From 3c5aba629c22c0d70942a66be3a13b453f1e75fe Mon Sep 17 00:00:00 2001 From: greg Date: Sat, 28 Dec 2019 22:09:25 -0500 Subject: [PATCH] reorganize headers and start adding btree support --- parallel_hashmap/btree.h | 4107 +++++++++++++++++++++++++++++++++ parallel_hashmap/phmap.h | 280 --- parallel_hashmap/phmap_base.h | 310 +++ 3 files changed, 4417 insertions(+), 280 deletions(-) create mode 100644 parallel_hashmap/btree.h diff --git a/parallel_hashmap/btree.h b/parallel_hashmap/btree.h new file mode 100644 index 0000000..1b244d0 --- /dev/null +++ b/parallel_hashmap/btree.h @@ -0,0 +1,4107 @@ +// --------------------------------------------------------------------------- +// Copyright (c) 2019, Gregory Popovitch - greg7mdp@gmail.com +// +// 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. +// +// Includes work from abseil-cpp (https://github.com/abseil/abseil-cpp) +// with modifications. +// +// 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 PHMAP_BTREE_BTREE_CONTAINER_H_ +#define PHMAP_BTREE_BTREE_CONTAINER_H_ + +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "phmap_base.h" + +#if PHMAP_HAVE_STD_STRING_VIEW + #include +#endif + +// MSVC constructibility traits do not detect destructor properties and so our +// implementations should not use them as a source-of-truth. +#if defined(_MSC_VER) && !defined(__clang__) && !defined(__GNUC__) + #define PHMAP_META_INTERNAL_STD_CONSTRUCTION_TRAITS_DONT_CHECK_DESTRUCTION 1 +#endif + + +namespace phmap { + + // Defined and documented later on in this file. + template + struct is_trivially_destructible; + + // Defined and documented later on in this file. + template + struct is_trivially_move_assignable; + + namespace type_traits_internal { + + // Silence MSVC warnings about the destructor being defined as deleted. +#if defined(_MSC_VER) && !defined(__GNUC__) + #pragma warning(push) + #pragma warning(disable : 4624) +#endif // defined(_MSC_VER) && !defined(__GNUC__) + + template + union SingleMemberUnion { + T t; + }; + + // Restore the state of the destructor warning that was silenced above. +#if defined(_MSC_VER) && !defined(__GNUC__) + #pragma warning(pop) +#endif // defined(_MSC_VER) && !defined(__GNUC__) + + template + struct IsTriviallyMoveConstructibleObject + : std::integral_constant< + bool, std::is_move_constructible< + type_traits_internal::SingleMemberUnion>::value && + phmap::is_trivially_destructible::value> {}; + + template + struct IsTriviallyCopyConstructibleObject + : std::integral_constant< + bool, std::is_copy_constructible< + type_traits_internal::SingleMemberUnion>::value && + phmap::is_trivially_destructible::value> {}; + + template + struct IsTriviallyMoveAssignableReference : std::false_type {}; + + template + struct IsTriviallyMoveAssignableReference + : phmap::is_trivially_move_assignable::type {}; + + template + struct IsTriviallyMoveAssignableReference + : phmap::is_trivially_move_assignable::type {}; + + } // namespace type_traits_internal + + + template + using void_t = typename type_traits_internal::VoidTImpl::type; + + + template + struct is_function + : std::integral_constant< + bool, !(std::is_reference::value || + std::is_const::type>::value)> {}; + + + namespace type_traits_internal { + + template + class is_trivially_copyable_impl { + using ExtentsRemoved = typename std::remove_all_extents::type; + static constexpr bool kIsCopyOrMoveConstructible = + std::is_copy_constructible::value || + std::is_move_constructible::value; + static constexpr bool kIsCopyOrMoveAssignable = + phmap::is_copy_assignable::value || + phmap::is_move_assignable::value; + + public: + static constexpr bool kValue = + (__has_trivial_copy(ExtentsRemoved) || !kIsCopyOrMoveConstructible) && + (__has_trivial_assign(ExtentsRemoved) || !kIsCopyOrMoveAssignable) && + (kIsCopyOrMoveConstructible || kIsCopyOrMoveAssignable) && + is_trivially_destructible::value && + // We need to check for this explicitly because otherwise we'll say + // references are trivial copyable when compiled by MSVC. + !std::is_reference::value; + }; + + template + struct is_trivially_copyable + : std::integral_constant< + bool, type_traits_internal::is_trivially_copyable_impl::kValue> {}; + } // namespace type_traits_internal + + // ----------------------------------------------------------------------------- + // C++14 "_t" trait aliases + // ----------------------------------------------------------------------------- + + template + using remove_cv_t = typename std::remove_cv::type; + + template + using remove_const_t = typename std::remove_const::type; + + template + using remove_volatile_t = typename std::remove_volatile::type; + + template + using add_cv_t = typename std::add_cv::type; + + template + using add_const_t = typename std::add_const::type; + + template + using add_volatile_t = typename std::add_volatile::type; + + template + using remove_reference_t = typename std::remove_reference::type; + + template + using add_lvalue_reference_t = typename std::add_lvalue_reference::type; + + template + using add_rvalue_reference_t = typename std::add_rvalue_reference::type; + + template + using remove_pointer_t = typename std::remove_pointer::type; + + template + using add_pointer_t = typename std::add_pointer::type; + + template + using make_signed_t = typename std::make_signed::type; + + template + using make_unsigned_t = typename std::make_unsigned::type; + + template + using remove_extent_t = typename std::remove_extent::type; + + template + using remove_all_extents_t = typename std::remove_all_extents::type; + + template ::value> + using aligned_storage_t = typename std::aligned_storage::type; + + template + using decay_t = typename std::decay::type; + + template + using enable_if_t = typename std::enable_if::type; + + template + using conditional_t = typename std::conditional::type; + + template + using common_type_t = typename std::common_type::type; + + template + using underlying_type_t = typename std::underlying_type::type; + + template + using result_of_t = typename std::result_of::type; + + namespace type_traits_internal { + // In MSVC we can't probe std::hash or stdext::hash because it triggers a + // static_assert instead of failing substitution. Libc++ prior to 4.0 + // also used a static_assert. + // +#if defined(_MSC_VER) || (defined(_LIBCPP_VERSION) && \ + _LIBCPP_VERSION < 4000 && _LIBCPP_STD_VER > 11) + #define PHMAP_META_INTERNAL_STD_HASH_SFINAE_FRIENDLY_ 0 +#else + #define PHMAP_META_INTERNAL_STD_HASH_SFINAE_FRIENDLY_ 1 +#endif + + } // namespace type_traits_internal + + namespace swap_internal { + + // Necessary for the traits. + using std::swap; + + // This declaration prevents global `swap` and `phmap::swap` overloads from being + // considered unless ADL picks them up. + void swap(); + + template + using IsSwappableImpl = decltype(swap(std::declval(), std::declval())); + + // NOTE: This dance with the default template parameter is for MSVC. + template (), std::declval()))>> + using IsNothrowSwappableImpl = typename std::enable_if::type; + + template + struct IsSwappable + : phmap::type_traits_internal::is_detected {}; + + template + struct IsNothrowSwappable + : phmap::type_traits_internal::is_detected {}; + + template ::value, int> = 0> + void Swap(T& lhs, T& rhs) noexcept(IsNothrowSwappable::value) { + swap(lhs, rhs); + } + + using StdSwapIsUnconstrained = IsSwappable; + + } // namespace swap_internal + + namespace type_traits_internal { + + // Make the swap-related traits/function accessible from this namespace. + using swap_internal::IsNothrowSwappable; + using swap_internal::IsSwappable; + using swap_internal::Swap; + using swap_internal::StdSwapIsUnconstrained; + + } // namespace type_traits_internal + + namespace compare_internal { + + using value_type = int8_t; + + template + struct Fail { + static_assert(sizeof(T) < 0, "Only literal `0` is allowed."); + }; + + template + struct OnlyLiteralZero { + constexpr OnlyLiteralZero(NullPtrT) noexcept {} // NOLINT + + template < + typename T, + typename = typename std::enable_if< + std::is_same::value || + (std::is_integral::value && !std::is_same::value)>::type, + typename = typename Fail::type> + OnlyLiteralZero(T); // NOLINT + }; + + enum class eq : value_type { + equal = 0, + equivalent = equal, + nonequal = 1, + nonequivalent = nonequal, + }; + + enum class ord : value_type { less = -1, greater = 1 }; + + enum class ncmp : value_type { unordered = -127 }; + +#ifdef __cpp_inline_variables + +#define PHMAP_COMPARE_INLINE_BASECLASS_DECL(name) + +#define PHMAP_COMPARE_INLINE_SUBCLASS_DECL(type, name) \ + static const type name + +#define PHMAP_COMPARE_INLINE_INIT(type, name, init) \ + inline constexpr type type::name(init) + +#else // __cpp_inline_variables + +#define PHMAP_COMPARE_INLINE_BASECLASS_DECL(name) \ + static const T name + +#define PHMAP_COMPARE_INLINE_SUBCLASS_DECL(type, name) + +#define PHMAP_COMPARE_INLINE_INIT(type, name, init) \ + template \ + const T compare_internal::type##_base::name(init) + +#endif // __cpp_inline_variables + + // These template base classes allow for defining the values of the constants + // in the header file (for performance) without using inline variables (which + // aren't available in C++11). + template + struct weak_equality_base { + PHMAP_COMPARE_INLINE_BASECLASS_DECL(equivalent); + PHMAP_COMPARE_INLINE_BASECLASS_DECL(nonequivalent); + }; + + template + struct strong_equality_base { + PHMAP_COMPARE_INLINE_BASECLASS_DECL(equal); + PHMAP_COMPARE_INLINE_BASECLASS_DECL(nonequal); + PHMAP_COMPARE_INLINE_BASECLASS_DECL(equivalent); + PHMAP_COMPARE_INLINE_BASECLASS_DECL(nonequivalent); + }; + + template + struct partial_ordering_base { + PHMAP_COMPARE_INLINE_BASECLASS_DECL(less); + PHMAP_COMPARE_INLINE_BASECLASS_DECL(equivalent); + PHMAP_COMPARE_INLINE_BASECLASS_DECL(greater); + PHMAP_COMPARE_INLINE_BASECLASS_DECL(unordered); + }; + + template + struct weak_ordering_base { + PHMAP_COMPARE_INLINE_BASECLASS_DECL(less); + PHMAP_COMPARE_INLINE_BASECLASS_DECL(equivalent); + PHMAP_COMPARE_INLINE_BASECLASS_DECL(greater); + }; + + template + struct strong_ordering_base { + PHMAP_COMPARE_INLINE_BASECLASS_DECL(less); + PHMAP_COMPARE_INLINE_BASECLASS_DECL(equal); + PHMAP_COMPARE_INLINE_BASECLASS_DECL(equivalent); + PHMAP_COMPARE_INLINE_BASECLASS_DECL(greater); + }; + + } // namespace compare_internal + + class weak_equality + : public compare_internal::weak_equality_base { + explicit constexpr weak_equality(compare_internal::eq v) noexcept + : value_(static_cast(v)) {} + friend struct compare_internal::weak_equality_base; + + public: + PHMAP_COMPARE_INLINE_SUBCLASS_DECL(weak_equality, equivalent); + PHMAP_COMPARE_INLINE_SUBCLASS_DECL(weak_equality, nonequivalent); + + // Comparisons + friend constexpr bool operator==( + weak_equality v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.value_ == 0; + } + friend constexpr bool operator!=( + weak_equality v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.value_ != 0; + } + friend constexpr bool operator==(compare_internal::OnlyLiteralZero<>, + weak_equality v) noexcept { + return 0 == v.value_; + } + friend constexpr bool operator!=(compare_internal::OnlyLiteralZero<>, + weak_equality v) noexcept { + return 0 != v.value_; + } + + private: + compare_internal::value_type value_; + }; + PHMAP_COMPARE_INLINE_INIT(weak_equality, equivalent, + compare_internal::eq::equivalent); + PHMAP_COMPARE_INLINE_INIT(weak_equality, nonequivalent, + compare_internal::eq::nonequivalent); + + class strong_equality + : public compare_internal::strong_equality_base { + explicit constexpr strong_equality(compare_internal::eq v) noexcept + : value_(static_cast(v)) {} + friend struct compare_internal::strong_equality_base; + + public: + PHMAP_COMPARE_INLINE_SUBCLASS_DECL(strong_equality, equal); + PHMAP_COMPARE_INLINE_SUBCLASS_DECL(strong_equality, nonequal); + PHMAP_COMPARE_INLINE_SUBCLASS_DECL(strong_equality, equivalent); + PHMAP_COMPARE_INLINE_SUBCLASS_DECL(strong_equality, nonequivalent); + + // Conversion + constexpr operator weak_equality() const noexcept { // NOLINT + return value_ == 0 ? weak_equality::equivalent + : weak_equality::nonequivalent; + } + // Comparisons + friend constexpr bool operator==( + strong_equality v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.value_ == 0; + } + friend constexpr bool operator!=( + strong_equality v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.value_ != 0; + } + friend constexpr bool operator==(compare_internal::OnlyLiteralZero<>, + strong_equality v) noexcept { + return 0 == v.value_; + } + friend constexpr bool operator!