Rocket.Chat.ReactNative/ios/Pods/Folly/folly/container/F14Set.h

1122 lines
32 KiB
C++

/*
* Copyright 2017-present Facebook, Inc.
*
* 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
*
* http://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.
*/
#pragma once
/**
* F14NodeSet, F14ValueSet, and F14VectorSet
*
* F14FastSet conditionally inherits from F14ValueSet or F14VectorSet
*
* See F14.md
*
* @author Nathan Bronson <ngbronson@fb.com>
* @author Xiao Shi <xshi@fb.com>
*/
#include <tuple>
#include <folly/lang/SafeAssert.h>
#include <folly/container/F14Set-fwd.h>
#include <folly/container/detail/F14Policy.h>
#include <folly/container/detail/F14Table.h>
#if !FOLLY_F14_VECTOR_INTRINSICS_AVAILABLE
//////// Compatibility for unsupported platforms (not x86_64 and not aarch64)
#include <unordered_set>
namespace folly {
namespace f14 {
namespace detail {
template <typename K, typename H, typename E, typename A>
class F14BasicSet : public std::unordered_set<K, H, E, A> {
using Super = std::unordered_set<K, H, E, A>;
public:
using typename Super::pointer;
using typename Super::value_type;
F14BasicSet() = default;
using Super::Super;
//// PUBLIC - F14 Extensions
// exact for libstdc++, approximate for others
std::size_t getAllocatedMemorySize() const {
std::size_t rv = 0;
visitAllocationClasses(
[&](std::size_t bytes, std::size_t n) { rv += bytes * n; });
return rv;
}
// exact for libstdc++, approximate for others
template <typename V>
void visitAllocationClasses(V&& visitor) const {
auto bc = this->bucket_count();
if (bc > 1) {
visitor(bc * sizeof(pointer), 1);
}
if (this->size() > 0) {
visitor(sizeof(StdNodeReplica<K, value_type, H>), this->size());
}
}
template <typename V>
void visitContiguousRanges(V&& visitor) const {
for (value_type const& entry : *this) {
value_type const* b = std::addressof(entry);
visitor(b, b + 1);
}
}
};
} // namespace detail
} // namespace f14
template <typename Key, typename Hasher, typename KeyEqual, typename Alloc>
class F14NodeSet
: public f14::detail::F14BasicSet<Key, Hasher, KeyEqual, Alloc> {
using Super = f14::detail::F14BasicSet<Key, Hasher, KeyEqual, Alloc>;
public:
using typename Super::value_type;
F14NodeSet() = default;
using Super::Super;
F14NodeSet& operator=(std::initializer_list<value_type> ilist) {
Super::operator=(ilist);
return *this;
}
};
template <typename Key, typename Hasher, typename KeyEqual, typename Alloc>
class F14ValueSet
: public f14::detail::F14BasicSet<Key, Hasher, KeyEqual, Alloc> {
using Super = f14::detail::F14BasicSet<Key, Hasher, KeyEqual, Alloc>;
public:
using typename Super::value_type;
F14ValueSet() : Super() {}
using Super::Super;
F14ValueSet& operator=(std::initializer_list<value_type> ilist) {
Super::operator=(ilist);
return *this;
}
};
template <typename Key, typename Hasher, typename KeyEqual, typename Alloc>
class F14VectorSet
: public f14::detail::F14BasicSet<Key, Hasher, KeyEqual, Alloc> {
using Super = f14::detail::F14BasicSet<Key, Hasher, KeyEqual, Alloc>;
public:
using typename Super::value_type;
F14VectorSet() = default;
using Super::Super;
F14VectorSet& operator=(std::initializer_list<value_type> ilist) {
Super::operator=(ilist);
return *this;
}
};
} // namespace folly
#else // FOLLY_F14_VECTOR_INTRINSICS_AVAILABLE
//////// Common case for supported platforms
namespace folly {
namespace f14 {
namespace detail {
template <typename Policy>
class F14BasicSet {
template <typename K, typename T>
using EnableHeterogeneousFind = std::enable_if_t<
EligibleForHeterogeneousFind<
typename Policy::Value,
typename Policy::Hasher,
typename Policy::KeyEqual,
K>::value,
T>;
template <typename K, typename T>
