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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
commit | 26a029d407be480d791972afb5975cf62c9360a6 (patch) | |
tree | f435a8308119effd964b339f76abb83a57c29483 /xpcom/ds/nsTHashSet.h | |
parent | Initial commit. (diff) | |
download | firefox-e51783d008170d9ab27d25da98ca3a38b0a41b67.tar.xz firefox-e51783d008170d9ab27d25da98ca3a38b0a41b67.zip |
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'xpcom/ds/nsTHashSet.h')
-rw-r--r-- | xpcom/ds/nsTHashSet.h | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/xpcom/ds/nsTHashSet.h b/xpcom/ds/nsTHashSet.h new file mode 100644 index 0000000000..4d905299db --- /dev/null +++ b/xpcom/ds/nsTHashSet.h @@ -0,0 +1,193 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef XPCOM_DS_NSTHASHSET_H_ +#define XPCOM_DS_NSTHASHSET_H_ + +#include "nsHashtablesFwd.h" +#include "nsTHashMap.h" // for nsKeyClass + +/** + * Templated hash set. Don't use this directly, but use nsTHashSet instead + * (defined as a type alias in nsHashtablesFwd.h). + * + * @param KeyClass a wrapper-class for the hashtable key, see nsHashKeys.h + * for a complete specification. + */ +template <class KeyClass> +class nsTBaseHashSet : protected nsTHashtable<KeyClass> { + using Base = nsTHashtable<KeyClass>; + typedef mozilla::fallible_t fallible_t; + + public: + // XXX We have a similar situation here like with DataType/UserDataType in + // nsBaseHashtable. It's less problematic here due to the more constrained + // interface, but it may still be confusing. KeyType is not the stored key + // type, but the one exposed to the user, i.e. as a parameter type, and as the + // value type when iterating. It is currently impossible to move-insert a + // RefPtr<T>, e.g., since the KeyType is T* in that case. + using ValueType = typename KeyClass::KeyType; + + // KeyType is defined just for compatibility with nsTHashMap. For a set, the + // key type is conceptually equivalent to the value type. + using KeyType = typename KeyClass::KeyType; + + using Base::Base; + + // Query operations. + + using Base::Contains; + using Base::GetGeneration; + using Base::ShallowSizeOfExcludingThis; + using Base::ShallowSizeOfIncludingThis; + using Base::SizeOfExcludingThis; + using Base::SizeOfIncludingThis; + + /** + * Return the number of entries in the table. + * @return number of entries + */ + [[nodiscard]] uint32_t Count() const { return Base::Count(); } + + /** + * Return whether the table is empty. + * @return whether empty + */ + [[nodiscard]] bool IsEmpty() const { return Base::IsEmpty(); } + + using iterator = ::detail::nsTHashtableKeyIterator<KeyClass>; + using const_iterator = iterator; + + [[nodiscard]] auto begin() const { return Base::Keys().begin(); } + + [[nodiscard]] auto end() const { return Base::Keys().end(); } + + [[nodiscard]] auto cbegin() const { return Base::Keys().cbegin(); } + + [[nodiscard]] auto cend() const { return Base::Keys().cend(); } + + // Mutating operations. + + using Base::Clear; + using Base::MarkImmutable; + + /** + * Inserts a value into the set. Has no effect if the value is already in the + * set. This overload is infallible and crashes if memory is exhausted. + * + * \note For strict consistency with nsTHashtable::EntryHandle method naming, + * this should rather be called OrInsert, as it is legal to call it when the + * value is already in the set. For simplicity, as we don't have two methods, + * we still use "Insert" instead. + */ + void Insert(ValueType aValue) { Base::PutEntry(aValue); } + + /** + * Inserts a value into the set. Has no effect if the value is already in the + * set. This overload is fallible and returns false if memory is exhausted. + * + * \note See note on infallible overload. + */ + [[nodiscard]] bool Insert(ValueType aValue, const mozilla::fallible_t&) { + return Base::PutEntry(aValue, mozilla::fallible); + } + + /** + * Inserts a value into the set. Has no effect if the value is already in the + * set. This member function is infallible and crashes if memory is exhausted. + * + * \return true if the value was actually inserted, false if it was already in + * the set. + */ + bool EnsureInserted(ValueType aValue) { return Base::EnsureInserted(aValue); } + + using Base::Remove; + + /** + * Removes a value from the set. Has no effect if the value is not in the set. + * + * \note For strict consistency with nsTHashtable::EntryHandle method naming, + * this should rather be called OrRemove, as it is legal to call it when the + * value is not in the set. For simplicity, as we don't have two methods, + * we still use "Remove" instead. + */ + void Remove(ValueType aValue) { Base::RemoveEntry(aValue); } + + using Base::EnsureRemoved; + + /** + * Removes all elements matching a predicate. + * + * The predicate must be compatible with signature bool (ValueType). + */ + template <typename Pred> + void RemoveIf(Pred&& aPred) { + for (auto it = cbegin(), end = cend(); it != end; ++it) { + if (aPred(static_cast<ValueType>(*it))) { + Remove(it); + } + } + } +}; + +template <typename KeyClass> +auto RangeSize(const nsTBaseHashSet<KeyClass>& aRange) { + return aRange.Count(); +} + +class nsCycleCollectionTraversalCallback; + +template <class KeyClass> +inline void ImplCycleCollectionUnlink(nsTBaseHashSet<KeyClass>& aField) { + aField.Clear(); +} + +template <class KeyClass> +inline void ImplCycleCollectionTraverse( + nsCycleCollectionTraversalCallback& aCallback, + const nsTBaseHashSet<KeyClass>& aField, const char* aName, + uint32_t aFlags = 0) { + for (const auto& entry : aField) { + CycleCollectionNoteChild(aCallback, mozilla::detail::PtrGetWeak(entry), + aName, aFlags); + } +} + +namespace mozilla { +template <typename SetT> +class nsTSetInserter { + SetT* mSet; + + class Proxy { + SetT& mSet; + + public: + explicit Proxy(SetT& aSet) : mSet{aSet} {} + + template <typename E2> + void operator=(E2&& aValue) { + mSet.Insert(std::forward<E2>(aValue)); + } + }; + + public: + using iterator_category = std::output_iterator_tag; + + explicit nsTSetInserter(SetT& aSet) : mSet{&aSet} {} + + Proxy operator*() { return Proxy(*mSet); } + + nsTSetInserter& operator++() { return *this; } + nsTSetInserter& operator++(int) { return *this; } +}; +} // namespace mozilla + +template <typename E> +auto MakeInserter(nsTBaseHashSet<E>& aSet) { + return mozilla::nsTSetInserter<nsTBaseHashSet<E>>{aSet}; +} + +#endif // XPCOM_DS_NSTHASHSET_H_ |