ArrayData* StructArray::CopyWithStrongIterators(const ArrayData* ad) {
auto const cpy = Copy(ad);
if (LIKELY(strong_iterators_exist())) {
// This returns its first argument just so we can tail call it.
return move_strong_iterators(cpy, const_cast<ArrayData*>(ad));
}
return cpy;
}
NEVER_INLINE
ArrayData* PackedArray::Grow(ArrayData* old) {
assert(checkInvariants(old));
assert(old->m_size == old->m_packedCap);
DEBUG_ONLY auto const oldPos = old->m_pos;
auto const oldCap = old->m_packedCap;
auto const cap = oldCap * 2;
if (UNLIKELY(cap >= kMaxPackedCap)) return nullptr;
auto const ad = static_cast<ArrayData*>(
MM().objMallocLogged(sizeof(ArrayData) + cap * sizeof(TypedValue))
);
auto const oldSize = old->m_size;
auto const oldPosUnsigned = uint64_t{static_cast<uint32_t>(old->m_pos)};
ad->m_kindAndSize = uint64_t{oldSize} << 32 | cap;
ad->m_posAndCount = oldPosUnsigned;
if (UNLIKELY(strong_iterators_exist())) {
move_strong_iterators(ad, old);
}
// Steal the old array payload. At the time of this writing, it was
// better not to reuse the memcpy return value here because gcc had
// `ad' in a callee saved register anyway. The reg-to-reg move was
// smaller than subtracting sizeof(ArrayData) from rax to return.
old->m_size = 0;
std::memcpy(packedData(ad), packedData(old), oldSize * sizeof(TypedValue));
// TODO(#2926276): it would be good to refactor callers to expect
// our refcount to start at 1.
assert(ad->m_kind == ArrayData::kPackedKind);
assert(ad->m_pos == oldPos);
assert(ad->m_count == 0);
assert(ad->m_packedCap == cap);
assert(ad->m_size == oldSize);
assert(checkInvariants(ad));
return ad;
}
StructArray* StructArray::Grow(StructArray* old, Shape* newShape) {
assert(old->shape()->transitionRequiresGrowth());
auto result = StructArray::create(newShape, old->data(),
old->shape()->size());
result->m_size = newShape->size();
if (UNLIKELY(strong_iterators_exist())) {
move_strong_iterators(result, old);
}
old->m_size = 0;
if (debug) {
// For debug builds, set m_pos to 0 as well to make the
// asserts in checkInvariants() happy.
old->m_pos = 0;
}
assert(result->hasExactlyOneRef());
return result;
}