/* hash.c -- hash table routines for BFD
Copyright 1993, 1994, 1995, 1997, 1999, 2001, 2002, 2003, 2004, 2005,
- 2006 Free Software Foundation, Inc.
+ 2006, 2007 Free Software Foundation, Inc.
Written by Steve Chamberlain <sac@cygnus.com>
This file is part of 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
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
- Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
+ Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+ MA 02110-1301, USA. */
-#include "bfd.h"
#include "sysdep.h"
+#include "bfd.h"
#include "libbfd.h"
#include "objalloc.h"
#include "libiberty.h"
/* The default number of entries to use when creating a hash table. */
#define DEFAULT_SIZE 4051
+
+/* The following function returns a nearest prime number which is
+ greater than N, and near a power of two. Copied from libiberty.
+ Returns zero for ridiculously large N to signify an error. */
+
+static unsigned long
+higher_prime_number (unsigned long n)
+{
+ /* These are primes that are near, but slightly smaller than, a
+ power of two. */
+ static const unsigned long primes[] = {
+ (unsigned long) 127,
+ (unsigned long) 2039,
+ (unsigned long) 32749,
+ (unsigned long) 65521,
+ (unsigned long) 131071,
+ (unsigned long) 262139,
+ (unsigned long) 524287,
+ (unsigned long) 1048573,
+ (unsigned long) 2097143,
+ (unsigned long) 4194301,
+ (unsigned long) 8388593,
+ (unsigned long) 16777213,
+ (unsigned long) 33554393,
+ (unsigned long) 67108859,
+ (unsigned long) 134217689,
+ (unsigned long) 268435399,
+ (unsigned long) 536870909,
+ (unsigned long) 1073741789,
+ (unsigned long) 2147483647,
+ /* 4294967291L */
+ ((unsigned long) 2147483647) + ((unsigned long) 2147483644),
+ };
+
+ const unsigned long *low = &primes[0];
+ const unsigned long *high = &primes[sizeof (primes) / sizeof (primes[0])];
+
+ while (low != high)
+ {
+ const unsigned long *mid = low + (high - low) / 2;
+ if (n >= *mid)
+ low = mid + 1;
+ else
+ high = mid;
+ }
+
+ if (n >= *low)
+ return 0;
+
+ return *low;
+}
+
static size_t bfd_default_hash_table_size = DEFAULT_SIZE;
/* Create a new hash table, given a number of entries. */
memset ((void *) table->table, 0, alloc);
table->size = size;
table->entsize = entsize;
+ table->count = 0;
+ table->frozen = 0;
table->newfunc = newfunc;
return TRUE;
}
hashp->hash = hash;
hashp->next = table->table[index];
table->table[index] = hashp;
+ table->count++;
+
+ if (!table->frozen && table->count > table->size * 3 / 4)
+ {
+ unsigned long newsize = higher_prime_number (table->size);
+ struct bfd_hash_entry **newtable;
+ unsigned int hi;
+ unsigned long alloc = newsize * sizeof (struct bfd_hash_entry *);
+
+ /* If we can't find a higher prime, or we can't possibly alloc
+ that much memory, don't try to grow the table. */
+ if (newsize == 0 || alloc / sizeof (struct bfd_hash_entry *) != newsize)
+ {
+ table->frozen = 1;
+ return hashp;
+ }
+
+ newtable = ((struct bfd_hash_entry **)
+ objalloc_alloc ((struct objalloc *) table->memory, alloc));
+ memset ((PTR) newtable, 0, alloc);
+
+ for (hi = 0; hi < table->size; hi ++)
+ while (table->table[hi])
+ {
+ struct bfd_hash_entry *chain = table->table[hi];
+ struct bfd_hash_entry *chain_end = chain;
+ int index;
+
+ while (chain_end->next && chain_end->next->hash == chain->hash)
+ chain_end = chain_end->next;
+
+ table->table[hi] = chain_end->next;
+ index = chain->hash % newsize;
+ chain_end->next = newtable[index];
+ newtable[index] = chain;
+ }
+ table->table = newtable;
+ table->size = newsize;
+ }
return hashp;
}
{
unsigned int i;
+ table->frozen = 1;
for (i = 0; i < table->size; i++)
{
struct bfd_hash_entry *p;
for (p = table->table[i]; p != NULL; p = p->next)
if (! (*func) (p, info))
- return;
+ goto out;
}
+ out:
+ table->frozen = 0;
}
\f
void