[deliverable/binutils-gdb.git] / include / hashtab.h

/* An expandable hash tables datatype.  
   Copyright (C) 1999, 2000 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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) PARAMS ((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) PARAMS ((const void *, const void *));

/* Cleanup function called whenever a live element is removed from
   the hash table.  */
typedef void (*htab_del) PARAMS ((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) PARAMS ((void **, void *));

/* 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. */

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;
};

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	PARAMS ((size_t, htab_hash,
					 htab_eq, htab_del));
extern void	htab_delete	PARAMS ((htab_t));
extern void	htab_empty	PARAMS ((htab_t));

extern void    *htab_find	PARAMS ((htab_t, const void *));
extern void   **htab_find_slot	PARAMS ((htab_t, const void *,
					 enum insert_option));
extern void    *htab_find_with_hash	  PARAMS ((htab_t, const void *,
						   hashval_t));
extern void   **htab_find_slot_with_hash  PARAMS ((htab_t, const void *,
						   hashval_t,
						   enum insert_option));
extern void	htab_clear_slot	PARAMS ((htab_t, void **));
extern void	htab_remove_elt	PARAMS ((htab_t, void *));

extern void	htab_traverse	PARAMS ((htab_t, htab_trav, void *));

extern size_t	htab_size	PARAMS ((htab_t));
extern size_t	htab_elements	PARAMS ((htab_t));
extern double	htab_collisions	PARAMS ((htab_t));

/* A hash function for pointers.  */
extern htab_hash htab_hash_pointer;

/* An equality function for pointers.  */
extern htab_eq htab_eq_pointer;

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* __HASHTAB_H */
Commit	Line	Data
	1	/* An expandable hash tables datatype.
	2	Copyright (C) 1999, 2000 Free Software Foundation, Inc.
	3	Contributed by Vladimir Makarov (vmakarov@cygnus.com).
	4
	5	This program is free software; you can redistribute it and/or modify
	6	it under the terms of the GNU General Public License as published by
	7	the Free Software Foundation; either version 2 of the License, or
	8	(at your option) any later version.
	9
	10	This program is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	GNU General Public License for more details.
	14
	15	You should have received a copy of the GNU General Public License
	16	along with this program; if not, write to the Free Software
	17	Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
	18
	19	/* This package implements basic hash table functionality. It is possible
	20	to search for an entry, create an entry and destroy an entry.
	21
	22	Elements in the table are generic pointers.
	23
	24	The size of the table is not fixed; if the occupancy of the table
	25	grows too high the hash table will be expanded.
	26
	27	The abstract data implementation is based on generalized Algorithm D
	28	from Knuth's book "The art of computer programming". Hash table is
	29	expanded by creation of new hash table and transferring elements from
	30	the old table to the new table. */
	31
	32	#ifndef __HASHTAB_H__
	33	#define __HASHTAB_H__
	34
	35	#ifdef __cplusplus
	36	extern "C" {
	37	#endif /* __cplusplus */
	38
	39	#include <ansidecl.h>
	40
	41	/* The type for a hash code. */
	42	typedef unsigned int hashval_t;
	43
	44	/* Callback function pointer types. */
	45
	46	/* Calculate hash of a table entry. */
	47	typedef hashval_t (htab_hash) PARAMS ((const void ));
	48
	49	/* Compare a table entry with a possible entry. The entry already in
	50	the table always comes first, so the second element can be of a
	51	different type (but in this case htab_find and htab_find_slot
	52	cannot be used; instead the variants that accept a hash value
	53	must be used). */
	54	typedef int (htab_eq) PARAMS ((const void , const void *));
	55
	56	/* Cleanup function called whenever a live element is removed from
	57	the hash table. */
	58	typedef void (htab_del) PARAMS ((void ));
	59
	60	/* Function called by htab_traverse for each live element. The first
	61	arg is the slot of the element (which can be passed to htab_clear_slot
	62	if desired), the second arg is the auxiliary pointer handed to
	63	htab_traverse. Return 1 to continue scan, 0 to stop. */
	64	typedef int (htab_trav) PARAMS ((void , void ));
	65
	66	/* Hash tables are of the following type. The structure
	67	(implementation) of this type is not needed for using the hash
	68	tables. All work with hash table should be executed only through
	69	functions mentioned below. */
	70
	71	struct htab
	72	{
	73	/* Pointer to hash function. */
	74	htab_hash hash_f;
	75
	76	/* Pointer to comparison function. */
	77	htab_eq eq_f;
	78
	79	/* Pointer to cleanup function. */
	80	htab_del del_f;
	81
	82	/* Table itself. */
	83	void **entries;
	84
	85	/* Current size (in entries) of the hash table */
	86	size_t size;
	87
	88	/* Current number of elements including also deleted elements */
	89	size_t n_elements;
	90
	91	/* Current number of deleted elements in the table */
	92	size_t n_deleted;
	93
	94	/* The following member is used for debugging. Its value is number
	95	of all calls of `htab_find_slot' for the hash table. */
	96	unsigned int searches;
	97
	98	/* The following member is used for debugging. Its value is number
	99	of collisions fixed for time of work with the hash table. */
	100	unsigned int collisions;
	101	};
	102
	103	typedef struct htab *htab_t;
	104
	105	/* An enum saying whether we insert into the hash table or not. */
	106	enum insert_option {NO_INSERT, INSERT};
	107
	108	/* The prototypes of the package functions. */
	109
	110	extern htab_t htab_create PARAMS ((size_t, htab_hash,
	111	htab_eq, htab_del));
	112	extern void htab_delete PARAMS ((htab_t));
	113	extern void htab_empty PARAMS ((htab_t));
	114
	115	extern void htab_find PARAMS ((htab_t, const void ));
	116	extern void *htab_find_slot PARAMS ((htab_t, const void ,
	117	enum insert_option));
	118	extern void htab_find_with_hash PARAMS ((htab_t, const void ,
	119	hashval_t));
	120	extern void *htab_find_slot_with_hash PARAMS ((htab_t, const void ,
	121	hashval_t,
	122	enum insert_option));
	123	extern void htab_clear_slot PARAMS ((htab_t, void **));
	124	extern void htab_remove_elt PARAMS ((htab_t, void *));
	125
	126	extern void htab_traverse PARAMS ((htab_t, htab_trav, void *));
	127
	128	extern size_t htab_size PARAMS ((htab_t));
	129	extern size_t htab_elements PARAMS ((htab_t));
	130	extern double htab_collisions PARAMS ((htab_t));
	131
	132	/* A hash function for pointers. */
	133	extern htab_hash htab_hash_pointer;
	134
	135	/* An equality function for pointers. */
	136	extern htab_eq htab_eq_pointer;
	137
	138	#ifdef __cplusplus
	139	}
	140	#endif /* __cplusplus */
	141
	142	#endif /* __HASHTAB_H */