perf: call reserve method in set and map casters (#4194)

* Call reserve method in set and map casters too

* Refactor template logic into has_reserve_method

* Adjust comment for reviews

* Rearrange reserve_maybe to not be underneath macro
This commit is contained in:
Aaron Gokaslan 2022-09-25 16:10:57 -04:00 committed by GitHub
parent f743bdf8e6
commit 5aa0fad5de
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@ -49,17 +49,31 @@ constexpr forwarded_type<T, U> forward_like(U &&u) {
return std::forward<detail::forwarded_type<T, U>>(std::forward<U>(u));
}
// Checks if a container has a STL style reserve method.
// This will only return true for a `reserve()` with a `void` return.
template <typename C>
using has_reserve_method = std::is_same<decltype(std::declval<C>().reserve(0)), void>;
template <typename Type, typename Key>
struct set_caster {
using type = Type;
using key_conv = make_caster<Key>;
private:
template <typename T = Type, enable_if_t<has_reserve_method<T>::value, int> = 0>
void reserve_maybe(const anyset &s, Type *) {
value.reserve(s.size());
}
void reserve_maybe(const anyset &, void *) {}
public:
bool load(handle src, bool convert) {
if (!isinstance<anyset>(src)) {
return false;
}
auto s = reinterpret_borrow<anyset>(src);
value.clear();
reserve_maybe(s, &value);
for (auto entry : s) {
key_conv conv;
if (!conv.load(entry, convert)) {
@ -94,12 +108,21 @@ struct map_caster {
using key_conv = make_caster<Key>;
using value_conv = make_caster<Value>;
private:
template <typename T = Type, enable_if_t<has_reserve_method<T>::value, int> = 0>
void reserve_maybe(const dict &d, Type *) {
value.reserve(d.size());
}
void reserve_maybe(const dict &, void *) {}
public:
bool load(handle src, bool convert) {
if (!isinstance<dict>(src)) {
return false;
}
auto d = reinterpret_borrow<dict>(src);
value.clear();
reserve_maybe(d, &value);
for (auto it : d) {
key_conv kconv;
value_conv vconv;
@ -160,9 +183,7 @@ struct list_caster {
}
private:
template <
typename T = Type,
enable_if_t<std::is_same<decltype(std::declval<T>().reserve(0)), void>::value, int> = 0>
template <typename T = Type, enable_if_t<has_reserve_method<T>::value, int> = 0>
void reserve_maybe(const sequence &s, Type *) {
value.reserve(s.size());
}