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AK: Simplify HashTable::remove_all_matching()

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Just walk the table from start to finish, deleting buckets as we go.
This removes the need for remove() to return an iterator, which is
preventing me from implementing hash table auto-shrinking.
This commit is contained in:
Andreas Kling 2022-03-06 19:11:17 +01:00
parent 6d1a9672a4
commit 623bdd8b6a
2 changed files with 35 additions and 33 deletions
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13
AK/HashMap.h
View file

@ -79,16 +79,9 @@ public:
template<typename TUnaryPredicate>
bool remove_all_matching(TUnaryPredicate predicate)
{
bool something_was_removed = false;
for (auto it = begin(); it != end();) {
if (predicate(it->key, it->value)) {
it = remove(it);
something_was_removed = true;
} else {
++it;
}
}
return something_was_removed;
return m_table.template remove_all_matching([&](auto& entry) {
return predicate(entry.key, entry.value);
});
}
using HashTableType = HashTable<Entry, EntryTraits, IsOrdered>;

55
AK/HashTable.h
View file

@ -402,40 +402,30 @@ public:
auto next_iterator = iterator;
++next_iterator;
bucket.slot()->~T();
bucket.used = false;
bucket.deleted = true;
delete_bucket(bucket);
--m_size;
++m_deleted_count;
if constexpr (IsOrdered) {
if (bucket.previous)
bucket.previous->next = bucket.next;
else
m_collection_data.head = bucket.next;
if (bucket.next)
bucket.next->previous = bucket.previous;
else
m_collection_data.tail = bucket.previous;
}
return next_iterator;
}
template<typename TUnaryPredicate>
bool remove_all_matching(TUnaryPredicate predicate)
{
bool something_was_removed = false;
for (auto it = begin(); it != end();) {
if (predicate(*it)) {
it = remove(it);
something_was_removed = true;
} else {
++it;
size_t removed_count = 0;
for (size_t i = 0; i < m_capacity; ++i) {
auto& bucket = m_buckets[i];
if (bucket.used && predicate(*bucket.slot())) {
delete_bucket(bucket);
++removed_count;
}
}
return something_was_removed;
if (removed_count) {
m_deleted_count += removed_count;
m_size -= removed_count;
return true;
}
return false;
}
private:
@ -558,6 +548,25 @@ private:
[[nodiscard]] size_t used_bucket_count() const { return m_size + m_deleted_count; }
[[nodiscard]] bool should_grow() const { return ((used_bucket_count() + 1) * 100) >= (m_capacity * load_factor_in_percent); }
void delete_bucket(auto& bucket)
{
bucket.slot()->~T();
bucket.used = false;
bucket.deleted = true;
if constexpr (IsOrdered) {
if (bucket.previous)
bucket.previous->next = bucket.next;
else
m_collection_data.head = bucket.next;
if (bucket.next)
bucket.next->previous = bucket.previous;
else
m_collection_data.tail = bucket.previous;
}
}
BucketType* m_buckets { nullptr };
[[no_unique_address]] CollectionDataType m_collection_data;