object-introspection/types/small_vec_type.toml

[info]
type_name = "folly::small_vector"
ctype = "SMALL_VEC_TYPE"
header = "folly/small_vector.h"
stub_template_params = [2]

# Old:
typeName = "folly::small_vector<"
ns = ["folly::small_vector_policy::policy_size_type", "folly::small_vector"]
numTemplateParams = 1
replaceTemplateParamIndex = []

[codegen]
decl = """
template <class V, std::size_t N, class P>
void getSizeType(const %1%<V, N, P> &container, size_t& returnArg);
"""

func = """
template <class V, std::size_t N, class P>
void getSizeType(const %1%<V, N, P> &container, size_t& returnArg)
{
    SAVE_SIZE(sizeof(%1%<V, N, P>));

    bool dataInlined = isStorageInline(container);

    if (dataInlined) {
      // Don't double count inlined elements
      SAVE_SIZE(-(container.size() * sizeof(V)));
    } else {
      // Account for wasted space in the buffer
      SAVE_SIZE((container.capacity() - container.size()) * sizeof(V));
    }

    SAVE_DATA((uintptr_t)(N));
    SAVE_DATA((uintptr_t)container.capacity());
    SAVE_DATA((uintptr_t)container.size());

    for (auto & it: container) {
        getSizeType(it, returnArg);
    }
}
"""

traversal_func = """
bool uses_intern_storage = isStorageInline(container);

auto tail = returnArg
  .write((uintptr_t)uses_intern_storage)
  .write(container.capacity())
  .write(container.size());

for (auto &&it: container) {
  tail = tail.delegate([&ctx, &it](typename TypeHandler<Ctx, T0>::type ret) {
    return OIInternal::getSizeType<Ctx>(ctx, it, ret);
  });
}

return tail.finish();
"""

[[codegen.processor]]
type = "types::st::VarInt<DB>"
func = """
// Using the container's pointer to temporarily store the uses_intern_storage boolean.
// TODO: Is there another way to pass a value across processors?
el.pointer = std::get<ParsedData::VarInt>(d.val).value;
"""

[[codegen.processor]]
type = "types::st::VarInt<DB>"
func = """
el.container_stats.emplace(result::Element::ContainerStats {
  .capacity = std::get<ParsedData::VarInt>(d.val).value,
});
"""

[[codegen.processor]]
type = "types::st::List<DB, typename TypeHandler<Ctx, T0>::type>"
func = """
// Reading the `uses_intern_storage` boolean that was stored in `pointer` by the processor above.
bool uses_intern_storage = std::exchange(el.pointer.value(), (uintptr_t)0);

auto list = std::get<ParsedData::List>(d.val);
el.container_stats->length = list.length;

if (uses_intern_storage) {
  // The storage is inlined, so don't double count for items using the intern storage.
  el.exclusive_size -= list.length * sizeof(T0);
} else {
  // The storage is heap allocated, so add any unused capacity.
  el.exclusive_size += (el.container_stats->capacity - el.container_stats->length) * sizeof(T0);
}

static constexpr auto childField = make_field<Ctx, T0>("[]");
for (size_t i = 0; i < list.length; i++)
  stack_ins(childField);
"""