=(compare_internal::OnlyLiteralZero<>, + strong_equality v) noexcept { + return 0 != v.value_; + } + + private: + compare_internal::value_type value_; + }; + + PHMAP_COMPARE_INLINE_INIT(strong_equality, equal, compare_internal::eq::equal); + PHMAP_COMPARE_INLINE_INIT(strong_equality, nonequal, + compare_internal::eq::nonequal); + PHMAP_COMPARE_INLINE_INIT(strong_equality, equivalent, + compare_internal::eq::equivalent); + PHMAP_COMPARE_INLINE_INIT(strong_equality, nonequivalent, + compare_internal::eq::nonequivalent); + + class partial_ordering + : public compare_internal::partial_ordering_base { + explicit constexpr partial_ordering(compare_internal::eq v) noexcept + : value_(static_cast(v)) {} + explicit constexpr partial_ordering(compare_internal::ord v) noexcept + : value_(static_cast(v)) {} + explicit constexpr partial_ordering(compare_internal::ncmp v) noexcept + : value_(static_cast(v)) {} + friend struct compare_internal::partial_ordering_base; + + constexpr bool is_ordered() const noexcept { + return value_ != + compare_internal::value_type(compare_internal::ncmp::unordered); + } + + public: + PHMAP_COMPARE_INLINE_SUBCLASS_DECL(partial_ordering, less); + PHMAP_COMPARE_INLINE_SUBCLASS_DECL(partial_ordering, equivalent); + PHMAP_COMPARE_INLINE_SUBCLASS_DECL(partial_ordering, greater); + PHMAP_COMPARE_INLINE_SUBCLASS_DECL(partial_ordering, unordered); + + // Conversion + constexpr operator weak_equality() const noexcept { // NOLINT + return value_ == 0 ? weak_equality::equivalent + : weak_equality::nonequivalent; + } + // Comparisons + friend constexpr bool operator==( + partial_ordering v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.is_ordered() && v.value_ == 0; + } + friend constexpr bool operator!=( + partial_ordering v, compare_internal::OnlyLiteralZero<>) noexcept { + return !v.is_ordered() || v.value_ != 0; + } + friend constexpr bool operator<( + partial_ordering v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.is_ordered() && v.value_ < 0; + } + friend constexpr bool operator<=( + partial_ordering v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.is_ordered() && v.value_ <= 0; + } + friend constexpr bool operator>( + partial_ordering v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.is_ordered() && v.value_ > 0; + } + friend constexpr bool operator>=( + partial_ordering v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.is_ordered() && v.value_ >= 0; + } + friend constexpr bool operator==(compare_internal::OnlyLiteralZero<>, + partial_ordering v) noexcept { + return v.is_ordered() && 0 == v.value_; + } + friend constexpr bool operator!=(compare_internal::OnlyLiteralZero<>, + partial_ordering v) noexcept { + return !v.is_ordered() || 0 != v.value_; + } + friend constexpr bool operator<(compare_internal::OnlyLiteralZero<>, + partial_ordering v) noexcept { + return v.is_ordered() && 0 < v.value_; + } + friend constexpr bool operator<=(compare_internal::OnlyLiteralZero<>, + partial_ordering v) noexcept { + return v.is_ordered() && 0 <= v.value_; + } + friend constexpr bool operator>(compare_internal::OnlyLiteralZero<>, + partial_ordering v) noexcept { + return v.is_ordered() && 0 > v.value_; + } + friend constexpr bool operator>=(compare_internal::OnlyLiteralZero<>, + partial_ordering v) noexcept { + return v.is_ordered() && 0 >= v.value_; + } + + private: + compare_internal::value_type value_; + }; + + PHMAP_COMPARE_INLINE_INIT(partial_ordering, less, compare_internal::ord::less); + PHMAP_COMPARE_INLINE_INIT(partial_ordering, equivalent, + compare_internal::eq::equivalent); + PHMAP_COMPARE_INLINE_INIT(partial_ordering, greater, + compare_internal::ord::greater); + PHMAP_COMPARE_INLINE_INIT(partial_ordering, unordered, + compare_internal::ncmp::unordered); + + class weak_ordering + : public compare_internal::weak_ordering_base { + explicit constexpr weak_ordering(compare_internal::eq v) noexcept + : value_(static_cast(v)) {} + explicit constexpr weak_ordering(compare_internal::ord v) noexcept + : value_(static_cast(v)) {} + friend struct compare_internal::weak_ordering_base; + + public: + PHMAP_COMPARE_INLINE_SUBCLASS_DECL(weak_ordering, less); + PHMAP_COMPARE_INLINE_SUBCLASS_DECL(weak_ordering, equivalent); + PHMAP_COMPARE_INLINE_SUBCLASS_DECL(weak_ordering, greater); + + // Conversions + constexpr operator weak_equality() const noexcept { // NOLINT + return value_ == 0 ? weak_equality::equivalent + : weak_equality::nonequivalent; + } + constexpr operator partial_ordering() const noexcept { // NOLINT + return value_ == 0 ? partial_ordering::equivalent + : (value_ < 0 ? partial_ordering::less + : partial_ordering::greater); + } + // Comparisons + friend constexpr bool operator==( + weak_ordering v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.value_ == 0; + } + friend constexpr bool operator!=( + weak_ordering v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.value_ != 0; + } + friend constexpr bool operator<( + weak_ordering v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.value_ < 0; + } + friend constexpr bool operator<=( + weak_ordering v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.value_ <= 0; + } + friend constexpr bool operator>( + weak_ordering v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.value_ > 0; + } + friend constexpr bool operator>=( + weak_ordering v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.value_ >= 0; + } + friend constexpr bool operator==(compare_internal::OnlyLiteralZero<>, + weak_ordering v) noexcept { + return 0 == v.value_; + } + friend constexpr bool operator!=(compare_internal::OnlyLiteralZero<>, + weak_ordering v) noexcept { + return 0 != v.value_; + } + friend constexpr bool operator<(compare_internal::OnlyLiteralZero<>, + weak_ordering v) noexcept { + return 0 < v.value_; + } + friend constexpr bool operator<=(compare_internal::OnlyLiteralZero<>, + weak_ordering v) noexcept { + return 0 <= v.value_; + } + friend constexpr bool operator>(compare_internal::OnlyLiteralZero<>, + weak_ordering v) noexcept { + return 0 > v.value_; + } + friend constexpr bool operator>=(compare_internal::OnlyLiteralZero<>, + weak_ordering v) noexcept { + return 0 >= v.value_; + } + + private: + compare_internal::value_type value_; + }; + + PHMAP_COMPARE_INLINE_INIT(weak_ordering, less, compare_internal::ord::less); + PHMAP_COMPARE_INLINE_INIT(weak_ordering, equivalent, + compare_internal::eq::equivalent); + PHMAP_COMPARE_INLINE_INIT(weak_ordering, greater, + compare_internal::ord::greater); + + class strong_ordering + : public compare_internal::strong_ordering_base { + explicit constexpr strong_ordering(compare_internal::eq v) noexcept + : value_(static_cast(v)) {} + explicit constexpr strong_ordering(compare_internal::ord v) noexcept + : value_(static_cast(v)) {} + friend struct compare_internal::strong_ordering_base; + + public: + PHMAP_COMPARE_INLINE_SUBCLASS_DECL(strong_ordering, less); + PHMAP_COMPARE_INLINE_SUBCLASS_DECL(strong_ordering, equal); + PHMAP_COMPARE_INLINE_SUBCLASS_DECL(strong_ordering, equivalent); + PHMAP_COMPARE_INLINE_SUBCLASS_DECL(strong_ordering, greater); + + // Conversions + constexpr operator weak_equality() const noexcept { // NOLINT + return value_ == 0 ? weak_equality::equivalent + : weak_equality::nonequivalent; + } + constexpr operator strong_equality() const noexcept { // NOLINT + return value_ == 0 ? strong_equality::equal : strong_equality::nonequal; + } + constexpr operator partial_ordering() const noexcept { // NOLINT + return value_ == 0 ? partial_ordering::equivalent + : (value_ < 0 ? partial_ordering::less + : partial_ordering::greater); + } + constexpr operator weak_ordering() const noexcept { // NOLINT + return value_ == 0 + ? weak_ordering::equivalent + : (value_ < 0 ? weak_ordering::less : weak_ordering::greater); + } + // Comparisons + friend constexpr bool operator==( + strong_ordering v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.value_ == 0; + } + friend constexpr bool operator!=( + strong_ordering v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.value_ != 0; + } + friend constexpr bool operator<( + strong_ordering v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.value_ < 0; + } + friend constexpr bool operator<=( + strong_ordering v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.value_ <= 0; + } + friend constexpr bool operator>( + strong_ordering v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.value_ > 0; + } + friend constexpr bool operator>=( + strong_ordering v, compare_internal::OnlyLiteralZero<>) noexcept { + return v.value_ >= 0; + } + friend constexpr bool operator==(compare_internal::OnlyLiteralZero<>, + strong_ordering v) noexcept { + return 0 == v.value_; + } + friend constexpr bool operator!=(compare_internal::OnlyLiteralZero<>, + strong_ordering v) noexcept { + return 0 != v.value_; + } + friend constexpr bool operator<(compare_internal::OnlyLiteralZero<>, + strong_ordering v) noexcept { + return 0 < v.value_; + } + friend constexpr bool operator<=(compare_internal::OnlyLiteralZero<>, + strong_ordering v) noexcept { + return 0 <= v.value_; + } + friend constexpr bool operator>(compare_internal::OnlyLiteralZero<>, + strong_ordering v) noexcept { + return 0 > v.value_; + } + friend constexpr bool operator>=(compare_internal::OnlyLiteralZero<>, + strong_ordering v) noexcept { + return 0 >= v.value_; + } + + private: + compare_internal::value_type value_; + }; + PHMAP_COMPARE_INLINE_INIT(strong_ordering, less, compare_internal::ord::less); + PHMAP_COMPARE_INLINE_INIT(strong_ordering, equal, compare_internal::eq::equal); + PHMAP_COMPARE_INLINE_INIT(strong_ordering, equivalent, + compare_internal::eq::equivalent); + PHMAP_COMPARE_INLINE_INIT(strong_ordering, greater, + compare_internal::ord::greater); + +#undef PHMAP_COMPARE_INLINE_BASECLASS_DECL +#undef PHMAP_COMPARE_INLINE_SUBCLASS_DECL +#undef PHMAP_COMPARE_INLINE_INIT + + namespace compare_internal { + // We also provide these comparator adapter functions for internal phmap use. + + // Helper functions to do a boolean comparison of two keys given a boolean + // or three-way comparator. + // SFINAE prevents implicit conversions to bool (such as from int). + template ::value, int> = 0> + constexpr bool compare_result_as_less_than(const Bool r) { return r; } + constexpr bool compare_result_as_less_than(const phmap::weak_ordering r) { + return r < 0; + } + + template + constexpr bool do_less_than_comparison(const Compare &compare, const K &x, + const LK &y) { + return compare_result_as_less_than(compare(x, y)); + } + + // Helper functions to do a three-way comparison of two keys given a boolean or + // three-way comparator. + // SFINAE prevents implicit conversions to int (such as from bool). + template ::value, int> = 0> + constexpr phmap::weak_ordering compare_result_as_ordering(const Int c) { + return c < 0 ? phmap::weak_ordering::less + : c == 0 ? phmap::weak_ordering::equivalent + : phmap::weak_ordering::greater; + } + constexpr phmap::weak_ordering compare_result_as_ordering( + const phmap::weak_ordering c) { + return c; + } + + template < + typename Compare, typename K, typename LK, + phmap::enable_if_t>::value, + int> = 0> + constexpr phmap::weak_ordering do_three_way_comparison(const Compare &compare, + const K &x, const LK &y) { + return compare_result_as_ordering(compare(x, y)); + } + template < + typename Compare, typename K, typename LK, + phmap::enable_if_t>::value, + int> = 0> + constexpr phmap::weak_ordering do_three_way_comparison(const Compare &compare, + const K &x, const LK &y) { + return compare(x, y) ? phmap::weak_ordering::less + : compare(y, x) ? phmap::weak_ordering::greater + : phmap::weak_ordering::equivalent; + } + + } // namespace compare_internal +} + + +namespace phmap { + +namespace container_internal { + + // A helper class that indicates if the Compare parameter is a key-compare-to + // comparator. + template + using btree_is_key_compare_to = + std::is_convertible, + phmap::weak_ordering>; + + struct StringBtreeDefaultLess { + using is_transparent = void; + + StringBtreeDefaultLess() = default; + + // Compatibility constructor. + StringBtreeDefaultLess(std::less) {} // NOLINT +#if PHMAP_HAVE_STD_STRING_VIEW + StringBtreeDefaultLess(std::less) {} // NOLINT + + phmap::weak_ordering operator()(std::string_view lhs, + std::string_view rhs) const { + return compare_internal::compare_result_as_ordering(lhs.compare(rhs)); + } +#else + phmap::weak_ordering operator()(std::string lhs, + std::string rhs) const { + return compare_internal::compare_result_as_ordering(lhs.compare(rhs)); + } +#endif + }; + + struct StringBtreeDefaultGreater { + using is_transparent = void; + + StringBtreeDefaultGreater() = default; + + StringBtreeDefaultGreater(std::greater) {} // NOLINT +#if PHMAP_HAVE_STD_STRING_VIEW + StringBtreeDefaultGreater(std::greater) {} // NOLINT + + phmap::weak_ordering operator()(std::string_view lhs, + std::string_view rhs) const { + return compare_internal::compare_result_as_ordering(rhs.compare(lhs)); + } +#else + phmap::weak_ordering operator()(std::string lhs, + std::string rhs) const { + return compare_internal::compare_result_as_ordering(rhs.compare(lhs)); + } +#endif + }; + + // 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, greater, + // less, and greater. + // + // 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 + struct key_compare_to_adapter { + using