using EnableHeterogeneousInsert = std::enable_if_t<
EligibleForHeterogeneousInsert<
typename Policy::Value,
typename Policy::Hasher,
typename Policy::KeyEqual,
K>::value,
T>;
template <typename K, typename T>
using EnableHeterogeneousErase = std::enable_if_t<
EligibleForHeterogeneousFind<
typename Policy::Value,
typename Policy::Hasher,
typename Policy::KeyEqual,
K>::value &&
!std::is_same<typename Policy::Iter, remove_cvref_t<K>>::value,
T>;
public:
//// PUBLIC - Member types
using key_type = typename Policy::Value;
using value_type = key_type;
using size_type = std::size_t;
using difference_type = std::ptrdiff_t;
using hasher = typename Policy::Hasher;
using key_equal = typename Policy::KeyEqual;
using allocator_type = typename Policy::Alloc;
using reference = value_type&;
using const_reference = value_type const&;
using pointer = typename Policy::AllocTraits::pointer;
using const_pointer = typename Policy::AllocTraits::const_pointer;
using iterator = typename Policy::Iter;
using const_iterator = iterator;
private:
using ItemIter = typename Policy::ItemIter;
public:
//// PUBLIC - Member functions
F14BasicSet() noexcept(Policy::kDefaultConstructIsNoexcept)
: F14BasicSet(0) {}
explicit F14BasicSet(
std::size_t initialCapacity,
hasher const& hash = hasher{},
key_equal const& eq = key_equal{},
allocator_type const& alloc = allocator_type{})
: table_{initialCapacity, hash, eq, alloc} {}
explicit F14BasicSet(std::size_t initialCapacity, allocator_type const& alloc)
: F14BasicSet(initialCapacity, hasher{}, key_equal{}, alloc) {}
explicit F14BasicSet(
std::size_t initialCapacity,
hasher const& hash,
allocator_type const& alloc)
: F14BasicSet(initialCapacity, hash, key_equal{}, alloc) {}
explicit F14BasicSet(allocator_type const& alloc)
: F14BasicSet(0, hasher{}, key_equal{}, alloc) {}
template <typename InputIt>
F14BasicSet(
InputIt first,
InputIt last,
std::size_t initialCapacity = 0,
hasher const& hash = hasher{},
key_equal const& eq = key_equal{},
allocator_type const& alloc = allocator_type{})
: table_{initialCapacity, hash, eq, alloc} {
initialInsert(first, last, initialCapacity);
}
template <typename InputIt>
F14BasicSet(
InputIt first,
InputIt last,
std::size_t initialCapacity,
allocator_type const& alloc)
: table_{initialCapacity, hasher{}, key_equal{}, alloc} {
initialInsert(first, last, initialCapacity);
}
template <typename InputIt>
F14BasicSet(
InputIt first,
InputIt last,
std::size_t initialCapacity,
hasher const& hash,
allocator_type const& alloc)
: table_{initialCapacity, hash, key_equal{}, alloc} {
initialInsert(first, last, initialCapacity);
}
F14BasicSet(F14BasicSet const& rhs) = default;
F14BasicSet(F14BasicSet const& rhs, allocator_type const& alloc)
: table_(rhs.table_, alloc) {}
F14BasicSet(F14BasicSet&& rhs) = default;
F14BasicSet(F14BasicSet&& rhs, allocator_type const& alloc) noexcept(
Policy::kAllocIsAlwaysEqual)
: table_{std::move(rhs.table_), alloc} {}
F14BasicSet(
std::initializer_list<value_type> init,
std::size_t initialCapacity = 0,
hasher const& hash = hasher{},
key_equal const& eq = key_equal{},
allocator_type const& alloc = allocator_type{})
: table_{initialCapacity, hash, eq, alloc} {
initialInsert(init.begin(), init.end(), initialCapacity);
}
F14BasicSet(
std::initializer_list<value_type> init,
std::size_t initialCapacity,
allocator_type const& alloc)
: table_{initialCapacity, hasher{}, key_equal{}, alloc} {
initialInsert(init.begin(), init.end(), initialCapacity);
}
F14BasicSet(
std::initializer_list<value_type> init,
std::size_t initialCapacity,
hasher const& hash,
allocator_type const& alloc)
: table_{initialCapacity, hash, key_equal{}, alloc} {
