distinguished estimate_memory_usage and `calculate_memory_for_copyi…

…ng` for arrays

runtime/array.inl

@@ -615,6 +615,16 @@ size_t array<T>::array_inner::estimate_memory_usage() const noexcept {
   return is_vector() ? sizeof_vector(buf_size) : sizeof_map(buf_size);
 }
 
+template<class T>
+size_t array<T>::array_inner::calculate_memory_for_copying() const noexcept {
+  int64_t int_elements = size;
+  const bool vector_structure = is_vector();
+  if (vector_structure) {
+    return estimate_size(int_elements, vector_structure);
+  }
+  return estimate_size(++int_elements, vector_structure);
+}
+
 template<class T>
 bool array<T>::is_vector() const {
   return p->is_vector();
@@ -780,6 +790,11 @@ size_t array<T>::estimate_memory_usage() const noexcept {
   return p->estimate_memory_usage();
 }
 
+template<class T>
+size_t array<T>::calculate_memory_for_copying() const noexcept {
+  return p->calculate_memory_for_copying();
+}
+
 template<class T>
 typename array<T>::const_iterator array<T>::cbegin() const {
   return const_iterator::make_begin(*this);

runtime/array_decl.inl

@@ -177,6 +177,7 @@ private:
     bool has_no_string_keys() const noexcept;
 
     size_t estimate_memory_usage() const noexcept;
+    size_t calculate_memory_for_copying() const noexcept;
 
     inline array_inner(const array_inner &other) = delete;
     inline array_inner &operator=(const array_inner &other) = delete;
@@ -418,6 +419,7 @@ public:
   void reserve(int64_t int_size, bool make_vector_if_possible);
 
   size_t estimate_memory_usage() const noexcept;
+  size_t calculate_memory_for_copying() const noexcept;
 
   template<typename U>
   static array<T> convert_from(const array<U> &);

runtime/instance-copy-processor.cpp

@@ -20,6 +20,8 @@ bool InstanceDeepCopyVisitor::process(string &str) noexcept {
     return true;
   }
 
+  // TODO: it seems we can use `str.estimate_memory_usage(str.size())` here,
+  //  because we don't need to take capacity into the account, only size.
   if (unlikely(!is_enough_memory_for(str.estimate_memory_usage()))) {
     str = string();
     memory_limit_exceeded_ = true;

runtime/instance-copy-processor.h

@@ -249,7 +249,7 @@ class InstanceDeepCopyVisitor : impl_::InstanceDeepBasicVisitor<InstanceDeepCopy
     if (arr.is_reference_counter(ExtraRefCnt::for_global_const)) {
       return true;
     }
-    if (unlikely(!is_enough_memory_for(arr.estimate_memory_usage()))) {
+    if (unlikely(!is_enough_memory_for(arr.calculate_memory_for_copying()))) {
       arr = array<T>();
       memory_limit_exceeded_ = true;
       return false;