + } + + void delete_internal_node(node_type *node) { + node->destroy(mutable_allocator()); + deallocate(node_type::InternalSize(), node); + } + void delete_leaf_node(node_type *node) { + node->destroy(mutable_allocator()); + deallocate(node_type::LeafSize(node->max_count()), node); + } + + // Rebalances or splits the node iter points to. + void rebalance_or_split(iterator *iter); + + // Merges the values of left, right and the delimiting key on their parent + // onto left, removing the delimiting key and deleting right. + void merge_nodes(node_type *left, node_type *right); + + // Tries to merge node with its left or right sibling, and failing that, + // rebalance with its left or right sibling. Returns true if a merge + // occurred, at which point it is no longer valid to access node. Returns + // false if no merging took place. + bool try_merge_or_rebalance(iterator *iter); + + // Tries to shrink the height of the tree by 1. + void try_shrink(); + + iterator internal_end(iterator iter) { + return iter.node != nullptr ? iter : end(); + } + const_iterator internal_end(const_iterator iter) const { + return iter.node != nullptr ? iter : end(); + } + + // Emplaces a value into the btree immediately before iter. Requires that + // key(v) <= iter.key() and (--iter).key() <= key(v). + template <typename... Args> + iterator internal_emplace(iterator iter, Args &&... args); + + // Returns an iterator pointing to the first value >= the value "iter" is + // pointing at. Note that "iter" might be pointing to an invalid location such + // as iter.position == iter.node->finish(). This routine simply moves iter up + // in the tree to a valid location. + // Requires: iter.node is non-null. + template <typename IterType> + static IterType internal_last(IterType iter); + + // Returns an iterator pointing to the leaf position at which key would + // reside in the tree. We provide 2 versions of internal_locate. The first + // version uses a less-than comparator and is incapable of distinguishing when + // there is an exact match. The second version is for the key-compare-to + // specialization and distinguishes exact matches. The key-compare-to + // specialization allows the caller to avoid a subsequent comparison to + // determine if an exact match was made, which is important for keys with + // expensive comparison, such as strings. + template <typename K> + SearchResult<iterator, is_key_compare_to::value> internal_locate( + const K &key) const; + + template <typename K> + SearchResult<iterator, false> internal_locate_impl( + const K &key, std::false_type /* IsCompareTo */) const; + + template <typename K> + SearchResult<iterator, true> internal_locate_impl( + const K &key, std::true_type /* IsCompareTo */) const; + + // Internal routine which implements lower_bound(). + template <typename K> + iterator internal_lower_bound(const K &key) const; + + // Internal routine which implements upper_bound(). + template <typename K> + iterator internal_upper_bound(const K &key) const; + + // Internal routine which implements find(). + template <typename K> + iterator internal_find(const K &key) const; + + // Deletes a node and all of its children. + void internal_clear(node_type *node); + + // Verifies the tree structure of node. + int internal_verify(const node_type *node, const key_type *lo, + const key_type *hi) const; + + node_stats internal_stats(const node_type *node) const { + // The root can be a static empty node. + if (node == nullptr || (node == root() && empty())) { + return node_stats(0, 0); + } + if (node->leaf()) { + return node_stats(1, 0); + } + node_stats res(0, 1); + for (int i = node->start(); i <= node->finish(); ++i) { + res += internal_stats(node->child(i)); + } + return res; + } + + public: + // Exposed only for tests. + static bool testonly_uses_linear_node_search() { + return node_type::testonly_uses_linear_node_search(); + } + + private: + // We use compressed tuple in order to save space because key_compare and + // allocator_type are usually empty. + absl::container_internal::CompressedTuple<key_compare, allocator_type, + node_type *> + root_; + + // A pointer to the rightmost node. Note that the leftmost node is stored as + // the root's parent. + node_type *rightmost_; + + // Number of values. + size_type size_; +}; + +//// +// btree_node methods +template <typename P> +template <typename... Args> +inline void btree_node<P>::emplace_value(const size_type i, + allocator_type *alloc, + Args &&... args) { + assert(i >= start()); + assert(i <= finish()); + // Shift old values to create space for new value and then construct it in + // place. + if (i < finish()) { + value_init(finish(), alloc, slot(finish() - 1)); + for (size_type j = finish() - 1; j > i; --j) + params_type::move(alloc, slot(j - 1), slot(j)); + value_destroy(i, alloc); + } + value_init(i, alloc, std::forward<Args>(args)...); + set_finish(finish() + 1); + + if (!leaf() && finish() > i + 1) { + for (int j = finish(); j > i + 1; --j) { + set_child(j, child(j - 1)); + } + clear_child(i + 1); + } +} + +template <typename P> +inline void btree_node<P>::remove_value(const int i, allocator_type *alloc) { + if (!leaf() && finish() > i + 1) { + assert(child(i + 1)->count() == 0); + for (size_type j = i + 1; j < finish(); ++j) { + set_child(j, child(j + 1)); + } + clear_child(finish()); + } + + remove_values_ignore_children(i, /*to_erase=*/1, alloc); +} + +template <typename P> +inline void btree_node<P>::remove_values_ignore_children( + const int i, const int to_erase, allocator_type *alloc) { + params_type::move(alloc, slot(i + to_erase), finish_slot(), slot(i)); + value_destroy_n(finish() - to_erase, to_erase, alloc); + set_finish(finish() - to_erase); +} + +template <typename P> +void btree_node<P>::rebalance_right_to_left(const int to_move, + btree_node *right, + allocator_type *alloc) { + assert(parent() == right->parent()); + assert(position() + 1 == right->position()); + assert(right->count() >= count()); + assert(to_move >= 1); + assert(to_move <= right->count()); + + // 1) Move the delimiting value in the parent to the left node. + value_init(finish(), alloc, parent()->slot(position())); + + // 2) Move the (to_move - 1) values from the right node to the left node. + right->uninitialized_move_n(to_move - 1, right->start(), finish() + 1, this, + alloc); + + // 3) Move the new delimiting value to the parent from the right node. + params_type::move(alloc, right->slot(to_move - 1), + parent()->slot(position())); + + // 4) Shift the values in the right node to their correct position. + params_type::move(alloc, right->slot(to_move), right->finish_slot(), + right->start_slot()); + + // 5) Destroy the now-empty to_move entries in the right node. + right->value_destroy_n(right->finish() - to_move, to_move, alloc); + + if (!leaf()) { + // Move the child pointers from the right to the left node. + for (int i = 0; i < to_move; ++i) { + init_child(finish() + i + 1, right->child(i)); + } + for (int i = right->start(); i <= right->finish() - to_move; ++i) { + assert(i + to_move <= right->max_count()); + right->init_child(i, right->child(i + to_move)); + right->clear_child(i + to_move); + } + } + + // Fixup `finish` on the left and right nodes. + set_finish(finish() + to_move); + right->set_finish(right->finish() - to_move); +} + +template <typename P> +void btree_node<P>::rebalance_left_to_right(const int to_move, + btree_node *right, + allocator_type *alloc) { + assert(parent() == right->parent()); + assert(position() + 1 == right->position()); + assert(count() >= right->count()); + assert(to_move >= 1); + assert(to_move <= count()); + + // Values in the right node are shifted to the right to make room for the + // new to_move values. Then, the delimiting value in the parent and the + // other (to_move - 1) values in the left node are moved into the right node. + // Lastly, a new delimiting value is moved from the left node into the + // parent, and the remaining empty left node entries are destroyed. + + if (right->count() >= to_move) { + // The original location of the right->count() values are sufficient to hold + // the new to_move entries from the parent and left node. + + // 1) Shift existing values in the right node to their correct positions. + right->uninitialized_move_n(to_move, right->finish() - to_move, + right->finish(), right, alloc); + for (slot_type *src = right->slot(right->finish() - to_move - 1), + *dest = right->slot(right->finish() - 1), + *end = right->start_slot(); + src >= end; --src, --dest) { + params_type::move(alloc, src, dest); + } + + // 2) Move the delimiting value in the parent to the right node. + params_type::move(alloc, parent()->slot(position()), + right->slot(to_move - 1)); + + // 3) Move the (to_move - 1) values from the left node to the right node. + params_type::move(alloc, slot(finish() - (to_move - 1)), finish_slot(), + right->start_slot()); + } else { + // The right node does not have enough initialized space to hold the new + // to_move entries, so part of them will move to uninitialized space. + + // 1) Shift existing values in the right node to their correct positions. + right->uninitialized_move_n(right->count(), right->start(), + right->start() + to_move, right, alloc); + + // 2) Move the delimiting value in the parent to the right node. + right->value_init(to_move - 1, alloc, parent()->slot(position())); + + // 3) Move the (to_move - 1) values from the left node to the right node. + const size_type uninitialized_remaining = to_move - right->count() - 1; + uninitialized_move_n(uninitialized_remaining, + finish() - uninitialized_remaining, right->finish(), + right, alloc); + params_type::move(alloc, slot(finish() - (to_move - 1)), + slot(finish() - uninitialized_remaining), + right->start_slot()); + } + + // 4) Move the new delimiting value to the parent from the left node. + params_type::move(alloc, slot(finish() - to_move), + parent()->slot(position())); + + // 5) Destroy the now-empty to_move entries in the left node. + value_destroy_n(finish() - to_move, to_move, alloc); + + if (!leaf()) { + // Move the child pointers from the left to the right node. + for (int i = right->finish(); i >= right->start(); --i) { + right->init_child(i + to_move, right->child(i)); + right->clear_child(i); + } + for (int i = 1; i <= to_move; ++i) { + right->init_child(i - 1, child(finish() - to_move + i)); + clear_child(finish() - to_move + i); + } + } + + // Fixup the counts on the left and right nodes. + set_finish(finish() - to_move); + right->set_finish(right->finish() + to_move); +} + +template <typename P> +void btree_node<P>::split(const int insert_position, btree_node *dest, + allocator_type *alloc) { + assert(dest->count() == 0); + assert(max_count() == kNodeValues); + + // We bias the split based on the position being inserted. If we're + // inserting at the beginning of the left node then bias the split to put + // more values on the right node. If we're inserting at the end of the + // right node then bias the split to put more values on the left node. + if (insert_position == start()) { + dest->set_finish(dest->start() + finish() - 1); + } else if (insert_position == kNodeValues) { + dest->set_finish(dest->start()); + } else { + dest->set_finish(dest->start() + count() / 2); + } + set_finish(finish() - dest->count()); + assert(count() >= 1); + + // Move values from the left sibling to the right sibling. + uninitialized_move_n(dest->count(), finish(), dest->start(), dest, alloc); + + // Destroy the now-empty entries in the left node. + value_destroy_n(finish(), dest->count(), alloc); + + // The split key is the largest value in the left sibling. + --mutable_finish(); + parent()->emplace_value(position(), alloc, finish_slot()); + value_destroy(finish(), alloc); + parent()->init_child(position() + 1, dest); + + if (!leaf()) { + for (int i = dest->start(), j = finish() + 1; i <= dest->finish(); + ++i, ++j) { + assert(child(j) != nullptr); + dest->init_child(i, child(j)); + clear_child(j); + } + } +} + +template <typename P> +void btree_node<P>::merge(btree_node *src, allocator_type *alloc) { + assert(parent() == src->parent()); + assert(position() + 1 == src->position()); + + // Move the delimiting value to the left node. + value_init(finish(), alloc, parent()->slot(position())); + + // Move the values from the right to the left node. + src->uninitialized_move_n(src->count(), src->start(), finish() + 1, this, + alloc); + + // Destroy the now-empty entries in the right node. + src->value_destroy_n(src->start(), src->count(), alloc); + + if (!leaf()) { + // Move the child pointers from the right to the left node. + for (int i = src->start(), j = finish() + 1; i <= src->finish(); ++i, ++j) { + init_child(j, src->child(i)); + src->clear_child(i); + } + } + + // Fixup `finish` on the src and dest nodes. + set_finish(start() + 1 + count() + src->count()); + src->set_finish(src->start()); + + // Remove the value on the parent node. + parent()->remove_value(position(), alloc); +} + +template <typename P> +void btree_node<P>::swap(btree_node *x, allocator_type *alloc) { + using std::swap; + assert(leaf() == x->leaf()); + + // Determine which is the smaller/larger node. + btree_node *smaller = this, *larger = x; + if (smaller->count() > larger->count()) { + swap(smaller, larger); + } + + // Swap the values. + for (slot_type *a = smaller->start_slot(), *b = larger->start_slot(), + *end = smaller->finish_slot(); + a != end; ++a, ++b) { + params_type::swap(alloc, a, b); + } + + // Move values that can't be swapped. + const size_type to_move = larger->count() - smaller->count(); + larger->uninitialized_move_n(to_move, smaller->finish(), smaller->finish(), + smaller, alloc); + larger->value_destroy_n(smaller->finish(), to_move, alloc); + + if (!leaf()) { + // Swap the child pointers. + std::swap_ranges(&smaller->mutable_child(smaller->start()), + &smaller->mutable_child(smaller->finish() + 1), + &larger->mutable_child(larger->start())); + // Update swapped children's parent pointers. + int i = smaller->start(); + int j = larger->start(); + for (; i <= smaller->finish(); ++i, ++j) { + smaller->child(i)->set_parent(smaller); + larger->child(j)->set_parent(larger); + } + // Move the child pointers that couldn't be swapped. + for (; j <= larger->finish(); ++i, ++j) { + smaller->init_child(i, larger->child(j)); + larger->clear_child(j); + } + } + + // Swap the `finish`s. + // TODO(ezb): with floating storage, will also need to swap starts. + swap(mutable_finish(), x->mutable_finish()); +} + +//// +// btree_iterator methods +template <typename N, typename R, typename P> +void btree_iterator<N, R, P>::increment_slow() { + if (node->leaf()) { + assert(position >= node->finish()); + btree_iterator save(*this); + while (position == node->finish() && !node->is_root()) { + assert(node->parent()->child(node->position()) == node); + position = node->position(); + node = node->parent(); + } + if (position == node->finish()) { + *this = save; + } + } else { + assert(position < node->finish()); + node = node->child(position + 1); + while (!node->leaf()) { + node = node->start_child(); + } + position = node->start(); + } +} + +template <typename N, typename R, typename P> +void btree_iterator<N, R, P>::decrement_slow() { + if (node->leaf()) { + assert(position <= -1); + btree_iterator save(*this); + while (position < node->start() && !node->is_root()) { + assert(node->parent()->child(node->position()) == node); + position = node->position() - 1; + node = node->parent(); + } + if (position < node->start()) { + *this = save; + } + } else { + assert(position >= node->start()); + node = node->child(position); + while (!node->leaf()) { + node = node->child(node->finish()); + } + position = node->finish() - 1; + } +} + +//// +// btree methods +template <typename P> +template <typename Btree> +void btree<P>::copy_or_move_values_in_order(Btree *x) { + static_assert(std::is_same<btree, Btree>::value || + std::is_same<const btree, Btree>::value, + "Btree type must be same or const."); + assert(empty()); + + // 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; + insert_multi(maybe_move_from_iterator(iter)); + ++iter; + for (; iter != x->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)); + } +} + +template <typename P> +constexpr bool btree<P>::static_assert_validation() { + static_assert(std::is_nothrow_copy_constructible<key_compare>::value, + "Key comparison must be nothrow copy constructible"); + static_assert(std::is_nothrow_copy_constructible<allocator_type>::value, + "Allocator must be nothrow copy constructible"); + static_assert(type_traits_internal::is_trivially_copyable<iterator>::value, + "iterator not trivially copyable."); + + // Note: We assert that kTargetValues, which is computed from + // Params::kTargetNodeSize, must fit the node_type::field_type. + static_assert( + kNodeValues < (1 << (8 * sizeof(typename node_type::field_type))), + "target node size too large"); + + // Verify that key_compare returns an absl::{weak,strong}_ordering or bool. + using compare_result_type = + absl::result_of_t<key_compare(key_type, key_type)>; + static_assert( + std::is_same<compare_result_type, bool>::value || + std::is_convertible<compare_result_type, absl::weak_ordering>::value, + "key comparison function must return absl::{weak,strong}_ordering or " + "bool."); + + // Test the assumption made in setting kNodeValueSpace. + static_assert(node_type::MinimumOverhead() >= sizeof(void *) + 4, + "node space assumption incorrect"); + + return true; +} + +template <typename P> +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); +} + +template <typename P> +template <typename... Args> +auto btree<P>::insert_unique(const key_type &key, Args &&... args) + -> std::pair<iterator, bool> { + if (empty()) { + mutable_root() = rightmost_ = new_leaf_root_node(1); + } + + auto res = internal_locate(key); + iterator &iter = res.value; + + if (res.HasMatch()) { + if (res.IsEq()) { + // The key already exists in the tree, do nothing. + return {iter, false}; + } + } else { + iterator last = internal_last(iter); + if (last.node && !compare_keys(key, last.key())) { + // The key already exists in the tree, do nothing. + return {last, false}; + } + } + return {internal_emplace(iter, std::forward<Args>(args)...), true}; +} + +template <typename P> +template <typename... Args> +inline auto btree<P>::insert_hint_unique(iterator position, const key_type &key, + Args &&... args) + -> std::pair<iterator, bool> { + if (!empty()) { + if (position == end() || compare_keys(key, position.key())) { + if (position == begin() || compare_keys(std::prev(position).key(), key)) { + // prev.key() < key < position.key() + return {internal_emplace(position, std::forward<Args>(args)...), true}; + } + } else if (compare_keys(position.key(), key)) { + ++position; + if (position == end() || compare_keys(key, position.key())) { + // {original `position`}.key() < key < {current `position`}.key() + return {internal_emplace(position, std::forward<Args>(args)...), true}; + } + } else { + // position.key() == key + return {position, false}; + } + } + return insert_unique(key, std::forward<Args>(args)...); +} + +template <typename P> +template <typename InputIterator> +void btree<P>::insert_iterator_unique(InputIterator b, InputIterator e) { + for (; b != e; ++b) { + insert_hint_unique(end(), params_type::key(*b), *b); + } +} + +template <typename P> +template <typename ValueType> +auto btree<P>::insert_multi(const key_type &key, ValueType &&v) -> iterator { + if (empty()) { + mutable_root() = rightmost_ = new_leaf_root_node(1); + } + + iterator iter = internal_upper_bound(key); + if (iter.node == nullptr) { + iter = end(); + } + return internal_emplace(iter, std::forward<ValueType>(v)); +} + +template <typename P> +template <typename ValueType> +auto btree<P>::insert_hint_multi(iterator position, ValueType &&v) -> iterator { + if (!empty()) { + const key_type &key = params_type::key(v); + if (position == end() || !compare_keys(position.key(), key)) { + if (position == begin() || + !compare_keys(key, std::prev(position).key())) { + // prev.key() <= key <= position.key() + return internal_emplace(position, std::forward<ValueType>(v)); + } + } else { + ++position; + if (position == end() || !compare_keys(position.key(), key)) { + // {original `position`}.key() < key < {current `position`}.key() + return internal_emplace(position, std::forward<ValueType>(v)); + } + } + } + return insert_multi(std::forward<ValueType>(v)); +} + +template <typename P> +template <typename InputIterator> +void btree<P>::insert_iterator_multi(InputIterator b, InputIterator e) { + for (; b != e; ++b) { + insert_hint_multi(end(), *b); + } +} + +template <typename P> +auto btree<P>::operator=(const btree &x) -> btree & { + if (this != &x) { + clear(); + + *mutable_key_comp() = x.key_comp(); + if (absl::allocator_traits< + allocator_type>::propagate_on_container_copy_assignment::value) { + *mutable_allocator() = x.allocator(); + } + + copy_or_move_values_in_order(&x); + } + return *this; +} + +template <typename P> +auto btree<P>::operator=(btree &&x) noexcept -> btree & { + if (this != &x) { + 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_); + } 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_); + } 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); + } + } + } + return *this; +} + +template <typename P> +auto btree<P>::erase(iterator iter) -> iterator { + bool internal_delete = false; + if (!iter.node->leaf()) { + // Deletion of a value on an internal node. First, move the largest value + // from our left child here, then delete that position (in remove_value() + // below). We can get to the largest value from our left child by + // decrementing iter. + iterator internal_iter(iter); + --iter; + assert(iter.node->leaf()); + params_type::move(mutable_allocator(), iter.node->slot(iter.position), + internal_iter.node->slot(internal_iter.position)); + internal_delete = true; + } + + // Delete the key from the leaf. + iter.node->remove_value(iter.position, mutable_allocator()); + --size_; + + // We want to return the next value after the one we just erased. If we + // erased from an internal node (internal_delete == true), then the next + // value is ++(++iter). If we erased from a leaf node (internal_delete == + // false) then the next value is ++iter. Note that ++iter may point to an + // internal node and the value in the internal node may move to a leaf node + // (iter.node) when rebalancing is performed at the leaf level. + + iterator res = rebalance_after_delete(iter); + + // If we erased from an internal node, advance the iterator. + if (internal_delete) { + ++res; + } + return res; +} + +template <typename P> +auto btree<P>::rebalance_after_delete(iterator iter) -> iterator { + // Merge/rebalance as we walk back up the tree. + iterator res(iter); + bool first_iteration = true; + for (;;) { + if (iter.node == root()) { + try_shrink(); + if (empty()) { + return end(); + } + break; + } + if (iter.node->count() >= kMinNodeValues) { + break; + } + bool merged = try_merge_or_rebalance(&iter); + // On the first iteration, we should update `res` with `iter` because `res` + // may have been invalidated. + if (first_iteration) { + res = iter; + first_iteration = false; + } + if (!merged) { + break; + } + iter.position = iter.node->position(); + iter.node = iter.node->parent(); + } + + // Adjust our return value. If we're pointing at the end of a node, advance + // the iterator. + if (res.position == res.node->finish()) { + res.position = res.node->finish() - 1; + ++res; + } + + return res; +} + +template <typename P> +auto btree<P>::erase_range(iterator begin, iterator end) + -> std::pair<size_type, iterator> { + difference_type count = std::distance(begin, end); + assert(count >= 0); + + if (count == 0) { + return {0, begin}; + } + + if (count == size_) { + clear(); + return {count, this->end()}; + } + + if (begin.node == end.node) { + erase_same_node(begin, end); + size_ -= count; + return {count, rebalance_after_delete(begin)}; + } + + const size_type target_size = size_ - count; + while (size_ > target_size) { + if (begin.node->leaf()) { + const size_type remaining_to_erase = size_ - target_size; + const size_type remaining_in_node = begin.node->finish() - begin.position; + begin = erase_from_leaf_node( + begin, (std::min)(remaining_to_erase, remaining_in_node)); + } else { + begin = erase(begin); + } + } + return {count, begin}; +} + +template <typename P> +void btree<P>::erase_same_node(iterator begin, iterator end) { + assert(begin.node == end.node); + assert(end.position > begin.position); + + node_type *node = begin.node; + size_type to_erase = end.position - begin.position; + if (!node->leaf()) { + // Delete all children between begin and end. + for (size_type i = 0; i < to_erase; ++i) { + internal_clear(node->child(begin.position + i + 1)); + } + // Rotate children after end into new positions. + for (size_type i = begin.position + to_erase + 1; i <= node->finish(); + ++i) { + node->set_child(i - to_erase, node->child(i)); + node->clear_child(i); + } + } + node->remove_values_ignore_children(begin.position, to_erase, + mutable_allocator()); + + // Do not need to update rightmost_, because + // * either end == this->end(), and therefore node == rightmost_, and still + // exists + // * or end != this->end(), and therefore rightmost_ hasn't been erased, since + // it wasn't covered in [begin, end) +} + +template <typename P> +auto btree<P>::erase_from_leaf_node(iterator begin, size_type to_erase) + -> iterator { + node_type *node = begin.node; + assert(node->leaf()); + assert(node->finish() > begin.position); + assert(begin.position + to_erase <= node->finish()); + + node->remove_values_ignore_children(begin.position, to_erase, + mutable_allocator()); + + size_ -= to_erase; + + return rebalance_after_delete(begin); +} + +template <typename P> +template <typename K> +auto btree<P>::erase_unique(const K &key) -> size_type { + const iterator iter = internal_find(key); + if (iter.node == nullptr) { + // The key doesn't exist in the tree, return nothing done. + return 0; + } + erase(iter); + return 1; +} + +template <typename P> +template <typename K> +auto btree<P>::erase_multi(const K &key) -> size_type { + const iterator begin = internal_lower_bound(key); + if (begin.node == nullptr) { + // The key doesn't exist in the tree, return nothing done. + return 0; + } + // Delete all of the keys between begin and upper_bound(key). + const iterator end = internal_end(internal_upper_bound(key)); + return erase_range(begin, end).first; +} + +template <typename P> +void btree<P>::clear() { + if (!empty()) { + internal_clear(root()); + } + mutable_root() = EmptyNode(); + rightmost_ = EmptyNode(); + size_ = 0; +} + +template <typename P> +void btree<P>::swap(btree &x) { + 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_); + } 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()); + } + swap(rightmost_, x.rightmost_); + swap(size_, x.size_); +} + +template <typename P> +void btree<P>::verify() const { + assert(root() != nullptr); + assert(leftmost() != nullptr); + assert(rightmost_ != nullptr); + assert(empty() || size() == internal_verify(root(), nullptr, nullptr)); + assert(leftmost() == (++const_iterator(root(), -1)).node); + assert(rightmost_ == (--const_iterator(root(), root()->finish())).node); + assert(leftmost()->leaf()); + assert(rightmost_->leaf()); +} + +template <typename P> +void btree<P>::rebalance_or_split(iterator *iter) { + node_type *&node = iter->node; + int &insert_position = iter->position; + assert(node->count() == node->max_count()); + assert(kNodeValues == node->max_count()); + + // First try to make room on the node by rebalancing. + node_type *parent = node->parent(); + if (node != root()) { + if (node->position() > parent->start()) { + // Try rebalancing with our left sibling. + node_type *left = parent->child(node->position() - 1); + assert(left->max_count() == kNodeValues); + if (left->count() < kNodeValues) { + // We bias rebalancing based on the position being inserted. If we're + // inserting at the end of the right node then we bias rebalancing to + // fill up the left node. + int to_move = (kNodeValues - left->count()) / + (1 + (insert_position < kNodeValues)); + to_move = (std::max)(1, to_move); + + if (insert_position - to_move >= node->start() || + left->count() + to_move < kNodeValues) { + left->rebalance_right_to_left(to_move, node, mutable_allocator()); + + assert(node->max_count() - node->count() == to_move); + insert_position = insert_position - to_move; + if (insert_position < node->start()) { + insert_position = insert_position + left->count() + 1; + node = left; + } + + assert(node->count() < node->max_count()); + return; + } + } + } + + if (node->position() < parent->finish()) { + // Try rebalancing with our right sibling. + node_type *right = parent->child(node->position() + 1); + assert(right->max_count() == kNodeValues); + if (right->count() < kNodeValues) { + // We bias rebalancing based on the position being inserted. If we're + // inserting at the beginning of the left node then we bias rebalancing + // to fill up the right node. + int to_move = (kNodeValues - right->count()) / + (1 + (insert_position > node->start())); + to_move = (std::max)(1, to_move); + + if (insert_position <= node->finish() - to_move || + right->count() + to_move < kNodeValues) { + node->rebalance_left_to_right(to_move, right, mutable_allocator()); + + if (insert_position > node->finish()) { + insert_position = insert_position - node->count() - 1; + node = right; + } + + assert(node->count() < node->max_count()); + return; + } + } + } + + // Rebalancing failed, make sure there is room on the parent node for a new + // value. + assert(parent->max_count() == kNodeValues); + if (parent->count() == kNodeValues) { + iterator parent_iter(node->parent(), node->position()); + rebalance_or_split(&parent_iter); + } + } else { + // Rebalancing not possible because this is the root node. + // Create a new root node and set the current root node as the child of the + // new root. + parent = new_internal_node(parent); + parent->init_child(parent->start(), root()); + mutable_root() = parent; + // If the former root was a leaf node, then it's now the rightmost node. + assert(!parent->start_child()->leaf() || + parent->start_child() == rightmost_); + } + + // Split the node. + node_type *split_node; + if (node->leaf()) { + split_node = new_leaf_node(parent); + node->split(insert_position, split_node, mutable_allocator()); + if (rightmost_ == node) rightmost_ = split_node; + } else { + split_node = new_internal_node(parent); + node->split(insert_position, split_node, mutable_allocator()); + } + + if (insert_position > node->finish()) { + insert_position = insert_position - node->count() - 1; + node = split_node; + } +} + +template <typename P> +void btree<P>::merge_nodes(node_type *left, node_type *right) { + left->merge(right, mutable_allocator()); + if (right->leaf()) { + if (rightmost_ == right) rightmost_ = left; + delete_leaf_node(right); + } else { + delete_internal_node(right); + } +} + +template <typename P> +bool btree<P>::try_merge_or_rebalance(iterator *iter) { + node_type *parent = iter->node->parent(); + if (iter->node->position() > parent->start()) { + // Try merging with our left sibling. + node_type *left = parent->child(iter->node->position() - 1); + assert(left->max_count() == kNodeValues); + if (1 + left->count() + iter->node->count() <= kNodeValues) { + iter->position += 1 + left->count(); + merge_nodes(left, iter->node); + iter->node = left; + return true; + } + } + if (iter->node->position() < parent->finish()) { + // Try merging with our right sibling. + node_type *right = parent->child(iter->node->position() + 1); + assert(right->max_count() == kNodeValues); + if (1 + iter->node->count() + right->count() <= kNodeValues) { + merge_nodes(iter->node, right); + return true; + } + // Try rebalancing with our right sibling. We don't perform rebalancing if + // we deleted the first element from iter->node and the node is not + // empty. This is a small optimization for the common pattern of deleting + // from the front of the tree. + if (right->count() > kMinNodeValues && + (iter->node->count() == 0 || iter->position > iter->node->start())) { + int to_move = (right->count() - iter->node->count()) / 2; + to_move = (std::min)(to_move, right->count() - 1); + iter->node->rebalance_right_to_left(to_move, right, mutable_allocator()); + return false; + } + } + if (iter->node->position() > parent->start()) { + // Try rebalancing with our left sibling. We don't perform rebalancing if + // we deleted the last element from iter->node and the node is not + // empty. This is a small optimization for the common pattern of deleting + // from the back of the tree. + node_type *left = parent->child(iter->node->position() - 1); + if (left->count() > kMinNodeValues && + (iter->node->count() == 0 || iter->position < iter->node->finish())) { + int to_move = (left->count() - iter->node->count()) / 2; + to_move = (std::min)(to_move, left->count() - 1); + left->rebalance_left_to_right(to_move, iter->node, mutable_allocator()); + iter->position += to_move; + return false; + } + } + return false; +} + +template <typename P> +void btree<P>::try_shrink() { + if (root()->count() > 0) { + return; + } + // Deleted the last item on the root node, shrink the height of the tree. + if (root()->leaf()) { + assert(size() == 0); + delete_leaf_node(root()); + mutable_root() = EmptyNode(); + rightmost_ = EmptyNode(); + } else { + node_type *child = root()->start_child(); + child->make_root(); + delete_internal_node(root()); + mutable_root() = child; + } +} + +template <typename P> +template <typename IterType> +inline IterType btree<P>::internal_last(IterType iter) { + assert(iter.node != nullptr); + while (iter.position == iter.node->finish()) { + iter.position = iter.node->position(); + iter.node = iter.node->parent(); + if (iter.node->leaf()) { + iter.node = nullptr; + break; + } + } + return iter; +} + +template <typename P> +template <typename... Args> +inline auto btree<P>::internal_emplace(iterator iter, Args &&... args) + -> iterator { + if (!iter.node->leaf()) { + // We can't insert on an internal node. Instead, we'll insert after the + // previous value which is guaranteed to be on a leaf node. + --iter; + ++iter.position; + } + const int max_count = iter.node->max_count(); + if (iter.node->count() == max_count) { + // Make room in the leaf for the new item. + if (max_count < kNodeValues) { + // Insertion into the root where the root is smaller than the full node + // size. Simply grow the size of the root node. + assert(iter.node == root()); + iter.node = + 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; + } else { + rebalance_or_split(&iter); + } + } + iter.node->emplace_value(iter.position, mutable_allocator(), + std::forward<Args>(args)...); + ++size_; + return iter; +} + +template <typename P> +template <typename K> +inline auto btree<P>::internal_locate(const K &key) const + -> SearchResult<iterator, is_key_compare_to::value> { + return internal_locate_impl(key, is_key_compare_to()); +} + +template <typename P> +template <typename K> +inline auto btree<P>::internal_locate_impl( + const K &key, std::false_type /* IsCompareTo */) const + -> SearchResult<iterator, false> { + iterator iter(const_cast<node_type *>(root())); + for (;;) { + iter.position = iter.node->lower_bound(key, key_comp()).value; + // NOTE: we don't need to walk all the way down the tree if the keys are + // equal, but determining equality would require doing an extra comparison + // on each node on the way down, and we will need to go all the way to the + // leaf node in the expected case. + if (iter.node->leaf()) { + break; + } + iter.node = iter.node->child(iter.position); + } + return {iter}; +} + +template <typename P> +template <typename K> +inline auto btree<P>::internal_locate_impl( + const K &key, std::true_type /* IsCompareTo */) const + -> SearchResult<iterator, true> { + iterator iter(const_cast<node_type *>(root())); + for (;;) { + SearchResult<int, true> res = iter.node->lower_bound(key, key_comp()); + iter.position = res.value; + if (res.match == MatchKind::kEq) { + return {iter, MatchKind::kEq}; + } + if (iter.node->leaf()) { + break; + } + iter.node = iter.node->child(iter.position); + } + return {iter, MatchKind::kNe}; +} + +template <typename P> +template <typename K> +auto btree<P>::internal_lower_bound(const K &key) const -> iterator { + iterator iter(const_cast<node_type *>(root())); + for (;;) { + iter.position = iter.node->lower_bound(key, key_comp()).value; + if (iter.node->leaf()) { + break; + } + iter.node = iter.node->child(iter.position); + } + return internal_last(iter); +} + +template <typename P> +template <typename K> +auto btree<P>::internal_upper_bound(const K &key) const -> iterator { + iterator iter(const_cast<node_type *>(root())); + for (;;) { + iter.position = iter.node->upper_bound(key, key_comp()); + if (iter.node->leaf()) { + break; + } + iter.node = iter.node->child(iter.position); + } + return internal_last(iter); +} + +template <typename P> +template <typename K> +auto btree<P>::internal_find(const K &key) const -> iterator { + auto res = internal_locate(key); + if (res.HasMatch()) { + if (res.IsEq()) { + return res.value; + } + } else { + const iterator iter = internal_last(res.value); + if (iter.node != nullptr && !compare_keys(key, iter.key())) { + return iter; + } + } + return {nullptr, 0}; +} + +template <typename P> +void btree<P>::internal_clear(node_type *node) { + if (!node->leaf()) { + for (int i = node->start(); i <= node->finish(); ++i) { + internal_clear(node->child(i)); + } + delete_internal_node(node); + } else { + delete_leaf_node(node); + } +} + +template <typename P> +int btree<P>::internal_verify(const node_type *node, const key_type *lo, + const key_type *hi) const { + assert(node->count() > 0); + assert(node->count() <= node->max_count()); + if (lo) { + assert(!compare_keys(node->key(node->start()), *lo)); + } + if (hi) { + assert(!compare_keys(*hi, node->key(node->finish() - 1))); + } + for (int i = node->start() + 1; i < node->finish(); ++i) { + assert(!compare_keys(node->key(i), node->key(i - 1))); + } + int count = node->count(); + if (!node->leaf()) { + for (int i = node->start(); i <= node->finish(); ++i) { + assert(node->child(i) != nullptr); + assert(node->child(i)->parent() == node); + assert(node->child(i)->position() == i); + count += internal_verify(node->child(i), + i == node->start() ? lo : &node->key(i - 1), + i == node->finish() ? hi : &node->key(i)); + } + } + return count; +} + +} // namespace container_internal +ABSL_NAMESPACE_END +} // namespace absl + +#endif // ABSL_CONTAINER_INTERNAL_BTREE_H_ diff --git a/absl/container/internal/btree_container.h b/absl/container/internal/btree_container.h new file mode 100644 index 00000000..f2e4c3a5 --- /dev/null +++ b/absl/container/internal/btree_container.h @@ -0,0 +1,672 @@ +// Copyright 2018 The Abseil Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +#ifndef ABSL_CONTAINER_INTERNAL_BTREE_CONTAINER_H_ +#define ABSL_CONTAINER_INTERNAL_BTREE_CONTAINER_H_ + +#include <algorithm> +#include <initializer_list> +#include <iterator> +#include <utility> + +#include "absl/base/internal/throw_delegate.h" +#include "absl/container/internal/btree.h" // IWYU pragma: export +#include "absl/container/internal/common.h" +#include "absl/meta/type_traits.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN +namespace container_internal { + +// A common base class for btree_set, btree_map, btree_multiset, and +// btree_multimap. +template <typename Tree> +class btree_container { + using params_type = typename Tree::params_type; + + protected: + // Alias used for heterogeneous lookup functions. + // `key_arg<K>` evaluates to `K` when the functors are transparent and to + // `key_type` otherwise. It permits template argument deduction on `K` for the + // transparent case. + template <class K> + using key_arg = + typename KeyArg<IsTransparent<typename Tree::key_compare>::value>:: + template type<K, typename Tree::key_type>; + + public: + using key_type = typename Tree::key_type; + using value_type = typename Tree::value_type; + using size_type = typename Tree::size_type; + using difference_type = typename Tree::difference_type; + using key_compare = typename Tree::key_compare; + using value_compare = typename Tree::value_compare; + using allocator_type = typename Tree::allocator_type; + using reference = typename Tree::reference; + using const_reference = typename Tree::const_reference; + using pointer = typename Tree::pointer; + using const_pointer = typename Tree::const_pointer; + using iterator = typename Tree::iterator; + using const_iterator = typename Tree::const_iterator; + using reverse_iterator = typename Tree::reverse_iterator; + using const_reverse_iterator = typename Tree::const_reverse_iterator; + using node_type = typename Tree::node_handle_type; + + // Constructors/assignments. + btree_container() : tree_(key_compare(), allocator_type()) {} + explicit btree_container(const key_compare &comp, + const allocator_type &alloc = allocator_type()) + : tree_(comp, alloc) {} + btree_container(const btree_container &x) = default; + btree_container(btree_container &&x) noexcept = default; + btree_container &operator=(const btree_container &x) = default; + btree_container &operator=(btree_container &&x) noexcept( + std::is_nothrow_move_assignable<Tree>::value) = default; + + // Iterator routines. + iterator begin() { return tree_.begin(); } + const_iterator begin() const { return tree_.begin(); } + const_iterator cbegin() const { return tree_.begin(); } + iterator end() { return tree_.end(); } + const_iterator end() const { return tree_.end(); } + const_iterator cend() const { return tree_.end(); } + reverse_iterator rbegin() { return tree_.rbegin(); } + const_reverse_iterator rbegin() const { return tree_.rbegin(); } + const_reverse_iterator crbegin() const { return tree_.rbegin(); } + reverse_iterator rend() { return tree_.rend(); } + const_reverse_iterator rend() const { return tree_.rend(); } + const_reverse_iterator crend() const { return tree_.rend(); } + + // Lookup routines. + template <typename K = key_type> + iterator find(const key_arg<K> &key) { + return tree_.find(key); + } + template <typename K = key_type> + const_iterator find(const key_arg<K> &key) const { + return tree_.find(key); + } + template <typename K = key_type> + bool contains(const key_arg<K> &key) const { + return find(key) != end(); + } + template <typename K = key_type> + iterator lower_bound(const key_arg<K> &key) { + return tree_.lower_bound(key); + } + template <typename K = key_type> + const_iterator lower_bound(const key_arg<K> &key) const { + return tree_.lower_bound(key); + } + template <typename K = key_type> + iterator upper_bound(const key_arg<K> &key) { + return tree_.upper_bound(key); + } + template <typename K = key_type> + const_iterator upper_bound(const key_arg<K> &key) const { + return tree_.upper_bound(key); + } + template <typename K = key_type> + std::pair<iterator, iterator> equal_range(const key_arg<K> &key) { + return tree_.equal_range(key); + } + template <typename K = key_type> + std::pair<const_iterator, const_iterator> equal_range( + const key_arg<K> &key) const { + return tree_.equal_range(key); + } + + // Deletion routines. Note that there is also a deletion routine that is + // specific to btree_set_container/btree_multiset_container. + + // Erase the specified iterator from the btree. The iterator must be valid + // (i.e. not equal to end()). Return an iterator pointing to the node after + // the one that was erased (or end() if none exists). + iterator erase(const_iterator iter) { return tree_.erase(iterator(iter)); } + iterator erase(iterator iter) { return tree_.erase(iter); } + iterator erase(const_iterator first, const_iterator last) { + return tree_.erase_range(iterator(first), iterator(last)).second; + } + + // Extract routines. + node_type extract(iterator position) { + // Use Move instead of Transfer, because the rebalancing code expects to + // have a valid object to scribble metadata bits on top of. + auto node = CommonAccess::Move<node_type>(get_allocator(), position.slot()); + erase(position); + return node; + } + node_type extract(const_iterator position) { + return extract(iterator(position)); + } + + public: + // Utility routines. + void clear() { tree_.clear(); } + void swap(btree_container &x) { tree_.swap(x.tree_); } + void verify() const { tree_.verify(); } + + // Size routines. + size_type size() const { return tree_.size(); } + size_type max_size() const { return tree_.max_size(); } + bool empty() const { return tree_.empty(); } + + friend bool operator==(const btree_container &x, const btree_container &y) { + if (x.size() != y.size()) return false; + return std::equal(x.begin(), x.end(), y.begin()); + } + + friend bool operator!=(const btree_container &x, const btree_container &y) { + return !(x == y); + } + + friend bool operator<(const btree_container &x, const btree_container &y) { + return std::lexicographical_compare(x.begin(), x.end(), y.begin(), y.end()); + } + + friend bool operator>(const btree_container &x, const btree_container &y) { + return y < x; + } + + friend bool operator<=(const btree_container &x, const btree_container &y) { + return !(y < x); + } + + friend bool operator>=(const btree_container &x, const btree_container &y) { + return !