type = Compare; + }; + + template <> + struct key_compare_to_adapter> { + using type = StringBtreeDefaultLess; + }; + + template <> + struct key_compare_to_adapter> { + using type = StringBtreeDefaultGreater; + }; + +#if PHMAP_HAVE_STD_STRING_VIEW + template <> + struct key_compare_to_adapter> { + using type = StringBtreeDefaultLess; + }; + + template <> + struct key_compare_to_adapter> { + using type = StringBtreeDefaultGreater; + }; +#endif + + template + 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::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; + + using allocator_type = Alloc; + using key_type = Key; + using size_type = std::make_signed::type; + using difference_type = ptrdiff_t; + + // True if this is a multiset or multimap. + using is_multi_container = std::integral_constant; + + 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 = + phmap::conditional_t<(kNodeValueSpace / sizeof(value_type) > + (std::numeric_limits::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 + static void construct(Alloc *alloc, slot_type *slot, Args &&... args) { + slot_policy::construct(alloc, slot, std::forward(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 + struct map_params : common_params> { + 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 + auto operator()(const T &left, const U &right) const + -> decltype(std::declval()(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 + // btree::container_internal::slot_type interface. + template + 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 + static void construct(Alloc *alloc, slot_type *slot, Args &&... args) { + phmap::allocator_traits::construct(*alloc, slot, + std::forward(args)...); + } + + template + static void construct(Alloc *alloc, slot_type *slot, slot_type *other) { + phmap::allocator_traits::construct(*alloc, slot, std::move(*other)); + } + + template + static void destroy(Alloc *alloc, slot_type *slot) { + phmap::allocator_traits::destroy(*alloc, slot); + } + + template + static void swap(Alloc * /*alloc*/, slot_type *a, slot_type *b) { + using std::swap; + swap(*a, *b); + } + + template + static void move(Alloc * /*alloc*/, slot_type *src, slot_type *dest) { + *dest = std::move(*src); + } + + template + 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 + struct set_params : common_params> { + 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 + struct upper_bound_adapter { + explicit upper_bound_adapter(const Compare &c) : comp(c) {} + template + bool operator()(const K &a, const LK &b) const { + // Returns true when a is not greater than b. + return !phmap::compare_internal::compare_result_as_less_than(comp(b, a)); + } + + private: + Compare comp; + }; + + enum class MatchKind : uint8_t { kEq, kNe }; + + template + 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 + struct SearchResult { + 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 + 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::value && + (std::is_same, key_compare>::value || + std::is_same, key_compare>::value)>; + + + ~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 = phmap::container_internal::Layout; + constexpr static size_type SizeWithNValues(size_type n) { + return layout_type(/*parent*/ 1, + /*position, start, count, 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, count, max_count*/ 4, + /*values*/ max_values, + /*children*/ 0); + } + constexpr static layout_type InternalLayout() { + return layout_type(/*parent*/ 1, + /*position, start, count, 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 is the Nth type in the Layout definition. + template + inline typename layout_type::template ElementType *GetField() { + // We assert that we don't read from values that aren't there. + assert(N < 3 || !leaf()); + return InternalLayout().template Pointer(reinterpret_cast(this)); + } + + template + inline const typename layout_type::template ElementType *GetField() const { + assert(N < 3 || !leaf()); + return InternalLayout().template Pointer( + reinterpret_cast(this)); + } + + void set_parent(btree_node *p) { *GetField<0>() = p; } + field_type &mutable_count() { return GetField<1>()[2]; } + slot_type *slot(int i) { return &GetField<2>()[i]; } + 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_count(field_type v) { GetField<1>()[2] = v; } + 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 { return GetField<1>()[1]; } + + // Getters for the number of values stored in this node. + field_type count() const { return GetField<1>()[2]; } + 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 *&mutable_child(int i) { return GetField<3>()[i]; } + void clear_child(int i) { + phmap::container_internal::SanitizerPoisonObject(&mutable_child(i)); + } + void set_child(int i, btree_node *c) { + phmap::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 + SearchResult 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 + int upper_bound(const K &k, const key_compare &comp) const { + auto upper_compare = upper_bound_adapter(comp); + return use_linear_search::value ? linear_search(k, upper_compare).value + : binary_search(k, upper_compare).value; + } + + template + SearchResult::value> + linear_search(const K &k, const Compare &comp) const { + return linear_search_impl(k, 0, count(), comp, + btree_is_key_compare_to()); + } + + template + SearchResult::value> + binary_search(const K &k, const Compare &comp) const { + return binary_search_impl(k, 0, count(), comp, + btree_is_key_compare_to()); + } + + // Returns the position of the first value whose key is not less than k using + // linear search performed using plain compare. + template + SearchResult 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 + SearchResult linear_search_impl( + const K &k, int s, const int e, const Compare &comp, + std::true_type /* IsCompareTo */) const { + while (s < e) { + const phmap::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 + SearchResult 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 + SearchResult 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 phmap::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 phmap::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 + 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_count(0); + n->set_max_count(max_count); + phmap::container_internal::SanitizerPoisonMemoryRegion( + n->slot(0), 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); + phmap::container_internal::SanitizerPoisonMemoryRegion( + &n->mutable_child(0), (kNodeValues + 1) * sizeof(btree_node *)); + return n; + } + void destroy(allocator_type *alloc) { + for (int i = 0; i < count(); ++i) { + value_destroy(i, alloc); + } + } + + public: + // Exposed only for tests. + static bool testonly_uses_linear_node_search() { + return use_linear_search::value; + } + + private: + template + void value_init(const size_type i, allocator_type *alloc, Args &&... args) { + phmap::container_internal::SanitizerUnpoisonObject(slot(i)); + params_type::construct(alloc, slot(i), std::forward(args)...); + } + void value_destroy(const size_type i, allocator_type *alloc) { + params_type::destroy(alloc, slot(i)); + phmap::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) { + phmap::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 + friend class btree; + template + friend struct btree_iterator; + friend class BtreeNodePeer; + }; + + template + 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::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; + using const_iterator = + btree_iterator; + + 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) {} + 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 , iterator>::value && + std::is_same::value, + int> = 0> + btree_iterator(const btree_iterator &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 , const_iterator>::value && + std::is_same::value, + int> = 0> + explicit btree_iterator(const btree_iterator &x) + : node(const_cast(x.node)), position(x.position) {} + + // Increment/decrement the iterator. + void increment() { + if (node->leaf() && ++position < node->count()) { + return; + } + increment_slow(); + } + void increment_slow(); + + void decrement() { + if (node->leaf() && --position >= 0) { + 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 + friend class btree; + template + friend class btree_container; + template + friend class btree_set_container; + template + friend class btree_map_container; + template + friend class btree_multiset_container; + template + friend struct btree_iterator; + template + 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 + class btree { + using node_type = btree_node; + 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 count = 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(&empty_node)); + return const_cast(&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; + using const_iterator = typename iterator::const_iterator; + using reverse_iterator = std::reverse_iterator; + using const_reverse_iterator = std::reverse_iterator; + using node_handle_type = node_handle; + + // 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 + 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_(phmap::exchange(x.rightmost_, EmptyNode())), + size_(phmap::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(), 0); + } + const_iterator begin() const { + return const_iterator(leftmost(), 0); + } + iterator end() { return iterator(rightmost_, rightmost_->count()); } + const_iterator end() const { + return const_iterator(rightmost_, rightmost_->count()); + } + 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 + iterator lower_bound(const K &key) { + return internal_end(internal_lower_bound(key)); + } + template + 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 + iterator upper_bound(const K &key) { + return internal_end(internal_upper_bound(key)); + } + template + 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 + std::pair equal_range(const K &key) { + return {lower_bound(key), upper_bound(key)}; + } + template + std::pair 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 + std::pair 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 + std::pair insert_hint_unique(iterator position, + const key_type &key, + Args &&... args); + + // Insert a range of values into the btree. + template + void insert_iterator_unique(InputIterator b, InputIterator e); + + // Inserts a value into the btree. + template + iterator insert_multi(const key_type &key, ValueType &&v); + + // Inserts a value into the btree. + template + iterator insert_multi(ValueType &&v) { + return insert_multi(params_type::key(v), std::forward(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 + iterator insert_hint_multi(iterator position, ValueType &&v); + + // Insert a range of values into the btree. + template + 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 erase(iterator begin, iterator end); + + // Erases the specified key from the btree. Returns 1 if an element was + // erased and 0 otherwise. + template + 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 + size_type erase_multi(const K &key); + + // Finds the iterator corresponding to a key or returns end() if the key is + // not present. + template + iterator find(const K &key) { + return internal_end(internal_find(key)); + } + template + 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 + 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 + 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 + 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::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(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(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( + phmap::container_internal::Allocate( + 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) { + phmap::container_internal::Deallocate( + 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 + 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 as + // iter.position == iter.node->count(). This routine simply moves iter up in + // the tree to a valid location. + // Requires: iter.node is non-null. + template + 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 + SearchResult internal_locate( + const K &key) const; + + template + SearchResult internal_locate_impl( + const K &key, std::false_type /* IsCompareTo */) const; + + template + SearchResult internal_locate_impl( + const K &key, std::true_type /* IsCompareTo */) const; + + // Internal routine which implements lower_bound(). + template + iterator internal_lower_bound(const K &key) const; + + // Internal routine which implements upper_bound(). + template + iterator internal_upper_bound(const K &key) const; + + // Internal routine which implements find(). + template + 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 = 0; i <= node->count(); ++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. + phmap::container_internal::CompressedTuple + 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 + template + inline void btree_node

