1/* hashlib.h -- the data structures used in hashing in Bash. */ 2 3/* Copyright (C) 1993 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 it under 8 the terms of the GNU General Public License as published by the Free 9 Software Foundation; either version 2, or (at your option) any later 10 version. 11 12 Bash is distributed in the hope that it will be useful, but WITHOUT ANY 13 WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 for more details. 16 17 You should have received a copy of the GNU General Public License along 18 with Bash; see the file COPYING. If not, write to the Free Software 19 Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. */ 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 34typedef 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 42typedef 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 48typedef int hash_wfunc __P((BUCKET_CONTENTS *)); 49 50/* Operations on tables as a whole */ 51extern HASH_TABLE *hash_create __P((int)); 52extern HASH_TABLE *hash_copy __P((HASH_TABLE *, sh_string_func_t *)); 53extern void hash_flush __P((HASH_TABLE *, sh_free_func_t *)); 54extern void hash_dispose __P((HASH_TABLE *)); 55extern void hash_walk __P((HASH_TABLE *, hash_wfunc *)); 56 57/* Operations to extract information from or pieces of tables */ 58extern int hash_bucket __P((const char *, HASH_TABLE *)); 59extern int hash_size __P((HASH_TABLE *)); 60 61/* Operations on hash table entries */ 62extern BUCKET_CONTENTS *hash_search __P((const char *, HASH_TABLE *, int)); 63extern BUCKET_CONTENTS *hash_insert __P((char *, HASH_TABLE *, int)); 64extern BUCKET_CONTENTS *hash_remove __P((const char *, HASH_TABLE *, int)); 65 66/* Miscellaneous */ 67extern 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 */ 93