You should have received a copy of the GNU Library General Public
License along with libiberty; see the file COPYING.LIB. If
-not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
+not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
+Boston, MA 02110-1301, USA. */
/* This package implements basic hash table functionality. It is possible
to search for an entry, create an entry and destroy an entry.
#define CHAR_BIT 8
#endif
-/* This macro defines reserved value for empty table entry. */
-
-#define EMPTY_ENTRY ((PTR) 0)
-
-/* This macro defines reserved value for table entry which contained
- a deleted element. */
-
-#define DELETED_ENTRY ((PTR) 1)
-
-static unsigned int higher_prime_index PARAMS ((unsigned long));
-static hashval_t htab_mod_1 PARAMS ((hashval_t, hashval_t, hashval_t, int));
-static hashval_t htab_mod PARAMS ((hashval_t, htab_t));
-static hashval_t htab_mod_m2 PARAMS ((hashval_t, htab_t));
-static hashval_t hash_pointer PARAMS ((const void *));
-static int eq_pointer PARAMS ((const void *, const void *));
-static int htab_expand PARAMS ((htab_t));
-static PTR *find_empty_slot_for_expand PARAMS ((htab_t, hashval_t));
+static unsigned int higher_prime_index (unsigned long);
+static hashval_t htab_mod_1 (hashval_t, hashval_t, hashval_t, int);
+static hashval_t htab_mod (hashval_t, htab_t);
+static hashval_t htab_mod_m2 (hashval_t, htab_t);
+static hashval_t hash_pointer (const void *);
+static int eq_pointer (const void *, const void *);
+static int htab_expand (htab_t);
+static PTR *find_empty_slot_for_expand (htab_t, hashval_t);
/* At some point, we could make these be NULL, and modify the
hash-table routines to handle NULL specially; that would avoid
nearest prime number which is greater than N, and near a power of two. */
static unsigned int
-higher_prime_index (n)
- unsigned long n;
+higher_prime_index (unsigned long n)
{
unsigned int low = 0;
unsigned int high = sizeof(prime_tab) / sizeof(prime_tab[0]);
/* Returns a hash code for P. */
static hashval_t
-hash_pointer (p)
- const PTR p;
+hash_pointer (const PTR p)
{
return (hashval_t) ((long)p >> 3);
}
/* Returns non-zero if P1 and P2 are equal. */
static int
-eq_pointer (p1, p2)
- const PTR p1;
- const PTR p2;
+eq_pointer (const PTR p1, const PTR p2)
{
return p1 == p2;
}
-/* Return the current size of given hash table. */
-inline size_t
-htab_size (htab)
- htab_t htab;
+/* The parens around the function names in the next two definitions
+ are essential in order to prevent macro expansions of the name.
+ The bodies, however, are expanded as expected, so they are not
+ recursive definitions. */
+
+/* Return the current size of given hash table. */
+
+#define htab_size(htab) ((htab)->size)
+
+size_t
+(htab_size) (htab_t htab)
{
- return htab->size;
+ return htab_size (htab);
}
/* Return the current number of elements in given hash table. */
-inline size_t
-htab_elements (htab)
- htab_t htab;
+#define htab_elements(htab) ((htab)->n_elements - (htab)->n_deleted)
+
+size_t
+(htab_elements) (htab_t htab)
{
- return htab->n_elements - htab->n_deleted;
+ return htab_elements (htab);
}
/* Return X % Y. */
static inline hashval_t
-htab_mod_1 (x, y, inv, shift)
- hashval_t x, y, inv;
- int shift;
+htab_mod_1 (hashval_t x, hashval_t y, hashval_t inv, int shift)
{
/* The multiplicative inverses computed above are for 32-bit types, and
requires that we be able to compute a highpart multiply. */
/* Compute the primary hash for HASH given HTAB's current size. */