(x < y); + } + + // The allocator used by the btree. + allocator_type get_allocator() const { return tree_.get_allocator(); } + + // The key comparator used by the btree. + key_compare key_comp() const { return tree_.key_comp(); } + value_compare value_comp() const { return tree_.value_comp(); } + + // Support absl::Hash. + template <typename State> + friend State AbslHashValue(State h, const btree_container &b) { + for (const auto &v : b) { + h = State::combine(std::move(h), v); + } + return State::combine(std::move(h), b.size()); + } + + protected: + Tree tree_; +}; + +// A common base class for btree_set and btree_map. +template <typename Tree> +class btree_set_container : public btree_container<Tree> { + using super_type = btree_container<Tree>; + using params_type = typename Tree::params_type; + using init_type = typename params_type::init_type; + using is_key_compare_to = typename params_type::is_key_compare_to; + friend class BtreeNodePeer; + + protected: + template <class K> + using key_arg = typename super_type::template key_arg<K>; + + public: + using key_type = typename Tree::key_type; + using value_type = typename Tree::value_type; + using size_type = typename Tree::size_type; + using key_compare = typename Tree::key_compare; + using allocator_type = typename Tree::allocator_type; + using iterator = typename Tree::iterator; + using const_iterator = typename Tree::const_iterator; + using node_type = typename super_type::node_type; + using insert_return_type = InsertReturnType<iterator, node_type>; + + // Inherit constructors. + using super_type::super_type; + btree_set_container() {} + + // Range constructor. + template <class InputIterator> + btree_set_container(InputIterator b, InputIterator e, + const key_compare &comp = key_compare(), + const allocator_type &alloc = allocator_type()) + : super_type(comp, alloc) { + insert(b, e); + } + + // Initializer list constructor. + btree_set_container(std::initializer_list<init_type> init, + const key_compare &comp = key_compare(), + const allocator_type &alloc = allocator_type()) + : btree_set_container(init.begin(), init.end(), comp, alloc) {} + + // Lookup routines. + template <typename K = key_type> + size_type count(const key_arg<K> &key) const { + return this->tree_.count_unique(key); + } + + // Insertion routines. + std::pair<iterator, bool> insert(const value_type &x) { + return this->tree_.insert_unique(params_type::key(x), x); + } + std::pair<iterator, bool> insert(value_type &&x) { + return this->tree_.insert_unique(params_type::key(x), std::move(x)); + } + template <typename... Args> + std::pair<iterator, bool> emplace(Args &&... args) { + init_type v(std::forward<Args>(args)...); + return this->tree_.insert_unique(params_type::key(v), std::move(v)); + } + iterator insert(const_iterator position, const value_type &x) { + return this->tree_ + .insert_hint_unique(iterator(position), params_type::key(x), x) + .first; + } + iterator insert(const_iterator position, value_type &&x) { + return this->tree_ + .insert_hint_unique(iterator(position), params_type::key(x), + std::move(x)) + .first; + } + template <typename... Args> + iterator emplace_hint(const_iterator position, Args &&... args) { + init_type v(std::forward<Args>(args)...); + return this->tree_ + .insert_hint_unique(iterator(position), params_type::key(v), + std::move(v)) + .first; + } + template <typename InputIterator> + void insert(InputIterator b, InputIterator e) { + this->tree_.insert_iterator_unique(b, e); + } + void insert(std::initializer_list<init_type> init) { + this->tree_.insert_iterator_unique(init.begin(), init.end()); + } + insert_return_type insert(node_type &&node) { + if (!node) return {this->end(), false, node_type()}; + std::pair<iterator, bool> res = + this->tree_.insert_unique(params_type::key(CommonAccess::GetSlot(node)), + CommonAccess::GetSlot(node)); + if (res.second) { + CommonAccess::Destroy(&node); + return {res.first, true, node_type()}; + } else { + return {res.first, false, std::move(node)}; + } + } + iterator insert(const_iterator hint, node_type &&node) { + if (!node) return this->end(); + std::pair<iterator, bool> res = this->tree_.insert_hint_unique( + iterator(hint), params_type::key(CommonAccess::GetSlot(node)), + CommonAccess::GetSlot(node)); + if (res.second) CommonAccess::Destroy(&node); + return res.first; + } + + // Deletion routines. + template <typename K = key_type> + size_type erase(const key_arg<K> &key) { + return this->tree_.erase_unique(key); + } + using super_type::erase; + + // Node extraction routines. + template <typename K = key_type> + node_type extract(const key_arg<K> &key) { + auto it = this->find(key); + return it == this->end() ? node_type() : extract(it); + } + using super_type::extract; + + // Merge routines. + // Moves elements from `src` into `this`. If the element already exists in + // `this`, it is left unmodified in `src`. + template < + typename T, + typename absl::enable_if_t< + absl::conjunction< + std::is_same<value_type, typename T::value_type>, + std::is_same<allocator_type, typename T::allocator_type>, + std::is_same<typename params_type::is_map_container, + typename T::params_type::is_map_container>>::value, + int> = 0> + void merge(btree_container<T> &src) { // NOLINT + for (auto src_it = src.begin(); src_it != src.end();) { + if (insert(std::move(*src_it)).second) { + src_it = src.erase(src_it); + } else { + ++src_it; + } + } + } + + template < + typename T, + typename absl::enable_if_t< + absl::conjunction< + std::is_same<value_type, typename T::value_type>, + std::is_same<allocator_type, typename T::allocator_type>, + std::is_same<typename params_type::is_map_container, + typename T::params_type::is_map_container>>::value, + int> = 0> + void merge(btree_container<T> &&src) { + merge(src); + } +}; + +// Base class for btree_map. +template <typename Tree> +class btree_map_container : public btree_set_container<Tree> { + using super_type = btree_set_container<Tree>; + using params_type = typename Tree::params_type; + + private: + template <class K> + using key_arg = typename super_type::template key_arg<K>; + + public: + using key_type = typename Tree::key_type; + using mapped_type = typename params_type::mapped_type; + using value_type = typename Tree::value_type; + using key_compare = typename Tree::key_compare; + using allocator_type = typename Tree::allocator_type; + using iterator = typename Tree::iterator; + using const_iterator = typename Tree::const_iterator; + + // Inherit constructors. + using super_type::super_type; + btree_map_container() {} + + // Insertion routines. + // Note: the nullptr template arguments and extra `const M&` overloads allow + // for supporting bitfield arguments. + // Note: when we call `std::forward<M>(obj)` twice, it's safe because + // insert_unique/insert_hint_unique are guaranteed to not consume `obj` when + // `ret.second` is false. + template <class M> + std::pair<iterator, bool> insert_or_assign(const key_type &k, const M &obj) { + const std::pair<iterator, bool> ret = this->tree_.insert_unique(k, k, obj); + if (!ret.second) ret.first->second = obj; + return ret; + } + template <class M, key_type * = nullptr> + std::pair<iterator, bool> insert_or_assign(key_type &&k, const M &obj) { + const std::pair<iterator, bool> ret = + this->tree_.insert_unique(k, std::move(k), obj); + if (!ret.second) ret.first->second = obj; + return ret; + } + template <class M, M * = nullptr> + std::pair<iterator, bool> insert_or_assign(const key_type &k, M &&obj) { + const std::pair<iterator, bool> ret = + this->tree_.insert_unique(k, k, std::forward<M>(obj)); + if (!ret.second) ret.first->second = std::forward<M>(obj); + return ret; + } + template <class M, key_type * = nullptr, M * = nullptr> + std::pair<iterator, bool> insert_or_assign(key_type &&k, M &&obj) { + const std::pair<iterator, bool> ret = + this->tree_.insert_unique(k, std::move(k), std::forward<M>(obj)); + if (!ret.second) ret.first->second = std::forward<M>(obj); + return ret; + } + template <class M> + iterator insert_or_assign(const_iterator position, const key_type &k, + const M &obj) { + const std::pair<iterator, bool> ret = + this->tree_.insert_hint_unique(iterator(position), k, k, obj); + if (!ret.second) ret.first->second = obj; + return ret.first; + } + template <class M, key_type * = nullptr> + iterator insert_or_assign(const_iterator position, key_type &&k, + const M &obj) { + const std::pair<iterator, bool> ret = this->tree_.insert_hint_unique( + iterator(position), k, std::move(k), obj); + if (!ret.second) ret.first->second = obj; + return ret.first; + } + template <class M, M * = nullptr> + iterator insert_or_assign(const_iterator position, const key_type &k, + M &&obj) { + const std::pair<iterator, bool> ret = this->tree_.insert_hint_unique( + iterator(position), k, k, std::forward<M>(obj)); + if (!ret.second) ret.first->second = std::forward<M>(obj); + return ret.first; + } + template <class M, key_type * = nullptr, M * = nullptr> + iterator insert_or_assign(const_iterator position, key_type &&k, M &&obj) { + const std::pair<iterator, bool> ret = this->tree_.insert_hint_unique( + iterator(position), k, std::move(k), std::forward<M>(obj)); + if (!ret.second) ret.first->second = std::forward<M>(obj); + return ret.first; + } + template <typename... Args> + std::pair<iterator, bool> try_emplace(const key_type &k, Args &&... args) { + return this->tree_.insert_unique( + k, std::piecewise_construct, std::forward_as_tuple(k), + std::forward_as_tuple(std::forward<Args>(args)...)); + } + template <typename... Args> + std::pair<iterator, bool> try_emplace(key_type &&k, Args &&... args) { + // Note: `key_ref` exists to avoid a ClangTidy warning about moving from `k` + // and then using `k` unsequenced. This is safe because the move is into a + // forwarding reference and insert_unique guarantees that `key` is never + // referenced after consuming `args`. + const key_type &key_ref = k; + return this->tree_.insert_unique( + key_ref, std::piecewise_construct, std::forward_as_tuple(std::move(k)), + std::forward_as_tuple(std::forward<Args>(args)...)); + } + template <typename... Args> + iterator try_emplace(const_iterator hint, const key_type &k, + Args &&... args) { + return this->tree_ + .insert_hint_unique(iterator(hint), k, std::piecewise_construct, + std::forward_as_tuple(k), + std::forward_as_tuple(std::forward<Args>(args)...)) + .first; + } + template <typename... Args> + iterator try_emplace(const_iterator hint, key_type &&k, Args &&... args) { + // Note: `key_ref` exists to avoid a ClangTidy warning about moving from `k` + // and then using `k` unsequenced. This is safe because the move is into a + // forwarding reference and insert_hint_unique guarantees that `key` is + // never referenced after consuming `args`. + const key_type &key_ref = k; + return this->tree_ + .insert_hint_unique(iterator(hint), key_ref, std::piecewise_construct, + std::forward_as_tuple(std::move(k)), + std::forward_as_tuple(std::forward<Args>(args)...)) + .first; + } + mapped_type &operator[](const key_type &k) { + return try_emplace(k).first->second; + } + mapped_type &operator[](key_type &&k) { + return try_emplace(std::move(k)).first->second; + } + + template <typename K = key_type> + mapped_type &at(const key_arg<K> &key) { + auto it = this->find(key); + if (it == this->end()) + base_internal::ThrowStdOutOfRange("absl::btree_map::at"); + return it->second; + } + template <typename K = key_type> + const mapped_type &at(const key_arg<K> &key) const { + auto it = this->find(key); + if (it == this->end()) + base_internal::ThrowStdOutOfRange("absl::btree_map::at"); + return it->second; + } +}; + +// A common base class for btree_multiset and btree_multimap. +template <typename Tree> +class btree_multiset_container : public btree_container<Tree> { + using super_type = btree_container<Tree>; + using params_type = typename Tree::params_type; + using init_type = typename params_type::init_type; + using is_key_compare_to = typename params_type::is_key_compare_to; + + template <class K> + using key_arg = typename super_type::template key_arg<K>; + + public: + using key_type = typename Tree::key_type; + using value_type = typename Tree::value_type; + using size_type = typename Tree::size_type; + using key_compare = typename Tree::key_compare; + using allocator_type = typename Tree::allocator_type; + using iterator = typename Tree::iterator; + using const_iterator = typename Tree::const_iterator; + using node_type = typename super_type::node_type; + + // Inherit constructors. + using super_type::super_type; + btree_multiset_container() {} + + // Range constructor. + template <class InputIterator> + btree_multiset_container(InputIterator b, InputIterator e, + const key_compare &comp = key_compare(), + const allocator_type &alloc = allocator_type()) + : super_type(comp, alloc) { + insert(b, e); + } + + // Initializer list constructor. + btree_multiset_container(std::initializer_list<init_type> init, + const key_compare &comp = key_compare(), + const allocator_type &alloc = allocator_type()) + : btree_multiset_container(init.begin(), init.end(), comp, alloc) {} + + // Lookup routines. + template <typename K = key_type> + size_type count(const key_arg<K> &key) const { + return this->tree_.count_multi(key); + } + + // Insertion routines. + iterator insert(const value_type &x) { return this->tree_.insert_multi(x); } + iterator insert(value_type &&x) { + return this->tree_.insert_multi(std::move(x)); + } + iterator insert(const_iterator position, const value_type &x) { + return this->tree_.insert_hint_multi(iterator(position), x); + } + iterator insert(const_iterator position, value_type &&x) { + return this->tree_.insert_hint_multi(iterator(position), std::move(x)); + } + template <typename InputIterator> + void insert(InputIterator b, InputIterator e) { + this->tree_.insert_iterator_multi(b, e); + } + void insert(std::initializer_list<init_type> init) { + this->tree_.insert_iterator_multi(init.begin(), init.end()); + } + template <typename... Args> + iterator emplace(Args &&... args) { + return this->tree_.insert_multi(init_type(std::forward<Args>(args)...)); + } + template <typename... Args> + iterator emplace_hint(const_iterator position, Args &&... args) { + return this->tree_.insert_hint_multi( + iterator(position), init_type(std::forward<Args>(args)...)); + } + iterator insert(node_type &&node) { + if (!node) return this->end(); + iterator res = + this->tree_.insert_multi(params_type::key(CommonAccess::GetSlot(node)), + CommonAccess::GetSlot(node)); + CommonAccess::Destroy(&node); + return res; + } + iterator insert(const_iterator hint, node_type &&node) { + if (!node) return this->end(); + iterator res = this->tree_.insert_hint_multi( + iterator(hint), + std::move(params_type::element(CommonAccess::GetSlot(node)))); + CommonAccess::Destroy(&node); + return res; + } + + // Deletion routines. + template <typename K = key_type> + size_type erase(const key_arg<K> &key) { + return this->tree_.erase_multi(key); + } + using super_type::erase; + + // Node extraction routines. + template <typename K = key_type> + node_type extract(const key_arg<K> &key) { + auto it = this->find(key); + return it == this->end() ? node_type() : extract(it); + } + using super_type::extract; + + // Merge routines. + // Moves all elements from `src` into `this`. + template < + typename T, + typename absl::enable_if_t< + absl::conjunction< + std::is_same<value_type, typename T::value_type>, + std::is_same<allocator_type, typename T::allocator_type>, + std::is_same<typename params_type::is_map_container, + typename T::params_type::is_map_container>>::value, + int> = 0> + void merge(btree_container<T> &src) { // NOLINT + insert(std::make_move_iterator(src.begin()), + std::make_move_iterator(src.end())); + src.clear(); + } + + template < + typename T, + typename absl::enable_if_t< + absl::conjunction< + std::is_same<value_type, typename T::value_type>, + std::is_same<allocator_type, typename T::allocator_type>, + std::is_same<typename params_type::is_map_container, + typename T::params_type::is_map_container>>::value, + int> = 0> + void merge(btree_container<T> &&src) { + merge(src); + } +}; + +// A base class for btree_multimap. +template <typename Tree> +class btree_multimap_container : public btree_multiset_container<Tree> { + using super_type = btree_multiset_container<Tree>; + using params_type = typename Tree::params_type; + + public: + using mapped_type = typename params_type::mapped_type; + + // Inherit constructors. + using super_type::super_type; + btree_multimap_container() {} +}; + +} // namespace container_internal +ABSL_NAMESPACE_END +} // namespace absl + +#endif // ABSL_CONTAINER_INTERNAL_BTREE_CONTAINER_H_ diff --git a/absl/container/internal/common.h b/absl/container/internal/common.h index a02cd5c3..5037d803 100644 --- a/absl/container/internal/common.h +++ b/absl/container/internal/common.h @@ -22,7 +22,7 @@ #include "absl/types/optional.