X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fhash.h;h=e795cdc836bf4c2b7c33ad96147c18b39a0d8782;hb=bda3b4454a255896a1aaa6ff89b677f52474b636;hp=1dbce5c2c0b707011be44275159670721abf9a29;hpb=358e52e8bb23ab6e5bcc42ca3546493a868d9591;p=gnulib.git diff --git a/lib/hash.h b/lib/hash.h index 1dbce5c2c..e795cdc83 100644 --- a/lib/hash.h +++ b/lib/hash.h @@ -1,193 +1,93 @@ -#ifndef HASH_H -# define HASH_H 1 +/* hash - hashing table processing. + Copyright (C) 1998-1999, 2001, 2003, 2009-2010 Free Software Foundation, + Inc. + Written by Jim Meyering , 1998. -# if HAVE_CONFIG_H -# include -# endif + This program 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. -# include -# include + This program 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. -# ifdef STDC_HEADERS -# include -# endif + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ -# ifndef HAVE_DECL_FREE -void free (); -# endif +/* A generic hash table package. */ -# ifndef HAVE_DECL_MALLOC -char *malloc (); -# endif +/* Make sure USE_OBSTACK is defined to 1 if you want the allocator to use + obstacks instead of malloc, and recompile `hash.c' with same setting. */ -# ifndef PARAMS -# if defined PROTOTYPES || (defined __STDC__ && __STDC__) -# define PARAMS(Args) Args -# else -# define PARAMS(Args) () +#ifndef HASH_H_ +# define HASH_H_ + +# include +# include + +/* The warn_unused_result attribute appeared first in gcc-3.4.0 */ +# ifndef __attribute__ +# if __GNUC__ < 3 || (__GNUC__ == 3 && __GNUC_MINOR__ < 4) +# define __attribute__(x) # endif # endif -# define USE_OBSTACK -# ifdef USE_OBSTACK -# include "obstack.h" +# ifndef ATTRIBUTE_WUR +# define ATTRIBUTE_WUR __attribute__ ((__warn_unused_result__)) # endif -# define obstack_chunk_alloc malloc -# define obstack_chunk_free free +typedef size_t (*Hash_hasher) (const void *, size_t); +typedef bool (*Hash_comparator) (const void *, const void *); +typedef void (*Hash_data_freer) (void *); +typedef bool (*Hash_processor) (void *, void *); -struct hash_ent +struct hash_tuning { - void *key; - struct hash_ent *next; + /* This structure is mainly used for `hash_initialize', see the block + documentation of `hash_reset_tuning' for more complete comments. */ + + float shrink_threshold; /* ratio of used buckets to trigger a shrink */ + float shrink_factor; /* ratio of new smaller size to original size */ + float growth_threshold; /* ratio of used buckets to trigger a growth */ + float growth_factor; /* ratio of new bigger size to original size */ + bool is_n_buckets; /* if CANDIDATE really means table size */ }; -typedef struct hash_ent HASH_ENT; - -/* This is particularly useful to cast uses in hash_initialize of the - system free function. */ -typedef void (*Hash_key_freer_type) PARAMS((void *key)); - -struct HT - { - /* User-supplied function for freeing keys. It is specified in - hash_initialize. If non-null, it is used by hash_free and - hash_clear. You should specify `free' here only if you want - these functions to free all of your `key' data. This is typically - the case when your key is simply an auxilliary struct that you - have malloc'd to aggregate several values. */ - Hash_key_freer_type hash_key_freer; - - /* User-supplied hash function that hashes entry E to an integer - in the range 0..TABLE_SIZE-1. */ - unsigned int (*hash_hash) PARAMS((const void *e, unsigned int table_size)); - - /* User-supplied function that determines whether a new entry is - unique by comparing the new entry to entries that hashed to the - same bucket index. It should return zero for a pair of entries - that compare equal, non-zero otherwise. */ - - int (*hash_key_comparator) PARAMS((const void *, const void *)); - - HASH_ENT **hash_table; - unsigned int hash_table_size; - unsigned int hash_n_slots_used; - unsigned int hash_max_chain_length; - - /* Gets set when an entry is deleted from a chain