initialInsert(init.begin(), init.end(), initialCapacity);
}
F14BasicSet& operator=(F14BasicSet const&) = default;
F14BasicSet& operator=(F14BasicSet&&) = default;
F14BasicSet& operator=(std::initializer_list<value_type> ilist) {
clear();
bulkInsert(ilist.begin(), ilist.end(), false);
return *this;
}
allocator_type get_allocator() const noexcept {
return table_.alloc();
}
//// PUBLIC - Iterators
iterator begin() noexcept {
return cbegin();
}
const_iterator begin() const noexcept {
return cbegin();
}
const_iterator cbegin() const noexcept {
return table_.makeIter(table_.begin());
}
iterator end() noexcept {
return cend();
}
const_iterator end() const noexcept {
return cend();
}
const_iterator cend() const noexcept {
return table_.makeIter(table_.end());
}
//// PUBLIC - Capacity
bool empty() const noexcept {
return table_.empty();
}
std::size_t size() const noexcept {
return table_.size();
}
std::size_t max_size() const noexcept {
return table_.max_size();
}
//// PUBLIC - Modifiers
void clear() noexcept {
table_.clear();
}
std::pair<iterator, bool> insert(value_type const& value) {
return emplace(value);
}
std::pair<iterator, bool> insert(value_type&& value) {
return emplace(std::move(value));
}
// std::unordered_set's hinted insertion API is misleading. No
// implementation I've seen actually uses the hint. Code restructuring
// by the caller to use the hinted API is at best unnecessary, and at
// worst a pessimization. It is used, however, so we provide it.
iterator insert(const_iterator /*hint*/, value_type const& value) {
return insert(value).first;
}
iterator insert(const_iterator /*hint*/, value_type&& value) {
return insert(std::move(value)).first;
}
template <typename K>
EnableHeterogeneousInsert<K, std::pair<iterator, bool>> insert(K&& value) {
return emplace(std::forward<K>(value));
}
private:
template <class InputIt>
FOLLY_ALWAYS_INLINE void
bulkInsert(InputIt first, InputIt last, bool autoReserve) {
if (autoReserve) {
table_.reserveForInsert(std::distance(first, last));
}
while (first != last) {
insert(*first);
++first;
}
}
template <class InputIt>
void initialInsert(InputIt first, InputIt last, std::size_t initialCapacity) {
FOLLY_SAFE_DCHECK(empty() && bucket_count() >= initialCapacity, "");
// It's possible that there are a lot of duplicates in first..last and
// so we will oversize ourself. The common case, however, is that
// we can avoid a lot of rehashing if we pre-expand. The behavior
// is easy to disable at a particular call site by asking for an
// initialCapacity of 1.
bool autoReserve =
std::is_same<
typename std::iterator_traits<InputIt>::iterator_category,
std::random_access_iterator_tag>::value &&
initialCapacity == 0;
bulkInsert(first, last, autoReserve);
}
public:
template <class InputIt>
void insert(InputIt first, InputIt last) {
// Bulk reserve is a heuristic choice, so it can backfire. We restrict
// ourself to situations that mimic bulk construction without an
// explicit initialCapacity.
bool autoReserve =
std::is_same<
typename std::iterator_traits<InputIt>::iterator_category,
std::random_access_iterator_tag>::value &&
bucket_count() == 0;
bulkInsert(first, last, autoReserve);
}
void insert(std::initializer_list<value_type> ilist) {
insert(ilist.begin(), ilist.end());
}
template <class... Args>
std::pair<iterator, bool> emplace(Args&&... args) {
using K = KeyTypeForEmplace<key_type, hasher, key_equal, Args...>;
// If args is a single arg that can be emplaced directly (either
// key_type or a heterogeneous find + conversion to key_type) key will
// just be a reference to that arg, otherwise this will construct an
// intermediate key.
