factor/vm/generic_arrays.hpp

65 lines
1.6 KiB
C++

namespace factor
{
template<typename Array> cell array_capacity(const Array *array)
{
#ifdef FACTOR_DEBUG
FACTOR_ASSERT(array->type() == Array::type_number);
#endif
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 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();
}
else
{
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;
}
}
}