*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#define HASHTABLE_SIZE_N (sizeof(hashtable_size)/sizeof(unsigned long))
-/* Turn an empty vector hash table into an opaque resizable one. */
-
static char *s_hashtable = "hashtable";
SCM weak_hashtables = SCM_EOL;
static SCM
-make_hash_table (int flags, unsigned long k, const char *func_name) {
+make_hash_table (int flags, unsigned long k, const char *func_name)
+{
SCM table, vector;
scm_t_hashtable *t;
int i = 0, n = k ? k : 31;
t->lower = 0;
t->upper = 9 * n / 10;
t->flags = flags;
+ t->hash_fn = NULL;
if (flags)
{
SCM_NEWSMOB3 (table, scm_tc16_hashtable, vector, t, weak_hashtables);
return table;
}
-
void
scm_i_rehash (SCM table,
unsigned long (*hash_fn)(),
if (i >= HASHTABLE_SIZE_N)
/* don't rehash */
return;
- /* store for use in rehash_after_gc */
- SCM_HASHTABLE (table)->hash_fn = hash_fn;
- SCM_HASHTABLE (table)->closure = closure;
+
+ /* Remember HASH_FN for rehash_after_gc, but only when CLOSURE
+ is not needed since CLOSURE can not be guaranteed to be valid
+ after this function returns.
+ */
+ if (closure == NULL)
+ SCM_HASHTABLE (table)->hash_fn = hash_fn;
}
SCM_HASHTABLE (table)->size_index = i;
else
new_buckets = scm_c_make_vector (new_size, SCM_EOL);
+ /* When this is a weak hashtable, running the GC might change it.
+ We need to cope with this while rehashing its elements. We do
+ this by first installing the new, empty bucket vector and turning
+ the old bucket vector into a regularily scanned weak vector.
+ Then we remove the elements from the old bucket vector and insert
+ them into the new one.
+ */
+
+ SCM_SET_HASHTABLE_VECTOR (table, new_buckets);
+ SCM_SET_HASHTABLE_N_ITEMS (table, 0);
+ if (SCM_HASHTABLE_WEAK_P (table))
+ SCM_I_SET_WVECT_TYPE (buckets, (SCM_HASHTABLE_FLAGS (table)));
+
old_size = SCM_SIMPLE_VECTOR_LENGTH (buckets);
for (i = 0; i < old_size; ++i)
{
- SCM ls = SCM_SIMPLE_VECTOR_REF (buckets, i), handle;
- while (!scm_is_null (ls))
+ SCM ls, cell, handle;
+
+ ls = SCM_SIMPLE_VECTOR_REF (buckets, i);
+ SCM_SIMPLE_VECTOR_SET (buckets, i, SCM_EOL);
+
+ while (scm_is_pair (ls))
{
unsigned long h;
- handle = SCM_CAR (ls);
+ cell = ls;
+ handle = SCM_CAR (cell);
+ ls = SCM_CDR (ls);
h = hash_fn (SCM_CAR (handle), new_size, closure);
if (h >= new_size)
scm_out_of_range (func_name, scm_from_ulong (h));
- SCM_SIMPLE_VECTOR_SET
- (new_buckets, h,
- scm_cons (handle,
- SCM_SIMPLE_VECTOR_REF (new_buckets, h)));
- ls = SCM_CDR (ls);
+ SCM_SETCDR (cell, SCM_SIMPLE_VECTOR_REF (new_buckets, h));
+ SCM_SIMPLE_VECTOR_SET (new_buckets, h, cell);
+ SCM_HASHTABLE_INCREMENT (table);
}
}
- SCM_SET_HASHTABLE_VECTOR (table, new_buckets);
}
h = first;
do
{
- scm_i_rehash (h,
- /* use same hash_fn and closure as last time */
- SCM_HASHTABLE (h)->hash_fn,
- SCM_HASHTABLE (h)->closure,
- "rehash_after_gc");
+ /* Rehash only when we have a hash_fn.