K key(std::forward<Args>(args)...);
auto rv = table_.tryEmplaceValue(key, std::forward<K>(key));
return std::make_pair(table_.makeIter(rv.first), rv.second);
}
template <class... Args>
iterator emplace_hint(const_iterator /*hint*/, Args&&... args) {
return emplace(std::forward<Args>(args)...).first;
}
FOLLY_ALWAYS_INLINE iterator erase(const_iterator pos) {
return eraseInto(pos, [](value_type&&) {});
}
iterator erase(const_iterator first, const_iterator last) {
return eraseInto(first, last, [](value_type&&) {});
}
size_type erase(key_type const& key) {
return eraseInto(key, [](value_type&&) {});
}
template <typename K>
EnableHeterogeneousErase<K, size_type> erase(K const& key) {
return eraseInto(key, [](value_type&&) {});
}
// eraseInto contains the same overloads as erase but provides
// an additional callback argument which is called with an rvalue
// reference to the item directly before it is destroyed. This can be
// used to extract an item out of a F14Set while avoiding a copy.
template <typename BeforeDestroy>
FOLLY_ALWAYS_INLINE iterator
eraseInto(const_iterator pos, BeforeDestroy&& beforeDestroy) {
auto itemPos = table_.unwrapIter(pos);
table_.eraseIterInto(itemPos, beforeDestroy);
// If we are inlined then gcc and clang can optimize away all of the
// work of ++pos if the caller discards it.
itemPos.advanceLikelyDead();
return table_.makeIter(itemPos);
}
template <typename BeforeDestroy>
iterator eraseInto(
const_iterator first,
const_iterator last,
BeforeDestroy&& beforeDestroy) {
while (first != last) {
first = eraseInto(first, beforeDestroy);
}
return first;
}
template <typename BeforeDestroy>
size_type eraseInto(key_type const& key, BeforeDestroy&& beforeDestroy) {
return table_.eraseKeyInto(key, beforeDestroy);
}
template <typename K, typename BeforeDestroy>
EnableHeterogeneousErase<K, size_type> eraseInto(
K const& key,
BeforeDestroy&& beforeDestroy) {
return table_.eraseKeyInto(key, beforeDestroy);
}
//// PUBLIC - Lookup
FOLLY_ALWAYS_INLINE std::size_t count(key_type const& key) const {
return table_.find(key).atEnd() ? 0 : 1;
}
template <typename K>
FOLLY_ALWAYS_INLINE EnableHeterogeneousFind<K, size_type> count(
K const& key) const {
return table_.find(key).atEnd() ? 0 : 1;
}
// prehash(key) does the work of evaluating hash_function()(key)
// (including additional bit-mixing for non-avalanching hash functions),
// wraps the result of that work in a token for later reuse, and
// begins prefetching of the first steps of looking for key into the
// local CPU cache.
//
// The returned token may be used at any time, may be used more than
// once, and may be used in other F14 sets and maps. Tokens are
// transferrable between any F14 containers (maps and sets) with the
// same key_type and equal hash_function()s.
//
// Hash tokens are not hints -- it is a bug to call any method on this
// class with a token t and key k where t isn't the result of a call
// to prehash(k2) with k2 == k.