static inline hashval_t
-htab_mod (hash, htab)
- hashval_t hash;
- htab_t htab;
+htab_mod (hashval_t hash, htab_t htab)
{
const struct prime_ent *p = &prime_tab[htab->size_prime_index];
return htab_mod_1 (hash, p->prime, p->inv, p->shift);
/* Compute the secondary hash for HASH given HTAB's current size. */
static inline hashval_t
-htab_mod_m2 (hash, htab)
- hashval_t hash;
- htab_t htab;
+htab_mod_m2 (hashval_t hash, htab_t htab)
{
const struct prime_ent *p = &prime_tab[htab->size_prime_index];
return 1 + htab_mod_1 (hash, p->prime - 2, p->inv_m2, p->shift);
/* This function creates table with length slightly longer than given
source length. Created hash table is initiated as empty (all the
- hash table entries are EMPTY_ENTRY). The function returns the
+ hash table entries are HTAB_EMPTY_ENTRY). The function returns the
created hash table, or NULL if memory allocation fails. */
htab_t
-htab_create_alloc (size, hash_f, eq_f, del_f, alloc_f, free_f)
- size_t size;
- htab_hash hash_f;
- htab_eq eq_f;
- htab_del del_f;
- htab_alloc alloc_f;
- htab_free free_f;
+htab_create_alloc (size_t size, htab_hash hash_f, htab_eq eq_f,
+ htab_del del_f, htab_alloc alloc_f, htab_free free_f)
{
htab_t result;
unsigned int size_prime_index;
an extra argument. */
htab_t
-htab_create_alloc_ex (size, hash_f, eq_f, del_f, alloc_arg, alloc_f,
- free_f)
- size_t size;
- htab_hash hash_f;
- htab_eq eq_f;
- htab_del del_f;
- PTR alloc_arg;
- htab_alloc_with_arg alloc_f;
- htab_free_with_arg free_f;
+htab_create_alloc_ex (size_t size, htab_hash hash_f, htab_eq eq_f,
+ htab_del del_f, void *alloc_arg,
+ htab_alloc_with_arg alloc_f,
+ htab_free_with_arg free_f)
{
htab_t result;
unsigned int size_prime_index;
/* Update the function pointers and allocation parameter in the htab_t. */
void
-htab_set_functions_ex (htab, hash_f, eq_f, del_f, alloc_arg, alloc_f, free_f)
- htab_t htab;
- htab_hash hash_f;
- htab_eq eq_f;
- htab_del del_f;
- PTR alloc_arg;
- htab_alloc_with_arg alloc_f;
- htab_free_with_arg free_f;
+htab_set_functions_ex (htab_t htab, htab_hash hash_f, htab_eq eq_f,
+ htab_del del_f, PTR alloc_arg,
+ htab_alloc_with_arg alloc_f, htab_free_with_arg free_f)
{
htab->hash_f = hash_f;
htab->eq_f = eq_f;
#undef htab_create
htab_t
-htab_create (size, hash_f, eq_f, del_f)
- size_t size;
- htab_hash hash_f;
- htab_eq eq_f;
- htab_del del_f;
+htab_create (size_t size, htab_hash hash_f, htab_eq eq_f, htab_del del_f)
{
return htab_create_alloc (size, hash_f, eq_f, del_f, xcalloc, free);
}
htab_t
-htab_try_create (size, hash_f, eq_f, del_f)
- size_t size;
- htab_hash hash_f;
- htab_eq eq_f;
- htab_del del_f;
+htab_try_create (size_t size, htab_hash hash_f, htab_eq eq_f, htab_del del_f)
{
return htab_create_alloc (size, hash_f, eq_f, del_f, calloc, free);
}
Naturally the hash table must already exist. */
void
-htab_delete (htab)
- htab_t htab;
+htab_delete (htab_t htab)
{
size_t size = htab_size (htab);
PTR *entries = htab->entries;
if (htab->del_f)
for (i = size - 1; i >= 0; i--)
- if (entries[i] != EMPTY_ENTRY && entries[i] != DELETED_ENTRY)
+ if (entries[i] != HTAB_EMPTY_ENTRY && entries[i] != HTAB_DELETED_ENTRY)
(*htab->del_f) (entries[i]);
if (htab->free_f != NULL)
/* This function clears all entries in the given hash table. */
void
-htab_empty (htab)
- htab_t htab;
+htab_empty (htab_t htab)
{
size_t size = htab_size (htab);
PTR *entries = htab->entries;
if (htab->del_f)
for (i = size - 1; i >= 0; i--)