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { template <class, class = void> @@ -56,7 +56,7 @@ class node_handle_base { public: using allocator_type = Alloc; - constexpr node_handle_base() {} + constexpr node_handle_base() = default; node_handle_base(node_handle_base&& other) noexcept { *this = std::move(other); } @@ -109,16 +109,15 @@ class node_handle_base { allocator_type* alloc() { return std::addressof(*alloc_); } private: - absl::optional<allocator_type> alloc_; - mutable absl::aligned_storage_t<sizeof(slot_type), alignof(slot_type)> - slot_space_; + absl::optional<allocator_type> alloc_ = {}; + alignas(slot_type) mutable unsigned char slot_space_[sizeof(slot_type)] = {}; }; // For sets. template <typename Policy, typename PolicyTraits, typename Alloc, typename = void> class node_handle : public node_handle_base<PolicyTraits, Alloc> { - using Base = typename node_handle::node_handle_base; + using Base = node_handle_base<PolicyTraits, Alloc>; public: using value_type = typename PolicyTraits::value_type; @@ -138,7 +137,7 @@ template <typename Policy, typename PolicyTraits, typename Alloc> class node_handle<Policy, PolicyTraits, Alloc, absl::void_t<typename Policy::mapped_type>> : public node_handle_base<PolicyTraits, Alloc> { - using Base = typename node_handle::node_handle_base; + using Base = node_handle_base<PolicyTraits, Alloc>; public: using key_type = typename Policy::key_type; @@ -168,6 +167,11 @@ struct CommonAccess { } template <typename Node> + static void Destroy(Node* node) { + node->destroy(); + } + + template <typename Node> static void Reset(Node* node) { node->reset(); } @@ -192,7 +196,7 @@ struct InsertReturnType { }; } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_CONTAINER_H_ diff --git a/absl/container/internal/compressed_tuple.h b/absl/container/internal/compressed_tuple.h index fbace496..4bfe92fd 100644 --- a/absl/container/internal/compressed_tuple.h +++ b/absl/container/internal/compressed_tuple.h @@ -48,7 +48,7 @@ #endif namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { template <typename... Ts> @@ -257,7 +257,7 @@ template <> class ABSL_INTERNAL_COMPRESSED_TUPLE_DECLSPEC CompressedTuple<> {}; } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #undef ABSL_INTERNAL_COMPRESSED_TUPLE_DECLSPEC diff --git a/absl/container/internal/compressed_tuple_test.cc b/absl/container/internal/compressed_tuple_test.cc index ec893b90..1dae12db 100644 --- a/absl/container/internal/compressed_tuple_test.cc +++ b/absl/container/internal/compressed_tuple_test.cc @@ -48,7 +48,7 @@ struct TwoValues { namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { namespace { @@ -333,10 +333,6 @@ TEST(CompressedTupleTest, AnyElements) { a = 0.5f; EXPECT_EQ(absl::any_cast<float>(x.get<1>()), 0.5); - - // Ensure copy construction work in the face of a type with a universal - // implicit constructor; - CompressedTuple<absl::any> c{}, d(c); // NOLINT } TEST(CompressedTupleTest, Constexpr) { @@ -409,5 +405,5 @@ TEST(CompressedTupleTest, EmptyFinalClass) { } // namespace } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl diff --git a/absl/container/internal/container_memory.h b/absl/container/internal/container_memory.h index eb6d7eb7..d24b0f84 100644 --- a/absl/container/internal/container_memory.h +++ b/absl/container/internal/container_memory.h @@ -34,7 +34,7 @@ #include "absl/utility/utility.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { // Allocates at least n bytes aligned to the specified alignment. @@ -434,7 +434,7 @@ struct map_slot_policy { }; } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_CONTAINER_MEMORY_H_ diff --git a/absl/container/internal/container_memory_test.cc b/absl/container/internal/container_memory_test.cc index ea9568dc..7942c7be 100644 --- a/absl/container/internal/container_memory_test.cc +++ b/absl/container/internal/container_memory_test.cc @@ -23,7 +23,7 @@ #include "absl/strings/string_view.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { namespace { @@ -186,5 +186,5 @@ TEST(DecomposePair, NotDecomposable) { } // namespace } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl diff --git a/absl/container/internal/counting_allocator.h b/absl/container/internal/counting_allocator.h index 94a457ca..9efdc662 100644 --- a/absl/container/internal/counting_allocator.h +++ b/absl/container/internal/counting_allocator.h @@ -19,8 +19,10 @@ #include <cstdint> #include <memory> +#include "absl/base/config.h" + namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { // This is a stateful allocator, but the state lives outside of the @@ -75,7 +77,7 @@ class CountingAllocator : public std::allocator<T> { }; } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_COUNTING_ALLOCATOR_H_ diff --git a/absl/container/internal/hash_function_defaults.h b/absl/container/internal/hash_function_defaults.h index 2155076d..401ddf4d 100644 --- a/absl/container/internal/hash_function_defaults.h +++ b/absl/container/internal/hash_function_defaults.h @@ -56,7 +56,7 @@ #include "absl/strings/string_view.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { // The hash of an object of type T is computed by using absl::Hash. @@ -140,7 +140,7 @@ template <class T> using hash_default_eq = typename container_internal::HashEq<T>::Eq; } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_HASH_FUNCTION_DEFAULTS_H_ diff --git a/absl/container/internal/hash_function_defaults_test.cc b/absl/container/internal/hash_function_defaults_test.cc index ce6133f8..2eefc7e0 100644 --- a/absl/container/internal/hash_function_defaults_test.cc +++ b/absl/container/internal/hash_function_defaults_test.cc @@ -22,7 +22,7 @@ #include "absl/strings/string_view.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { namespace { @@ -249,7 +249,7 @@ TYPED_TEST_SUITE(StringLikeTest, StringTypesCartesianProduct); } // namespace } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl enum Hash : size_t { @@ -280,7 +280,7 @@ struct hash<Hashable<H>> { } // namespace std namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { namespace { @@ -295,5 +295,5 @@ TEST(Delegate, HashDispatch) { } // namespace } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl diff --git a/absl/container/internal/hash_generator_testing.cc b/absl/container/internal/hash_generator_testing.cc index 36b2571b..75c4db6c 100644 --- a/absl/container/internal/hash_generator_testing.cc +++ b/absl/container/internal/hash_generator_testing.cc @@ -17,7 +17,7 @@ #include <deque> namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { namespace hash_internal { namespace { @@ -70,5 +70,5 @@ absl::string_view Generator<absl::string_view>::operator()() const { } // namespace hash_internal } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl diff --git a/absl/container/internal/hash_generator_testing.h b/absl/container/internal/hash_generator_testing.h index 27962c35..6869fe45 100644 --- a/absl/container/internal/hash_generator_testing.h +++ b/absl/container/internal/hash_generator_testing.h @@ -19,6 +19,7 @@ #define ABSL_CONTAINER_INTERNAL_HASH_GENERATOR_TESTING_H_ #include <stdint.h> + #include <algorithm> #include <iosfwd> #include <random> @@ -27,11 +28,12 @@ #include <utility> #include "absl/container/internal/hash_policy_testing.h" +#include "absl/memory/memory.h" #include "absl/meta/type_traits.h" #include "absl/strings/string_view.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { namespace hash_internal { namespace generator_internal { @@ -130,6 +132,13 @@ struct Generator<std::tuple<Ts...>> { } }; +template <class T> +struct Generator<std::unique_ptr<T>> { + std::unique_ptr<T> operator()() const { + return absl::make_unique<T>(Generator<T>()()); + } +}; + template <class U> struct Generator<U, absl::void_t<decltype(std::declval<U&>().key()), decltype(std::declval<U&>().value())>> @@ -146,7 +155,7 @@ using GeneratedType = decltype( } // namespace hash_internal } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_HASH_GENERATOR_TESTING_H_ diff --git a/absl/container/internal/hash_policy_testing.h b/absl/container/internal/hash_policy_testing.h index 8f0d2a52..01c40d2e 100644 --- a/absl/container/internal/hash_policy_testing.h +++ b/absl/container/internal/hash_policy_testing.h @@ -30,7 +30,7 @@ #include "absl/strings/string_view.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { namespace hash_testing_internal { @@ -163,7 +163,7 @@ auto keys(const Set& s) } } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl // ABSL_UNORDERED_SUPPORTS_ALLOC_CTORS is false for glibcxx versions diff --git a/absl/container/internal/hash_policy_testing_test.cc b/absl/container/internal/hash_policy_testing_test.cc index 8fd1df00..f0b20fe3 100644 --- a/absl/container/internal/hash_policy_testing_test.cc +++ b/absl/container/internal/hash_policy_testing_test.cc @@ -17,7 +17,7 @@ #include "gtest/gtest.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { namespace { @@ -41,5 +41,5 @@ TEST(_, Hash) { } // namespace } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl diff --git a/absl/container/internal/hash_policy_traits.h b/absl/container/internal/hash_policy_traits.h index 3d87e821..3e1209c6 100644 --- a/absl/container/internal/hash_policy_traits.h +++ b/absl/container/internal/hash_policy_traits.h @@ -23,7 +23,7 @@ #include "absl/meta/type_traits.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { // Defines how slots are initialized/destroyed/moved. @@ -185,7 +185,7 @@ struct hash_policy_traits { }; } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_HASH_POLICY_TRAITS_H_ diff --git a/absl/container/internal/hash_policy_traits_test.cc b/absl/container/internal/hash_policy_traits_test.cc index edfaf63e..6ef8b9e0 100644 --- a/absl/container/internal/hash_policy_traits_test.cc +++ b/absl/container/internal/hash_policy_traits_test.cc @@ -22,7 +22,7 @@ #include "gtest/gtest.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { namespace { @@ -140,5 +140,5 @@ TEST_F(Test, with_transfer) { } // namespace } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl diff --git a/absl/container/internal/hashtable_debug.h b/absl/container/internal/hashtable_debug.h index 1d1a9c28..19d52121 100644 --- a/absl/container/internal/hashtable_debug.h +++ b/absl/container/internal/hashtable_debug.h @@ -38,7 +38,7 @@ #include "absl/container/internal/hashtable_debug_hooks.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { // Returns the number of probes required to lookup `key`. Returns 0 for a @@ -104,7 +104,7 @@ size_t LowerBoundAllocatedByteSize(size_t num_elements) { } } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_HASHTABLE_DEBUG_H_ diff --git a/absl/container/internal/hashtable_debug_hooks.h b/absl/container/internal/hashtable_debug_hooks.h index 7b95fcef..3e9ea595 100644 --- a/absl/container/internal/hashtable_debug_hooks.h +++ b/absl/container/internal/hashtable_debug_hooks.h @@ -23,8 +23,10 @@ #include <type_traits> #include <vector> +#include "absl/base/config.h" + namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { namespace hashtable_debug_internal { @@ -77,7 +79,7 @@ struct HashtableDebugAccess { } // namespace hashtable_debug_internal } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_HASHTABLE_DEBUG_HOOKS_H_ diff --git a/absl/container/internal/hashtablez_sampler.cc b/absl/container/internal/hashtablez_sampler.cc index 2338045d..56447251 100644 --- a/absl/container/internal/hashtablez_sampler.cc +++ b/absl/container/internal/hashtablez_sampler.cc @@ -21,13 +21,14 @@ #include <limits> #include "absl/base/attributes.h" +#include "absl/base/internal/exponential_biased.h" #include "absl/container/internal/have_sse.h" #include "absl/debugging/stacktrace.h" #include "absl/memory/memory.h" #include "absl/synchronization/mutex.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { constexpr int HashtablezInfo::kMaxStackDepth; @@ -38,80 +39,17 @@ ABSL_CONST_INIT std::atomic<bool> g_hashtablez_enabled{ ABSL_CONST_INIT std::atomic<int32_t> g_hashtablez_sample_parameter{1 << 10}; ABSL_CONST_INIT std::atomic<int32_t> g_hashtablez_max_samples{1 << 20}; -// Returns the next pseudo-random value. -// pRNG is: aX+b mod c with a = 0x5DEECE66D, b = 0xB, c = 1<<48 -// This is the lrand64 generator. -uint64_t NextRandom(uint64_t rnd) { - const uint64_t prng_mult = uint64_t{0x5DEECE66D}; - const uint64_t prng_add = 0xB; - const uint64_t prng_mod_power = 48; - const uint64_t prng_mod_mask = ~(~uint64_t{0} << prng_mod_power); - return (prng_mult * rnd + prng_add) & prng_mod_mask; -} - -// Generates a geometric variable with the specified mean. -// This is done by generating a random number between 0 and 1 and applying -// the inverse cumulative distribution function for an exponential. -// Specifically: Let m be the inverse of the sample period, then -// the probability distribution function is m*exp(-mx) so the CDF is -// p = 1 - exp(-mx), so -// q = 1 - p = exp(-mx) -// log_e(q) = -mx -// -log_e(q)/m = x -// log_2(q) * (-log_e(2) * 1/m) = x -// In the code, q is actually in the range 1 to 2**26, hence the -26 below -// -int64_t GetGeometricVariable(int64_t mean) { -#if ABSL_HAVE_THREAD_LOCAL - thread_local -#else // ABSL_HAVE_THREAD_LOCAL - // SampleSlow and hence GetGeometricVariable is guarded by a single mutex when - // there are not thread locals. Thus, a single global rng is acceptable for - // that case. - static -#endif // ABSL_HAVE_THREAD_LOCAL - uint64_t rng = []() { - // We don't get well distributed numbers from this so we call - // NextRandom() a bunch to mush the bits around. We use a global_rand - // to handle the case where the same thread (by memory address) gets - // created and destroyed repeatedly. - ABSL_CONST_INIT static std::atomic<uint32_t> global_rand(0); - uint64_t r = reinterpret_cast<uint64_t>(&rng) + - global_rand.fetch_add(1, std::memory_order_relaxed); - for (int i = 0; i < 20; ++i) { - r = NextRandom(r); - } - return r; - }(); - - rng = NextRandom(rng); - - // Take the top 26 bits as the random number - // (This plus the 1<<58 sampling bound give a max possible step of - // 5194297183973780480 bytes.) - const uint64_t prng_mod_power = 48; // Number of bits in prng - // The uint32_t cast is to prevent a (hard-to-reproduce) NAN - // under piii debug for some binaries. - double q = static_cast<uint32_t>(rng >> (prng_mod_power - 26)) + 1.0; - // Put the computed p-value through the CDF of a geometric. - double interval = (log2(q) - 26) * (-std::log(2.0) * mean); - - // Very large values of interval overflow int64_t. If we happen to - // hit such improbable condition, we simply cheat and clamp interval - // to largest supported value. - if (interval > static_cast<double>(std::numeric_limits<int64_t>::max() / 2)) { - return std::numeric_limits<int64_t>::max() / 2; - } - - // Small values of interval are equivalent to just sampling next time. - if (interval < 1) { - return 1; - } - return static_cast<int64_t>(interval); -} +#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) +ABSL_PER_THREAD_TLS_KEYWORD