of length - hash_max_chain_length. Indicates that hash_max_chain_length - may no longer be valid. */ - unsigned int hash_dirty_max_chain_length; - - /* Sum of lengths of all chains (not counting any dummy - header entries). */ - unsigned int hash_n_keys; - - /* A linked list of freed HASH_ENT structs. - FIXME: Perhaps this is unnecessary and we should simply free - and reallocate such structs. */ - HASH_ENT *hash_free_entry_list; - - /* FIXME: comment. */ -# ifdef USE_OBSTACK - struct obstack ht_obstack; -# endif - }; - -typedef struct HT HT; - -unsigned int - hash_get_n_slots_used PARAMS((const HT *ht)); - -unsigned int - hash_get_max_chain_length PARAMS((HT *ht)); - -int - hash_rehash PARAMS((HT *ht, unsigned int new_table_size)); - -unsigned int - hash_get_table_size PARAMS((const HT *ht)); - -HT * - hash_initialize PARAMS((unsigned int table_size, - void (*key_freer) PARAMS((void *key)), - unsigned int (*hash) PARAMS((const void *, - unsigned int)), - int (*equality_tester) PARAMS((const void *, - const void *)))); - -unsigned int - hash_get_n_keys PARAMS((const HT *ht)); - -int - hash_query_in_table PARAMS((const HT *ht, const void *e)); - -void * - hash_lookup PARAMS((const HT *ht, const void *e)); - -void * - hash_insert_if_absent PARAMS((HT *ht, - const void *e, - int *failed)); - -void * - hash_delete_if_present PARAMS((HT *ht, const void *e)); - -void - hash_print_statistics PARAMS((const HT *ht, FILE *stream)); - -int - hash_get_statistics PARAMS((const HT *ht, unsigned int *n_slots_used, - unsigned int *n_keys, - unsigned int *max_chain_length)); - -int - hash_table_ok PARAMS((HT *ht)); - -void - hash_do_for_each PARAMS((HT *ht, - void (*f) PARAMS((void *e, void *aux)), - void *aux)); - -int - hash_do_for_each_2 PARAMS((HT *ht, - int (*f) PARAMS((void *e, void *aux)), - void *aux)); - -int - hash_do_for_each_in_selected_bucket PARAMS((HT *ht, - const void *key, - int (*f) PARAMS((const void *bucket_key, - void *e, - void *aux)), - void *aux)); - -void - hash_clear PARAMS((HT *ht)); - -void - hash_free PARAMS((HT *ht)); - -void - hash_get_key_list PARAMS((const HT *ht, - unsigned int bufsize, - void **buf)); - -void * - hash_get_first PARAMS((const HT *ht)); - -void * - hash_get_next PARAMS((const HT *ht, const void *e)); - -/* This interface to hash_insert_if_absent is used frequently enough to - merit a macro here. */ - -# define HASH_INSERT_NEW_ITEM(Ht, Item, Failp) \ - do \ - { \ - void *_already; \ - _already = hash_insert_if_absent ((Ht), (Item), Failp); \ - assert (_already == NULL); \ - } \ - while (0) -#endif /* HASH_H */ +typedef struct hash_tuning Hash_tuning; + +struct hash_table; + +typedef struct hash_table Hash_table; + +/* Information and lookup. */ +size_t hash_get_n_buckets (const Hash_table *); +size_t hash_get_n_buckets_used (const Hash_table *); +size_t hash_get_n_entries (const Hash_table *); +size_t hash_get_max_bucket_length (const Hash_table *); +bool hash_table_ok (const Hash_table *); +void hash_print_statistics (const Hash_table *, FILE *); +void *hash_lookup (const Hash_table *, const void *); + +/* Walking. */ +void *hash_get_first (const Hash_table *); +void *hash_get_next (const Hash_table *, const void *); +size_t hash_get_entries (const Hash_table *, void **, size_t); +size_t hash_do_for_each (const Hash_table *, Hash_processor, void *); + +/* Allocation and clean-up. */ +size_t hash_string (const char *, size_t); +void hash_reset_tuning (Hash_tuning *); +Hash_table *hash_initialize (size_t, const Hash_tuning *, + Hash_hasher, Hash_comparator, + Hash_data_freer) ATTRIBUTE_WUR; +void hash_clear (Hash_table *); +void hash_free (Hash_table *); + +/* Insertion and deletion. */ +bool hash_rehash (Hash_table *, size_t) ATTRIBUTE_WUR; +void *hash_insert (Hash_table *, const void *) ATTRIBUTE_WUR; +void *hash_delete (Hash_table *, const void *); + +#endif