You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
82 lines
2.1 KiB
82 lines
2.1 KiB
// find_univpoly_ring().
|
|
|
|
// General includes.
|
|
#include "cl_sysdep.h"
|
|
|
|
// Specification.
|
|
#include "cln/univpoly.h"
|
|
|
|
|
|
// Implementation.
|
|
|
|
#include "cl_UP.h"
|
|
|
|
// The table of univariate polynomial rings without named variable.
|
|
// A weak hash table cl_ring -> cl_univpoly_ring.
|
|
// (It could also be a weak hashuniq table cl_ring -> cl_univpoly_ring.)
|
|
|
|
#include "cl_rcpointer_hashweak_rcpointer.h"
|
|
|
|
namespace cln {
|
|
|
|
// An entry can be collected when the value (the ring) isn't referenced any more
|
|
// except from the hash table, and when the key (the base ring) isn't referenced
|
|
// any more except from the hash table and the ring. Note that the ring contains
|
|
// exactly one reference to the base ring.
|
|
|
|
static bool maygc_htentry (const cl_htentry_from_rcpointer_to_rcpointer& entry)
|
|
{
|
|
if (!entry.key.pointer_p() || (entry.key.heappointer->refcount == 2))
|
|
if (!entry.val.pointer_p() || (entry.val.heappointer->refcount == 1))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
class univpoly_ring_cache
|
|
{
|
|
static cl_wht_from_rcpointer_to_rcpointer* univpoly_ring_table;
|
|
static int count;
|
|
public:
|
|
inline cl_univpoly_ring* get_univpoly_ring(const cl_ring& r)
|
|
{
|
|
return (cl_univpoly_ring*) univpoly_ring_table->get(r);
|
|
}
|
|
inline void store_univpoly_ring(const cl_univpoly_ring& R)
|
|
{
|
|
univpoly_ring_table->put(R->basering(), R);
|
|
}
|
|
univpoly_ring_cache();
|
|
~univpoly_ring_cache();
|
|
};
|
|
|
|
cl_wht_from_rcpointer_to_rcpointer* univpoly_ring_cache::univpoly_ring_table = 0;
|
|
int univpoly_ring_cache::count = 0;
|
|
|
|
univpoly_ring_cache::univpoly_ring_cache()
|
|
{
|
|
if (count++ == 0)
|
|
univpoly_ring_table = new cl_wht_from_rcpointer_to_rcpointer(maygc_htentry);
|
|
}
|
|
|
|
univpoly_ring_cache::~univpoly_ring_cache()
|
|
{
|
|
if (--count == 0)
|
|
delete univpoly_ring_table;
|
|
}
|
|
|
|
const cl_univpoly_ring find_univpoly_ring (const cl_ring& r)
|
|
{
|
|
static univpoly_ring_cache cache;
|
|
var cl_univpoly_ring* ring_in_table = cache.get_univpoly_ring(r);
|
|
if (!ring_in_table) {
|
|
var cl_univpoly_ring R = cl_make_univpoly_ring(r);
|
|
cache.store_univpoly_ring(R);
|
|
ring_in_table = cache.get_univpoly_ring(r);
|
|
if (!ring_in_table)
|
|
throw runtime_exception();
|
|
}
|
|
return *ring_in_table;
|
|
}
|
|
|
|
} // namespace cln
|
|
|