#ifndef WTF_HashTraits_h
#define WTF_HashTraits_h
#include <wtf/HashFunctions.h>
#include <wtf/StdLibExtras.h>
#include <utility>
#include <limits>
namespace WTF {
class String;
template<typename T> class OwnPtr;
template<typename T> class PassOwnPtr;
template<typename T> struct HashTraits;
template<bool isInteger, typename T> struct GenericHashTraitsBase;
template<typename T> struct GenericHashTraitsBase<false, T> {
static const bool emptyValueIsZero = false;
static const bool hasIsEmptyValueFunction = false;
static const int minimumTableSize = 8;
};
template<typename T> struct GenericHashTraitsBase<true, T> : GenericHashTraitsBase<false, T> {
static const bool emptyValueIsZero = true;
static void constructDeletedValue(T& slot) { slot = static_cast<T>(-1); }
static bool isDeletedValue(T value) { return value == static_cast<T>(-1); }
};
template<typename T> struct GenericHashTraits : GenericHashTraitsBase<std::is_integral<T>::value, T> {
typedef T TraitType;
typedef T EmptyValueType;
static T emptyValue() { return T(); }
typedef T PeekType;
static PeekType peek(const T& value) { return value; }
static T& peek(T& value) { return value; } };
template<typename T> struct HashTraits : GenericHashTraits<T> { };
template<typename T> struct FloatHashTraits : GenericHashTraits<T> {
static T emptyValue() { return std::numeric_limits<T>::infinity(); }
static void constructDeletedValue(T& slot) { slot = -std::numeric_limits<T>::infinity(); }
static bool isDeletedValue(T value) { return value == -std::numeric_limits<T>::infinity(); }
};
template<> struct HashTraits<float> : FloatHashTraits<float> { };
template<> struct HashTraits<double> : FloatHashTraits<double> { };
template<typename T> struct UnsignedWithZeroKeyHashTraits : GenericHashTraits<T> {
static const bool emptyValueIsZero = false;
static T emptyValue() { return std::numeric_limits<T>::max(); }
static void constructDeletedValue(T& slot) { slot = std::numeric_limits<T>::max() - 1; }
static bool isDeletedValue(T value) { return value == std::numeric_limits<T>::max() - 1; }
};
template<typename P> struct HashTraits<P*> : GenericHashTraits<P*> {
static const bool emptyValueIsZero = true;
static void constructDeletedValue(P*& slot) { slot = reinterpret_cast<P*>(-1); }
static bool isDeletedValue(P* value) { return value == reinterpret_cast<P*>(-1); }
};
template<typename T> struct SimpleClassHashTraits : GenericHashTraits<T> {
static const bool emptyValueIsZero = true;
static void constructDeletedValue(T& slot) { new (NotNull, &slot) T(HashTableDeletedValue); }
static bool isDeletedValue(const T& value) { return value.isHashTableDeletedValue(); }
};
template<typename T, typename Deleter> struct HashTraits<std::unique_ptr<T, Deleter>> : SimpleClassHashTraits<std::unique_ptr<T, Deleter>> {
typedef std::nullptr_t EmptyValueType;
static EmptyValueType emptyValue() { return nullptr; }
typedef T* PeekType;
static T* peek(const std::unique_ptr<T, Deleter>& value) { return value.get(); }
static T* peek(std::nullptr_t) { return nullptr; }
};
template<typename T> struct HashTraits<OwnPtr<T>> : SimpleClassHashTraits<OwnPtr<T>> {
typedef std::nullptr_t EmptyValueType;
static EmptyValueType emptyValue() { return nullptr; }
typedef T* PeekType;
static T* peek(const OwnPtr<T>& value) { return value.get(); }
static T* peek(std::nullptr_t) { return nullptr; }
};
template<typename P> struct HashTraits<RefPtr<P>> : SimpleClassHashTraits<RefPtr<P>> {
static P* emptyValue() { return 0; }
typedef P* PeekType;
static PeekType peek(const RefPtr<P>& value) { return value.get(); }
static PeekType peek(P* value) { return value; }
};
template<> struct HashTraits<String> : SimpleClassHashTraits<String> {
static const bool hasIsEmptyValueFunction = true;
static bool isEmptyValue(const String&);
};
template<typename Traits, bool hasEmptyValueFunction> struct HashTraitsEmptyValueChecker;
template<typename Traits> struct HashTraitsEmptyValueChecker<Traits, true> {
template<typename T> static bool isEmptyValue(const T& value) { return Traits::isEmptyValue(value); }