+ */
+ if (SCM_HASHTABLE (h)->hash_fn)
+ scm_i_rehash (h, SCM_HASHTABLE (h)->hash_fn, NULL,
+ "rehash_after_gc");
last = h;
h = SCM_HASHTABLE_NEXT (h);
} while (!scm_is_null (h));
SCM_DEFINE (scm_make_hash_table, "make-hash-table", 0, 1, 0,
(SCM n),
- "Make a hash table with optional minimum number of buckets @var{n}\n")
+ "Make a new abstract hash table object with minimum number of buckets @var{n}\n")
#define FUNC_NAME s_scm_make_hash_table
{
if (SCM_UNBNDP (n))
(SCM n),
"@deffnx {Scheme Procedure} make-weak-value-hash-table size\n"
"@deffnx {Scheme Procedure} make-doubly-weak-hash-table size\n"
- "Return a weak hash table with @var{size} buckets. As with any\n"
- "hash table, choosing a good size for the table requires some\n"
- "caution.\n"
+ "Return a weak hash table with @var{size} buckets.\n"
"\n"
"You can modify weak hash tables in exactly the same way you\n"
"would modify regular hash tables. (@pxref{Hash Tables})")
SCM_DEFINE (scm_hash_table_p, "hash-table?", 1, 0, 0,
(SCM obj),
- "Return @code{#t} if @var{obj} is a hash table.")
+ "Return @code{#t} if @var{obj} is an abstract hash table object.")
#define FUNC_NAME s_scm_hash_table_p
{
return scm_from_bool (SCM_HASHTABLE_P (obj));
return it;
else
{
- SCM old_bucket = SCM_SIMPLE_VECTOR_REF (buckets, k);
- SCM new_bucket = scm_acons (obj, init, old_bucket);
+ /* When this is a weak hashtable, running the GC can change it.
+ Thus, we must allocate the new cells first and can only then
+ access BUCKETS. Also, we need to fetch the bucket vector
+ again since the hashtable might have been rehashed. This
+ necessitates a new hash value as well.
+ */
+ SCM new_bucket = scm_acons (obj, init, SCM_EOL);
+ if (!scm_is_eq (table, buckets)
+ && !scm_is_eq (SCM_HASHTABLE_VECTOR (table), buckets))
+ {
+ buckets = SCM_HASHTABLE_VECTOR (table);
+ k = hash_fn (obj, SCM_SIMPLE_VECTOR_LENGTH (buckets), closure);
+ if (k >= SCM_SIMPLE_VECTOR_LENGTH (buckets))
+ scm_out_of_range ("hash_fn_create_handle_x", scm_from_ulong (k));
+ }
+ SCM_SETCDR (new_bucket, SCM_SIMPLE_VECTOR_REF (buckets, k));
SCM_SIMPLE_VECTOR_SET (buckets, k, new_bucket);
- if (table != buckets)
+ if (!scm_is_eq (table, buckets))
{
+ /* Update element count and maybe rehash the table. The
+ table might have too few entries here since weak hash
+ tables used with the hashx_* functions can not be
+ rehashed after GC.
+ */
SCM_HASHTABLE_INCREMENT (table);
- if (SCM_HASHTABLE_N_ITEMS (table) > SCM_HASHTABLE_UPPER (table))
+ if (SCM_HASHTABLE_N_ITEMS (table) < SCM_HASHTABLE_LOWER (table)
+ || SCM_HASHTABLE_N_ITEMS (table) > SCM_HASHTABLE_UPPER (table))
scm_i_rehash (table, hash_fn, closure, FUNC_NAME);
}
return SCM_CAR (new_bucket);
}
-
-
-
SCM
-scm_hash_fn_remove_x (SCM table, SCM obj, unsigned long (*hash_fn)(), SCM (*assoc_fn)(),
- SCM (*delete_fn)(), void * closure)
+scm_hash_fn_remove_x (SCM table, SCM obj,
+ unsigned long (*hash_fn)(),
+ SCM (*assoc_fn)(),
+ void *closure)
{
unsigned long k;
SCM buckets, h;
if (scm_is_true (h))
{
SCM_SIMPLE_VECTOR_SET
- (buckets, k,
- delete_fn (h, SCM_SIMPLE_VECTOR_REF (buckets, k)));
- if (table != buckets)
+ (buckets, k, scm_delq_x (h, SCM_SIMPLE_VECTOR_REF (buckets, k)));
+ if (!scm_is_eq (table, buckets))
{
SCM_HASHTABLE_DECREMENT (table);
if (SCM_HASHTABLE_N_ITEMS (table) < SCM_HASHTABLE_LOWER (table))
SCM_DEFINE (scm_hash_clear_x, "hash-clear!", 1, 0, 0,
(SCM table),
- "Remove all items from TABLE (without triggering a resize).")