- if (entries[i] != EMPTY_ENTRY && entries[i] != DELETED_ENTRY)
+ if (entries[i] != HTAB_EMPTY_ENTRY && entries[i] != HTAB_DELETED_ENTRY)
(*htab->del_f) (entries[i]);
- memset (entries, 0, size * sizeof (PTR));
+ /* Instead of clearing megabyte, downsize the table. */
+ if (size > 1024*1024 / sizeof (PTR))
+ {
+ int nindex = higher_prime_index (1024 / sizeof (PTR));
+ int nsize = prime_tab[nindex].prime;
+
+ if (htab->free_f != NULL)
+ (*htab->free_f) (htab->entries);
+ else if (htab->free_with_arg_f != NULL)
+ (*htab->free_with_arg_f) (htab->alloc_arg, htab->entries);
+ if (htab->alloc_with_arg_f != NULL)
+ htab->entries = (PTR *) (*htab->alloc_with_arg_f) (htab->alloc_arg, nsize,
+ sizeof (PTR *));
+ else
+ htab->entries = (PTR *) (*htab->alloc_f) (nsize, sizeof (PTR *));
+ htab->size = nsize;
+ htab->size_prime_index = nindex;
+ }
+ else
+ memset (entries, 0, size * sizeof (PTR));
+ htab->n_deleted = 0;
+ htab->n_elements = 0;
}
/* Similar to htab_find_slot, but without several unwanted side effects:
HASH is the hash value for the element to be inserted. */
static PTR *
-find_empty_slot_for_expand (htab, hash)
- htab_t htab;
- hashval_t hash;
+find_empty_slot_for_expand (htab_t htab, hashval_t hash)
{
hashval_t index = htab_mod (hash, htab);
size_t size = htab_size (htab);
PTR *slot = htab->entries + index;
hashval_t hash2;
- if (*slot == EMPTY_ENTRY)
+ if (*slot == HTAB_EMPTY_ENTRY)
return slot;
- else if (*slot == DELETED_ENTRY)
+ else if (*slot == HTAB_DELETED_ENTRY)
abort ();
hash2 = htab_mod_m2 (hash, htab);
index -= size;
slot = htab->entries + index;
- if (*slot == EMPTY_ENTRY)
+ if (*slot == HTAB_EMPTY_ENTRY)
return slot;
- else if (*slot == DELETED_ENTRY)
+ else if (*slot == HTAB_DELETED_ENTRY)
abort ();
}
}
expanded. If all goes well, it will return a non-zero value. */
static int
-htab_expand (htab)
- htab_t htab;
+htab_expand (htab_t htab)
{
PTR *oentries;
PTR *olimit;
{
PTR x = *p;
- if (x != EMPTY_ENTRY && x != DELETED_ENTRY)
+ if (x != HTAB_EMPTY_ENTRY && x != HTAB_DELETED_ENTRY)
{
PTR *q = find_empty_slot_for_expand (htab, (*htab->hash_f) (x));
element. It cannot be used to insert or delete an element. */
PTR
-htab_find_with_hash (htab, element, hash)
- htab_t htab;
- const PTR element;
- hashval_t hash;
+htab_find_with_hash (htab_t htab, const PTR element, hashval_t hash)
{
hashval_t index, hash2;
size_t size;
index = htab_mod (hash, htab);
entry = htab->entries[index];
- if (entry == EMPTY_ENTRY
- || (entry != DELETED_ENTRY && (*htab->eq_f) (entry, element)))
+ if (entry == HTAB_EMPTY_ENTRY
+ || (entry != HTAB_DELETED_ENTRY && (*htab->eq_f) (entry, element)))
return entry;
hash2 = htab_mod_m2 (hash, htab);
index -= size;
entry = htab->entries[index];
- if (entry == EMPTY_ENTRY
- || (entry != DELETED_ENTRY && (*htab->eq_f) (entry, element)))
+ if (entry == HTAB_EMPTY_ENTRY
+ || (entry != HTAB_DELETED_ENTRY && (*htab->eq_f) (entry, element)))
return entry;
}
}
element. */
PTR
-htab_find (htab, element)
- htab_t htab;
- const PTR element;
+htab_find (htab_t htab, const PTR element)
{
return htab_find_with_hash (htab, element, (*htab->hash_f) (element));
}
/* This function searches for a hash table slot containing an entry
equal to the given element. To delete an entry, call this with
- INSERT = 0, then call htab_clear_slot on the slot returned (possibly
- after doing some checks). To insert an entry, call this with
- INSERT = 1, then write the value you want into the returned slot.