};
template<typename Traits> struct HashTraitsEmptyValueChecker<Traits, false> {
template<typename T> static bool isEmptyValue(const T& value) { return value == Traits::emptyValue(); }
};
template<typename Traits, typename T> inline bool isHashTraitsEmptyValue(const T& value)
{
return HashTraitsEmptyValueChecker<Traits, Traits::hasIsEmptyValueFunction>::isEmptyValue(value);
}
template<typename FirstTraitsArg, typename SecondTraitsArg>
struct PairHashTraits : GenericHashTraits<std::pair<typename FirstTraitsArg::TraitType, typename SecondTraitsArg::TraitType>> {
typedef FirstTraitsArg FirstTraits;
typedef SecondTraitsArg SecondTraits;
typedef std::pair<typename FirstTraits::TraitType, typename SecondTraits::TraitType> TraitType;
typedef std::pair<typename FirstTraits::EmptyValueType, typename SecondTraits::EmptyValueType> EmptyValueType;
static const bool emptyValueIsZero = FirstTraits::emptyValueIsZero && SecondTraits::emptyValueIsZero;
static EmptyValueType emptyValue() { return std::make_pair(FirstTraits::emptyValue(), SecondTraits::emptyValue()); }
static const int minimumTableSize = FirstTraits::minimumTableSize;
static void constructDeletedValue(TraitType& slot) { FirstTraits::constructDeletedValue(slot.first); }
static bool isDeletedValue(const TraitType& value) { return FirstTraits::isDeletedValue(value.first); }
};
template<typename First, typename Second>
struct HashTraits<std::pair<First, Second>> : public PairHashTraits<HashTraits<First>, HashTraits<Second>> { };
template<typename KeyTypeArg, typename ValueTypeArg>
struct KeyValuePair {
typedef KeyTypeArg KeyType;
KeyValuePair()
{
}
template<typename K, typename V>
KeyValuePair(K&& key, V&& value)
: key(std::forward<K>(key))
, value(std::forward<V>(value))
{
}
template <typename OtherKeyType, typename OtherValueType>
KeyValuePair(KeyValuePair<OtherKeyType, OtherValueType>&& other)
: key(std::forward<OtherKeyType>(other.key))
, value(std::forward<OtherValueType>(other.value))
{
}
KeyTypeArg key;
ValueTypeArg value;
};
template<typename KeyTraitsArg, typename ValueTraitsArg>
struct KeyValuePairHashTraits : GenericHashTraits<KeyValuePair<typename KeyTraitsArg::TraitType, typename ValueTraitsArg::TraitType>> {
typedef KeyTraitsArg KeyTraits;
typedef ValueTraitsArg ValueTraits;
typedef KeyValuePair<typename KeyTraits::TraitType, typename ValueTraits::TraitType> TraitType;
typedef KeyValuePair<typename KeyTraits::EmptyValueType, typename ValueTraits::EmptyValueType> EmptyValueType;
static const bool emptyValueIsZero = KeyTraits::emptyValueIsZero && ValueTraits::emptyValueIsZero;
static EmptyValueType emptyValue() { return KeyValuePair<typename KeyTraits::EmptyValueType, typename ValueTraits::EmptyValueType>(KeyTraits::emptyValue(), ValueTraits::emptyValue()); }
static const int minimumTableSize = KeyTraits::minimumTableSize;
static void constructDeletedValue(TraitType& slot) { KeyTraits::constructDeletedValue(slot.key); }
static bool isDeletedValue(const TraitType& value) { return KeyTraits::isDeletedValue(value.key); }
};
template<typename Key, typename Value>
struct HashTraits<KeyValuePair<Key, Value>> : public KeyValuePairHashTraits<HashTraits<Key>, HashTraits<Value>> { };
template<typename T>
struct NullableHashTraits : public HashTraits<T> {
static const bool emptyValueIsZero = false;
static T emptyValue() { return reinterpret_cast<T>(1); }
};
template<typename T>
struct CustomHashTraits : public GenericHashTraits<T> {
static const bool emptyValueIsZero = false;
static const bool hasIsEmptyValueFunction = true;
static void constructDeletedValue(T& slot)
{
new (NotNull, &slot) T(T::DeletedValue);
}
static bool isDeletedValue(const T& value)
{
return value.isDeletedValue();
}
static T emptyValue()
{
return T(T::EmptyValue);
}
static bool isEmptyValue(const T& value)
{
return value.isEmptyValue();
}
};
}
using WTF::HashTraits;
using WTF::PairHashTraits;
using WTF::NullableHashTraits;
using WTF::SimpleClassHashTraits;
#endif // WTF_HashTraits_h