::emplace_value(const size_type i, + allocator_type *alloc, + Args &&... args) { + assert(i <= count()); + // Shift old values to create space for new value and then construct it in + // place. + if (i < count()) { + value_init(count(), alloc, slot(count() - 1)); + for (size_type j = count() - 1; j > i; --j) + params_type::move(alloc, slot(j - 1), slot(j)); + value_destroy(i, alloc); + } + value_init(i, alloc, std::forward(args)...); + set_count(count() + 1); + + if (!leaf() && count() > i + 1) { + for (int j = count(); j > i + 1; --j) { + set_child(j, child(j - 1)); + } + clear_child(i + 1); + } + } + + template + inline void btree_node

::remove_value(const int i, allocator_type *alloc) { + if (!leaf() && count() > i + 1) { + assert(child(i + 1)->count() == 0); + for (size_type j = i + 1; j < count(); ++j) { + set_child(j, child(j + 1)); + } + clear_child(count()); + } + + remove_values_ignore_children(i, /*to_erase=*/1, alloc); + } + + template + inline void btree_node

::remove_values_ignore_children( + const int i, const int to_erase, allocator_type *alloc) { + params_type::move(alloc, slot(i + to_erase), slot(count()), slot(i)); + value_destroy_n(count() - to_erase, to_erase, alloc); + set_count(count() - to_erase); + } + + template + void btree_node

::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(count(), 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, 0, count() + 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->slot(right->count()), + right->slot(0)); + + // 5) Destroy the now-empty to_move entries in the right node. + right->value_destroy_n(right->count() - 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(count() + i + 1, right->child(i)); + } + for (int i = 0; i <= right->count() - 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 the counts on the left and right nodes. + set_count(count() + to_move); + right->set_count(right->count() - to_move); + } + + template + void btree_node

::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->count() - to_move, + right->count(), right, alloc); + for (slot_type *src = right->slot(right->count() - to_move - 1), + *dest = right->slot(right->count() - 1), + *end = right->slot(0); + 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(count() - (to_move - 1)), slot(count()), + right->slot(0)); + } 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(), 0, 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, + count() - uninitialized_remaining, right->count(), + right, alloc); + params_type::move(alloc, slot(count() - (to_move - 1)), + slot(count() - uninitialized_remaining), right->slot(0)); + } + + // 4) Move the new delimiting value to the parent from the left node. + params_type::move(alloc, slot(count() - to_move), parent()->slot(position())); + + // 5) Destroy the now-empty to_move entries in the left node. + value_destroy_n(count() - to_move, to_move, alloc); + + if (!leaf()) { + // Move the child pointers from the left to the right node. + for (int i = right->count(); i >= 0; --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(count() - to_move + i)); + clear_child(count() - to_move + i); + } + } + + // Fixup the counts on the left and right nodes. + set_count(count() - to_move); + right->set_count(right->count() + to_move); + } + + template + void btree_node

::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 == 0) { + dest->set_count(count() - 1); + } else if (insert_position == kNodeValues) { + dest->set_count(0); + } else { + dest->set_count(count() / 2); + } + set_count(count() - dest->count()); + assert(count() >= 1); + + // Move values from the left sibling to the right sibling. + uninitialized_move_n(dest->count(), count(), 0, dest, alloc); + + // Destroy the now-empty entries in the left node. + value_destroy_n(count(), dest->count(), alloc); + + // The split key is the largest value in the left sibling. + set_count(count() - 1); + parent()->emplace_value(position(), alloc, slot(count())); + value_destroy(count(), alloc); + parent()->init_child(position() + 1, dest); + + if (!leaf()) { + for (int i = 0; i <= dest->count(); ++i) { + assert(child(count() + i + 1) != nullptr); + dest->init_child(i, child(count() + i + 1)); + clear_child(count() + i + 1); + } + } + } + + template + void btree_node