F14HashToken prehash(key_type const& key) const {
return table_.prehash(key);
}
template <typename K>
EnableHeterogeneousFind<K, F14HashToken> prehash(K const& key) const {
return table_.prehash(key);
}
FOLLY_ALWAYS_INLINE iterator find(key_type const& key) {
return const_cast<F14BasicSet const*>(this)->find(key);
}
FOLLY_ALWAYS_INLINE const_iterator find(key_type const& key) const {
return table_.makeIter(table_.find(key));
}
FOLLY_ALWAYS_INLINE iterator
find(F14HashToken const& token, key_type const& key) {
return const_cast<F14BasicSet const*>(this)->find(token, key);
}
FOLLY_ALWAYS_INLINE const_iterator
find(F14HashToken const& token, key_type const& key) const {
return table_.makeIter(table_.find(token, key));
}
template <typename K>
FOLLY_ALWAYS_INLINE EnableHeterogeneousFind<K, iterator> find(K const& key) {
return const_cast<F14BasicSet const*>(this)->find(key);
}
template <typename K>
FOLLY_ALWAYS_INLINE EnableHeterogeneousFind<K, const_iterator> find(
K const& key) const {
return table_.makeIter(table_.find(key));
}
template <typename K>
FOLLY_ALWAYS_INLINE EnableHeterogeneousFind<K, iterator> find(
F14HashToken const& token,
K const& key) {
return const_cast<F14BasicSet const*>(this)->find(token, key);
}
template <typename K>
FOLLY_ALWAYS_INLINE EnableHeterogeneousFind<K, const_iterator> find(
F14HashToken const& token,
K const& key) const {
return table_.makeIter(table_.find(token, key));
}
std::pair<iterator, iterator> equal_range(key_type const& key) {
return equal_range(*this, key);
}
std::pair<const_iterator, const_iterator> equal_range(
key_type const& key) const {
return equal_range(*this, key);
}
template <typename K>
EnableHeterogeneousFind<K, std::pair<iterator, iterator>> equal_range(
K const& key) {
return equal_range(*this, key);
}
template <typename K>
EnableHeterogeneousFind<K, std::pair<const_iterator, const_iterator>>
equal_range(K const& key) const {
return equal_range(*this, key);
}
//// PUBLIC - Bucket interface
std::size_t bucket_count() const noexcept {
return table_.bucket_count();
}
std::size_t max_bucket_count() const noexcept {
return table_.max_bucket_count();
}
//// PUBLIC - Hash policy
float load_factor() const noexcept {
return table_.load_factor();
}
float max_load_factor() const noexcept {
return table_.max_load_factor();
}
void max_load_factor(float v) {
table_.max_load_factor(v);
}
void rehash(std::size_t bucketCapacity) {
// The standard's rehash() requires understanding the max load factor,
// which is easy to get wrong. Since we don't actually allow adjustment
// of max_load_factor there is no difference.
reserve(bucketCapacity);
}
void reserve(std::size_t capacity) {
table_.reserve(capacity);
}
//// PUBLIC - Observers
hasher hash_function() const {
return table_.hasher();
}
key_equal key_eq() const {
return table_.keyEqual();
}
//// PUBLIC - F14 Extensions
// Get memory footprint, not including sizeof(*this).
std::size_t getAllocatedMemorySize() const {
return table_.getAllocatedMemorySize();
}
// Enumerates classes of allocated memory blocks currently owned
// by this table, calling visitor(allocationSize, allocationCount).
// This can be used to get a more accurate indication of memory footprint
// than getAllocatedMemorySize() if you have some way of computing the
// internal fragmentation of the allocator, such as JEMalloc's nallocx.
// The visitor might be called twice with the same allocationSize. The
// visitor's computation should produce the same result for visitor(8,
// 2) as for two calls to visitor(8, 1), for example. The visitor may
// be called with a zero allocationCount.
template <typename V>
void visitAllocationClasses(V&& visitor) const {
return table_.visitAllocationClasses(visitor);
}
// Calls visitor with two value_type const*, b and e, such that every
// entry in the table is included in exactly one of the ranges [b,e).
// This can be used to efficiently iterate elements in bulk when crossing
// an API boundary that supports contiguous blocks of items.
