[thirdparty/bash.git] / hashlib.h

/* hashlib.h -- the data structures used in hashing in Bash. */

/* Copyright (C) 1993-2009 Free Software Foundation, Inc.

   This file is part of GNU Bash, the Bourne Again SHell.

   Bash 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 3 of the License, or
   (at your option) any later version.

   Bash 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 Bash.  If not, see <http://www.gnu.org/licenses/>.
*/

#if !defined (_HASHLIB_H_)
#define _HASHLIB_H_

#include "stdc.h"

#ifndef PTR_T
#  ifdef __STDC__
#    define PTR_T void *
#  else
#    define PTR_T char *
#  endif
#endif

typedef struct bucket_contents {
  struct bucket_contents *next;	/* Link to next hashed key in this bucket. */
  char *key;			/* What we look up. */
  PTR_T data;			/* What we really want. */
  unsigned int khash;		/* What key hashes to */
  int times_found;		/* Number of times this item has been found. */
} BUCKET_CONTENTS;

typedef struct hash_table {
  BUCKET_CONTENTS **bucket_array;	/* Where the data is kept. */
  int nbuckets;			/* How many buckets does this table have. */
  int nentries;			/* How many entries does this table have. */
} HASH_TABLE;

typedef int hash_wfunc __P((BUCKET_CONTENTS *));

/* Operations on tables as a whole */
extern HASH_TABLE *hash_create __P((int));
extern HASH_TABLE *hash_copy __P((HASH_TABLE *, sh_string_func_t *));
extern void hash_flush __P((HASH_TABLE *, sh_free_func_t *));
extern void hash_dispose __P((HASH_TABLE *));
extern void hash_walk __P((HASH_TABLE *, hash_wfunc *));

/* Operations to extract information from or pieces of tables */
extern int hash_bucket __P((const char *, HASH_TABLE *));
extern int hash_size __P((HASH_TABLE *));

/* Operations on hash table entries */
extern BUCKET_CONTENTS *hash_search __P((const char *, HASH_TABLE *, int));
extern BUCKET_CONTENTS *hash_insert __P((char *, HASH_TABLE *, int));
extern BUCKET_CONTENTS *hash_remove __P((const char *, HASH_TABLE *, int));

/* Miscellaneous */
extern unsigned int hash_string __P((const char *));

/* Redefine the function as a macro for speed. */
#define hash_items(bucket, table) \
	((table && (bucket < table->nbuckets)) ?  \
		table->bucket_array[bucket] : \
		(BUCKET_CONTENTS *)NULL)

/* Default number of buckets in the hash table. */
#define DEFAULT_HASH_BUCKETS 64	/* was 107, then 53, must be power of two now */

#define HASH_ENTRIES(ht)	((ht) ? (ht)->nentries : 0)

/* flags for hash_search and hash_insert */
#define HASH_NOSRCH	0x01
#define HASH_CREATE	0x02

#if !defined (NULL)
#  if defined (__STDC__)
#    define NULL ((void *) 0)
#  else
#    define NULL 0x0
#  endif /* !__STDC__ */
#endif /* !NULL */

#endif /* _HASHLIB_H */
Commit	Line	Data
	1	/* hashlib.h -- the data structures used in hashing in Bash. */
	2
	3	/* Copyright (C) 1993-2009 Free Software Foundation, Inc.
	4
	5	This file is part of GNU Bash, the Bourne Again SHell.
	6
	7	Bash is free software: you can redistribute it and/or modify
	8	it under the terms of the GNU General Public License as published by
	9	the Free Software Foundation, either version 3 of the License, or
	10	(at your option) any later version.
	11
	12	Bash is distributed in the hope that it will be useful,
	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	GNU General Public License for more details.
	16
	17	You should have received a copy of the GNU General Public License
	18	along with Bash. If not, see <http://www.gnu.org/licenses/>.
	19	*/
	20
	21	#if !defined (_HASHLIB_H_)
	22	#define _HASHLIB_H_
	23
	24	#include "stdc.h"
	25
	26	#ifndef PTR_T
	27	# ifdef __STDC__
	28	# define PTR_T void *
	29	# else
	30	# define PTR_T char *
	31	# endif
	32	#endif
	33
	34	typedef struct bucket_contents {
	35	struct bucket_contents next; / Link to next hashed key in this bucket. */
	36	char key; / What we look up. */
	37	PTR_T data; /* What we really want. */
	38	unsigned int khash; /* What key hashes to */
	39	int times_found; /* Number of times this item has been found. */
	40	} BUCKET_CONTENTS;
	41
	42	typedef struct hash_table {
	43	BUCKET_CONTENTS *bucket_array; / Where the data is kept. */
	44	int nbuckets; /* How many buckets does this table have. */
	45	int nentries; /* How many entries does this table have. */
	46	} HASH_TABLE;
	47
	48	typedef int hash_wfunc __P((BUCKET_CONTENTS *));
	49
	50	/* Operations on tables as a whole */
	51	extern HASH_TABLE *hash_create __P((int));
	52	extern HASH_TABLE hash_copy __P((HASH_TABLE , sh_string_func_t *));
	53	extern void hash_flush __P((HASH_TABLE , sh_free_func_t ));
	54	extern void hash_dispose __P((HASH_TABLE *));
	55	extern void hash_walk __P((HASH_TABLE , hash_wfunc ));
	56
	57	/* Operations to extract information from or pieces of tables */
	58	extern int hash_bucket __P((const char , HASH_TABLE ));
	59	extern int hash_size __P((HASH_TABLE *));
	60
	61	/* Operations on hash table entries */
	62	extern BUCKET_CONTENTS hash_search __P((const char , HASH_TABLE *, int));
	63	extern BUCKET_CONTENTS hash_insert __P((char , HASH_TABLE *, int));
	64	extern BUCKET_CONTENTS hash_remove __P((const char , HASH_TABLE *, int));
	65
	66	/* Miscellaneous */
	67	extern unsigned int hash_string __P((const char *));
	68
	69	/* Redefine the function as a macro for speed. */
	70	#define hash_items(bucket, table) \
	71	((table && (bucket < table->nbuckets)) ? \
	72	table->bucket_array[bucket] : \
	73	(BUCKET_CONTENTS *)NULL)
	74
	75	/* Default number of buckets in the hash table. */
	76	#define DEFAULT_HASH_BUCKETS 64 /* was 107, then 53, must be power of two now */
	77
	78	#define HASH_ENTRIES(ht) ((ht) ? (ht)->nentries : 0)
	79
	80	/* flags for hash_search and hash_insert */
	81	#define HASH_NOSRCH 0x01
	82	#define HASH_CREATE 0x02
	83
	84	#if !defined (NULL)
	85	# if defined (__STDC__)
	86	# define NULL ((void *) 0)
	87	# else
	88	# define NULL 0x0
	89	# endif /* !__STDC__ */
	90	#endif /* !NULL */
	91
	92	#endif /* _HASHLIB_H */