::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(count(), alloc, parent()->slot(position())); + + // Move the values from the right to the left node. + src->uninitialized_move_n(src->count(), 0, count() + 1, this, alloc); + + // Destroy the now-empty entries in the right node. + src->value_destroy_n(0, src->count(), alloc); + + if (!leaf()) { + // Move the child pointers from the right to the left node. + for (int i = 0; i <= src->count(); ++i) { + init_child(count() + i + 1, src->child(i)); + src->clear_child(i); + } + } + + // Fixup the counts on the src and dest nodes. + set_count(1 + count() + src->count()); + src->set_count(0); + + // Remove the value on the parent node. + parent()->remove_value(position(), alloc); + } + + template + void btree_node

::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->slot(0), *b = larger->slot(0), + *end = a + smaller->count(); + 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->count(), smaller->count(), + smaller, alloc); + larger->value_destroy_n(smaller->count(), to_move, alloc); + + if (!leaf()) { + // Swap the child pointers. + std::swap_ranges(&smaller->mutable_child(0), + &smaller->mutable_child(smaller->count() + 1), + &larger->mutable_child(0)); + // Update swapped children's parent pointers. + int i = 0; + for (; i <= smaller->count(); ++i) { + smaller->child(i)->set_parent(smaller); + larger->child(i)->set_parent(larger); + } + // Move the child pointers that couldn't be swapped. + for (; i <= larger->count(); ++i) { + smaller->init_child(i, larger->child(i)); + larger->clear_child(i); + } + } + + // Swap the counts. + swap(mutable_count(), x->mutable_count()); + } + + //// + // btree_iterator methods + template + void btree_iterator::increment_slow() { + if (node->leaf()) { + assert(position >= node->count()); + btree_iterator save(*this); + while (position == node->count() && !node->is_root()) { + assert(node->parent()->child(node->position()) == node); + position = node->position(); + node = node->parent(); + } + if (position == node->count()) { + *this = save; + } + } else { + assert(position < node->count()); + node = node->child(position + 1); + while (!node->leaf()) { + node = node->child(0); + } + position = 0; + } + } + + template + void btree_iterator::decrement_slow() { + if (node->leaf()) { + assert(position <= -1); + btree_iterator save(*this); + while (position < 0 && !node->is_root()) { + assert(node->parent()->child(node->position()) == node); + position = node->position() - 1; + node = node->parent(); + } + if (position < 0) { + *this = save; + } + } else { + assert(position >= 0); + node = node->child(position); + while (!node->leaf()) { + node = node->child(node->count()); + } + position = node->count() - 1; + } + } + + //// + // btree methods + template + template + void btree

::copy_or_move_values_in_order(Btree *x) { + static_assert(std::is_same::value || + std::is_same::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 + constexpr bool btree

::static_assert_validation() { + static_assert(std::is_nothrow_copy_constructible::value, + "Key comparison must be nothrow copy constructible"); + static_assert(std::is_nothrow_copy_constructible::value, + "Allocator must be nothrow copy constructible"); + static_assert(type_traits_internal::is_trivially_copyable::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 phmap::{weak,strong}_ordering or bool. + using compare_result_type = + phmap::result_of_t; + static_assert( + std::is_same::value || + std::is_convertible::value, + "key comparison function must return phmap::{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 + btree

::btree(const key_compare &comp, const allocator_type &alloc) + : root_(comp, alloc, EmptyNode()), rightmost_(EmptyNode()), size_(0) {} + + template + btree

::btree(const btree &x) : btree(x.key_comp(), x.allocator()) { + copy_or_move_values_in_order(&x); + } + + template + template + auto btree

::insert_unique(const key_type &key, Args &&... args) + -> std::pair { + 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)...), true}; + } + + template + template + inline auto btree

::insert_hint_unique(iterator position, const key_type &key, + Args &&... args) + -> std::pair { + if (!empty()) { + if (position == end() || compare_keys(key, position.key())) { + iterator prev = position; + if (position == begin() || compare_keys((--prev).key(), key)) { + // prev.key() < key < position.key() + return {internal_emplace(position, std::forward(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)...), true}; + } + } else { + // position.key() == key + return {position, false}; + } + } + return insert_unique(key, std::forward(args)...); + } + + template + template + void btree

::insert_iterator_unique(InputIterator b, InputIterator e) { + for (; b != e; ++b) { + insert_hint_unique(end(), params_type::key(*b), *b); + } + } + + template + template + auto btree

::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(v)); + } + + template + template + auto btree

::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)) { + iterator prev = position; + if (position == begin() || !compare_keys(key, (--prev).key())) { + // prev.key() <= key <= position.key() + return internal_emplace(position, std::forward(v)); + } + } else { + iterator next = position; + ++next; + if (next == end() || !compare_keys(next.key(), key)) { + // position.key() < key <= next.key() + return internal_emplace(next, std::forward(v)); + } + } + } + return insert_multi(std::forward(v)); + } + + template + template + void btree

::insert_iterator_multi(InputIterator b, InputIterator e) { + for (; b != e; ++b) { + insert_hint_multi(end(), *b); + } + } + + template + auto btree

::operator=(const btree &x) -> btree & { + if (this != &x) { + clear(); + + *mutable_key_comp() = x.key_comp(); + if (phmap::allocator_traits< + allocator_type>::propagate_on_container_copy_assignment::value) { + *mutable_allocator() = x.allocator(); + } + + copy_or_move_values_in_order(&x); + } + return *this; + } + + template + auto btree

::operator=(btree &&x) noexcept -> btree & { + if (this != &x) { + clear(); + + using std::swap; + if (phmap::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 + auto btree

::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 + auto btree

::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->count()) { + res.position = res.node->count() - 1; + ++res; + } + + return res; + } + + template + auto btree

::erase(iterator begin, iterator end) + -> std::pair { + 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->count() - begin.position; + begin = erase_from_leaf_node( + begin, (std::min)(remaining_to_erase, remaining_in_node)); + } else { + begin = erase(begin); + } + } + return {count, begin}; + } + + template + void btree

::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->count(); ++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 + auto btree

::erase_from_leaf_node(iterator begin, size_type to_erase) + -> iterator { + node_type *node = begin.node; + assert(node->leaf()); + assert(node->count() > begin.position); + assert(begin.position + to_erase <= node->count()); + + node->remove_values_ignore_children(begin.position, to_erase, + mutable_allocator()); + + size_ -= to_erase; + + return rebalance_after_delete(begin); + } + + template + template + auto btree

::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 + template + auto btree

::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(begin, end).first; + } + + template + void btree

::clear() { + if (!empty()) { + internal_clear(root()); + } + mutable_root() = EmptyNode(); + rightmost_ = EmptyNode(); + size_ = 0; + } + + template + void btree

::swap(btree &x) { + using std::swap; + if (phmap::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 + void btree

::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()->count())).node); + assert(leftmost()->leaf()); + assert(rightmost_->leaf()); + } + + template + void btree

::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() > 0) { + // 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) >= 0) || + ((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 < 0) { + insert_position = insert_position + left->count() + 1; + node = left; + } + + assert(node->count() < node->max_count()); + return; + } + } + } + + if (node->position() < parent->count()) { + // 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 > 0)); + to_move = (std::max)(1, to_move); + + if ((insert_position <= (node->count() - to_move)) || + ((right->count() + to_move) < kNodeValues)) { + node->rebalance_left_to_right(to_move, right, mutable_allocator()); + + if (insert_position > node->count()) { + 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(0, root()); + mutable_root() = parent; + // If the former root was a leaf node, then it's now the rightmost node. + assert(!parent->child(0)->leaf() || parent->child(0) == 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->count()) { + insert_position = insert_position - node->count() - 1; + node = split_node; + } + } + + template + void btree

::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 + bool btree

::try_merge_or_rebalance(iterator *iter) { + node_type *parent = iter->node->parent(); + if (iter->node->position() > 0) { + // 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->count()) { + // 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 > 0))) { + 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() > 0) { + // 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->count()))) { + 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 + void btree

::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()->child(0); + child->make_root(); + delete_internal_node(root()); + mutable_root() = child; + } + } + + template + template + inline IterType btree

::internal_last(IterType iter) { + assert(iter.node != nullptr); + while (iter.position == iter.node->count()) { + iter.position = iter.node->position(); + iter.node = iter.node->parent(); + if (iter.node->leaf()) { + iter.node = nullptr; + break; + } + } + return iter; + } + + template + template + inline auto btree

::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)(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)...); + ++size_; + return iter; + } + + template + template + inline auto btree

::internal_locate(const K &key) const + -> SearchResult { + return internal_locate_impl(key, is_key_compare_to()); + } + + template + template + inline auto btree

::internal_locate_impl( + const K &key, std::false_type /* IsCompareTo */) const + -> SearchResult { + iterator iter(const_cast(root()), 0); + 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 + template + inline auto btree

::internal_locate_impl( + const K &key, std::true_type /* IsCompareTo */) const + -> SearchResult { + iterator iter(const_cast(root()), 0); + for (;;) { + SearchResult 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 + template + auto btree

::internal_lower_bound(const K &key) const -> iterator { + iterator iter(const_cast(root()), 0); + 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 + template + auto btree

::internal_upper_bound(const K &key) const -> iterator { + iterator iter(const_cast(root()), 0); + 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 + template + auto btree

::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 + void btree

::internal_clear(node_type *node) { + if (!node->leaf()) { + for (int i = 0; i <= node->count(); ++i) { + internal_clear(node->child(i)); + } + delete_internal_node(node); + } else { + delete_leaf_node(node); + } + } + + template + int btree

