0,0 → 1,209 |
/* An expandable hash tables datatype. |
Copyright (C) 1999, 2000, 2002, 2003, 2004, 2005, 2009, 2010 |
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" |
|
#ifndef GTY |
#define GTY(X) |
#endif |
|
/* 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 GTY(()) 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 ** 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 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 * 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 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 */ |