absl::base_internal::ExponentialBiased + g_exponential_biased_generator; +#endif } // namespace +#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) +ABSL_PER_THREAD_TLS_KEYWORD int64_t global_next_sample = 0; +#endif // defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) + HashtablezSampler& HashtablezSampler::Global() { static auto* sampler = new HashtablezSampler(); return *sampler; @@ -229,15 +167,39 @@ int64_t HashtablezSampler::Iterate( return dropped_samples_.load(std::memory_order_relaxed); } +static bool ShouldForceSampling() { + enum ForceState { + kDontForce, + kForce, + kUninitialized + }; + ABSL_CONST_INIT static std::atomic<ForceState> global_state{ + kUninitialized}; + ForceState state = global_state.load(std::memory_order_relaxed); + if (ABSL_PREDICT_TRUE(state == kDontForce)) return false; + + if (state == kUninitialized) { + state = AbslContainerInternalSampleEverything() ? kForce : kDontForce; + global_state.store(state, std::memory_order_relaxed); + } + return state == kForce; +} + HashtablezInfo* SampleSlow(int64_t* next_sample) { - if (kAbslContainerInternalSampleEverything) { + if (ABSL_PREDICT_FALSE(ShouldForceSampling())) { *next_sample = 1; return HashtablezSampler::Global().Register(); } +#if !defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) + *next_sample = std::numeric_limits<int64_t>::max(); + return nullptr; +#else bool first = *next_sample < 0; - *next_sample = GetGeometricVariable( + *next_sample = g_exponential_biased_generator.GetStride( g_hashtablez_sample_parameter.load(std::memory_order_relaxed)); + // Small values of interval are equivalent to just sampling next time. + ABSL_ASSERT(*next_sample >= 1); // g_hashtablez_enabled can be dynamically flipped, we need to set a threshold // low enough that we will start sampling in a reasonable time, so we just use @@ -252,12 +214,9 @@ HashtablezInfo* SampleSlow(int64_t* next_sample) { } return HashtablezSampler::Global().Register(); +#endif } -#if ABSL_PER_THREAD_TLS == 1 -ABSL_PER_THREAD_TLS_KEYWORD int64_t global_next_sample = 0; -#endif // ABSL_PER_THREAD_TLS == 1 - void UnsampleSlow(HashtablezInfo* info) { HashtablezSampler::Global().Unregister(info); } @@ -306,5 +265,5 @@ void SetHashtablezMaxSamples(int32_t max) { } } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl diff --git a/absl/container/internal/hashtablez_sampler.h b/absl/container/internal/hashtablez_sampler.h index f17c425c..34d5e572 100644 --- a/absl/container/internal/hashtablez_sampler.h +++ b/absl/container/internal/hashtablez_sampler.h @@ -51,7 +51,7 @@ #include "absl/utility/utility.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { // Stores information about a sampled hashtable. All mutations to this *must* @@ -66,7 +66,7 @@ struct HashtablezInfo { // Puts the object into a clean state, fills in the logically `const` members, // blocking for any readers that are currently sampling the object. - void PrepareForSampling() EXCLUSIVE_LOCKS_REQUIRED(init_mu); + void PrepareForSampling() ABSL_EXCLUSIVE_LOCKS_REQUIRED(init_mu); // These fields are mutated by the various Record* APIs and need to be // thread-safe. @@ -84,7 +84,7 @@ struct HashtablezInfo { // prevents races with sampling and resurrecting an object. absl::Mutex init_mu; HashtablezInfo* next; - HashtablezInfo* dead GUARDED_BY(init_mu); + HashtablezInfo* dead ABSL_GUARDED_BY(init_mu); // All of the fields below are set by `PrepareForSampling`, they must not be // mutated in `Record*` functions. They are logically `const` in that sense. @@ -180,23 +180,30 @@ class HashtablezInfoHandle { HashtablezInfo* info_; }; -#if ABSL_PER_THREAD_TLS == 1 +#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) +#error ABSL_INTERNAL_HASHTABLEZ_SAMPLE cannot be directly set +#endif // defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) + +#if (ABSL_PER_THREAD_TLS == 1) && !defined(ABSL_BUILD_DLL) && \ + !defined(ABSL_CONSUME_DLL) +#define ABSL_INTERNAL_HASHTABLEZ_SAMPLE +#endif + +#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) extern ABSL_PER_THREAD_TLS_KEYWORD int64_t global_next_sample; #endif // ABSL_PER_THREAD_TLS // Returns an RAII sampling handle that manages registration and unregistation // with the global sampler. inline HashtablezInfoHandle Sample() { -#if ABSL_PER_THREAD_TLS == 0 - static auto* mu = new absl::Mutex; - static int64_t global_next_sample = 0; - absl::MutexLock l(mu); -#endif // !ABSL_HAVE_THREAD_LOCAL - +#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) if (ABSL_PREDICT_TRUE(--global_next_sample > 0)) { return HashtablezInfoHandle(nullptr); } return HashtablezInfoHandle(SampleSlow(&global_next_sample)); +#else + return HashtablezInfoHandle(nullptr); +#endif // !ABSL_PER_THREAD_TLS } // Holds samples and their associated stack traces with a soft limit of @@ -281,10 +288,10 @@ void SetHashtablezMaxSamples(int32_t max); // initialization of static storage duration objects. // The definition of this constant is weak, which allows us to inject a // different value for it at link time. -extern "C" const bool kAbslContainerInternalSampleEverything; +extern "C" bool AbslContainerInternalSampleEverything(); } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_HASHTABLEZ_SAMPLER_H_ diff --git a/absl/container/internal/hashtablez_sampler_force_weak_definition.cc b/absl/container/internal/hashtablez_sampler_force_weak_definition.cc index d3f41c7c..78b9d362 100644 --- a/absl/container/internal/hashtablez_sampler_force_weak_definition.cc +++ b/absl/container/internal/hashtablez_sampler_force_weak_definition.cc @@ -17,13 +17,14 @@ #include "absl/base/attributes.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { // See hashtablez_sampler.h for details. -extern "C" ABSL_ATTRIBUTE_WEAK const bool - kAbslContainerInternalSampleEverything = false; +extern "C" ABSL_ATTRIBUTE_WEAK bool AbslContainerInternalSampleEverything() { + return false; +} } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl diff --git a/absl/container/internal/hashtablez_sampler_test.cc b/absl/container/internal/hashtablez_sampler_test.cc index bdae75f3..36f5ccdd 100644 --- a/absl/container/internal/hashtablez_sampler_test.cc +++ b/absl/container/internal/hashtablez_sampler_test.cc @@ -36,7 +36,7 @@ constexpr int kProbeLength = 8; #endif namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { class HashtablezInfoHandlePeer { public: @@ -169,6 +169,7 @@ TEST(HashtablezInfoTest, RecordRehash) { EXPECT_EQ(info.num_erases.load(), 0); } +#if defined(ABSL_HASHTABLEZ_SAMPLE) TEST(HashtablezSamplerTest, SmallSampleParameter) { SetHashtablezEnabled(true); SetHashtablezSampleParameter(100); @@ -212,6 +213,7 @@ TEST(HashtablezSamplerTest, Sample) { } EXPECT_NEAR(sample_rate, 0.01, 0.005); } +#endif TEST(HashtablezSamplerTest, Handle) { auto& sampler = HashtablezSampler::Global(); @@ -353,5 +355,5 @@ TEST(HashtablezSamplerTest, Callback) { } // namespace } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl diff --git a/absl/container/internal/inlined_vector.h b/absl/container/internal/inlined_vector.h index 123e04c9..4d80b727 100644 --- a/absl/container/internal/inlined_vector.h +++ b/absl/container/internal/inlined_vector.h @@ -30,7 +30,7 @@ #include "absl/types/span.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace inlined_vector_internal { template <typename Iterator> @@ -38,16 +38,17 @@ using IsAtLeastForwardIterator = std::is_convertible< typename std::iterator_traits<Iterator>::iterator_category, std::forward_iterator_tag>; -template <typename AllocatorType> -using IsMemcpyOk = absl::conjunction< - std::is_same<std::allocator<typename AllocatorType::value_type>, - AllocatorType>, - absl::is_trivially_copy_constructible<typename AllocatorType::value_type>, - absl::is_trivially_copy_assignable<typename AllocatorType::value_type>, - absl::is_trivially_destructible<typename AllocatorType::value_type>>; - -template <typename AllocatorType, typename ValueType, typename SizeType> -void DestroyElements(AllocatorType* alloc_ptr, ValueType* destroy_first, +template <typename AllocatorType, + typename ValueType = + typename absl::allocator_traits<AllocatorType>::value_type> +using IsMemcpyOk = + absl::conjunction<std::is_same<AllocatorType, std::allocator<ValueType>>, + absl::is_trivially_copy_constructible<ValueType>, + absl::is_trivially_copy_assignable<ValueType>, + absl::is_trivially_destructible<ValueType>>; + +template <typename AllocatorType, typename Pointer, typename SizeType> +void DestroyElements(AllocatorType* alloc_ptr, Pointer destroy_first, SizeType destroy_size) { using AllocatorTraits = absl::allocator_traits<AllocatorType>; @@ -57,21 +58,26 @@ void DestroyElements(AllocatorType* alloc_ptr, ValueType* destroy_first, 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. - auto* memory_ptr = static_cast<void*>(destroy_first); - auto memory_size = sizeof(ValueType) * destroy_size; - std::memset(memory_ptr, 0xab, memory_size); -#endif // NDEBUG +#if !defined(NDEBUG) + { + using ValueType = typename AllocatorTraits::value_type; + + // 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_ptr = destroy_first; + auto memory_size = destroy_size * sizeof(ValueType); + std::memset(memory_ptr, 0xab, memory_size); + } +#endif // !defined(NDEBUG) } } -template <typename AllocatorType, typename ValueType, typename ValueAdapter, +template <typename AllocatorType, typename Pointer, typename ValueAdapter, typename SizeType> -void ConstructElements(AllocatorType* alloc_ptr, ValueType* construct_first, +void ConstructElements(AllocatorType* alloc_ptr, Pointer construct_first, ValueAdapter* values_ptr, SizeType construct_size) { for (SizeType i = 0; i < construct_size; ++i) { ABSL_INTERNAL_TRY { @@ -84,8 +90,8 @@ void ConstructElements(AllocatorType* alloc_ptr, ValueType* construct_first, } } -template <typename ValueType, typename ValueAdapter, typename SizeType> -void AssignElements(ValueType* assign_first, ValueAdapter* values_ptr, +template <typename Pointer, typename ValueAdapter, typename SizeType> +void AssignElements(Pointer assign_first, ValueAdapter* values_ptr, SizeType assign_size) { for (SizeType i = 0; i < assign_size; ++i) { values_ptr->AssignNext(assign_first + i); @@ -94,28 +100,29 @@ void AssignElements(ValueType* assign_first, ValueAdapter* values_ptr, template <typename AllocatorType> struct StorageView { - using pointer = typename AllocatorType::pointer; - using size_type = typename AllocatorType::size_type; + using AllocatorTraits = absl::allocator_traits<AllocatorType>; + using Pointer = typename AllocatorTraits::pointer; + using SizeType = typename AllocatorTraits::size_type; - pointer data; - size_type size; - size_type capacity; + Pointer data; + SizeType size; + SizeType capacity; }; template <typename AllocatorType, typename Iterator> class IteratorValueAdapter { - using pointer = typename AllocatorType::pointer; using AllocatorTraits = absl::allocator_traits<AllocatorType>; + using Pointer = typename AllocatorTraits::pointer; public: explicit IteratorValueAdapter(const Iterator& it) : it_(it) {} - void ConstructNext(AllocatorType* alloc_ptr, pointer construct_at) { + void ConstructNext(AllocatorType* alloc_ptr, Pointer construct_at) { AllocatorTraits::construct(*alloc_ptr, construct_at, *it_); ++it_; } - void AssignNext(pointer assign_at) { + void AssignNext(Pointer assign_at) { *assign_at = *it_; ++it_; } @@ -126,46 +133,45 @@ class IteratorValueAdapter { template <typename AllocatorType> class CopyValueAdapter { - using pointer = typename AllocatorType::pointer; - using const_pointer = typename AllocatorType::const_pointer; - using const_reference = typename AllocatorType::const_reference; using AllocatorTraits = absl::allocator_traits<AllocatorType>; + using ValueType = typename AllocatorTraits::value_type; + using Pointer = typename AllocatorTraits::pointer; + using ConstPointer = typename AllocatorTraits::const_pointer; public: - explicit CopyValueAdapter(const_reference v) : ptr_(std::addressof(v)) {} + explicit CopyValueAdapter(const ValueType& v) : ptr_(std::addressof(v)) {} - void ConstructNext(AllocatorType* alloc_ptr, pointer construct_at) { + void ConstructNext(AllocatorType* alloc_ptr, Pointer construct_at) { AllocatorTraits::construct(*alloc_ptr, construct_at, *ptr_); } - void AssignNext(pointer assign_at) { *assign_at = *ptr_; } + void AssignNext(Pointer assign_at) { *assign_at = *ptr_; } private: - const_pointer ptr_; + ConstPointer ptr_; }; template <typename AllocatorType> class DefaultValueAdapter { - using pointer = typename AllocatorType::pointer; - using value_type = typename AllocatorType::value_type; using AllocatorTraits = absl::allocator_traits<AllocatorType>; + using ValueType = typename AllocatorTraits::value_type; + using Pointer = typename AllocatorTraits::pointer; public: explicit DefaultValueAdapter() {} - void ConstructNext(AllocatorType* alloc_ptr, pointer construct_at) { + void ConstructNext(AllocatorType* alloc_ptr, Pointer construct_at) { AllocatorTraits::construct(*alloc_ptr, construct_at); } - void AssignNext(pointer assign_at) { *assign_at = value_type(); } + void AssignNext(Pointer assign_at) { *assign_at = ValueType(); } }; template <typename AllocatorType> class AllocationTransaction { - using value_type = typename AllocatorType::value_type; - using pointer = typename AllocatorType::pointer; - using size_type = typename AllocatorType::size_type; using AllocatorTraits = absl::allocator_traits<AllocatorType>; + using Pointer = typename AllocatorTraits::pointer; + using SizeType = typename AllocatorTraits::size_type; public: explicit AllocationTransaction(AllocatorType* alloc_ptr) @@ -181,25 +187,31 @@ class AllocationTransaction { void operator=(const AllocationTransaction&) = delete; AllocatorType& GetAllocator() { return alloc_data_.template get<0>(); } - pointer& GetData() { return alloc_data_.template get<1>(); } - size_type& GetCapacity() { return capacity_; } + Pointer& GetData() { return alloc_data_.template get<1>(); } + SizeType& GetCapacity() { return capacity_; } bool DidAllocate() { return GetData() != nullptr; } - pointer Allocate(size_type capacity) { + Pointer Allocate(SizeType capacity) { GetData() = AllocatorTraits::allocate(GetAllocator(), capacity); GetCapacity() = capacity; return GetData(); } + void Reset() { + GetData() = nullptr; + GetCapacity() = 0; + } + private: - container_internal::CompressedTuple<AllocatorType, pointer> alloc_data_; - size_type capacity_ = 0; + container_internal::CompressedTuple<AllocatorType, Pointer> alloc_data_; + SizeType capacity_ = 0; }; template <typename AllocatorType> class ConstructionTransaction { - using pointer = typename AllocatorType::pointer; - using size_type = typename AllocatorType::size_type; + using AllocatorTraits = absl::allocator_traits<AllocatorType>; + using Pointer = typename AllocatorTraits::pointer; + using SizeType = typename AllocatorTraits::size_type; public: explicit ConstructionTransaction(AllocatorType* alloc_ptr) @@ -216,12 +228,12 @@ class ConstructionTransaction { void operator=(const ConstructionTransaction&) = delete; AllocatorType& GetAllocator() { return alloc_data_.template get<0>(); } - pointer& GetData() { return alloc_data_.template get<1>(); } - size_type& GetSize() { return size_; } + Pointer& GetData() { return alloc_data_.template get<1>(); } + SizeType& GetSize() { return size_; } bool DidConstruct() { return GetData() != nullptr; } template <typename ValueAdapter> - void Construct(pointer data, ValueAdapter* values_ptr, size_type