mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-23 11:18:54 +00:00
159 lines
4.9 KiB
C
159 lines
4.9 KiB
C
#ifndef HASH_H
|
||
#define HASH_H
|
||
/* hash.h */
|
||
/************************************************************************
|
||
Copyright 1988, 1991 by Carnegie Mellon University
|
||
|
||
All Rights Reserved
|
||
|
||
Permission to use, copy, modify, and distribute this software and its
|
||
documentation for any purpose and without fee is hereby granted, provided
|
||
that the above copyright notice appear in all copies and that both that
|
||
copyright notice and this permission notice appear in supporting
|
||
documentation, and that the name of Carnegie Mellon University not be used
|
||
in advertising or publicity pertaining to distribution of the software
|
||
without specific, written prior permission.
|
||
|
||
CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
|
||
SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
|
||
IN NO EVENT SHALL CMU BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
|
||
DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
|
||
PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
|
||
ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
|
||
SOFTWARE.
|
||
************************************************************************/
|
||
|
||
/*
|
||
* Generalized hash table ADT
|
||
*
|
||
* Provides multiple, dynamically-allocated, variable-sized hash tables on
|
||
* various data and keys.
|
||
*
|
||
* This package attempts to follow some of the coding conventions suggested
|
||
* by Bob Sidebotham and the AFS Clean Code Committee.
|
||
*/
|
||
|
||
|
||
/*
|
||
* The user must supply the following:
|
||
*
|
||
* 1. A comparison function which is declared as:
|
||
*
|
||
* int compare(data1, data2)
|
||
* hash_datum *data1, *data2;
|
||
*
|
||
* This function must compare the desired fields of data1 and
|
||
* data2 and return TRUE (1) if the data should be considered
|
||
* equivalent (i.e. have the same key value) or FALSE (0)
|
||
* otherwise. This function is called through a pointer passed to
|
||
* the various hashtable functions (thus pointers to different
|
||
* functions may be passed to effect different tests on different
|
||
* hash tables).
|
||
*
|
||
* Internally, all the functions of this package always call the
|
||
* compare function with the "key" parameter as the first parameter,
|
||
* and a full data element as the second parameter. Thus, the key
|
||
* and element arguments to functions such as hash_Lookup() may
|
||
* actually be of different types and the programmer may provide a
|
||
* compare function which compares the two different object types
|
||
* as desired.
|
||
*
|
||
* Example:
|
||
*
|
||
* int compare(key, element)
|
||
* char *key;
|
||
* struct some_complex_structure *element;
|
||
* {
|
||
* return !strcmp(key, element->name);
|
||
* }
|
||
*
|
||
* key = "John C. Doe"
|
||
* element = &some_complex_structure
|
||
* hash_Lookup(table, hashcode, compare, key);
|
||
*
|
||
* 2. A hash function yielding an unsigned integer value to be used
|
||
* as the hashcode (index into the hashtable). Thus, the user
|
||
* may hash on whatever data is desired and may use several
|
||
* different hash functions for various different hash tables.
|
||
* The actual hash table index will be the passed hashcode modulo
|
||
* the hash table size.
|
||
*
|
||
* A generalized hash function, hash_HashFunction(), is included
|
||
* with this package to make things a little easier. It is not
|
||
* guarenteed to use the best hash algorithm in existence. . . .
|
||
*/
|
||
|
||
|
||
|
||
/*
|
||
* Various hash table definitions
|
||
*/
|
||
|
||
|
||
/*
|
||
* Define "hash_datum" as a universal data type
|
||
*/
|
||
#ifdef __STDC__
|
||
typedef void hash_datum;
|
||
#else
|
||
typedef char hash_datum;
|
||
#endif
|
||
|
||
typedef struct hash_memberstruct hash_member;
|
||
typedef struct hash_tblstruct hash_tbl;
|
||
typedef struct hash_tblstruct_hdr hash_tblhdr;
|
||
|
||
struct hash_memberstruct {
|
||
hash_member *next;
|
||
hash_datum *data;
|
||
};
|
||
|
||
struct hash_tblstruct_hdr {
|
||
unsigned size, bucketnum;
|
||
hash_member *member;
|
||
};
|
||
|
||
struct hash_tblstruct {
|
||
unsigned size, bucketnum;
|
||
hash_member *member; /* Used for linear dump */
|
||
hash_member *table[1]; /* Dynamically extended */
|
||
};
|
||
|
||
/* ANSI function prototypes or empty arg list? */
|
||
#ifdef __STDC__
|
||
#define P(args) args
|
||
#else
|
||
#define P(args) ()
|
||
#endif
|
||
|
||
typedef int (*hash_cmpfp) P((hash_datum *, hash_datum *));
|
||
typedef void (*hash_freefp) P((hash_datum *));
|
||
|
||
extern hash_tbl *hash_Init P((u_int tablesize));
|
||
|
||
extern void hash_Reset P((hash_tbl *tbl, hash_freefp));
|
||
|
||
extern unsigned hash_HashFunction P((u_char *str, u_int len));
|
||
|
||
extern int hash_Exists P((hash_tbl *, u_int code,
|
||
hash_cmpfp, hash_datum *key));
|
||
|
||
extern int hash_Insert P((hash_tbl *, u_int code,
|
||
hash_cmpfp, hash_datum *key,
|
||
hash_datum *element));
|
||
|
||
extern int hash_Delete P((hash_tbl *, u_int code,
|
||
hash_cmpfp, hash_datum *key,
|
||
hash_freefp));
|
||
|
||
extern hash_datum *hash_Lookup P((hash_tbl *, u_int code,
|
||
hash_cmpfp, hash_datum *key));
|
||
|
||
extern hash_datum *hash_FirstEntry P((hash_tbl *));
|
||
|
||
extern hash_datum *hash_NextEntry P((hash_tbl *));
|
||
|
||
#undef P
|
||
|
||
#endif /* HASH_H */
|