Home | History | Annotate | Line # | Download | only in make
hash.h revision 1.1 
      1 /*
      2  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
      3  * Copyright (c) 1988, 1989 by Adam de Boor
      4  * Copyright (c) 1989 by Berkeley Softworks
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * Adam de Boor.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the University of
     21  *	California, Berkeley and its contributors.
     22  * 4. Neither the name of the University nor the names of its contributors
     23  *    may be used to endorse or promote products derived from this software
     24  *    without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  * SUCH DAMAGE.
     37  *
     38  *	@(#)hash.h	5.4 (Berkeley) 12/28/90
     39  */
     40 
     41 /* hash.h --
     42  *
     43  * 	This file contains definitions used by the hash module,
     44  * 	which maintains hash tables.
     45  */
     46 
     47 #ifndef	_HASH
     48 #define	_HASH
     49 
     50 /*
     51  * The following defines one entry in the hash table.
     52  */
     53 
     54 typedef struct Hash_Entry {
     55     struct Hash_Entry *next;		/* Used to link together all the
     56     					 * entries associated with the same
     57 					 * bucket. */
     58     ClientData	      clientData;	/* Arbitrary piece of data associated
     59     					 * with key. */
     60     unsigned	      namehash;		/* hash value of key */
     61     char	      name[1];		/* key string */
     62 } Hash_Entry;
     63 
     64 typedef struct Hash_Table {
     65     struct Hash_Entry **bucketPtr;/* Pointers to Hash_Entry, one
     66     				 * for each bucket in the table. */
     67     int 	size;		/* Actual size of array. */
     68     int 	numEntries;	/* Number of entries in the table. */
     69     int 	mask;		/* Used to select bits for hashing. */
     70 } Hash_Table;
     71 
     72 /*
     73  * The following structure is used by the searching routines
     74  * to record where we are in the search.
     75  */
     76 
     77 typedef struct Hash_Search {
     78     Hash_Table  *tablePtr;	/* Table being searched. */
     79     int 	nextIndex;	/* Next bucket to check (after current). */
     80     Hash_Entry 	*hashEntryPtr;	/* Next entry to check in current bucket. */
     81 } Hash_Search;
     82 
     83 /*
     84  * Macros.
     85  */
     86 
     87 /*
     88  * ClientData Hash_GetValue(h)
     89  *     Hash_Entry *h;
     90  */
     91 
     92 #define Hash_GetValue(h) ((h)->clientData)
     93 
     94 /*
     95  * Hash_SetValue(h, val);
     96  *     Hash_Entry *h;
     97  *     char *val;
     98  */
     99 
    100 #define Hash_SetValue(h, val) ((h)->clientData = (ClientData) (val))
    101 
    102 /*
    103  * Hash_Size(n) returns the number of words in an object of n bytes
    104  */
    105 
    106 #define	Hash_Size(n)	(((n) + sizeof (int) - 1) / sizeof (int))
    107 
    108 /*
    109  * The following procedure declarations and macros
    110  * are the only things that should be needed outside
    111  * the implementation code.
    112  */
    113 
    114 extern Hash_Entry *	Hash_CreateEntry();
    115 extern void		Hash_DeleteTable();
    116 extern void		Hash_DeleteEntry();
    117 extern void		Hash_DeleteTable();
    118 extern Hash_Entry *	Hash_EnumFirst();
    119 extern Hash_Entry *	Hash_EnumNext();
    120 extern Hash_Entry *	Hash_FindEntry();
    121 extern void		Hash_InitTable();
    122 extern void		Hash_PrintStats();
    123 
    124 #endif _HASH
    125