#pragma once
#include <wtf/HashFunctions.h>
#include <wtf/HashTraits.h>
#include <wtf/Optional.h>
#include <wtf/text/TextStream.h>
#include <wtf/text/WTFString.h>
namespace WebKit {
template<typename T> class MonotonicObjectIdentifier {
public:
MonotonicObjectIdentifier() = default;
MonotonicObjectIdentifier(WTF::HashTableDeletedValueType)
: m_identifier(hashTableDeletedValue())
{ }
bool isHashTableDeletedValue() const { return m_identifier == hashTableDeletedValue(); }
template<typename Encoder> void encode(Encoder& encoder) const
{
ASSERT(isValidIdentifier(m_identifier));
encoder << m_identifier;
}
template<typename Decoder> static Optional<MonotonicObjectIdentifier> decode(Decoder& decoder)
{
Optional<uint64_t> identifier;
decoder >> identifier;
if (!identifier)
return WTF::nullopt;
ASSERT(isValidIdentifier(*identifier));
return MonotonicObjectIdentifier { *identifier };
}
bool operator==(const MonotonicObjectIdentifier& other) const
{
return m_identifier == other.m_identifier;
}
bool operator>(const MonotonicObjectIdentifier& other) const
{
return m_identifier > other.m_identifier;
}
bool operator>=(const MonotonicObjectIdentifier& other) const
{
return m_identifier >= other.m_identifier;
}
bool operator<(const MonotonicObjectIdentifier& other) const
{
return m_identifier < other.m_identifier;
}
bool operator<=(const MonotonicObjectIdentifier& other) const
{
return m_identifier <= other.m_identifier;
}
bool operator!=(const MonotonicObjectIdentifier& other) const
{
return m_identifier != other.m_identifier;
}
MonotonicObjectIdentifier& increment()
{
++m_identifier;
return *this;
}
MonotonicObjectIdentifier next() const
{
return MonotonicObjectIdentifier(m_identifier + 1);
}
uint64_t toUInt64() const { return m_identifier; }
explicit operator bool() const { return m_identifier; }
String loggingString() const
{
return String::number(m_identifier);
}
private:
template<typename U> friend MonotonicObjectIdentifier<U> makeMonotonicObjectIdentifier(uint64_t);
friend struct HashTraits<MonotonicObjectIdentifier>;
template<typename U> friend struct MonotonicObjectIdentifierHash;
static uint64_t hashTableDeletedValue() { return std::numeric_limits<uint64_t>::max(); }
static bool isValidIdentifier(uint64_t identifier) { return identifier != hashTableDeletedValue(); }
explicit MonotonicObjectIdentifier(uint64_t identifier)
: m_identifier(identifier)
{
}
uint64_t m_identifier { 0 };
};
template<typename T>
TextStream& operator<<(TextStream& ts, const MonotonicObjectIdentifier<T>& identifier)
{
ts << identifier.toUInt64();
return ts;
}
enum TransactionIDType { };
using TransactionID = MonotonicObjectIdentifier<TransactionIDType>;
}