::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(0), *lo)); + } + if (hi) { + assert(!compare_keys(*hi, node->key(node->count() - 1))); + } + for (int i = 1; i < node->count(); ++i) { + assert(!compare_keys(node->key(i), node->key(i - 1))); + } + int count = node->count(); + if (!node->leaf()) { + for (int i = 0; i <= node->count(); ++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 == 0) ? lo : &node->key(i - 1), + (i == node->count()) ? hi : &node->key(i)); + } + } + return count; + } + + // A common base class for btree_set, btree_map, btree_multiset, and btree_multimap. + // --------------------------------------------------------------------------------- + template + class btree_container { + using params_type = typename Tree::params_type; + + protected: + // Alias used for heterogeneous lookup functions. + // `key_arg` 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 + using key_arg = + typename KeyArg::value>:: + template 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::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 + iterator find(const key_arg &key) { + return tree_.find(key); + } + template + const_iterator find(const key_arg &key) const { return tree_.find(key); } + + template + bool contains(const key_arg &key) const { return find(key) != end(); } + + template + iterator lower_bound(const key_arg &key) { return tree_.lower_bound(key); } + + template + const_iterator lower_bound(const key_arg &key) const { return tree_.lower_bound(key); } + + template + iterator upper_bound(const key_arg &key) { return tree_.upper_bound(key); } + + template + const_iterator upper_bound(const key_arg &key) const { return tree_.upper_bound(key); } + + template + std::pair equal_range(const key_arg &key) { return tree_.equal_range(key); } + + template + std::pair equal_range( + const key_arg &key) const { + return tree_.equal_range(key); + } + + 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(iterator(first), iterator(last)).second; + } + + 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(get_allocator(), position.slot()); + erase(position); + return node; + } + + node_type extract(const_iterator position) { + return extract(iterator(position)); + } + + public: + void clear() { tree_.clear(); } + void swap(btree_container &x) { tree_.swap(x.tree_); } + void verify() const { tree_.verify(); } + + 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 + 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 + class btree_set_container : public btree_container { + using super_type = btree_container; + 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 + using key_arg = typename super_type::template key_arg; + + 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; + using super_type::super_type; + btree_set_container() {} + + template + 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); + } + + btree_set_container(std::initializer_list 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 + size_type count(const key_arg &key) const { + return this->tree_.count_unique(key); + } + + // Insertion routines. + std::pair insert(const value_type &x) { + return this->tree_.insert_unique(params_type::key(x), x); + } + std::pair insert(value_type &&x) { + return this->tree_.insert_unique(params_type::key(x), std::move(x)); + } + template + std::pair emplace(Args &&... args) { + init_type v(std::forward(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 + iterator emplace_hint(const_iterator position, Args &&... args) { + init_type v(std::forward(args)...); + return this->tree_ + .insert_hint_unique(iterator(position), params_type::key(v), + std::move(v)) + .first; + } + + template + void insert(InputIterator b, InputIterator e) { + this->tree_.insert_iterator_unique(b, e); + } + + void insert(std::initializer_list 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 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 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; + } + + template + size_type erase(const key_arg &key) { return this->tree_.erase_unique(key); } + using super_type::erase; + + template + node_type extract(const key_arg &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 phmap::enable_if_t< + phmap::conjunction< + std::is_same, + std::is_same, + std::is_same>::value, + int> = 0> + void merge(btree_container &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 phmap::enable_if_t< + phmap::conjunction< + std::is_same, + std::is_same, + std::is_same>::value, + int> = 0> + void merge(btree_container &&src) { + merge(src); + } + }; + + // Base class for btree_map. + // ------------------------- + template + class btree_map_container : public btree_set_container { + using super_type = btree_set_container; + using params_type = typename Tree::params_type; + + protected: + template + using key_arg = typename super_type::template key_arg; + + 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. + template + std::pair 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)...)); + } + template + std::pair 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)...)); + } + template + 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)...)) + .first; + } + template + 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)...)) + .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 + mapped_type &at(const key_arg &key) { + auto it = this->find(key); + if (it == this->end()) + base_internal::ThrowStdOutOfRange("phmap::btree_map::at"); + return it->second; + } + template + const mapped_type &at(const key_arg &key) const { + auto it = this->find(key); + if (it == this->end()) + base_internal::ThrowStdOutOfRange("phmap::btree_map::at"); + return it->second; + } + }; + + // A common base class for btree_multiset and btree_multimap. + template + class btree_multiset_container : public btree_container { + using super_type = btree_container; + 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 + using key_arg = typename super_type::template key_arg; + + 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 + 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, + const key_compare &comp = key_compare(), + const allocator_type &alloc = allocator_type()) + : btree_multiset_container(init.begin(), init.end(), comp, alloc) {} + + // Lookup routines. + template + size_type count(const key_arg &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 + void insert(InputIterator b, InputIterator e) { + this->tree_.insert_iterator_multi(b, e); + } + void insert(std::initializer_list init) { + this->tree_.insert_iterator_multi(init.begin(), init.end()); + } + template + iterator emplace(Args &&... args) { + return this->tree_.insert_multi(init_type(std::forward(args)...)); + } + template + iterator emplace_hint(const_iterator position, Args &&... args) { + return this->tree_.insert_hint_multi( + iterator(position), init_type(std::forward(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 + size_type erase(const key_arg &key) { + return this->tree_.erase_multi(key); + } + using super_type::erase; + + // Node extraction routines. + template + node_type extract(const key_arg &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 phmap::enable_if_t< + phmap::conjunction< + std::is_same, + std::is_same, + std::is_same>::value, + int> = 0> + void merge(btree_container &src) { // NOLINT + insert(std::make_move_iterator(src.begin()), + std::make_move_iterator(src.end())); + src.clear(); + } + + template < + typename T, + typename phmap::enable_if_t< + phmap::conjunction< + std::is_same, + std::is_same, + std::is_same>::value, + int> = 0> + void merge(btree_container &&src) { + merge(src); + } + }; + + // A base class for btree_multimap. + template + class btree_multimap_container : public btree_multiset_container { + using super_type = btree_multiset_container; + 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 + + + + // ---------------------------------------------------------------------- + template , + typename Alloc = std::allocator> + class btree_set : public container_internal::btree_set_container< + container_internal::btree>> + { + using Base = typename btree_set::btree_set_container; + + public: + btree_set() {} + using Base::Base; + using Base::begin; + using Base::cbegin; + using Base::end; + using Base::cend; + using Base::empty; + using Base::max_size; + using Base::size; + using Base::clear; + using Base::erase; + using Base::insert; + using Base::emplace; + using Base::emplace_hint; + using Base::extract; + using Base::merge; + using Base::swap; + using Base::contains; + using Base::count; + using Base::equal_range; + using Base::find; + using Base::get_allocator; + using Base::key_comp; + using Base::value_comp; + }; + + // Swaps the contents of two `phmap::btree_set` containers. + // ------------------------------------------------------- + template + void swap(btree_set &x, btree_set &y) { + return x.swap(y); + } + + // Erases all elements that satisfy the predicate pred from the container. + // ---------------------------------------------------------------------- + template + void erase_if(btree_set &set, Pred pred) { + for (auto it = set.begin(); it != set.end();) { + if (pred(*it)) { + it = set.erase(it); + } else { + ++it; + } + } + } + + // ---------------------------------------------------------------------- + template , + typename Alloc = std::allocator> + class btree_multiset : public container_internal::btree_multiset_container< + container_internal::btree>> + { + using Base = typename btree_multiset::btree_multiset_container; + + public: + btree_multiset() {} + using Base::Base; + using Base::begin; + using Base::cbegin; + using Base::end; + using Base::cend; + using Base::empty; + using Base::max_size; + using Base::size; + using Base::clear; + using Base::erase; + using Base::insert; + using Base::emplace; + using Base::emplace_hint; + using Base::extract; + using Base::merge; + using Base::swap; + using Base::contains; + using Base::count; + using Base::equal_range; + using Base::find; + using Base::get_allocator; + using Base::key_comp; + using Base::value_comp; + }; + + // Swaps the contents of two `phmap::btree_multiset` containers. + // ------------------------------------------------------------ + template + void swap(btree_multiset &x, btree_multiset &y) { + return x.swap(y); + } + + // Erases all elements that satisfy the predicate pred from the container. + // ---------------------------------------------------------------------- + template + void erase_if(btree_multiset &set, Pred pred) { + for (auto it = set.begin(); it != set.end();) { + if (pred(*it)) { + it = set.erase(it); + } else { + ++it; + } + } + } + + + // ---------------------------------------------------------------------- + template , + typename Alloc = std::allocator>> + class btree_map : public container_internal::btree_map_container< + container_internal::btree>> + { + using Base = typename btree_map::btree_map_container; + + public: + btree_map() {} + using Base::Base; + using Base::begin; + using Base::cbegin; + using Base::end; + using Base::cend; + using Base::empty; + using Base::max_size; + using Base::size; + using Base::clear; + using Base::erase; + using Base::insert; + using Base::emplace; + using Base::emplace_hint; + using Base::try_emplace; + using Base::extract; + using Base::merge; + using Base::swap; + using Base::at; + using Base::contains; + using Base::count; + using Base::equal_range; + using Base::find; + using Base::operator[]; + using Base::get_allocator; + using Base::key_comp; + using Base::value_comp; + }; + + // Swaps the contents of two `phmap::btree_map` containers. + // ------------------------------------------------------- + template + void swap(btree_map &x, btree_map &y) { + return x.swap(y); + } + + // ---------------------------------------------------------------------- + template + void erase_if(btree_map &map, Pred pred) { + for (auto it = map.begin(); it != map.end();) { + if (pred(*it)) { + it = map.erase(it); + } else { + ++it; + } + } + } + + // ---------------------------------------------------------------------- + template , + typename Alloc = std::allocator>> + class btree_multimap : public container_internal::btree_multimap_container< + container_internal::btree>> + { + using Base = typename btree_multimap::btree_multimap_container; + + public: + btree_multimap() {} + using Base::Base; + using Base::begin; + using Base::cbegin; + using Base::end; + using Base::cend; + using Base::empty; + using Base::max_size; + using Base::size; + using Base::clear; + using Base::erase; + using Base::insert; + using Base::emplace; + using Base::emplace_hint; + using Base::extract; + using Base::merge; + using Base::swap; + using Base::contains; + using Base::count; + using Base::equal_range; + using Base::find; + using Base::get_allocator; + using Base::key_comp; + using Base::value_comp; + }; + + // Swaps the contents of two `phmap::btree_multimap` containers. + // ------------------------------------------------------------ + template + void swap(btree_multimap &x, btree_multimap &y) { + return x.swap(y); + } + + // Erases all elements that satisfy the predicate pred from the container. + // ---------------------------------------------------------------------- + template + void erase_if(btree_multimap &map, Pred pred) { + for (auto it = map.begin(); it != map.end();) { + if (pred(*it)) { + it = map.erase(it); + } else { + ++it; + } + } + } + + +} // namespace btree + +#endif // PHMAP_BTREE_BTREE_CONTAINER_H_ diff --git a/parallel_hashmap/phmap.h b/parallel_hashmap/phmap.h index b388e23..297c6c2 100644 --- a/parallel_hashmap/phmap.h +++ b/parallel_hashmap/phmap.h @@ -643,78 +643,6 @@ DecomposePairImpl(F&& f, std::pair, V> p) { } // namespace memory_internal -// Helper functions for asan and msan. -// ---------------------------------------------------------------------------- -inline void SanitizerPoisonMemoryRegion(const void* m, size_t s) { -#ifdef ADDRESS_SANITIZER - ASAN_POISON_MEMORY_REGION(m, s); -#endif -#ifdef MEMORY_SANITIZER - __msan_poison(m, s); -#endif - (void)m; - (void)s; -} - -inline void SanitizerUnpoisonMemoryRegion(const void* m, size_t s) { -#ifdef ADDRESS_SANITIZER - ASAN_UNPOISON_MEMORY_REGION(m, s); -#endif -#ifdef MEMORY_SANITIZER - __msan_unpoison(m, s); -#endif - (void)m; - (void)s; -} - -template -inline void SanitizerPoisonObject(const T* object) { - SanitizerPoisonMemoryRegion(object, sizeof(T)); -} - -template -inline void SanitizerUnpoisonObject(const T* object) { - SanitizerUnpoisonMemoryRegion(object, sizeof(T)); -} - -// ---------------------------------------------------------------------------- -// Allocates at least n bytes aligned to the specified alignment. -// Alignment must be a power of 2. It must be positive. -// -// Note that many allocators don't honor alignment requirements above certain -// threshold (usually either alignof(std::max_align_t) or alignof(void*)). -// Allocate() doesn't apply alignment corrections. If the underlying allocator -// returns insufficiently alignment pointer, that's what you are going to get. -// ---------------------------------------------------------------------------- -template -void* Allocate(Alloc* alloc, size_t n) { - static_assert(Alignment > 0, ""); - assert(n && "n must be positive"); - struct alignas(Alignment) M {}; - using A = typename phmap::allocator_traits::template rebind_alloc; - using AT = typename phmap::allocator_traits::template rebind_traits; - A mem_alloc(*alloc); - void* p = AT::allocate(mem_alloc, (n + sizeof(M) - 1) / sizeof(M)); - assert(reinterpret_cast(p) % Alignment == 0 && - "allocator does not respect alignment"); - return p; -} - -// ---------------------------------------------------------------------------- -// The pointer must have been previously obtained by calling -// Allocate(alloc, n). -// ---------------------------------------------------------------------------- -template -void Deallocate(Alloc* alloc, void* p, size_t n) { - static_assert(Alignment > 0, ""); - assert(n && "n must be positive"); - struct alignas(Alignment) M {}; - using A = typename phmap::allocator_traits::template rebind_alloc; - using AT = typename phmap::allocator_traits::template rebind_traits; - A mem_alloc(*alloc); - AT::deallocate(mem_alloc, static_cast(p), - (n + sizeof(M) - 1) / sizeof(M)); -} // ---------------------------------------------------------------------------- // R A W _ H A S H _ S E T @@ -3549,214 +3477,6 @@ DecomposeValue(F&& f, Arg&& arg) { } -namespace memory_internal { - -// ---------------------------------------------------------------------------- -// If Pair is a standard-layout type, OffsetOf::kFirst and -// OffsetOf::kSecond are equivalent to offsetof(Pair, first) and -// offsetof(Pair, second) respectively. Otherwise they are -1. -// -// The purpose of OffsetOf is to avoid calling offsetof() on non-standard-layout -// type, which is non-portable. -// ---------------------------------------------------------------------------- -template -struct OffsetOf { - static constexpr size_t kFirst = (size_t)-1; - static constexpr size_t kSecond = (size_t)-1; -}; - -template -struct OffsetOf::type> -{ - static constexpr size_t kFirst = offsetof(Pair, first); - static constexpr size_t kSecond = offsetof(Pair, second); -}; - -// ---------------------------------------------------------------------------- -template -struct IsLayoutCompatible -{ -private: - struct Pair { - K first; - V second; - }; - - // Is P layout-compatible with Pair? - template - static constexpr bool LayoutCompatible() { - return std::is_standard_layout

