/* An expandable hash tables datatype.
- Copyright (C) 1999 Free Software Foundation, Inc.
+ Copyright (C) 1999, 2000, 2002, 2003, 2004, 2005, 2009
+ Free Software Foundation, Inc.
Contributed by Vladimir Makarov (vmakarov@cygnus.com).
This program is free software; you can redistribute it and/or modify
You should have received a copy of the GNU General Public License
along with this program; 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. */
/* This package implements basic hash table functionality. It is possible
to search for an entry, create an entry and destroy an entry.
extern "C" {
#endif /* __cplusplus */
-#include <ansidecl.h>
+#include "ansidecl.h"
-/* The hash table element is represented by the following type. */
+#ifndef GTY
+#define GTY(X)
+#endif
-typedef const void *hash_table_entry_t;
+/* The type for a hash code. */
+typedef unsigned int hashval_t;
+
+/* Callback function pointer types. */
+
+/* Calculate hash of a table entry. */
+typedef hashval_t (*htab_hash) (const void *);
+
+/* Compare a table entry with a possible entry. The entry already in
+ the table always comes first, so the second element can be of a
+ different type (but in this case htab_find and htab_find_slot
+ cannot be used; instead the variants that accept a hash value
+ must be used). */
+typedef int (*htab_eq) (const void *, const void *);
+
+/* Cleanup function called whenever a live element is removed from
+ the hash table. */
+typedef void (*htab_del) (void *);
+
+/* Function called by htab_traverse for each live element. The first
+ arg is the slot of the element (which can be passed to htab_clear_slot
+ if desired), the second arg is the auxiliary pointer handed to
+ htab_traverse. Return 1 to continue scan, 0 to stop. */
+typedef int (*htab_trav) (void **, void *);
+
+/* Memory-allocation function, with the same functionality as calloc().
+ Iff it returns NULL, the hash table implementation will pass an error
+ code back to the user, so if your code doesn't handle errors,
+ best if you use xcalloc instead. */
+typedef void *(*htab_alloc) (size_t, size_t);
+
+/* We also need a free() routine. */
+typedef void (*htab_free) (void *);
+
+/* Memory allocation and deallocation; variants which take an extra
+ argument. */
+typedef void *(*htab_alloc_with_arg) (void *, size_t, size_t);
+typedef void (*htab_free_with_arg) (void *, void *);
+
+/* This macro defines reserved value for empty table entry. */
+
+#define HTAB_EMPTY_ENTRY ((PTR) 0)
+
+/* This macro defines reserved value for table entry which contained
+ a deleted element. */
+
+#define HTAB_DELETED_ENTRY ((PTR) 1)
/* Hash tables are of the following type. The structure
(implementation) of this type is not needed for using the hash
tables. All work with hash table should be executed only through
- functions mentioned below. */
+ functions mentioned below. The size of this structure is subject to
+ change. */
+
+struct GTY(()) htab {
+ /* Pointer to hash function. */
+ htab_hash hash_f;
+
+ /* Pointer to comparison function. */
+ htab_eq eq_f;
-typedef struct
-{
- /* Current size (in entries) of the hash table */
+ /* Pointer to cleanup function. */
+ htab_del del_f;
+
+ /* Table itself. */
+ void ** GTY ((use_param, length ("%h.size"))) entries;
+
+ /* Current size (in entries) of the hash table. */
size_t size;
- /* Current number of elements including also deleted elements */
- size_t number_of_elements;
- /* Current number of deleted elements in the table */
- size_t number_of_deleted_elements;
+
+ /* Current number of elements including also deleted elements. */
+ size_t n_elements;
+
+ /* Current number of deleted elements in the table. */
+ size_t n_deleted;
+
/* The following member is used for debugging. Its value is number
- of all calls of `find_hash_table_entry' for the hash table. */
- int searches;
+ of all calls of `htab_find_slot' for the hash table. */
+ unsigned int searches;
+
/* The following member is used for debugging. Its value is number
of collisions fixed for time of work with the hash table. */
- int collisions;
- /* Pointer to function for evaluation of hash value (any unsigned value).