template <typename V>
void visitContiguousRanges(V&& visitor) const;
F14TableStats computeStats() const noexcept {
return table_.computeStats();
}
private:
template <typename Self, typename K>
static auto equal_range(Self& self, K const& key) {
auto first = self.find(key);
auto last = first;
if (last != self.end()) {
++last;
}
return std::make_pair(first, last);
}
protected:
F14Table<Policy> table_;
};
template <typename S>
bool setsEqual(S const& lhs, S const& rhs) {
if (lhs.size() != rhs.size()) {
return false;
}
for (auto& k : lhs) {
auto iter = rhs.find(k);
if (iter == rhs.end()) {
return false;
}
if (!std::is_same<
typename S::key_equal,
std::equal_to<typename S::value_type>>::value) {
// spec says we compare key with == as well as with key_eq()
if (!(k == *iter)) {
return false;
}
}
}
return true;
}
} // namespace detail
} // namespace f14
template <typename Key, typename Hasher, typename KeyEqual, typename Alloc>
class F14ValueSet
: public f14::detail::F14BasicSet<f14::detail::SetPolicyWithDefaults<
f14::detail::ValueContainerPolicy,
Key,
Hasher,
KeyEqual,
Alloc>> {
using Policy = f14::detail::SetPolicyWithDefaults<
f14::detail::ValueContainerPolicy,
Key,
Hasher,
KeyEqual,
Alloc>;
using Super = f14::detail::F14BasicSet<Policy>;
public:
using typename Super::value_type;
F14ValueSet() = default;
using Super::Super;
F14ValueSet& operator=(std::initializer_list<value_type> ilist) {
Super::operator=(ilist);
return *this;
}
void swap(F14ValueSet& rhs) noexcept(Policy::kSwapIsNoexcept) {
this->table_.swap(rhs.table_);
}
template <typename V>
void visitContiguousRanges(V&& visitor) const {
this->table_.visitContiguousItemRanges(std::forward<V>(visitor));
}
};
template <typename K, typename H, typename E, typename A>
bool operator==(
F14ValueSet<K, H, E, A> const& lhs,
F14ValueSet<K, H, E, A> const& rhs) {
return setsEqual(lhs, rhs);
}
template <typename K, typename H, typename E, typename A>
bool operator!=(
F14ValueSet<K, H, E, A> const& lhs,
F14ValueSet<K, H, E, A> const& rhs) {
return !(lhs == rhs);
}
template <typename Key, typename Hasher, typename KeyEqual, typename Alloc>
class F14NodeSet
: public f14::detail::F14BasicSet<f14::detail::SetPolicyWithDefaults<
f14::detail::NodeContainerPolicy,
Key,
Hasher,
KeyEqual,
Alloc>> {
using Policy = f14::detail::SetPolicyWithDefaults<
f14::detail::NodeContainerPolicy,
Key,
Hasher,
KeyEqual,
Alloc>;
using Super = f14::detail::F14BasicSet<Policy>;
public:
using typename Super::value_type;
F14NodeSet() = default;
using Super::Super;
F14NodeSet& operator=(std::initializer_list<value_type> ilist) {
Super::operator=(ilist);
return *this;
}
void swap(F14NodeSet& rhs) noexcept(Policy::kSwapIsNoexcept) {
this->table_.swap(rhs.table_);
}
template <typename V>
void visitContiguousRanges(V&& visitor) const {
this->table_.visitItems([&](typename Policy::Item ptr) {
value_type const* b = std::addressof(*ptr);
visitor(b, b + 1);
});
}
};
template <typename K, typename H, typename E, typename A>
bool operator==(
F14NodeSet<K, H, E, A> const& lhs,
F14NodeSet<K, H, E, A> const& rhs) {
return setsEqual(lhs, rhs);
}
template <typename K, typename H, typename E, typename A>
bool operator!=(
F14NodeSet<K, H, E, A> const& lhs,
F14NodeSet<K, H, E, A> const& rhs) {
return !(lhs == rhs);
}
template <typename Key, typename Hasher, typename KeyEqual, typename Alloc>
class F14VectorSet
: public f14::detail::F14BasicSet<f14::detail::SetPolicyWithDefaults<
f14::detail::VectorContainerPolicy,
Key,
Hasher,
KeyEqual,
Alloc>> {
using Policy = f14::detail::SetPolicyWithDefaults<
f14::detail::VectorContainerPolicy,
Key,
Hasher,
KeyEqual,
Alloc>;
using Super = f14::detail::F14BasicSet<Policy>;
template <typename K, typename T>
using EnableHeterogeneousVectorErase = std::enable_if_t<
f14::detail::EligibleForHeterogeneousFind<
typename Policy::Value,
typename Policy::Hasher,
typename Policy::KeyEqual,
K>::value &&
!std::is_same<typename Policy::Iter, remove_cvref_t<K>>::value &&
!std::is_same<typename Policy::ReverseIter, remove_cvref_t<K>>::value,
T>;
public:
using typename Super::const_iterator;
using typename Super::iterator;
using typename Super::key_type;
using typename Super::value_type;
using reverse_iterator = typename Policy::ReverseIter;
using const_reverse_iterator = reverse_iterator;
F14VectorSet() = default;
using Super::Super;
F14VectorSet& operator=(std::initializer_list<value_type> ilist) {
Super::operator=(ilist);
return *this;
}
void swap(F14VectorSet& rhs) noexcept(Policy::kSwapIsNoexcept) {
this->table_.swap(rhs.table_);
}
// ITERATION ORDER
//
// Deterministic iteration order for insert-only workloads is part of
// F14VectorSet's supported API: iterator is LIFO and reverse_iterator
// is FIFO.