+ "Remove all items from @var{table} (without triggering a resize).")
#define FUNC_NAME s_scm_hash_clear_x
{
- SCM_VALIDATE_HASHTABLE (1, table);
- scm_vector_fill_x (SCM_HASHTABLE_VECTOR (table), SCM_EOL);
- SCM_SET_HASHTABLE_N_ITEMS (table, 0);
+ if (SCM_HASHTABLE_P (table))
+ {
+ scm_vector_fill_x (SCM_HASHTABLE_VECTOR (table), SCM_EOL);
+ SCM_SET_HASHTABLE_N_ITEMS (table, 0);
+ }
+ else
+ scm_vector_fill_x (table, SCM_EOL);
return SCM_UNSPECIFIED;
}
#undef FUNC_NAME
"@var{table}. Uses @code{eq?} for equality tests.")
#define FUNC_NAME s_scm_hashq_remove_x
{
- return scm_hash_fn_remove_x (table, key, scm_ihashq, scm_sloppy_assq,
- scm_delq_x, 0);
+ return scm_hash_fn_remove_x (table, key, scm_ihashq, scm_sloppy_assq, 0);
}
#undef FUNC_NAME
"@var{table}. Uses @code{eqv?} for equality tests.")
#define FUNC_NAME s_scm_hashv_remove_x
{
- return scm_hash_fn_remove_x (table, key, scm_ihashv, scm_sloppy_assv,
- scm_delv_x, 0);
+ return scm_hash_fn_remove_x (table, key, scm_ihashv, scm_sloppy_assv, 0);
}
#undef FUNC_NAME
"@var{table}. Uses @code{equal?} for equality tests.")
#define FUNC_NAME s_scm_hash_remove_x
{
- return scm_hash_fn_remove_x (table, key, scm_ihash, scm_sloppy_assoc,
- scm_delete_x, 0);
+ return scm_hash_fn_remove_x (table, key, scm_ihash, scm_sloppy_assoc, 0);
}
#undef FUNC_NAME
{
SCM hash;
SCM assoc;
- SCM delete;
} scm_t_ihashx_closure;
}
-
-
-static SCM
-scm_delx_x (SCM obj, SCM alist, scm_t_ihashx_closure *closure)
-{
- return scm_call_2 (closure->delete, obj, alist);
-}
-
-
-
SCM_DEFINE (scm_hashx_get_handle, "hashx-get-handle", 4, 0, 0,
(SCM hash, SCM assoc, SCM table, SCM key),
"This behaves the same way as the corresponding\n"
}
#undef FUNC_NAME
-
-
-SCM
-scm_hashx_remove_x (SCM hash, SCM assoc, SCM delete, SCM table, SCM obj)
+SCM_DEFINE (scm_hashx_remove_x, "hashx-remove!", 4, 0, 0,
+ (SCM hash, SCM assoc, SCM table, SCM obj),
+ "This behaves the same way as the corresponding @code{remove!}\n"
+ "function, but uses @var{hash} as a hash function and\n"
+ "@var{assoc} to compare keys. @code{hash} must be a function\n"
+ "that takes two arguments, a key to be hashed and a table size.\n"
+ "@code{assoc} must be an associator function, like @code{assoc},\n"
+ "@code{assq} or @code{assv}.\n"
+ "\n"
+ " By way of illustration, @code{hashq-remove! table key} is\n"
+ "equivalent to @code{hashx-remove! hashq assq #f table key}.")
+#define FUNC_NAME s_scm_hashx_remove_x
{
scm_t_ihashx_closure closure;
closure.hash = hash;
closure.assoc = assoc;
- closure.delete = delete;
- return scm_hash_fn_remove_x (table, obj, scm_ihashx, scm_sloppy_assx, scm_delx_x, 0);
+ return scm_hash_fn_remove_x (table, obj, scm_ihashx, scm_sloppy_assx,
+ (void *) &closure);
}
+#undef FUNC_NAME
/* Hash table iterators */
HCoop / bpt / guile.git / blobdiff