factor/vm/generic_arrays.hpp

56 lines
1.6 KiB
C++

namespace factor {
template <typename Array> cell array_capacity(const Array* array) {
FACTOR_ASSERT(array->type() == Array::type_number);
return array->capacity >> TAG_BITS;
}
template <typename Array> cell array_size(cell capacity) {
return sizeof(Array) + capacity * Array::element_size;
}
template <typename Array> cell array_size(Array* array) {
return array_size<Array>(array_capacity(array));
}
// Allocates memory
template <typename Array>
Array* factor_vm::allot_uninitialized_array(cell capacity) {
Array* array = allot<Array>(array_size<Array>(capacity));
array->capacity = tag_fixnum(capacity);
return array;
}
template <typename Array>
bool factor_vm::reallot_array_in_place_p(Array* array, cell capacity) {
return data->nursery->contains_p(array) &&
capacity <= array_capacity(array);
}
// Allocates memory (sometimes)
template <typename Array>
Array* factor_vm::reallot_array(Array* array_, cell capacity) {
data_root<Array> array(array_, this);
if (array_capacity(array.untagged()) == capacity)
return array.untagged();
if (reallot_array_in_place_p(array.untagged(), capacity)) {
array->capacity = tag_fixnum(capacity);
return array.untagged();
}
cell to_copy = array_capacity(array.untagged());
if (capacity < to_copy)
to_copy = capacity;
Array* new_array = allot_uninitialized_array<Array>(capacity);
memcpy(new_array + 1, array.untagged() + 1, to_copy * Array::element_size);
memset((char*)(new_array + 1) + to_copy * Array::element_size, 0,
(capacity - to_copy) * Array::element_size);
return new_array;
}
}