#pragma once
#include <wtf/Assertions.h>
#include <wtf/HashTraits.h>
#include <wtf/UniqueArray.h>
namespace WTF {
class StackShot {
public:
StackShot() { }
ALWAYS_INLINE StackShot(size_t size)
: m_size(size)
{
if (size) {
m_array = makeUniqueArray<void*>(size);
int intSize = size;
WTFGetBacktrace(m_array.get(), &intSize);
RELEASE_ASSERT(static_cast<size_t>(intSize) <= size);
m_size = intSize;
if (!m_size)
m_array = nullptr;
}
}
StackShot(WTF::HashTableDeletedValueType)
: m_array(deletedValueArray())
, m_size(0)
{
}
StackShot& operator=(const StackShot& other)
{
auto newArray = makeUniqueArray<void*>(other.m_size);
for (size_t i = other.m_size; i--;)
newArray[i] = other.m_array[i];
m_size = other.m_size;
m_array = WTFMove(newArray);
return *this;
}
StackShot(const StackShot& other)
{
*this = other;
}
void** array() const { return m_array.get(); }
size_t size() const { return m_size; }
explicit operator bool() const { return !!m_array; }
bool operator==(const StackShot& other) const
{
if (m_size != other.m_size)
return false;
for (size_t i = m_size; i--;) {
if (m_array[i] != other.m_array[i])
return false;
}
return true;
}
unsigned hash() const
{
unsigned result = m_size;
for (size_t i = m_size; i--;)
result ^= PtrHash<void*>::hash(m_array[i]);
return result;
}
bool isHashTableDeletedValue() const
{
return !m_size && m_array.get() == deletedValueArray();
}
bool operator>(const StackShot&) const { return false; }
private:
static void** deletedValueArray() { return bitwise_cast<void**>(static_cast<uintptr_t>(1)); }
UniqueArray<void*> m_array;
size_t m_size { 0 };
};
struct StackShotHash {
static unsigned hash(const StackShot& shot) { return shot.hash(); }
static bool equal(const StackShot& a, const StackShot& b) { return a == b; }
static const bool safeToCompareToEmptyOrDeleted = false;
};
template<typename T> struct DefaultHash;
template<> struct DefaultHash<StackShot> {
typedef StackShotHash Hash;
};
template<> struct HashTraits<StackShot> : SimpleClassHashTraits<StackShot> { };
}