- This function has one parameter of type hash_table_entry_t. */
- unsigned (*hash_function) PARAMS ((hash_table_entry_t));
- /* Pointer to function for test on equality of hash table elements (two
- parameter of type hash_table_entry_t. */
- int (*eq_function) PARAMS ((hash_table_entry_t, hash_table_entry_t));
- /* Table itself */
- hash_table_entry_t *entries;
-} *hash_table_t;
+ unsigned int collisions;
+
+ /* Pointers to allocate/free functions. */
+ htab_alloc alloc_f;
+ htab_free free_f;
+ /* Alternate allocate/free functions, which take an extra argument. */
+ void * GTY((skip)) alloc_arg;
+ htab_alloc_with_arg alloc_with_arg_f;
+ htab_free_with_arg free_with_arg_f;
+
+ /* Current size (in entries) of the hash table, as an index into the
+ table of primes. */
+ unsigned int size_prime_index;
+};
+
+typedef struct htab *htab_t;
+
+/* An enum saying whether we insert into the hash table or not. */
+enum insert_option {NO_INSERT, INSERT};
/* The prototypes of the package functions. */
-extern hash_table_t create_hash_table
- PARAMS ((size_t, unsigned (*) (hash_table_entry_t),
- int (*) (hash_table_entry_t, hash_table_entry_t)));
+extern htab_t htab_create_alloc (size_t, htab_hash,
+ htab_eq, htab_del,
+ htab_alloc, htab_free);
+
+extern htab_t htab_create_alloc_ex (size_t, htab_hash,
+ htab_eq, htab_del,
+ void *, htab_alloc_with_arg,
+ htab_free_with_arg);
+
+/* Backward-compatibility functions. */
+extern htab_t htab_create (size_t, htab_hash, htab_eq, htab_del);
+extern htab_t htab_try_create (size_t, htab_hash, htab_eq, htab_del);
+
+extern void htab_set_functions_ex (htab_t, htab_hash,
+ htab_eq, htab_del,
+ void *, htab_alloc_with_arg,
+ htab_free_with_arg);
-extern void delete_hash_table PARAMS ((hash_table_t));
+extern void htab_delete (htab_t);
+extern void htab_empty (htab_t);
-extern void empty_hash_table PARAMS ((hash_table_t));
+extern void * htab_find (htab_t, const void *);
+extern void ** htab_find_slot (htab_t, const void *, enum insert_option);
+extern void * htab_find_with_hash (htab_t, const void *, hashval_t);
+extern void ** htab_find_slot_with_hash (htab_t, const void *,
+ hashval_t, enum insert_option);
+extern void htab_clear_slot (htab_t, void **);
+extern void htab_remove_elt (htab_t, void *);
+extern void htab_remove_elt_with_hash (htab_t, void *, hashval_t);
-extern hash_table_entry_t *find_hash_table_entry
- PARAMS ((hash_table_t, hash_table_entry_t, int));
+extern void htab_traverse (htab_t, htab_trav, void *);
+extern void htab_traverse_noresize (htab_t, htab_trav, void *);
-extern void remove_element_from_hash_table_entry PARAMS ((hash_table_t,
- hash_table_entry_t));
+extern size_t htab_size (htab_t);
+extern size_t htab_elements (htab_t);
+extern double htab_collisions (htab_t);
-extern size_t hash_table_size PARAMS ((hash_table_t));
+/* A hash function for pointers. */
+extern htab_hash htab_hash_pointer;
-extern size_t hash_table_elements_number PARAMS ((hash_table_t));
+/* An equality function for pointers. */
+extern htab_eq htab_eq_pointer;
-extern int hash_table_collisions PARAMS ((hash_table_t));
+/* A hash function for null-terminated strings. */
+extern hashval_t htab_hash_string (const void *);
-extern int all_hash_table_collisions ();
+/* An iterative hash function for arbitrary data. */
+extern hashval_t iterative_hash (const void *, size_t, hashval_t);
+/* Shorthand for hashing something with an intrinsic size. */
+#define iterative_hash_object(OB,INIT) iterative_hash (&OB, sizeof (OB), INIT)
#ifdef __cplusplus
}
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