//
// If there have been no calls to erase() then iterator and
// const_iterator enumerate entries in the opposite of insertion order.
// begin()->first is the key most recently inserted. reverse_iterator
// and reverse_const_iterator, therefore, enumerate in LIFO (insertion)
// order for insert-only workloads. Deterministic iteration order is
// only guaranteed if no keys were removed since the last time the
// set was empty. Iteration order is preserved across rehashes and
// F14VectorSet copies and moves.
//
// iterator uses LIFO order so that erasing while iterating with begin()
// and end() is safe using the erase(it++) idiom, which is supported
// by std::set and std::unordered_set. erase(iter) invalidates iter
// and all iterators before iter in the non-reverse iteration order.
// Every successful erase invalidates all reverse iterators.
iterator begin() {
return cbegin();
}
const_iterator begin() const {
return cbegin();
}
const_iterator cbegin() const {
return this->table_.linearBegin(this->size());
}
iterator end() {
return cend();
}
const_iterator end() const {
return cend();
}
const_iterator cend() const {
return this->table_.linearEnd();
}
reverse_iterator rbegin() {
return this->table_.values_;
}
const_reverse_iterator rbegin() const {
return crbegin();
}
const_reverse_iterator crbegin() const {
return this->table_.values_;
}
reverse_iterator rend() {
return this->table_.values_ + this->table_.size();
}
const_reverse_iterator rend() const {
return crend();
}
const_reverse_iterator crend() const {
return this->table_.values_ + this->table_.size();
}
// explicit conversions between iterator and reverse_iterator
iterator iter(reverse_iterator riter) {
return this->table_.iter(riter);
}
const_iterator iter(const_reverse_iterator riter) const {
return this->table_.iter(riter);
}
reverse_iterator riter(iterator it) {
return this->table_.riter(it);
}
const_reverse_iterator riter(const_iterator it) const {
return this->table_.riter(it);
}
private:
template <typename BeforeDestroy>
void eraseUnderlying(
typename Policy::ItemIter underlying,
BeforeDestroy&& beforeDestroy) {
Alloc& a = this->table_.alloc();
auto values = this->table_.values_;
// destroy the value and remove the ptr from the base table
auto index = underlying.item();
this->table_.eraseIterInto(underlying, beforeDestroy);
Policy::AllocTraits::destroy(a, std::addressof(values[index]));
// move the last element in values_ down and fix up the inbound index
auto tailIndex = this->size();
if (tailIndex != index) {
auto tail = this->table_.find(f14::detail::VectorContainerIndexSearch{
static_cast<uint32_t>(tailIndex)});
tail.item() = index;
auto p = std::addressof(values[index]);
assume(p != nullptr);
this->table_.transfer(a, std::addressof(values[tailIndex]), p, 1);
}
}
template <typename K, typename BeforeDestroy>
std::size_t eraseUnderlyingKey(K const& key, BeforeDestroy&& beforeDestroy) {
auto underlying = this->table_.find(key);
if (underlying.atEnd()) {
return 0;
} else {
eraseUnderlying(underlying, beforeDestroy);
return 1;
}
}
public:
FOLLY_ALWAYS_INLINE iterator erase(const_iterator pos) {
return eraseInto(pos, [](value_type&&) {});
}
iterator erase(const_iterator first, const_iterator last) {
return eraseInto(first, last, [](value_type&&) {});
}
// No erase is provided for reverse_iterator (AKA const_reverse_iterator)
// to make it harder to shoot yourself in the foot by erasing while
// reverse-iterating. You can write that as set.erase(set.iter(riter)).
std::size_t erase(key_type const& key) {
return eraseInto(key, [](value_type&&) {});
}
template <typename K>
EnableHeterogeneousVectorErase<K, std::size_t> erase(K const& key) {
return eraseInto(key, [](value_type&&) {});
}
template <typename BeforeDestroy>
FOLLY_ALWAYS_INLINE iterator
eraseInto(const_iterator pos, BeforeDestroy&& beforeDestroy) {
auto underlying = this->table_.find(
f14::detail::VectorContainerIndexSearch{this->table_.iterToIndex(pos)});
eraseUnderlying(underlying, beforeDestroy);
return ++pos;
}
template <typename BeforeDestroy>
iterator eraseInto(
const_iterator first,
const_iterator last,
BeforeDestroy&& beforeDestroy) {
while (first != last) {
first = eraseInto(first, beforeDestroy);
}
return first;
}
template <typename BeforeDestroy>
std::size_t eraseInto(key_type const& key, BeforeDestroy&& beforeDestroy) {
return eraseUnderlyingKey(key, beforeDestroy);
}
template <typename K, typename BeforeDestroy>
EnableHeterogeneousVectorErase<K, std::size_t> eraseInto(
K const& key,
BeforeDestroy&& beforeDestroy) {
return eraseUnderlyingKey(key, beforeDestroy);
}
template <typename V>
void visitContiguousRanges(V&& visitor) const {
auto n = this->table_.size();
if (n > 0) {
value_type const* b = std::addressof(this->table_.values_[0]);
visitor(b, b + n);
}
}
};
template <typename K, typename H, typename E, typename A>
bool operator==(
F14VectorSet<K, H, E, A> const& lhs,
F14VectorSet<K, H, E, A> const& rhs) {
return setsEqual(lhs, rhs);
}
template <typename K, typename H, typename E, typename A>
bool operator!=(
F14VectorSet<K, H, E, A> const& lhs,
F14VectorSet<K, H, E, A> const& rhs) {
return !(lhs == rhs);
}
} // namespace folly
#endif // FOLLY_F14_VECTOR_INTRINSICS_AVAILABLE
namespace folly {
template <typename Key, typename Hasher, typename KeyEqual, typename Alloc>
class F14FastSet : public std::conditional_t<
sizeof(Key) < 24,
F14ValueSet<Key, Hasher, KeyEqual, Alloc>,
F14VectorSet<Key, Hasher, KeyEqual, Alloc>> {
using Super = std::conditional_t<
sizeof(Key) < 24,
F14ValueSet<Key, Hasher, KeyEqual, Alloc>,
F14VectorSet<Key, Hasher, KeyEqual, Alloc>>;
public:
using typename Super::value_type;
F14FastSet() = default;
using Super::Super;
F14FastSet& operator=(std::initializer_list<value_type> ilist) {
Super::operator=(ilist);
return *this;
}
};
template <typename K, typename H, typename E, typename A>
void swap(F14ValueSet<K, H, E, A>& lhs, F14ValueSet<K, H, E, A>& rhs) noexcept(
noexcept(lhs.swap(rhs))) {
lhs.swap(rhs);
}
template <typename K, typename H, typename E, typename A>
void swap(F14NodeSet<K, H, E, A>& lhs, F14NodeSet<K, H, E, A>& rhs) noexcept(
noexcept(lhs.swap(rhs))) {
lhs.swap(rhs);
}
template <typename K, typename H, typename E, typename A>
void swap(
F14VectorSet<K, H, E, A>& lhs,
F14VectorSet<K, H, E, A>& rhs) noexcept(noexcept(lhs.swap(rhs))) {
lhs.swap(rhs);
}
template <typename K, typename H, typename E, typename A>
void swap(F14FastSet<K, H, E, A>& lhs, F14FastSet<K, H, E, A>& rhs) noexcept(
noexcept(lhs.swap(rhs))) {
lhs.swap(rhs);
}
} // namespace folly