mirror of
https://github.com/QB64-Phoenix-Edition/QB64pe.git
synced 2024-09-08 11:10:16 +00:00
204 lines
7.1 KiB
C
204 lines
7.1 KiB
C
/* An expandable hash tables datatype.
|
|
Copyright (C) 1999-2018 Free Software Foundation, Inc.
|
|
Contributed by Vladimir Makarov (vmakarov@cygnus.com).
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
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., 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.
|
|
|
|
Elements in the table are generic pointers.
|
|
|
|
The size of the table is not fixed; if the occupancy of the table
|
|
grows too high the hash table will be expanded.
|
|
|
|
The abstract data implementation is based on generalized Algorithm D
|
|
from Knuth's book "The art of computer programming". Hash table is
|
|
expanded by creation of new hash table and transferring elements from
|
|
the old table to the new table. */
|
|
|
|
#ifndef __HASHTAB_H__
|
|
#define __HASHTAB_H__
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif /* __cplusplus */
|
|
|
|
#include "ansidecl.h"
|
|
|
|
/* 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. The size of this structure is subject to
|
|
change. */
|
|
|
|
struct htab {
|
|
/* Pointer to hash function. */
|
|
htab_hash hash_f;
|
|
|
|
/* Pointer to comparison function. */
|
|
htab_eq eq_f;
|
|
|
|
/* Pointer to cleanup function. */
|
|
htab_del del_f;
|
|
|
|
/* Table itself. */
|
|
void **entries;
|
|
|
|
/* Current size (in entries) of the hash table. */
|
|
size_t size;
|
|
|
|
/* 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 `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. */
|
|
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 *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 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);
|
|
|
|
extern htab_t htab_create_typed_alloc (size_t, htab_hash, htab_eq, htab_del,
|
|
htab_alloc, htab_alloc, htab_free);
|
|
|
|
/* 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 htab_delete (htab_t);
|
|
extern void htab_empty (htab_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 void htab_traverse (htab_t, htab_trav, void *);
|
|
extern void htab_traverse_noresize (htab_t, htab_trav, void *);
|
|
|
|
extern size_t htab_size (htab_t);
|
|
extern size_t htab_elements (htab_t);
|
|
extern double htab_collisions (htab_t);
|
|
|
|
/* A hash function for pointers. */
|
|
extern htab_hash htab_hash_pointer;
|
|
|
|
/* An equality function for pointers. */
|
|
extern htab_eq htab_eq_pointer;
|
|
|
|
/* A hash function for null-terminated strings. */
|
|
extern hashval_t htab_hash_string (const void *);
|
|
|
|
/* 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
|
|
}
|
|
#endif /* __cplusplus */
|
|
|
|
#endif /* __HASHTAB_H */
|