() && sizeof(P) == sizeof(Pair) && - alignof(P) == alignof(Pair) && - memory_internal::OffsetOf

::kFirst == - memory_internal::OffsetOf::kFirst && - memory_internal::OffsetOf

::kSecond == - memory_internal::OffsetOf::kSecond; - } - -public: - // Whether pair and pair are layout-compatible. If they are, - // then it is safe to store them in a union and read from either. - static constexpr bool value = std::is_standard_layout() && - std::is_standard_layout() && - memory_internal::OffsetOf::kFirst == 0 && - LayoutCompatible>() && - LayoutCompatible>(); -}; - -} // namespace memory_internal - -// ---------------------------------------------------------------------------- -// The internal storage type for key-value containers like flat_hash_map. -// -// It is convenient for the value_type of a flat_hash_map to be -// pair; the "const K" prevents accidental modification of the key -// when dealing with the reference returned from find() and similar methods. -// However, this creates other problems; we want to be able to emplace(K, V) -// efficiently with move operations, and similarly be able to move a -// pair in insert(). -// -// The solution is this union, which aliases the const and non-const versions -// of the pair. This also allows flat_hash_map to work, even though -// that has the same efficiency issues with move in emplace() and insert() - -// but people do it anyway. -// -// If kMutableKeys is false, only the value member can be accessed. -// -// If kMutableKeys is true, key can be accessed through all slots while value -// and mutable_value must be accessed only via INITIALIZED slots. Slots are -// created and destroyed via mutable_value so that the key can be moved later. -// -// Accessing one of the union fields while the other is active is safe as -// long as they are layout-compatible, which is guaranteed by the definition of -// kMutableKeys. For C++11, the relevant section of the standard is -// https://timsong-cpp.github.io/cppwp/n3337/class.mem#19 (9.2.19) -// ---------------------------------------------------------------------------- -template -union map_slot_type -{ - map_slot_type() {} - ~map_slot_type() = delete; - using value_type = std::pair; - using mutable_value_type = std::pair; - - value_type value; - mutable_value_type mutable_value; - K key; -}; - -// ---------------------------------------------------------------------------- -// ---------------------------------------------------------------------------- -template -struct map_slot_policy -{ - using slot_type = map_slot_type; - using value_type = std::pair; - using mutable_value_type = std::pair; - -private: - static void emplace(slot_type* slot) { - // The construction of union doesn't do anything at runtime but it allows us - // to access its members without violating aliasing rules. - new (slot) slot_type; - } - // If pair and pair are layout-compatible, we can accept one - // or the other via slot_type. We are also free to access the key via - // slot_type::key in this case. - using kMutableKeys = memory_internal::IsLayoutCompatible; - -public: - static value_type& element(slot_type* slot) { return slot->value; } - static const value_type& element(const slot_type* slot) { - return slot->value; - } - - static const K& key(const slot_type* slot) { - return kMutableKeys::value ? slot->key : slot->value.first; - } - - template - static void construct(Allocator* alloc, slot_type* slot, Args&&... args) { - emplace(slot); - if (kMutableKeys::value) { - phmap::allocator_traits::construct(*alloc, &slot->mutable_value, - std::forward(args)...); - } else { - phmap::allocator_traits::construct(*alloc, &slot->value, - std::forward(args)...); - } - } - - // Construct this slot by moving from another slot. - template - static void construct(Allocator* alloc, slot_type* slot, slot_type* other) { - emplace(slot); - if (kMutableKeys::value) { - phmap::allocator_traits::construct( - *alloc, &slot->mutable_value, std::move(other->mutable_value)); - } else { - phmap::allocator_traits::construct(*alloc, &slot->value, - std::move(other->value)); - } - } - - template - static void destroy(Allocator* alloc, slot_type* slot) { - if (kMutableKeys::value) { - phmap::allocator_traits::destroy(*alloc, &slot->mutable_value); - } else { - phmap::allocator_traits::destroy(*alloc, &slot->value); - } - } - - template - static void transfer(Allocator* alloc, slot_type* new_slot, - slot_type* old_slot) { - emplace(new_slot); - if (kMutableKeys::value) { - phmap::allocator_traits::construct( - *alloc, &new_slot->mutable_value, std::move(old_slot->mutable_value)); - } else { - phmap::allocator_traits::construct(*alloc, &new_slot->value, - std::move(old_slot->value)); - } - destroy(alloc, old_slot); - } - - template - static void swap(Allocator* alloc, slot_type* a, slot_type* b) { - if (kMutableKeys::value) { - using std::swap; - swap(a->mutable_value, b->mutable_value); - } else { - value_type tmp = std::move(a->value); - phmap::allocator_traits::destroy(*alloc, &a->value); - phmap::allocator_traits::construct(*alloc, &a->value, - std::move(b->value)); - phmap::allocator_traits::destroy(*alloc, &b->value); - phmap::allocator_traits::construct(*alloc, &b->value, - std::move(tmp)); - } - } - - template - static void move(Allocator* alloc, slot_type* src, slot_type* dest) { - if (kMutableKeys::value) { - dest->mutable_value = std::move(src->mutable_value); - } else { - phmap::allocator_traits::destroy(*alloc, &dest->value); - phmap::allocator_traits::construct(*alloc, &dest->value, - std::move(src->value)); - } - } - - template - static void move(Allocator* 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); - } -}; - // -------------------------------------------------------------------------- // Policy: a policy defines how to perform different operations on // the slots of the hashtable (see hash_policy_traits.h for the full interface diff --git a/parallel_hashmap/phmap_base.h b/parallel_hashmap/phmap_base.h index ad9277e..0e273c3 100644 --- a/parallel_hashmap/phmap_base.h +++ b/parallel_hashmap/phmap_base.h @@ -2972,6 +2972,21 @@ struct CommonAccess static T Make(Args&&... args) { return T(std::forward(args)...); } + + template + static void Destroy(Node* node) { + node->destroy(); + } + + template + static T Transfer(Args&&... args) { + return T(typename T::transfer_tag_t{}, std::forward(args)...); + } + + template + static T Move(Args&&... args) { + return T(typename T::move_tag_t{}, std::forward(args)...); + } }; // Implement the insert_return_type<> concept of C++17. @@ -4395,6 +4410,89 @@ class PHMAP_INTERNAL_COMPRESSED_TUPLE_DECLSPEC CompressedTuple<> {}; } // namespace container_internal } // namespace phmap + +namespace phmap { +namespace container_internal { + + + +// ---------------------------------------------------------------------------- +// Allocates at least n bytes aligned to the specified alignment. +// Alignment must be a power of 2. It must be positive. +// +// Note that many allocators don't honor alignment requirements above certain +// threshold (usually either alignof(std::max_align_t) or alignof(void*)). +// Allocate() doesn't apply alignment corrections. If the underlying allocator +// returns insufficiently alignment pointer, that's what you are going to get. +// ---------------------------------------------------------------------------- +template +void* Allocate(Alloc* alloc, size_t n) { + static_assert(Alignment > 0, ""); + assert(n && "n must be positive"); + struct alignas(Alignment) M {}; + using A = typename phmap::allocator_traits::template rebind_alloc; + using AT = typename phmap::allocator_traits::template rebind_traits; + A mem_alloc(*alloc); + void* p = AT::allocate(mem_alloc, (n + sizeof(M) - 1) / sizeof(M)); + assert(reinterpret_cast(p) % Alignment == 0 && + "allocator does not respect alignment"); + return p; +} + +// ---------------------------------------------------------------------------- +// The pointer must have been previously obtained by calling +// Allocate(alloc, n). +// ---------------------------------------------------------------------------- +template +void Deallocate(Alloc* alloc, void* p, size_t n) { + static_assert(Alignment > 0, ""); + assert(n && "n must be positive"); + struct alignas(Alignment) M {}; + using A = typename phmap::allocator_traits::template rebind_alloc; + using AT = typename phmap::allocator_traits::template rebind_traits; + A mem_alloc(*alloc); + AT::deallocate(mem_alloc, static_cast(p), + (n + sizeof(M) - 1) / sizeof(M)); +} + +// Helper functions for asan and msan. +// ---------------------------------------------------------------------------- +inline void SanitizerPoisonMemoryRegion(const void* m, size_t s) { +#ifdef ADDRESS_SANITIZER + ASAN_POISON_MEMORY_REGION(m, s); +#endif +#ifdef MEMORY_SANITIZER + __msan_poison(m, s); +#endif + (void)m; + (void)s; +} + +inline void SanitizerUnpoisonMemoryRegion(const void* m, size_t s) { +#ifdef ADDRESS_SANITIZER + ASAN_UNPOISON_MEMORY_REGION(m, s); +#endif +#ifdef MEMORY_SANITIZER + __msan_unpoison(m, s); +#endif + (void)m; + (void)s; +} + +template +inline void SanitizerPoisonObject(const T* object) { + SanitizerPoisonMemoryRegion(object, sizeof(T)); +} + +template +inline void SanitizerUnpoisonObject(const T* object) { + SanitizerUnpoisonMemoryRegion(object, sizeof(T)); +} + +} // namespace container_internal +} // namespace phmap + + // --------------------------------------------------------------------------- // thread_annotations.h // --------------------------------------------------------------------------- @@ -4504,6 +4602,218 @@ inline T& ts_unchecked_read(T& v) PHMAP_NO_THREAD_SAFETY_ANALYSIS { } } // namespace thread_safety_analysis + +namespace container_internal { + +namespace memory_internal { + +// ---------------------------------------------------------------------------- +// If Pair is a standard-layout type, OffsetOf::kFirst and +// OffsetOf::kSecond are equivalent to offsetof(Pair, first) and +// offsetof(Pair, second) respectively. Otherwise they are -1. +// +// The purpose of OffsetOf is to avoid calling offsetof() on non-standard-layout +// type, which is non-portable. +// ---------------------------------------------------------------------------- +template +struct OffsetOf { + static constexpr size_t kFirst = (size_t)-1; + static constexpr size_t kSecond = (size_t)-1; +}; + +template +struct OffsetOf::type> +{ + static constexpr size_t kFirst = offsetof(Pair, first); + static constexpr size_t kSecond = offsetof(Pair, second); +}; + +// ---------------------------------------------------------------------------- +template +struct IsLayoutCompatible +{ +private: + struct Pair { + K first; + V second; + }; + + // Is P layout-compatible with Pair? + template + static constexpr bool LayoutCompatible() { + return std::is_standard_layout