- When inserting an entry, NULL may be returned if memory allocation
- fails. */
+ insert=NO_INSERT, then call htab_clear_slot on the slot returned
+ (possibly after doing some checks). To insert an entry, call this
+ with insert=INSERT, then write the value you want into the returned
+ slot. When inserting an entry, NULL may be returned if memory
+ allocation fails. */
PTR *
-htab_find_slot_with_hash (htab, element, hash, insert)
- htab_t htab;
- const PTR element;
- hashval_t hash;
- enum insert_option insert;
+htab_find_slot_with_hash (htab_t htab, const PTR element,
+ hashval_t hash, enum insert_option insert)
{
PTR *first_deleted_slot;
hashval_t index, hash2;
first_deleted_slot = NULL;
entry = htab->entries[index];
- if (entry == EMPTY_ENTRY)
+ if (entry == HTAB_EMPTY_ENTRY)
goto empty_entry;
- else if (entry == DELETED_ENTRY)
+ else if (entry == HTAB_DELETED_ENTRY)
first_deleted_slot = &htab->entries[index];
else if ((*htab->eq_f) (entry, element))
return &htab->entries[index];
index -= size;
entry = htab->entries[index];
- if (entry == EMPTY_ENTRY)
+ if (entry == HTAB_EMPTY_ENTRY)
goto empty_entry;
- else if (entry == DELETED_ENTRY)
+ else if (entry == HTAB_DELETED_ENTRY)
{
if (!first_deleted_slot)
first_deleted_slot = &htab->entries[index];
if (first_deleted_slot)
{
htab->n_deleted--;
- *first_deleted_slot = EMPTY_ENTRY;
+ *first_deleted_slot = HTAB_EMPTY_ENTRY;
return first_deleted_slot;
}
element. */
PTR *
-htab_find_slot (htab, element, insert)
- htab_t htab;
- const PTR element;
- enum insert_option insert;
+htab_find_slot (htab_t htab, const PTR element, enum insert_option insert)
{
return htab_find_slot_with_hash (htab, element, (*htab->hash_f) (element),
insert);
element in the hash table, this function does nothing. */
void
-htab_remove_elt (htab, element)
- htab_t htab;
- PTR element;
+htab_remove_elt (htab_t htab, PTR element)
{
htab_remove_elt_with_hash (htab, element, (*htab->hash_f) (element));
}
function does nothing. */
void
-htab_remove_elt_with_hash (htab, element, hash)
- htab_t htab;
- PTR element;
- hashval_t hash;
+htab_remove_elt_with_hash (htab_t htab, PTR element, hashval_t hash)
{
PTR *slot;
slot = htab_find_slot_with_hash (htab, element, hash, NO_INSERT);
- if (*slot == EMPTY_ENTRY)
+ if (*slot == HTAB_EMPTY_ENTRY)
return;
if (htab->del_f)
(*htab->del_f) (*slot);
- *slot = DELETED_ENTRY;
+ *slot = HTAB_DELETED_ENTRY;
htab->n_deleted++;
}
again. */
void
-htab_clear_slot (htab, slot)
- htab_t htab;
- PTR *slot;
+htab_clear_slot (htab_t htab, PTR *slot)
{
if (slot < htab->entries || slot >= htab->entries + htab_size (htab)
- || *slot == EMPTY_ENTRY || *slot == DELETED_ENTRY)
+ || *slot == HTAB_EMPTY_ENTRY || *slot == HTAB_DELETED_ENTRY)
abort ();
if (htab->del_f)
(*htab->del_f) (*slot);
- *slot = DELETED_ENTRY;
+ *slot = HTAB_DELETED_ENTRY;
htab->n_deleted++;
}
argument. */
void
-htab_traverse_noresize (htab, callback, info)
- htab_t htab;
- htab_trav callback;
- PTR info;
+htab_traverse_noresize (htab_t htab, htab_trav callback, PTR info)
{
PTR *slot;
PTR *limit;
-
+
slot = htab->entries;
limit = slot + htab_size (htab);
{
PTR x = *slot;
- if (x != EMPTY_ENTRY && x != DELETED_ENTRY)
+ if (x != HTAB_EMPTY_ENTRY && x != HTAB_DELETED_ENTRY)
if (!(*callback) (slot, info))
break;
}
too empty to improve effectivity of subsequent calls. */
void
-htab_traverse (htab, callback, info)
- htab_t htab;
- htab_trav callback;
- PTR info;
+htab_traverse (htab_t htab, htab_trav callback, PTR info)
{
if (htab_elements (htab) * 8 < htab_size (htab))
htab_expand (htab);
hash table. */
double
-htab_collisions (htab)
- htab_t htab;
+htab_collisions (htab_t htab)
{
if (htab->searches == 0)
return 0.0;
function they just started using for Perl's hashes. */
hashval_t
-htab_hash_string (p)
- const PTR p;
+htab_hash_string (const PTR p)
{
const unsigned char *str = (const unsigned char *) p;
hashval_t r = 0;
--------------------------------------------------------------------
*/
-hashval_t iterative_hash (k_in, length, initval)
- const PTR k_in; /* the key */
- register size_t length; /* the length of the key */
- register hashval_t initval; /* the previous hash, or an arbitrary value */
+hashval_t
+iterative_hash (const PTR k_in /* the key */,
+ register size_t length /* the length of the key */,
+ register hashval_t initval /* the previous hash, or
+ an arbitrary value */)
{
register const unsigned char *k = (const unsigned char *)k_in;
register hashval_t a,b,c,len;
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