githubmirror/lsof

hash.h
72 строки2 KB
Jiajie Chen
[linux] Move duplicate hash table code to hash.h
17 янв 2023, 15:21
17 янв 2023, 15:21796e136

/*
 * hash.sh - utilty functions for hash tables 
 */


/*
 * Copyright 1994 Purdue Research Foundation, West Lafayette, Indiana
 * 47907.  All rights reserved.
 *
 * Written by Victor A. Abell
 *
 * This software is not subject to any license of the American Telephone
 * and Telegraph Company or the Regents of the University of California.
 *
 * Permission is granted to anyone to use this software for any purpose on
 * any computer system, and to alter it and redistribute it freely, subject
 * to the following restrictions:
 *
 * 1. Neither the authors nor Purdue University are responsible for any
 *    consequences of the use of this software.
 *
 * 2. The origin of this software must not be misrepresented, either by
 *    explicit claim or by omission.  Credit to the authors and Purdue
 *    University must appear in documentation and sources.
 *
 * 3. Altered versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 *
 * 4. This notice may not be removed or altered.
 */



#if	!defined(LSOF_HASH_H)
#define	LSOF_HASH_H	1

/* Find element in hash table by key, return NULL if not found
 * 
 * table: hash table
 * hash: hash function/macro
 * type: struct type
 * member: member to match key
 * key: key
 * 
 * the struct type should have a member called next
 **/
#define HASH_FIND_ELEMENT(table, hash, type, member, key)		\
    ({type *__value = NULL;						\
	int __h = hash(key);						\
	if ((table)) {							\
	    for (__value = (table)[__h];__value;__value = __value->next) { \
		if ((key) == __value->member) break;			\
	    };								\
	};								\
	__value;})

/* Insert element into hash table
 * 
 * table: hash table
 * hash: hash function/macro
 * element: element
 * member: member name containing key
 * 
 * the type of element should have a member called next
 **/
#define HASH_INSERT_ELEMENT(table, hash, element, member)	\
    ({int __h = hash((element)->member);			\
	(element)->next = (table)[__h];				\
	(table)[__h] = (element);				\
    })

#endif