() && sizeof(P) == sizeof(Pair) && + alignof(P) == alignof(Pair) && + memory_internal::OffsetOf

::kFirst == + memory_internal::OffsetOf::kFirst && + memory_internal::OffsetOf

::kSecond == + memory_internal::OffsetOf::kSecond; + } + +public: + // Whether pair and pair are layout-compatible. If they are, + // then it is safe to store them in a union and read from either. + static constexpr bool value = std::is_standard_layout() && + std::is_standard_layout() && + memory_internal::OffsetOf::kFirst == 0 && + LayoutCompatible>() && + LayoutCompatible>(); +}; + +} // namespace memory_internal + +// ---------------------------------------------------------------------------- +// The internal storage type for key-value containers like flat_hash_map. +// +// It is convenient for the value_type of a flat_hash_map to be +// pair; the "const K" prevents accidental modification of the key +// when dealing with the reference returned from find() and similar methods. +// However, this creates other problems; we want to be able to emplace(K, V) +// efficiently with move operations, and similarly be able to move a +// pair in insert(). +// +// The solution is this union, which aliases the const and non-const versions +// of the pair. This also allows flat_hash_map to work, even though +// that has the same efficiency issues with move in emplace() and insert() - +// but people do it anyway. +// +// If kMutableKeys is false, only the value member can be accessed. +// +// If kMutableKeys is true, key can be accessed through all slots while value +// and mutable_value must be accessed only via INITIALIZED slots. Slots are +// created and destroyed via mutable_value so that the key can be moved later. +// +// Accessing one of the union fields while the other is active is safe as +// long as they are layout-compatible, which is guaranteed by the definition of +// kMutableKeys. For C++11, the relevant section of the standard is +// https://timsong-cpp.github.io/cppwp/n3337/class.mem#19 (9.2.19) +// ---------------------------------------------------------------------------- +template +union map_slot_type +{ + map_slot_type() {} + ~map_slot_type() = delete; + using value_type = std::pair; + using mutable_value_type = std::pair; + + value_type value; + mutable_value_type mutable_value; + K key; +}; + +// ---------------------------------------------------------------------------- +// ---------------------------------------------------------------------------- +template +struct map_slot_policy +{ + using slot_type = map_slot_type; + using value_type = std::pair; + using mutable_value_type = std::pair; + +private: + static void emplace(slot_type* slot) { + // The construction of union doesn't do anything at runtime but it allows us + // to access its members without violating aliasing rules. + new (slot) slot_type; + } + // If pair and pair are layout-compatible, we can accept one + // or the other via slot_type. We are also free to access the key via + // slot_type::key in this case. + using kMutableKeys = memory_internal::IsLayoutCompatible; + +public: + static value_type& element(slot_type* slot) { return slot->value; } + static const value_type& element(const slot_type* slot) { + return slot->value; + } + + static const K& key(const slot_type* slot) { + return kMutableKeys::value ? slot->key : slot->value.first; + } + + template + static void construct(Allocator* alloc, slot_type* slot, Args&&... args) { + emplace(slot); + if (kMutableKeys::value) { + phmap::allocator_traits::construct(*alloc, &slot->mutable_value, + std::forward(args)...); + } else { + phmap::allocator_traits::construct(*alloc, &slot->value, + std::forward(args)...); + } + } + + // Construct this slot by moving from another slot. + template + static void construct(Allocator* alloc, slot_type* slot, slot_type* other) { + emplace(slot); + if (kMutableKeys::value) { + phmap::allocator_traits::construct( + *alloc, &slot->mutable_value, std::move(other->mutable_value)); + } else { + phmap::allocator_traits::construct(*alloc, &slot->value, + std::move(other->value)); + } + } + + template + static void destroy(Allocator* alloc, slot_type* slot) { + if (kMutableKeys::value) { + phmap::allocator_traits::destroy(*alloc, &slot->mutable_value); + } else { + phmap::allocator_traits::destroy(*alloc, &slot->value); + } + } + + template + static void transfer(Allocator* alloc, slot_type* new_slot, + slot_type* old_slot) { + emplace(new_slot); + if (kMutableKeys::value) { + phmap::allocator_traits::construct( + *alloc, &new_slot->mutable_value, std::move(old_slot->mutable_value)); + } else { + phmap::allocator_traits::construct(*alloc, &new_slot->value, + std::move(old_slot->value)); + } + destroy(alloc, old_slot); + } + + template + static void swap(Allocator* alloc, slot_type* a, slot_type* b) { + if (kMutableKeys::value) { + using std::swap; + swap(a->mutable_value, b->mutable_value); + } else { + value_type tmp = std::move(a->value); + phmap::allocator_traits::destroy(*alloc, &a->value); + phmap::allocator_traits::construct(*alloc, &a->value, + std::move(b->value)); + phmap::allocator_traits::destroy(*alloc, &b->value); + phmap::allocator_traits::construct(*alloc, &b->value, + std::move(tmp)); + } + } + + template + static void move(Allocator* alloc, slot_type* src, slot_type* dest) { + if (kMutableKeys::value) { + dest->mutable_value = std::move(src->mutable_value); + } else { + phmap::allocator_traits::destroy(*alloc, &dest->value); + phmap::allocator_traits::construct(*alloc, &dest->value, + std::move(src->value)); + } + } + + template + static void move(Allocator* 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); + } +}; + +} // namespace container_internal } // phmap