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freebsd/contrib/gcc/hash.h
1999-10-16 06:09:09 +00:00

132 lines
4.6 KiB
C

/* Header file for generic hash table support.
Copyright (C) 1993, 1994, 1997, 1998 Free Software Foundation, Inc.
Written by Steve Chamberlain <sac@cygnus.com>
This file was lifted from BFD, the Binary File Descriptor library.
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 2 of the License, or
(at your option) any later version.
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.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#ifndef IN_GCC
#include <ansidecl.h>
#endif /* ! IN_GCC */
#include "obstack.h"
typedef enum {false, true} boolean;
typedef PTR hash_table_key;
/* Hash table routines. There is no way to free up a hash table. */
/* An element in the hash table. Most uses will actually use a larger
structure, and an instance of this will be the first field. */
struct hash_entry
{
/* Next entry for this hash code. */
struct hash_entry *next;
/* The thing being hashed. */
hash_table_key key;
/* Hash code. This is the full hash code, not the index into the
table. */
unsigned long hash;
};
/* A hash table. */
struct hash_table
{
/* The hash array. */
struct hash_entry **table;
/* The number of slots in the hash table. */
unsigned int size;
/* A function used to create new elements in the hash table. The
first entry is itself a pointer to an element. When this
function is first invoked, this pointer will be NULL. However,
having the pointer permits a hierarchy of method functions to be
built each of which calls the function in the superclass. Thus
each function should be written to allocate a new block of memory
only if the argument is NULL. */
struct hash_entry *(*newfunc) PARAMS ((struct hash_entry *,
struct hash_table *,
hash_table_key));
/* A function to compute the hash code for a key in the hash table. */
unsigned long (*hash) PARAMS ((hash_table_key));
/* A function to compare two keys. */
boolean (*comp) PARAMS ((hash_table_key, hash_table_key));
/* An obstack for this hash table. */
struct obstack memory;
};
/* Initialize a hash table. */
extern boolean hash_table_init
PARAMS ((struct hash_table *,
struct hash_entry *(*) (struct hash_entry *,
struct hash_table *,
hash_table_key),
unsigned long (*hash) (hash_table_key),
boolean (*comp) (hash_table_key, hash_table_key)));
/* Initialize a hash table specifying a size. */
extern boolean hash_table_init_n
PARAMS ((struct hash_table *,
struct hash_entry *(*) (struct hash_entry *,
struct hash_table *,
hash_table_key),
unsigned long (*hash) (hash_table_key),
boolean (*comp) (hash_table_key, hash_table_key),
unsigned int size));
/* Free up a hash table. */
extern void hash_table_free PARAMS ((struct hash_table *));
/* Look up KEY in a hash table. If CREATE is true, a new entry
will be created for this KEY if one does not already exist. If
COPY is non-NULL, it is used to copy the KEY before storing it in
the hash table. */
extern struct hash_entry *hash_lookup
PARAMS ((struct hash_table *, hash_table_key key, boolean create,
hash_table_key (*copy)(struct obstack*, hash_table_key)));
/* Base method for creating a hash table entry. */
extern struct hash_entry *hash_newfunc
PARAMS ((struct hash_entry *, struct hash_table *,
hash_table_key key));
/* Grab some space for a hash table entry. */
extern PTR hash_allocate PARAMS ((struct hash_table *,
unsigned int));
/* Traverse a hash table in a random order, calling a function on each
element. If the function returns false, the traversal stops. The
INFO argument is passed to the function. */
extern void hash_traverse PARAMS ((struct hash_table *,
boolean (*) (struct hash_entry *,
hash_table_key),
hash_table_key info));
/* Hash a string K, which is really of type `char*'. */
extern unsigned long string_hash PARAMS ((hash_table_key k));
/* Compare two strings K1, K2 which are really of type `char*'. */
extern boolean string_compare PARAMS ((hash_table_key k1,
hash_table_key k2));
/* Copy a string K, which is really of type `char*'. */
extern hash_table_key string_copy PARAMS ((struct obstack* memory,
hash_table_key k));