[k2] prevent copying of array in some cases (#1431)

Author: apolyakov

runtime-light/state/component-state.cpp

@@ -27,7 +27,7 @@ void set_reference_counter_recursive(mixed obj, ExtraRefCnt rc) noexcept {
   switch (obj.get_type()) {
   case mixed::type::ARRAY:
     obj.set_reference_counter_to(rc);
-    for (const auto& it : obj.as_array()) {
+    for (const auto& it : std::as_const(obj.as_array())) {
       set_reference_counter_recursive(it.get_key(), rc);
       set_reference_counter_recursive(it.get_value(), rc);
     }

runtime-light/stdlib/fork/fork-functions.h

@@ -142,7 +142,7 @@ inline kphp::coro::task<bool> f$wait_concurrently(const mixed& fork_id) noexcept
 template<typename T>
 kphp::coro::task<T> f$wait_multi(array<int64_t> fork_ids) noexcept {
   T res{};
-  for (const auto& it : fork_ids) {
+  for (const auto& it : std::as_const(fork_ids)) {
     res.set_value(it.get_key(), co_await f$wait<typename T::value_type>(it.get_value()));
   }
   co_return std::move(res);

runtime-light/stdlib/rpc/rpc-api.h

@@ -238,7 +238,7 @@ inline kphp::coro::task<array<int64_t>> f$rpc_send_requests(string actor, array<
   array<kphp::rpc::request_extra_info> req_extra_info_arr{tl_objects.size()};
   auto opt_timeout{timeout.has_value() ? std::optional<double>{timeout.val()} : std::optional<double>{}};
 
-  for (const auto& it : tl_objects) {
+  for (const auto& it : std::as_const(tl_objects)) {
     const auto query_info{co_await kphp::forks::id_managed(
         kphp::rpc::detail::rpc_tl_query_one_impl({actor.c_str(), actor.size()}, it.get_value(), opt_timeout, collect_resp_extra_info, ignore_answer))};
     query_ids.set_value(it.get_key(), query_info.id);
@@ -253,7 +253,7 @@ inline kphp::coro::task<array<int64_t>> f$rpc_send_requests(string actor, array<
 
 inline kphp::coro::task<array<array<mixed>>> f$rpc_fetch_responses(array<int64_t> query_ids) noexcept {
   array<array<mixed>> res{query_ids.size()};
-  for (const auto& it : query_ids) {
+  for (const auto& it : std::as_const(query_ids)) {
     res.set_value(it.get_key(), co_await kphp::forks::id_managed(kphp::rpc::detail::rpc_tl_query_result_one_impl(it.get_value())));
   }
   co_return std::move(res);
@@ -288,7 +288,7 @@ kphp::coro::task<array<int64_t>> f$rpc_send_typed_query_requests(string actor, a
   array<kphp::rpc::request_extra_info> req_extra_info_arr{query_functions.size()};
   auto opt_timeout{timeout.has_value() ? std::optional<double>{timeout.val()} : std::optional<double>{}};
 
-  for (const auto& it : query_functions) {
+  for (const auto& it : std::as_const(query_functions)) {
     const auto query_info{co_await kphp::forks::id_managed(kphp::rpc::detail::typed_rpc_tl_query_one_impl(
         {actor.c_str(), actor.size()}, rpc_request_t{it.get_value()}, opt_timeout, collect_resp_extra_info, ignore_answer))};
     query_ids.set_value(it.get_key(), query_info.id);
@@ -305,7 +305,7 @@ template<std::same_as<int64_t> query_id_t = int64_t, std::same_as<RpcResponseErr
 requires std::default_initializable<error_factory_t>
 kphp::coro::task<array<class_instance<C$VK$TL$RpcResponse>>> f$rpc_fetch_typed_responses(array<query_id_t> query_ids) noexcept {
   array<class_instance<C$VK$TL$RpcResponse>> res{query_ids.size()};
-  for (const auto& it : query_ids) {
+  for (const auto& it : std::as_const(query_ids)) {
     res.set_value(it.get_key(), co_await kphp::forks::id_managed(kphp::rpc::detail::typed_rpc_tl_query_result_one_impl(it.get_value(), error_factory_t{})));
   }
   co_return std::move(res);

runtime-light/stdlib/string/regex-functions.cpp

@@ -15,6 +15,7 @@
 #include <optional>
 #include <string_view>
 #include <type_traits>
+#include <utility>
 #include <variant>
 
 #include "common/containers/final_action.h"
@@ -406,7 +407,7 @@ PCRE2_SIZE set_all_matches(const RegexInfo& regex_info, int64_t flags, std::opti
 
   mixed& all_matches{(*opt_all_matches).get()};
   if (pattern_order) [[likely]] {
-    for (auto& it : matches) {
+    for (auto& it : std::as_const(matches)) {
       all_matches[it.get_key()].push_back(it.get_value());
     }
   } else {

runtime-light/stdlib/string/regex-functions.h

@@ -106,7 +106,7 @@ kphp::coro::task<Optional<string>> f$preg_replace_callback(string pattern, F cal
     }
 
     matches = array<string>{mixed_matches.as_array().size()};
-    for (auto& elem : mixed_matches.as_array()) {
+    for (auto& elem : std::as_const(mixed_matches.as_array())) {
       matches.set_value(elem.get_key(), std::move(elem.get_value().as_string()));
     }
   }