size) { + void Construct(Pointer data, ValueAdapter* values_ptr, SizeType size) { inlined_vector_internal::ConstructElements(std::addressof(GetAllocator()), data, values_ptr, size); GetData() = data; @@ -233,28 +245,29 @@ class ConstructionTransaction { } private: - container_internal::CompressedTuple<AllocatorType, pointer> alloc_data_; - size_type size_ = 0; + container_internal::CompressedTuple<AllocatorType, Pointer> alloc_data_; + SizeType size_ = 0; }; template <typename T, size_t N, typename A> class Storage { public: - using allocator_type = A; - using value_type = typename allocator_type::value_type; - using pointer = typename allocator_type::pointer; - using const_pointer = typename allocator_type::const_pointer; - using reference = typename allocator_type::reference; - using const_reference = typename allocator_type::const_reference; - using rvalue_reference = typename allocator_type::value_type&&; - using size_type = typename allocator_type::size_type; - using difference_type = typename allocator_type::difference_type; + using AllocatorTraits = absl::allocator_traits<A>; + using allocator_type = typename AllocatorTraits::allocator_type; + using value_type = typename AllocatorTraits::value_type; + using pointer = typename AllocatorTraits::pointer; + using const_pointer = typename AllocatorTraits::const_pointer; + using size_type = typename AllocatorTraits::size_type; + using difference_type = typename AllocatorTraits::difference_type; + + using reference = value_type&; + using const_reference = const value_type&; + using RValueReference = value_type&&; using iterator = pointer; using const_iterator = const_pointer; using reverse_iterator = std::reverse_iterator<iterator>; using const_reverse_iterator = std::reverse_iterator<const_iterator>; using MoveIterator = std::move_iterator<iterator>; - using AllocatorTraits = absl::allocator_traits<allocator_type>; using IsMemcpyOk = inlined_vector_internal::IsMemcpyOk<allocator_type>; using StorageView = inlined_vector_internal::StorageView<allocator_type>; @@ -287,8 +300,7 @@ class Storage { Storage() : metadata_() {} - explicit Storage(const allocator_type& alloc) - : metadata_(alloc, /* empty and inlined */ 0) {} + explicit Storage(const allocator_type& alloc) : metadata_(alloc, {}) {} ~Storage() { pointer data = GetIsAllocated() ? GetAllocatedData() : GetInlinedData(); @@ -414,8 +426,8 @@ class Storage { void AcquireAllocatedData(AllocationTransaction* allocation_tx_ptr) { SetAllocatedData(allocation_tx_ptr->GetData(), allocation_tx_ptr->GetCapacity()); - allocation_tx_ptr->GetData() = nullptr; - allocation_tx_ptr->GetCapacity() = 0; + + allocation_tx_ptr->Reset(); } void MemcpyFrom(const Storage& other_storage) { @@ -442,9 +454,7 @@ class Storage { }; struct Inlined { - using InlinedDataElement = - absl::aligned_storage_t<sizeof(value_type), alignof(value_type)>; - InlinedDataElement inlined_data[N]; + alignas(value_type) char inlined_data[sizeof(value_type[N])]; }; union Data { @@ -465,18 +475,14 @@ auto Storage<T, N, A>::Initialize(ValueAdapter values, size_type new_size) assert(GetSize() == 0); pointer construct_data; - if (new_size > GetInlinedCapacity()) { // Because this is only called from the `InlinedVector` constructors, it's // safe to take on the allocation with size `0`. If `ConstructElements(...)` // throws, deallocation will be automatically handled by `~Storage()`. size_type new_capacity = ComputeCapacity(GetInlinedCapacity(), new_size); - pointer new_data = AllocatorTraits::allocate(*GetAllocPtr(), new_capacity); - - SetAllocatedData(new_data, new_capacity); + construct_data = AllocatorTraits::allocate(*GetAllocPtr(), new_capacity); + SetAllocatedData(construct_data, new_capacity); SetIsAllocated(); - - construct_data = new_data; } else { construct_data = GetInlinedData(); } @@ -503,9 +509,7 @@ auto Storage<T, N, A>::Assign(ValueAdapter values, size_type new_size) -> void { if (new_size > storage_view.capacity) { size_type new_capacity = ComputeCapacity(storage_view.capacity, new_size); - pointer new_data = allocation_tx.Allocate(new_capacity); - - construct_loop = {new_data, new_size}; + construct_loop = {allocation_tx.Allocate(new_capacity), new_size}; destroy_loop = {storage_view.data, storage_view.size}; } else if (new_size > storage_view.size) { assign_loop = {storage_view.data, storage_view.size}; @@ -539,12 +543,12 @@ 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)); + 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; @@ -687,19 +691,17 @@ auto Storage<T, N, A>::EmplaceBack(Args&&... args) -> reference { MoveIterator(storage_view.data)); pointer construct_data; - if (storage_view.size == storage_view.capacity) { size_type new_capacity = NextCapacity(storage_view.capacity); - pointer new_data = allocation_tx.Allocate(new_capacity); - - construct_data = new_data; + construct_data = allocation_tx.Allocate(new_capacity); } else { construct_data = storage_view.data; } - pointer end = construct_data + storage_view.size; + pointer last_ptr = construct_data + storage_view.size; - AllocatorTraits::construct(*GetAllocPtr(), end, std::forward<Args>(args)...); + AllocatorTraits::construct(*GetAllocPtr(), last_ptr, + std::forward<Args>(args)...); if (allocation_tx.DidAllocate()) { ABSL_INTERNAL_TRY { @@ -708,7 +710,7 @@ auto Storage<T, N, A>::EmplaceBack(Args&&... args) -> reference { storage_view.size); } ABSL_INTERNAL_CATCH_ANY { - AllocatorTraits::destroy(*GetAllocPtr(), end); + AllocatorTraits::destroy(*GetAllocPtr(), last_ptr); ABSL_INTERNAL_RETHROW; } @@ -721,14 +723,12 @@ auto Storage<T, N, A>::EmplaceBack(Args&&... args) -> reference { } AddSize(1); - return *end; + return *last_ptr; } template <typename T, size_t N, typename A> auto Storage<T, N, A>::Erase(const_iterator from, const_iterator to) -> iterator { - assert(from != to); - StorageView storage_view = MakeStorageView(); size_type erase_size = std::distance(from, to); @@ -793,12 +793,9 @@ auto Storage<T, N, A>::ShrinkToFit() -> void { MoveIterator(storage_view.data)); pointer construct_data; - if (storage_view.size > GetInlinedCapacity()) { size_type new_capacity = storage_view.size; - pointer new_data = allocation_tx.Allocate(new_capacity); - - construct_data = new_data; + construct_data = allocation_tx.Allocate(new_capacity); } else { construct_data = GetInlinedData(); } @@ -889,7 +886,7 @@ auto Storage<T, N, A>::Swap(Storage* other_storage_ptr) -> void { } } // namespace inlined_vector_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_INLINED_VECTOR_INTERNAL_H_ diff --git a/absl/container/internal/layout.h b/absl/container/internal/layout.h index 3924b8aa..69cc85dd 100644 --- a/absl/container/internal/layout.h +++ b/absl/container/internal/layout.h @@ -188,7 +188,7 @@ #endif namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { // A type wrapper that instructs `Layout` to use the specific alignment for the @@ -735,7 +735,7 @@ class Layout : public internal_layout::LayoutType<sizeof...(Ts), Ts...> { }; } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_LAYOUT_H_ diff --git a/absl/container/internal/layout_test.cc b/absl/container/internal/layout_test.cc index 44d84607..8f3628a1 100644 --- a/absl/container/internal/layout_test.cc +++ b/absl/container/internal/layout_test.cc @@ -28,7 +28,7 @@ #include "absl/types/span.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { namespace { @@ -1563,5 +1563,5 @@ TEST(CompactString, Works) { } // namespace } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl diff --git a/absl/container/internal/node_hash_policy.h b/absl/container/internal/node_hash_policy.h index d7581360..4617162f 100644 --- a/absl/container/internal/node_hash_policy.h +++ b/absl/container/internal/node_hash_policy.h @@ -39,8 +39,10 @@ #include <type_traits> #include <utility> +#include "absl/base/config.h" + namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { template <class Reference, class Policy> @@ -84,7 +86,7 @@ struct node_hash_policy { }; } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_NODE_HASH_POLICY_H_ diff --git a/absl/container/internal/node_hash_policy_test.cc b/absl/container/internal/node_hash_policy_test.cc index d53b7364..84aabba9 100644 --- a/absl/container/internal/node_hash_policy_test.cc +++ b/absl/container/internal/node_hash_policy_test.cc @@ -21,7 +21,7 @@ #include "absl/container/internal/hash_policy_traits.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { namespace { @@ -65,5 +65,5 @@ TEST_F(NodeTest, transfer) { } // namespace } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl diff --git a/absl/container/internal/raw_hash_map.h b/absl/container/internal/raw_hash_map.h index 00caa373..0a02757d 100644 --- a/absl/container/internal/raw_hash_map.h +++ b/absl/container/internal/raw_hash_map.h @@ -24,7 +24,7 @@ #include "absl/container/internal/raw_hash_set.h" // IWYU pragma: export namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { template <class Policy, class Hash, class Eq, class Alloc> @@ -110,6 +110,9 @@ class raw_hash_map : public raw_hash_set<Policy, Hash, Eq, Alloc> { return insert_or_assign(k, v).first; } + // All `try_emplace()` overloads make the same guarantees regarding rvalue + // arguments as `std::unordered_map::try_emplace()`, namely that these + // functions will not move from rvalue arguments if insertions do not happen. template <class K = key_type, class... Args, typename std::enable_if< !std::is_convertible<K, const_iterator>::value, int>::type = 0, @@ -188,7 +191,7 @@ class raw_hash_map : public raw_hash_set<Policy, Hash, Eq, Alloc> { }; } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_RAW_HASH_MAP_H_ diff --git a/absl/container/internal/raw_hash_set.cc b/absl/container/internal/raw_hash_set.cc index 02e74e21..919ac074 100644 --- a/absl/container/internal/raw_hash_set.cc +++ b/absl/container/internal/raw_hash_set.cc @@ -20,7 +20,7 @@ #include "absl/base/config.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { constexpr size_t Group::kWidth; @@ -44,5 +44,5 @@ bool ShouldInsertBackwards(size_t hash, ctrl_t* ctrl) { } } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl diff --git a/absl/container/internal/raw_hash_set.h b/absl/container/internal/raw_hash_set.h index 7b379d4f..ca7be8d8 100644 --- a/absl/container/internal/raw_hash_set.h +++ b/absl/container/internal/raw_hash_set.h @@ -118,7 +118,7 @@ #include "absl/utility/utility.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { template <size_t Width> @@ -615,13 +615,17 @@ class raw_hash_set { iterator() {} // PRECONDITION: not an end() iterator. - reference operator*() const { return PolicyTraits::element(slot_); } + reference operator*() const { + assert_is_full(); + return PolicyTraits::element(slot_); + } // PRECONDITION: not an end() iterator. pointer operator->() const { return &operator*(); } // PRECONDITION: not an end() iterator. iterator& operator++() { + assert_is_full(); ++ctrl_; ++slot_; skip_empty_or_deleted(); @@ -635,6 +639,8 @@ class raw_hash_set { } friend bool operator==(const iterator& a, const iterator& b) { + a.assert_is_valid(); + b.assert_is_valid(); return a.ctrl_ == b.ctrl_; } friend bool operator!=(const iterator& a, const iterator& b) { @@ -645,6 +651,11 @@ class raw_hash_set { iterator(ctrl_t* ctrl) : ctrl_(ctrl) {} // for end() iterator(ctrl_t* ctrl, slot_type* slot) : ctrl_(ctrl), slot_(slot) {} + void assert_is_full() const { assert(IsFull(*ctrl_)); } + void assert_is_valid() const { + assert(!ctrl_ || IsFull(*ctrl_) || *ctrl_ == kSentinel); + } + void skip_empty_or_deleted() { while (IsEmptyOrDeleted(*ctrl_)) { // ctrl is not necessarily aligned to Group::kWidth. It is also likely @@ -658,7 +669,7 @@ class raw_hash_set { } ctrl_t* ctrl_ = nullptr; - // To avoid uninitialized member warnigs, put slot_ in an anonymous union. + // To avoid uninitialized member warnings, put slot_ in an anonymous union. // The member is not initialized on singleton and end iterators. union { slot_type* slot_; @@ -939,8 +950,11 @@ class raw_hash_set { // // flat_hash_map<std::string, int> m; // m.insert(std::make_pair("abc", 42)); + // TODO(cheshire): A type alias T2 is introduced as a workaround for the nvcc + // bug. template <class T, RequiresInsertable<T> = 0, - typename std::enable_if<IsDecomposable<T>::value, int>::type = 0, + class T2 = T, + typename std::enable_if<IsDecomposable<T2>::value, int>::type = 0, T* = nullptr> std::pair<iterator, bool> insert(T&& value) { return emplace(std::forward<T>(value)); @@ -976,8 +990,10 @@ class raw_hash_set { return emplace(std::move(value)); } - template <class T, RequiresInsertable<T> = 0, - typename std::enable_if<IsDecomposable<T>::value, int>::type = 0, + // TODO(cheshire): A type alias T2 is introduced as a workaround for the nvcc + // bug. + template <class T, RequiresInsertable<T> = 0, class T2 = T, + typename std::enable_if<IsDecomposable<T2>::value, int>::type = 0, T* = nullptr> iterator insert(const_iterator, T&& value) { return insert(std::forward<T>(value)).first; @@ -1051,8 +1067,7 @@ class raw_hash_set { template <class... Args, typename std::enable_if< !IsDecomposable<Args...>::value, int>::type = 0> std::pair<iterator, bool> emplace(Args&&... args) { - typename std::aligned_storage<sizeof(slot_type), alignof(slot_type)>::type - raw; + alignas(slot_type) unsigned char raw[sizeof(slot_type)]; slot_type* slot = reinterpret_cast<slot_type*>(&raw); PolicyTraits::construct(&alloc_ref(), slot, std::forward<Args>(args)...); @@ -1068,10 +1083,15 @@ class raw_hash_set { // Extension API: support for lazy emplace. // // Looks up key in the table. If found, returns the iterator to the element. - // Otherwise calls f with one argument of type raw_hash_set::constructor. f - // MUST call raw_hash_set::constructor with arguments as if a - // raw_hash_set::value_type is constructed, otherwise the behavior is - // undefined. + // Otherwise calls `f` with one argument of type `raw_hash_set::constructor`. + // + // `f` must abide by several restrictions: + // - it MUST call `raw_hash_set::constructor` with arguments as if a + // `raw_hash_set::value_type` is constructed, + // - it MUST NOT access the container before the call to + // `raw_hash_set::constructor`, and + // - it MUST NOT erase the lazily emplaced element. + // Doing any of these is undefined behavior. // // For example: // @@ -1134,15 +1154,16 @@ class raw_hash_set { } // Erases the element pointed to by `it`. Unlike `std::unordered_set::erase`, - // this method returns void to reduce algorithmic complexity to O(1). In - // order to erase while iterating across a map, use the following idiom (which - // also works for standard containers): + // this method returns void to reduce algorithmic complexity to O(1). The + // iterator is invalidated, so any increment should be done before calling + // erase. In order to erase while iterating across a map, use the following + // idiom (which also works for standard containers): // // for (auto it = m.begin(), end = m.end(); it != end;) { + // // `erase()` will invalidate `it`, so advance `it` first. + // auto copy_it = it++; // if (<pred>) { - // m.erase(it++); - // } else { - // ++it; + // m.erase(copy_it); // } // } void erase(const_iterator cit) { erase(cit.inner_); } @@ -1150,7 +1171,7 @@ class raw_hash_set { // This overload is necessary because otherwise erase<K>(const K&) would be // a better match if non-const iterator is passed as an argument. void erase(iterator it) { - assert(it != end()); + it.assert_is_full(); PolicyTraits::destroy(&alloc_ref(), it.slot_); erase_meta_only(it); } @@ -1167,12 +1188,14 @@ class raw_hash_set { template <typename H, typename E> void merge(raw_hash_set<Policy, H, E, Alloc>& src) { // NOLINT assert(this != &src); - for (auto it = src.begin(), e = src.end(); it != e; ++it) { + for (auto it = src.begin(), e = src.end(); it != e;) { + auto next = std::next(it); if (PolicyTraits::apply(InsertSlot<false>{*this, std::move(*it.slot_)}, PolicyTraits::element(it.slot_)) .second) { src.erase_meta_only(it); } + it = next; } } @@ -1182,6 +1205,7 @@ class raw_hash_set { } node_type extract(const_iterator position) { + position.inner_.assert_is_full(); auto node = CommonAccess::Transfer<node_type>(alloc_ref(), position.inner_.slot_); erase_meta_only(position); @@ -1531,8 +1555,7 @@ class raw_hash_set { // mark target as FULL // repeat procedure for current slot with moved from element (target) ConvertDeletedToEmptyAndFullToDeleted(ctrl_, capacity_); - typename std::aligned_storage<sizeof(slot_type), alignof(slot_type)>::type - raw; + alignas(slot_type) unsigned char raw[sizeof(slot_type)]; size_t total_probe_length = 0; slot_type* slot = reinterpret_cast<slot_type*>(&raw); for (size_t i = 0; i != capacity_; ++i) { @@ -1781,6 +1804,17 @@ class raw_hash_set { settings_{0, hasher{}, key_equal{}, allocator_type{}}; }; +// Erases all elements that satisfy the predicate `pred` from the container `c`. +template <typename P, typename H, typename E, typename A, typename Predicate> +void EraseIf(Predicate pred, raw_hash_set<P, H, E, A>* c) { + for (auto it = c->begin(), last = c->end(); it != last;) { + auto copy_it = it++; + if (pred(*copy_it)) { + c->erase(copy_it); + } + } +} + namespace hashtable_debug_internal { template <typename Set> struct HashtableDebugAccess<Set, absl::void_t<typename Set::raw_hash_set>> { @@ -1842,7 +1876,7 @@ struct HashtableDebugAccess<Set, absl::void_t<typename Set::raw_hash_set>> { } // namespace hashtable_debug_internal } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_RAW_HASH_SET_H_ diff --git a/absl/container/internal/raw_hash_set_allocator_test.cc b/absl/container/internal/raw_hash_set_allocator_test.cc index 5188b3ae..7ac4b9f7 100644 --- a/absl/container/internal/raw_hash_set_allocator_test.cc +++ b/absl/container/internal/raw_hash_set_allocator_test.cc @@ -20,7 +20,7 @@ #include "absl/container/internal/tracked.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { namespace { @@ -426,5 +426,5 @@ TEST_F(PropagateOnAll, Swap) { } // namespace } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl diff --git a/absl/container/internal/raw_hash_set_test.cc b/absl/container/internal/raw_hash_set_test.cc index 2783f5c4..a96ae68a 100644 --- a/absl/container/internal/raw_hash_set_test.cc +++ b/absl/container/internal/raw_hash_set_test.cc @@ -35,7 +35,7 @@ #include "absl/strings/string_view.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { struct RawHashSetTestOnlyAccess { @@ -418,53 +418,6 @@ TEST(Table, Empty) { EXPECT_TRUE(t.empty()); } -#ifdef __GNUC__ -template <class T> -ABSL_ATTRIBUTE_ALWAYS_INLINE inline void DoNotOptimize(const T& v) { - asm volatile("" : : "r,m"(v) : "memory"); -} -#endif - -TEST(Table, Prefetch) { - IntTable t; - t.emplace(1); - // Works for both present and absent keys. - t.prefetch(1); - t.prefetch(2); - - // Do not run in debug mode, when prefetch is not implemented, or when - // sanitizers are enabled, or on WebAssembly. -#if defined(NDEBUG) && defined(__GNUC__) && defined(__x86_64__) && \ - !defined(ADDRESS_SANITIZER) && !defined(MEMORY_SANITIZER) && \ - !defined(THREAD_SANITIZER) && !defined(UNDEFINED_BEHAVIOR_SANITIZER) && \ - !defined(__EMSCRIPTEN__) - const auto now = [] { return absl::base_internal::CycleClock::Now(); }; - - // Make size enough to not fit in L2 cache (16.7 Mb) - static constexpr int size = 1 << 22; - for (int i = 0; i < size; ++i) t.insert(i); - - int64_t no_prefetch = 0, prefetch = 0; - for (int iter = 0; iter < 10; ++iter) { - int64_t time = now(); - for (int i = 0; i < size; ++i) { - DoNotOptimize(t.find(i)); - } - no_prefetch += now() - time; - - time = now(); - for (int i = 0; i < size; ++i) { - t.prefetch(i + 20); - DoNotOptimize(t.find(i)); - } - prefetch += now() - time; - } - - // no_prefetch is at least 30% slower. - EXPECT_GE(1.0 * no_prefetch / prefetch, 1.3); -#endif -} - TEST(Table, LookupEmpty) { IntTable t; auto it = t.find(0); @@ -1838,10 +1791,11 @@ TEST(TableDeathTest, EraseOfEndAsserts) { IntTable t; // Extra simple "regexp" as regexp support is highly varied across platforms. - constexpr char kDeathMsg[] = "it != end"; + constexpr char kDeathMsg[] = "IsFull"; EXPECT_DEATH_IF_SUPPORTED(t.erase(t.end()), kDeathMsg); } +#if defined(ABSL_HASHTABLEZ_SAMPLE) TEST(RawHashSamplerTest, Sample) { // Enable the feature even if the prod default is off. SetHashtablezEnabled(true); @@ -1862,6 +1816,7 @@ TEST(RawHashSamplerTest, Sample) { EXPECT_NEAR((end_size - start_size) / static_cast<double>(tables.size()), 0.01, 0.005); } +#endif // ABSL_HASHTABLEZ_SAMPLER TEST(RawHashSamplerTest, DoNotSampleCustomAllocators) { // Enable the feature even if the prod default is off. @@ -1912,5 +1867,5 @@ TEST(Sanitizer, PoisoningOnErase) { } // namespace } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl diff --git a/absl/container/internal/test_instance_tracker.cc b/absl/container/internal/test_instance_tracker.cc index f4b283fd..f9947f04 100644 --- a/absl/container/internal/test_instance_tracker.cc +++ b/absl/container/internal/test_instance_tracker.cc @@ -15,7 +15,7 @@ #include "absl/container/internal/test_instance_tracker.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace test_internal { int BaseCountedInstance::num_instances_ = 0; int BaseCountedInstance::num_live_instances_ = 0; @@ -25,5 +25,5 @@ int BaseCountedInstance::num_swaps_ = 0; int BaseCountedInstance::num_comparisons_ = 0; } // namespace test_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl diff --git a/absl/container/internal/test_instance_tracker.h b/absl/container/internal/test_instance_tracker.h index ab7f9f22..5ff6fd71 100644 --- a/absl/container/internal/test_instance_tracker.h +++ b/absl/container/internal/test_instance_tracker.h @@ -21,7 +21,7 @@ #include "absl/types/compare.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace test_internal { // A type that counts number of occurrences of the type, the live occurrences of @@ -268,7 +268,7 @@ class MovableOnlyInstance : public BaseCountedInstance { }; } // namespace test_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_TEST_INSTANCE_TRACKER_H_ diff --git a/absl/container/internal/tracked.h b/absl/container/internal/tracked.h index e9e6b95d..29f5829f 100644 --- a/absl/container/internal/tracked.h +++ b/absl/container/internal/tracked.h @@ -16,11 +16,14 @@ #define ABSL_CONTAINER_INTERNAL_TRACKED_H_ #include <stddef.h> + #include <memory> #include <utility> +#include "absl/base/config.h" + namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { // A class that tracks its copies and moves so that it can be queried in tests. @@ -74,7 +77,7 @@ class Tracked { }; } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_TRACKED_H_ diff --git a/absl/container/internal/unordered_map_constructor_test.h b/absl/container/internal/unordered_map_constructor_test.h index b64b5520..76ee95e6 100644 --- a/absl/container/internal/unordered_map_constructor_test.h +++ b/absl/container/internal/unordered_map_constructor_test.h @@ -24,7 +24,7 @@ #include "absl/container/internal/hash_policy_testing.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { template <class UnordMap> @@ -483,7 +483,7 @@ REGISTER_TYPED_TEST_CASE_P( AssignmentFromInitializerListOverwritesExisting, AssignmentOnSelf); } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_UNORDERED_MAP_CONSTRUCTOR_TEST_H_ diff --git a/absl/container/internal/unordered_map_lookup_test.h b/absl/container/internal/unordered_map_lookup_test.h index 9ad78a79..e76421e5 100644 --- a/absl/container/internal/unordered_map_lookup_test.h +++ b/absl/container/internal/unordered_map_lookup_test.h @@ -21,7 +21,7 @@ #include "absl/container/internal/hash_policy_testing.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { template <class UnordMap> @@ -111,7 +111,7 @@ REGISTER_TYPED_TEST_CASE_P(LookupTest, At, OperatorBracket, Count, Find, EqualRange); } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_UNORDERED_MAP_LOOKUP_TEST_H_ diff --git a/absl/container/internal/unordered_map_members_test.h b/absl/container/internal/unordered_map_members_test.h index c4600405..7d48cdb8 100644 --- a/absl/container/internal/unordered_map_members_test.h +++ b/absl/container/internal/unordered_map_members_test.h @@ -21,7 +21,7 @@ #include "absl/meta/type_traits.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { template <class UnordMap> @@ -81,7 +81,7 @@ TYPED_TEST_P(MembersTest, BeginEnd) { REGISTER_TYPED_TEST_SUITE_P(MembersTest, Typedefs, SimpleFunctions, BeginEnd); } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_UNORDERED_MAP_MEMBERS_TEST_H_ diff --git a/absl/container/internal/unordered_map_modifiers_test.h b/absl/container/internal/unordered_map_modifiers_test.h index 89dd7894..b8c513f1 100644 --- a/absl/container/internal/unordered_map_modifiers_test.h +++ b/absl/container/internal/unordered_map_modifiers_test.h @@ -15,13 +15,15 @@ #ifndef ABSL_CONTAINER_INTERNAL_UNORDERED_MAP_MODIFIERS_TEST_H_ #define ABSL_CONTAINER_INTERNAL_UNORDERED_MAP_MODIFIERS_TEST_H_ +#include <memory> + #include "gmock/gmock.h" #include "gtest/gtest.h" #include "absl/container/internal/hash_generator_testing.h" #include "absl/container/internal/hash_policy_testing.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { template <class UnordMap> @@ -268,8 +270,47 @@ REGISTER_TYPED_TEST_CASE_P(ModifiersTest, Clear, Insert, InsertHint, Emplace, EmplaceHint, TryEmplace, TryEmplaceHint, Erase, EraseRange, EraseKey, Swap); +template <typename Type> +struct is_unique_ptr : std::false_type {}; + +template <typename Type> +struct is_unique_ptr<std::unique_ptr<Type>> : std::true_type {}; + +template <class UnordMap> +class UniquePtrModifiersTest : public ::testing::Test { + protected: + UniquePtrModifiersTest() { + static_assert(is_unique_ptr<typename UnordMap::mapped_type>::value, + "UniquePtrModifiersTyest may only be called with a " + "std::unique_ptr value type."); + } +}; + +TYPED_TEST_SUITE_P(UniquePtrModifiersTest); + +// Test that we do not move from rvalue arguments if an insertion does not +// happen. +TYPED_TEST_P(UniquePtrModifiersTest, TryEmplace) { +#ifdef UNORDERED_MAP_CXX17 + using T = hash_internal::GeneratedType<TypeParam>; + using V = typename TypeParam::mapped_type; + T val = hash_internal::Generator<T>()(); + TypeParam m; + auto p = m.try_emplace(val.first, std::move(val.second)); + EXPECT_TRUE(p.second); + // A moved from std::unique_ptr is guaranteed to be nullptr. + EXPECT_EQ(val.second, nullptr); + T val2 = {val.first, hash_internal::Generator<V>()()}; + p = m.try_emplace(val2.first, std::move(val2.second)); + EXPECT_FALSE(p.second); + EXPECT_NE(val2.second, nullptr); +#endif +} + +REGISTER_TYPED_TEST_SUITE_P(UniquePtrModifiersTest, TryEmplace); + } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_UNORDERED_MAP_MODIFIERS_TEST_H_ diff --git a/absl/container/internal/unordered_map_test.cc b/absl/container/internal/unordered_map_test.cc index 51a90af8..9cbf512f 100644 --- a/absl/container/internal/unordered_map_test.cc +++ b/absl/container/internal/unordered_map_test.cc @@ -12,6 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. +#include <memory> #include <unordered_map> #include "absl/container/internal/unordered_map_constructor_test.h" @@ -20,7 +21,7 @@ #include "absl/container/internal/unordered_map_modifiers_test.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { namespace { @@ -36,7 +37,14 @@ INSTANTIATE_TYPED_TEST_SUITE_P(UnorderedMap, LookupTest, MapTypes); INSTANTIATE_TYPED_TEST_SUITE_P(UnorderedMap, MembersTest, MapTypes); INSTANTIATE_TYPED_TEST_SUITE_P(UnorderedMap, ModifiersTest, MapTypes); +using UniquePtrMapTypes = ::testing::Types<std::unordered_map< + int, std::unique_ptr<int>, StatefulTestingHash, StatefulTestingEqual, + Alloc<std::pair<const int, std::unique_ptr<int>>>>>; + +INSTANTIATE_TYPED_TEST_SUITE_P(UnorderedMap, UniquePtrModifiersTest, + UniquePtrMapTypes); + } // namespace } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl diff --git a/absl/container/internal/unordered_set_constructor_test.h b/absl/container/internal/unordered_set_constructor_test.h index ac73a896..41165b05 100644 --- a/absl/container/internal/unordered_set_constructor_test.h +++ b/absl/container/internal/unordered_set_constructor_test.h @@ -26,7 +26,7 @@ #include "absl/meta/type_traits.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { template <class UnordMap> @@ -490,7 +490,7 @@ REGISTER_TYPED_TEST_CASE_P( AssignmentFromInitializerListOverwritesExisting, AssignmentOnSelf); } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_UNORDERED_SET_CONSTRUCTOR_TEST_H_ diff --git a/absl/container/internal/unordered_set_lookup_test.h b/absl/container/internal/unordered_set_lookup_test.h index 722fb1c2..8f2f4b20 100644 --- a/absl/container/internal/unordered_set_lookup_test.h +++ b/absl/container/internal/unordered_set_lookup_test.h @@ -21,7 +21,7 @@ #include "absl/container/internal/hash_policy_testing.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { template <class UnordSet> @@ -85,7 +85,7 @@ TYPED_TEST_P(LookupTest, EqualRange) { REGISTER_TYPED_TEST_CASE_P(LookupTest, Count, Find, EqualRange); } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_UNORDERED_SET_LOOKUP_TEST_H_ diff --git a/absl/container/internal/unordered_set_members_test.h b/absl/container/internal/unordered_set_members_test.h index 756a95cb..4c5e104a 100644 --- a/absl/container/internal/unordered_set_members_test.h +++ b/absl/container/internal/unordered_set_members_test.h @@ -21,7 +21,7 @@ #include "absl/meta/type_traits.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { template <class UnordSet> @@ -80,7 +80,7 @@ TYPED_TEST_P(MembersTest, BeginEnd) { REGISTER_TYPED_TEST_SUITE_P(MembersTest, Typedefs, SimpleFunctions, BeginEnd); } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_UNORDERED_SET_MEMBERS_TEST_H_ diff --git a/absl/container/internal/unordered_set_modifiers_test.h b/absl/container/internal/unordered_set_modifiers_test.h index d3e534d3..26be58d9 100644 --- a/absl/container/internal/unordered_set_modifiers_test.h +++ b/absl/container/internal/unordered_set_modifiers_test.h @@ -21,7 +21,7 @@ #include "absl/container/internal/hash_policy_testing.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { template <class UnordSet> @@ -184,7 +184,7 @@ REGISTER_TYPED_TEST_CASE_P(ModifiersTest, Clear, Insert, InsertHint, EraseKey, Swap); } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_CONTAINER_INTERNAL_UNORDERED_SET_MODIFIERS_TEST_H_ diff --git a/absl/container/internal/unordered_set_test.cc b/absl/container/internal/unordered_set_test.cc index 2356e187..a134b539 100644 --- a/absl/container/internal/unordered_set_test.cc +++ b/absl/container/internal/unordered_set_test.cc @@ -20,7 +20,7 @@ #include "absl/container/internal/unordered_set_modifiers_test.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace container_internal { namespace { @@ -37,5 +37,5 @@ INSTANTIATE_TYPED_TEST_SUITE_P(UnorderedSet, ModifiersTest, SetTypes); } // namespace } // namespace container_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl |