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dense_set:

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* emplace create-and-discard mode if strictly required only
* insert uses the insert_or_do_nothing utility internally
* opaque value_to_bucket function
This commit is contained in:
Michele Caini
2022-03-21 10:41:28 +01:00
parent e5dcea1fa0
commit 1b4fc54405
1 changed files with 51 additions and 24 deletions
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75
src/entt/container/dense_set.hpp
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@@ -235,6 +235,11 @@ class dense_set {
using sparse_container_type = std::vector<std::size_t, typename alloc_traits::template rebind_alloc<std::size_t>>;
using packed_container_type = std::vector<node_type, typename alloc_traits::template rebind_alloc<node_type>>;
template<typename Other>
[[nodiscard]] std::size_t value_to_bucket(const Other &value) const ENTT_NOEXCEPT {
return fast_mod(sparse.second()(value), bucket_count());
}
template<typename Other>
[[nodiscard]] auto constrained_find(const Other &value, std::size_t bucket) {
for(auto it = begin(bucket), last = end(bucket); it != last; ++it) {
@@ -257,10 +262,25 @@ class dense_set {
return cend();
}
template<typename Other>
[[nodiscard]] auto insert_or_do_nothing(Other &&value) {
const auto index = value_to_bucket(value);
if(auto it = constrained_find(value, index); it != end()) {
return std::make_pair(it, false);
}
const auto next = std::exchange(sparse.first()[index], packed.first().size());
packed.first().emplace_back(next, std::forward<Other>(value));
rehash_if_required();
return std::make_pair(--end(), true);
}
void move_and_pop(const std::size_t pos) {
if(const auto last = size() - 1u; pos != last) {
packed.first()[pos] = std::move(packed.first().back());
size_type *curr = sparse.first().data() + bucket(packed.first().back().second);
size_type *curr = sparse.first().data() + value_to_bucket(packed.first().back().second);
for(; *curr != last; curr = &packed.first()[*curr].first) {}
*curr = pos;
}
@@ -268,6 +288,12 @@ class dense_set {
packed.first().pop_back();
}
void rehash_if_required() {
if(size() > (bucket_count() * max_load_factor())) {
rehash(bucket_count() * 2u);
}
}
public:
/*! @brief Key type of the container. */
using key_type = Type;
@@ -458,12 +484,12 @@ public:
* insertion took place.
*/
std::pair<iterator, bool> insert(const value_type &value) {
return emplace(value);
return insert_or_do_nothing(value);
}
/*! @copydoc insert */
std::pair<iterator, bool> insert(value_type &&value) {
return emplace(std::move(value));
return insert_or_do_nothing(std::move(value));
}
/**
@@ -475,7 +501,7 @@ public:
template<typename It>
void insert(It first, It last) {
for(; first != last; ++first) {
emplace(*first);
insert(*first);
}
}
@@ -494,21 +520,22 @@ public:
*/
template<typename... Args>
std::pair<iterator, bool> emplace(Args &&...args) {
auto &node = packed.first().emplace_back(std::piecewise_construct, std::make_tuple(packed.first().size()), std::forward_as_tuple(std::forward<Args>(args)...));
const auto index = bucket(node.second);
if constexpr(((sizeof...(Args) == 1u) && ... && std::is_same_v<std::remove_const_t<std::remove_reference_t<Args>>, value_type>)) {
return insert_or_do_nothing(std::forward<Args>(args)...);
} else {
auto &node = packed.first().emplace_back(std::piecewise_construct, std::make_tuple(packed.first().size()), std::forward_as_tuple(std::forward<Args>(args)...));
const auto index = value_to_bucket(node.second);
if(auto it = constrained_find(node.second, index); it != end()) {
packed.first().pop_back();
return std::make_pair(it, false);
if(auto it = constrained_find(node.second, index); it != end()) {
packed.first().pop_back();
return std::make_pair(it, false);
}
std::swap(node.first, sparse.first()[index]);
rehash_if_required();
return std::make_pair(--end(), true);
}
std::swap(node.first, sparse.first()[index]);
if(size() > (bucket_count() * max_load_factor())) {
rehash(bucket_count() * 2u);
}
return std::make_pair(--end(), true);
}
/**
@@ -542,7 +569,7 @@ public:
* @return Number of elements removed (either 0 or 1).
*/
size_type erase(const value_type &value) {
for(size_type *curr = sparse.first().data() + bucket(value); *curr != std::numeric_limits<size_type>::max(); curr = &packed.first()[*curr].first) {
for(size_type *curr = sparse.first().data() + value_to_bucket(value); *curr != std::numeric_limits<size_type>::max(); curr = &packed.first()[*curr].first) {
if(packed.second()(packed.first()[*curr].second, value)) {
const auto index = *curr;
*curr = packed.first()[*curr].first;
@@ -572,12 +599,12 @@ public:
* element is found, a past-the-end iterator is returned.
*/
[[nodiscard]] iterator find(const value_type &value) {
return constrained_find(value, bucket(value));
return constrained_find(value, value_to_bucket(value));
}
/*! @copydoc find */
[[nodiscard]] const_iterator find(const value_type &value) const {
return constrained_find(value, bucket(value));
return constrained_find(value, value_to_bucket(value));
}
/**
@@ -590,14 +617,14 @@ public:
template<typename Other>
[[nodiscard]] std::enable_if_t<is_transparent_v<hasher> && is_transparent_v<key_equal>, std::conditional_t<false, Other, iterator>>
find(const Other &value) {
return constrained_find(value, bucket(value));
return constrained_find(value, value_to_bucket(value));
}
/*! @copydoc find */
template<typename Other>
[[nodiscard]] std::enable_if_t<is_transparent_v<hasher> && is_transparent_v<key_equal>, std::conditional_t<false, Other, const_iterator>>
find(const Other &value) const {
return constrained_find(value, bucket(value));
return constrained_find(value, value_to_bucket(value));
}
/**
@@ -707,7 +734,7 @@ public:
* @return The bucket for the given element.
*/
[[nodiscard]] size_type bucket(const value_type &value) const {
return fast_mod(sparse.second()(value), bucket_count());
return value_to_bucket(value);
}
/**
@@ -750,7 +777,7 @@ public:
std::fill(sparse.first().begin(), sparse.first().end(), std::numeric_limits<size_type>::max());
for(size_type pos{}, last = size(); pos < last; ++pos) {
const auto index = bucket(packed.first()[pos].second);
const auto index = value_to_bucket(packed.first()[pos].second);
packed.first()[pos].first = std::exchange(sparse.first()[index], pos);
}
}