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Diffstat (limited to '')
| -rw-r--r-- | hashlib.h | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/hashlib.h b/hashlib.h new file mode 100644 index 0000000..cf2de98 --- /dev/null +++ b/hashlib.h @@ -0,0 +1,92 @@ +/* hashlib.h -- the data structures used in hashing in Bash. */ + +/* Copyright (C) 1993-2020 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 PARAMS((BUCKET_CONTENTS *)); + +/* Operations on tables as a whole */ +extern HASH_TABLE *hash_create PARAMS((int)); +extern HASH_TABLE *hash_copy PARAMS((HASH_TABLE *, sh_string_func_t *)); +extern void hash_flush PARAMS((HASH_TABLE *, sh_free_func_t *)); +extern void hash_dispose PARAMS((HASH_TABLE *)); +extern void hash_walk PARAMS((HASH_TABLE *, hash_wfunc *)); + +/* Operations to extract information from or pieces of tables */ +extern int hash_bucket PARAMS((const char *, HASH_TABLE *)); +extern int hash_size PARAMS((HASH_TABLE *)); + +/* Operations on hash table entries */ +extern BUCKET_CONTENTS *hash_search PARAMS((const char *, HASH_TABLE *, int)); +extern BUCKET_CONTENTS *hash_insert PARAMS((char *, HASH_TABLE *, int)); +extern BUCKET_CONTENTS *hash_remove PARAMS((const char *, HASH_TABLE *, int)); + +/* Miscellaneous */ +extern unsigned int hash_string PARAMS((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 128 /* must be power of two */ + +#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 */ |