TemplateObjectDescriptor.h [plain text]
#pragma once
#include <limits>
#include <wtf/Vector.h>
#include <wtf/text/StringHash.h>
#include <wtf/text/WTFString.h>
namespace JSC {
class TemplateObjectDescriptorTable;
class TemplateObjectDescriptor : public RefCounted<TemplateObjectDescriptor> {
public:
typedef Vector<String, 4> StringVector;
typedef Vector<Optional<String>, 4> OptionalStringVector;
enum DeletedValueTag { DeletedValue };
TemplateObjectDescriptor(DeletedValueTag);
enum EmptyValueTag { EmptyValue };
TemplateObjectDescriptor(EmptyValueTag);
bool isDeletedValue() const { return m_rawStrings.isEmpty() && m_hash == std::numeric_limits<unsigned>::max(); }
bool isEmptyValue() const { return m_rawStrings.isEmpty() && !m_hash; }
unsigned hash() const { return m_hash; }
const StringVector& rawStrings() const { return m_rawStrings; }
const OptionalStringVector& cookedStrings() const { return m_cookedStrings; }
bool operator==(const TemplateObjectDescriptor& other) const { return m_hash == other.m_hash && m_rawStrings == other.m_rawStrings; }
bool operator!=(const TemplateObjectDescriptor& other) const { return m_hash != other.m_hash || m_rawStrings != other.m_rawStrings; }
struct Hasher {
static unsigned hash(const TemplateObjectDescriptor& key) { return key.hash(); }
static bool equal(const TemplateObjectDescriptor& a, const TemplateObjectDescriptor& b) { return a == b; }
static constexpr bool safeToCompareToEmptyOrDeleted = false;
};
static unsigned calculateHash(const StringVector& rawStrings);
~TemplateObjectDescriptor();
static Ref<TemplateObjectDescriptor> create(StringVector&& rawStrings, OptionalStringVector&& cookedStrings)
{
return adoptRef(*new TemplateObjectDescriptor(WTFMove(rawStrings), WTFMove(cookedStrings)));
}
private:
TemplateObjectDescriptor(StringVector&& rawStrings, OptionalStringVector&& cookedStrings);
StringVector m_rawStrings;
OptionalStringVector m_cookedStrings;
unsigned m_hash { 0 };
};
inline TemplateObjectDescriptor::TemplateObjectDescriptor(StringVector&& rawStrings, OptionalStringVector&& cookedStrings)
: m_rawStrings(WTFMove(rawStrings))
, m_cookedStrings(WTFMove(cookedStrings))
, m_hash(calculateHash(m_rawStrings))
{
}
inline TemplateObjectDescriptor::TemplateObjectDescriptor(DeletedValueTag)
: m_hash(std::numeric_limits<unsigned>::max())
{
}
inline TemplateObjectDescriptor::TemplateObjectDescriptor(EmptyValueTag)
: m_hash(0)
{
}
inline unsigned TemplateObjectDescriptor::calculateHash(const StringVector& rawStrings)
{
StringHasher hasher;
for (const String& string : rawStrings) {
if (string.is8Bit())
hasher.addCharacters(string.characters8(), string.length());
else
hasher.addCharacters(string.characters16(), string.length());
}
return hasher.hash();
}
}
namespace WTF {
template<typename T> struct DefaultHash;
template<> struct DefaultHash<JSC::TemplateObjectDescriptor> {
typedef JSC::TemplateObjectDescriptor::Hasher Hash;
};
template<> struct HashTraits<JSC::TemplateObjectDescriptor> : CustomHashTraits<JSC::TemplateObjectDescriptor> {
};
}